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1 //! The webview renderer for [`makeover_layout`].
2 //!
3 //! <!-- wiki: makeover-webview -->
4 //!
5 //! # The renderer that needs no palette
6 //!
7 //! `makeover-immediate` and `makeover-tui` both take a `Palette`, because egui
8 //! and a terminal need an actual colour before they can put anything on
9 //! screen. A webview does not: `var(--surface-raised)` *is* the late binding,
10 //! and the browser resolves it against whatever `themes.js` last wrote onto
11 //! `:root`.
12 //!
13 //! So this crate emits text naming intents, and never learns a colour. It is
14 //! the deferral rule with no adapter in the way, and it is why the webview was
15 //! always the wrong renderer to derive a vocabulary from: it can express
16 //! anything, so it never pushes back.
17 //!
18 //! # Phase A: the stylesheet
19 //!
20 //! This module emits component CSS and no markup, deliberately. GoingsOn has
21 //! 145 `innerHTML` sites and Balanced Breakfast 175 `createElement` sites, so
22 //! moving markup is a migration where adopting a generated stylesheet is not.
23 //! The apps keep every line of their markup and gain the classes.
24 //!
25 //! It is not a deletion either, which this header claimed until the measurement
26 //! came in. Adoption across goingson removed 49 declarations net and *added* 25
27 //! lines: a rule loses its depth declarations and gains a variant selector next
28 //! to it, so the file stays the same size. What phase A moves is where depth is
29 //! defined, not how much CSS exists. Numbers and method in the wiki note under
30 //! "The deletion test, run".
31 //!
32 //! The bevel properties are byte-identical to what both apps already
33 //! hand-write, which is asserted below.
34 //!
35 //! Some of what phase A emits is not a look but the withdrawal of one. A
36 //! renderer that picks its element from the description inherits that element's
37 //! user-agent chrome, and [`reset`] is where a primitive says which parts of it
38 //! were never asked for.
39 //!
40 //! # Phase B: the markup, one description at a time
41 //!
42 //! [`form`] renders [`makeover_layout::Field`], which is the half of phase B
43 //! whose description is settled. It emits strings, because both apps
44 //! interpolate their fields into larger string-built forms and returning nodes
45 //! would rewrite those too. It owns its own escaping, on the reasoning in that
46 //! module: a Rust encoder can cover element text and attribute values with one
47 //! function, where the apps need four and have to choose correctly at every
48 //! call site.
49 //!
50 //! [`facet`] renders `makeover_layout::Facet`: a dimension a set is narrowed by,
51 //! and the one phase-B emitter whose markup an app is not keeping, because the
52 //! markup it replaces was two mechanisms rather than one. A tag's selection and
53 //! a tag's browse position were separate state on MNW's discover page, which is
54 //! why every filter row there carries a tick box *and* a chevron; one gesture
55 //! doing both is what lets the second one go.
56 //!
57 //! [`list`] is the other half: column tracks, the narrowing rules, and the cell
58 //! containers a row is made of. It stops at the cell boundary and does not
59 //! render what goes inside one, on the reasoning in that module. So phase B is
60 //! now the frame around content in both directions, and what an app still owns
61 //! is the content itself.
62 //!
63 //! # What phase A settled, and what it costs
64 //!
65 //! Decided 2026-07-29 against goingson's `styles.css` rather than against a
66 //! component list. The useful finding there was that `.btn` (line 644),
67 //! `.card` (768) and `.tag, .badge` (882) each hand-write the same
68 //! composition, so three quarters of phase A is one rule with several names.
69 //!
70 //! Two of the four decisions change how goingson looks, and adoption should
71 //! not be described as a pure deletion:
72 //!
73 //! - **Pressed carries its fill.** [`interactive_rules`] emits
74 //! [`Depth::pressed`] whole. goingson presses to `--surface-sunken` today and
75 //! will press to `--surface-well`, and hovers to `--surface-overlay` today
76 //! and will hover to `--hover-surface`. Since `surface-well` inverts by theme
77 //! where `surface-sunken` does not, a dark theme presses *lighter* than it
78 //! hovers. That falls out of `makeover`'s own derivation, which says outright
79 //! that `surface-sunken` cannot serve as a well, so if it reads wrong the
80 //! answer is there and not here.
81 //! - **Badges go flat.** See [`token_rules`].
82 //!
83 //! The other two: the progress trough is renderer-local and the scrollbar
84 //! track was dropped ([`component_rules`]), and no class prefix ships by
85 //! default, so adoption means deleting the app's hand-written rule in the same
86 //! commit that adds the generated one. `.card`, `.badge` and the tab classes
87 //! all already exist in goingson, and while both rules exist the cascade order
88 //! decides which wins. That is the one real risk in adopting this, and it is
89 //! why the migration lands per component rather than in one commit.
90 //!
91 //! # 0.10.0: the states this crate used to leave to its consumers
92 //!
93 //! [`interactive_rules`] emitted hover and pressed and stopped, because
94 //! `makeover-layout` modelled no interaction state. Focus and disabled were
95 //! therefore unsayable, and every app completed the primitive from outside the
96 //! only way that works: by out-specifying a rule it does not own. goingson
97 //! carries 19 such rules and the MNW server 21, and the three focus rings do
98 //! not match each other.
99 //!
100 //! That also blocked the cascade-layer work outright. An app that declares
101 //! `@layer` puts its own rules in a named layer, and unlayered declarations
102 //! outrank every named layer regardless of specificity, so all of those
103 //! overrides lose in the commit that adopts layers. They cannot simply be
104 //! deleted, because they are the only thing supplying the missing states.
105 //! Emitting the states here is what turns that adoption into a deletion.
106 //!
107 //! Four states now, in emission order, and the order is load-bearing: they are
108 //! all specificity (0,2,0), so disabled beats hover by coming last and by
109 //! nothing else. Nothing here reaches for `:not(:disabled)`, which would raise
110 //! a selector this crate will shortly be wrapping in its own layer.
111 //!
112 //! Hover additionally sits inside a capability query now. `makeover-touch`
113 //! answers whether a fingertip has hover and `makeover-geometry` spells the
114 //! condition; this crate asks and does not decide. goingson's section 60 exists
115 //! solely to take the hover state back on touch, which is a fight it should
116 //! never have been handed.
117 //!
118 //! # 0.11.0: the layer contract
119 //!
120 //! [`stylesheet`] emits into the `makeover` cascade layer ([`CSS_LAYER`], which
121 //! lives in `makeover-geometry` because that is the one crate every CSS emitter
122 //! in the family already depends on). `makeover-geometry` 0.6.0 does the same
123 //! for `geometry.css`.
124 //!
125 //! The cascade resolves origin and importance, then layer, then specificity,
126 //! then source order, and **unlayered normal declarations outrank every named
127 //! layer**. So before this, an app that declared `@layer base, components,
128 //! responsive` put every rule it owns into a named layer and lost all of them to
129 //! this unlayered file, regardless of specificity and regardless of loading
130 //! last. Nothing errors when that happens: the CSS is valid, the minifier is
131 //! happy, and buttons and badges look subtly wrong.
132 //!
133 //! That is why the layer belongs here rather than in each app. An app cannot fix
134 //! it from its own stylesheet, because the fix is to layer the file it does not
135 //! own.
136 //!
137 //! **What it flips**, and the reason each app wants a look when it bumps the
138 //! pin: a generated rule that currently beats an app rule by being more specific
139 //! stops beating it. The direction is always "the app wins", which is what the
140 //! apps already assume, but a hand-written rule an app thought was dead can come
141 //! back to life.
142 //!
143 //! An app should declare the order once, or the layer's position is decided by
144 //! whichever generated file the browser happens to see first:
145 //!
146 //! ```css
147 //! @layer makeover, base, components, responsive;
148 //! ```
149 //!
150 //! [`in_css_layer`] is re-exported for an app that assembles its own stylesheet
151 //! from this crate's pieces. goingson builds `tables.css` in its own `build.rs`
152 //! out of [`list::narrowing_css`] and [`list::grid_template_columns`], and those
153 //! rules are as generated as the ones here, so they belong in the same layer and
154 //! this crate cannot put them there on the app's behalf.
155 //!
156 //! # 0.12.0: the ring gets its own width
157 //!
158 //! [`focus_rule`] reused [`Emit::border_width`] and emitted a 1px ring. That was
159 //! an implementation convenience dressed as consistency with the invalid-field
160 //! ring: a bevel and a focus indicator answer different questions, and only one
161 //! of them has to be noticed from across a desk.
162 //!
163 //! Caught while adopting 0.11.0 into goingson, by the check the adoption tasks
164 //! ask for. Every consumer had already written its own ring and all three chose
165 //! at least 2px: the MNW server 2px across 10 rules, Balanced Breakfast 2px,
166 //! goingson 2px on three rules and 3px on the one covering twelve selectors. The
167 //! design system was the only thing in the tree saying 1px, so deleting the app
168 //! rules in favour of it would have thinned the focus indicator everywhere.
169 //!
170 //! [`Emit::focus_width`] now carries it, defaulting to `2px`, and the offset is
171 //! the same magnitude with its sign off the depth. Both values are the measured
172 //! consensus rather than a new opinion.
173 //!
174 //! # 0.57.0: a suggestion's second line, in place of a reason it cannot be picked
175 //!
176 //! `1fcf2e9b`, ruled by Max 2026-08-21. `Outcome::Suggestions` now carries
177 //! `Candidate` rather than `Choice`, and a candidate has no `unavailable`: a
178 //! suggestion that cannot be picked is a row a route should not have offered.
179 //! What it has instead is a `detail`, the line that tells it from a row reading
180 //! the same -- "Format" under audio, software, writing and video.
181 //!
182 //! So `.form-suggestion-why` is gone and `.form-suggestion-detail` is here, and
183 //! the difference is not only the name. `why` was drawn in the disabled token,
184 //! which said the row was refusing. A detail orients rather than refuses, so it
185 //! is `--content-muted`, which is what every other secondary line in this crate
186 //! reads as.
187 //!
188 //! No consumer is affected: the only emitter is `quasi-webview`, which moves in
189 //! the same cascade.
190 //!
191 //! # 0.56.0: an interval, as the group MNW already wrote by hand
192 //!
193 //! [`makeover_layout::FieldKind::Interval`] emits a `role="group"` named by the
194 //! field's label, holding one `<input type="number">` per end. That is not a
195 //! shape invented here: MNW's discover sidebar has a `role="group"` with
196 //! `aria-labelledby` over `min_price` and `max_price` today, written by hand
197 //! because nothing in the description could say the two boxes were one
198 //! question. The markup is what the measurement found, and this emits it.
199 //!
200 //! - **The group carries the error and the descriptions**, on the split
201 //! [`makeover_layout::FieldKind::Radio`] already uses here: what is wrong is
202 //! the answer, and a crossed interval is not the fault of either end.
203 //! - **Both boxes take the whole extent.** `min`, `max` and `step` describe the
204 //! axis, so they are written twice. The crossing rule is not emitted, because
205 //! HTML has no attribute for it and the description does not carry it: it
206 //! comes back as an error on the group, like every other refusal.
207 //! - **Which end is which is `aria-label` and nothing more.** The description
208 //! states direction structurally, by which member holds which name, and never
209 //! in words. Visible Min and Max captions are a page's own and reach the
210 //! group through [`form::Filling::trailing`].
211 //!
212 //! [`form::Value::Between`] is the second value. A separator inside one string
213 //! would have made this crate the owner of a delimiter that either end could
214 //! contain.
215 //!
216 //! # 0.55.0: a number's unit, as adjacent text
217 //!
218 //! `makeover-layout` 0.33.0's `Field::unit`. HTML has no unit attribute and
219 //! inventing one would be markup nothing reads, so it is a `<span>` after the
220 //! control -- and it is named in `aria-describedby` rather than left as
221 //! decoration, because a number and what it is measured in are one fact and
222 //! reading the first without the second is reading it wrong.
223 //!
224 //! This is the renderer the member costs something. egui already had somewhere
225 //! better than the label to put a unit; here the two placements are equally
226 //! adjacent, and what is bought is that the unit is a value a consumer can read
227 //! back rather than a suffix on a label it would have to parse.
228 //!
229 //! # 0.54.0: a curve this renderer can carry, and one it declines
230 //!
231 //! `makeover-layout` 0.32.0's `Curve`. A range takes its granularity from the
232 //! curve now (`Field::curve.step()`), every other kind keeps `Field::step`, and
233 //! `Curve::Linear` emits exactly what it emitted before.
234 //!
235 //! **A constant-ratio curve emits a linear track, and that is the answer, not a
236 //! debt.** HTML has no logarithmic range input, so a described screen asking
237 //! for one is asking the browser for something it does not have, the same class
238 //! of request as [`makeover_layout::FieldKind::Date`] on a host with no
239 //! calendar. The renderer answers with the nearest control the host really
240 //! offers and keeps every fact that survives the translation: the extent, the
241 //! granularity, and the value's own units. What does not survive is resolution
242 //! at the small end. The value submitted is still a value in the field's own
243 //! units, which is what every handler on this path reads.
244 //!
245 //! The alternatives are worse in the specific way this stack exists to avoid.
246 //! Shipping JS that maps thumb position to value puts app code back in the
247 //! renderer. Changing what the control submits from a value to a fraction moves
248 //! the mapping to whoever reads the form, and the MNW server reads these forms
249 //! with its own handlers, so a fraction arriving where a value is expected
250 //! would be silent.
251 //!
252 //! When this reopens: the day a described screen on the webview path asks for a
253 //! non-linear range. The answer then is mapping in `quasi-router`, where one
254 //! implementation serves every host, not JS here. Nothing asks today. No
255 //! described screen in the tree uses a non-linear curve; the one real consumer
256 //! is audiofiles' ADSR (`instrument_panel.rs:643`), which is egui and stays
257 //! egui because audiofiles takes only `quasi-immediate` and
258 //! `makeover-immediate`; and the two webview-served consumers, goingson and the
259 //! MNW server, use no [`makeover_layout::FieldKind::Range`] at all.
260 //!
261 //! # 0.52.0: a markdown field gets the preview it was permitted
262 //!
263 //! 0.50.0 marked a [`makeover_layout::FieldKind::Rich`] field with
264 //! `data-format="markdown"` and stopped there, and nothing read the mark: no
265 //! rule, no markup, no selector anywhere in the tree. So a described editor was
266 //! a plain textarea carrying an attribute, and MNW converting its four
267 //! hand-written section editors onto the member would have *lost* the
268 //! Write/Preview pair one of them already has. A permission taken and not spent
269 //! turns every conversion into a regression.
270 //!
271 //! [`form::editor_rules`] and the chrome beside it are the spending. The pair is
272 //! a segmented control, so it takes the depth, the focus ring and the chosen
273 //! state from rules that already existed; the preview pane is a well, because it
274 //! stands where the control stood. Both are gated on the attribute rather than
275 //! on a class, which is what the attribute was for.
276 //!
277 //! **This crate still renders no markdown.** The pane arrives empty and is
278 //! filled by whatever binds the editor, which is where the host's sanitiser
279 //! already is. A converter here would have moved that guarantee into a crate
280 //! with no view of the host's content-security posture.
281 //!
282 //! # 0.47.0: a range, a chooser's ghost text, and an option that cannot be
283 //! picked yet
284 //!
285 //! `makeover-layout` 0.28.0's three form findings, all of them cheap here and
286 //! none of them cheap in the app that found them.
287 //!
288 //! - `FieldKind::Range` emits `<input type="range">`, and `Field::step` emits
289 //! `step`. The step is emitted only when the description carries one: the
290 //! browser's own default is `step="1"`, which is what a description means by
291 //! saying nothing, and is also what turns a 0-to-1 threshold into a
292 //! two-position control.
293 //! - A select with nothing chosen emits a disabled, selected, valueless first
294 //! option carrying `Field::placeholder`. HTML has no placeholder attribute on
295 //! `<select>`; this is the idiom, and `required` keeps working through it
296 //! because the option's value is empty.
297 //! - `Choice::unavailable` emits `disabled` plus the reason. Where it goes
298 //! differs by control and the difference is forced: a radio group gets a
299 //! `.form-option-reason` span beside the label, and a `<select>` option has
300 //! room for no element at all, so the reason runs into its text.
301 //! - `Choice::detail` takes the same split for the same reason, one release
302 //! later (makeover-layout 0.39.0): a `.form-option-detail` span in a radio
303 //! group, run into the text of a `<select>`'s option. An option carrying both
304 //! reads what it is before why it cannot be picked.
305 //!
306 //! # 0.25.0: a cell says what it holds
307 //!
308 //! 0.23.0 gave a table its layout and left every cell the same. One `.cell`
309 //! carried the whole thing, so a cell holding text and a cell holding a button
310 //! were one class and one content colour, and a control in a cell was painted
311 //! as text. That is the drift [`RowPart::intent`](makeover_layout::RowPart)
312 //! has prevented for list rows since 0.2.0 and prevented for nothing here.
313 //!
314 //! makeover-layout 0.14.0's [`CellPart`](makeover_layout::CellPart) names the
315 //! four things a cell holds, and [`table_rules`] turns them into
316 //! `.cell-value`, `.cell-tokens`, `.cell-actions` and `.cell-link`. Only the
317 //! first takes a colour: a token carries its own tone, an action is a control
318 //! rather than text, and a link takes the action colour from the anchor it is.
319 //!
320 //! The colour going on `.cell-value` rather than on `.cell` is the fix rather
321 //! than an implementation detail. On the container it cascades into the parts
322 //! that are not text, which is the bug said in one rule.
323 //!
324 //! [`list::Cell::part`] is `Option<CellPart>` here, where it was
325 //! `Option<RowPart>`. A table cell borrowing the list row's vocabulary was the
326 //! drift with a type on it: the two answer different questions, and only one of
327 //! them was ever about a cell.
328 //!
329 //! # 0.23.0: a table lays itself out, and a row shows its controls
330 //!
331 //! Three things a description could say and this renderer had no rule for,
332 //! found together by rendering the MNW server's SSH-keys settings tab through
333 //! `quasi` and preferring the hand-written Askama original.
334 //!
335 //! **A table had no layout at all.** [`list::narrowing_css`] emits the track
336 //! list, and it has to be called with the columns, so it works where the
337 //! columns are known at build time: goingson builds `tables.css` in its own
338 //! `build.rs` and is untouched. A table a description produced knows its
339 //! columns at render time, and the rules would have had to travel with the
340 //! markup: a `<style>` element per table, which needs `style-src
341 //! 'unsafe-inline'` that the MNW server is working to drop, or the head, which
342 //! an htmx fragment swap does not carry. [`table_rules`] lays a table out with
343 //! `display: table` instead, which aligns columns across rows knowing nothing
344 //! about how many there are. [`Priority`](makeover_layout::Priority) hiding
345 //! moves from a generated rule per dropped column to one rule per drop class,
346 //! and [`list::column_classes`] is what puts those classes on a cell. A header
347 //! row emitted by a renderer's own code should call it too, or the header and
348 //! the body disagree about which column just dropped.
349 //!
350 //! **A destructive button had nowhere for its tone to land.** `.button` carried
351 //! no tone, on the reading that a control's colour is its surface. Every
352 //! consumer had written the danger rule itself. It joins the badge in taking
353 //! the four tones as colour, off `data-tone`.
354 //!
355 //! **A list rendered as a bulleted list**, because nothing here reset the `ul`
356 //! a renderer emits for one.
357 //!
358 //! `RowPart::revealed_on_hover` also stops being honoured, which its own doc
359 //! sanctioned: a renderer decides. It was retired outright in makeover-layout
360 //! 0.13.0, once this had been its only consumer for a release. The rule hid a
361 //! row's actions until hover,
362 //! and every escape it grew was a report that hiding was wrong for somebody:
363 //! `focus-within` for the keyboard, the capability gate for a fingertip with no
364 //! way to unhide. What survived hid the controls from pointer users alone, who
365 //! are the ones scanning a list to learn what can be done to a row.
366 //!
367 //! # 0.17.0: the depth classes stop being controls
368 //!
369 //! [`depth_rules`] gave `.raised` the whole interactive set. A depth is a
370 //! statement about shape, so that left the vocabulary with no raised surface
371 //! that is merely an object, and an app wanting one had two moves: write its
372 //! own class from tokens, or take a control class and cancel the control half.
373 //! goingson took the second, in three variants over sixteen elements
374 //! (`.card--static` at 14 call sites, `.card--muted` at 2, `.card--shell` at 1),
375 //! each re-asserting the resting fill and bevel on `:hover` and `:active`.
376 //!
377 //! Measured before changing it: `.raised` is emitted into goingson, Balanced
378 //! Breakfast and the MNW server, and none of the three has a single call site.
379 //! The states were unasked-for everywhere at once, and dropping them costs no
380 //! migration anywhere.
381 //!
382 //! `.card` and `.button` are unchanged. They are the same depth *and* controls,
383 //! and they take their states from [`surface_rules`], which is where a state
384 //! belongs: on the thing that claims to answer a pointer.
385 //!
386 //! # Substitution, three ways
387 //!
388 //! `Fill::Well` has no colour on makeover before 2.3.0, and each renderer
389 //! answers that differently, which is the evidence that dropping
390 //! `Fill::fallback` from the description was right:
391 //!
392 //! - `makeover-immediate` substitutes the page in Rust.
393 //! - `makeover-tui` refuses to substitute and draws an edge instead, because a
394 //! terminal would quantise the two together.
395 //! - here, CSS already has the mechanism: `var(--surface-well,
396 //! var(--surface-page))` falls back in the browser, and nothing in Rust
397 //! decides anything.
398
399 #![forbid(unsafe_code)]
400
401 pub mod facet;
402 pub mod figure;
403 pub mod form;
404 pub mod list;
405 pub mod meter;
406 pub mod placeholder;
407 pub mod reset;
408 pub mod vocabulary;
409
410 /// A render of every emitter, scraped for the classes it wrote.
411 ///
412 /// Test-only, and the guard behind [`vocabulary::names`]. See the module's own
413 /// header for why the check renders rather than reads the source.
414 #[cfg(test)]
415 mod corpus;
416
417 use crate::list::{cell_part_class, part_class};
418 use crate::reset::{Chrome, Reset};
419 use makeover_geometry::{Density, SizeClass};
420 // Re-exported rather than redefined. An app assembling its own stylesheet out
421 // of this crate's pieces needs the same layer name, and most such apps depend
422 // on this crate and not on `makeover-geometry` directly: goingson builds
423 // `tables.css` in its own build.rs from [`list::narrowing_css`], and those
424 // rules are as generated as the ones here.
425 pub use makeover_geometry::{CSS_LAYER, in_css_layer};
426
427 /// This crate's version, as the generated stylesheet reports it.
428 ///
429 /// A consumer whose lockfile still pins an old `makeover-webview` gets a
430 /// well-formed sheet with components missing and no error anywhere, so the
431 /// emitter has to name itself in what it writes. Read by
432 /// `makeover_build::layout_css` through [`stylesheet`].
433 pub const VERSION: &str = env!("CARGO_PKG_VERSION");
434 use makeover_layout::{
435 Bevel, CellPart, Depth, Fallback, Fill, Flow, Intent, RowPart, Selector, Sort, State, Token,
436 Tone,
437 };
438 use makeover_touch::Affordance;
439 use std::fmt::Write as _;
440
441 /// How the emitted CSS is shaped.
442 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
443 pub struct Emit {
444 /// Bevel thickness, as a CSS length.
445 ///
446 /// A value, so it arrives from the caller: border widths belong to
447 /// `makeover-geometry` and will come from there once it carries them.
448 pub border_width: &'static str,
449 /// Focus ring thickness, as a CSS length.
450 ///
451 /// Separate from [`border_width`](Self::border_width), which it reused
452 /// until 0.12.0. That reuse was an implementation convenience dressed as
453 /// consistency, and it emitted a 1px ring: a bevel and a focus indicator
454 /// are answering different questions, and only one of them has to be
455 /// noticed from across a desk.
456 ///
457 /// The default is the measured consensus rather than a new opinion. Every
458 /// consumer had already written its own ring and all three chose at least
459 /// 2px: the MNW server 2px across 10 rules, Balanced Breakfast 2px,
460 /// goingson 2px on three rules and 3px on the one covering twelve
461 /// selectors. The design system was the only thing in the tree saying 1px.
462 pub focus_width: &'static str,
463 /// Prefix for emitted class names, without the leading dot.
464 pub class_prefix: &'static str,
465 }
466
467 impl Default for Emit {
468 fn default() -> Self {
469 Self {
470 border_width: "1px",
471 focus_width: "2px",
472 class_prefix: "",
473 }
474 }
475 }
476
477 /// A string as CSS escapes, for a `content` value.
478 ///
479 /// `\u{25B2}` becomes `\25B2`. Emitted escaped rather than literally so the
480 /// stylesheet is ASCII whatever the description spells: a `content` string is
481 /// read by whatever encoding the consumer serves the file as, and a caret that
482 /// depends on that is a caret that works on one machine.
483 ///
484 /// Terminated by the closing quote at every site here. A CSS hex escape takes
485 /// up to six digits and ends at the first character that cannot be one, so an
486 /// escape followed by more text would need a space that these do not.
487 fn css_escape(text: &str) -> String {
488 text.chars().fold(String::new(), |mut out, c| {
489 let _ = write!(out, "\\{:X}", c as u32);
490 out
491 })
492 }
493
494 /// The CSS custom property holding a bevel's composition.
495 #[must_use]
496 pub fn bevel_var(bevel: Bevel) -> &'static str {
497 match bevel {
498 Bevel::Raised => "--bevel-raised",
499 Bevel::Inset => "--bevel-inset",
500 }
501 }
502
503 /// A `var()` reference to a fill intent, with the browser's own fallback where
504 /// the intent may be absent.
505 ///
506 /// The fallback is CSS syntax, not a decision made here. That is the whole
507 /// difference between this renderer and the other two.
508 #[must_use]
509 pub fn fill_var(fill: Fill) -> String {
510 match fill {
511 Fill::Well => format!("var(--{}, var(--{}))", fill.token(), Fill::Page.token()),
512 other => format!("var(--{})", other.token()),
513 }
514 }
515
516 /// The two-tone edge as a `box-shadow` value.
517 ///
518 /// Two inset shadows, one per corner pair: the light one offset down and
519 /// right so it lands on the top and left edges, the dark one the other way.
520 /// The same assignment `makeover-immediate` draws with polylines and
521 /// `makeover-tui` draws with box-drawing characters.
522 #[must_use]
523 pub fn bevel_shadow(bevel: Bevel, opts: &Emit) -> String {
524 let (top_left, bottom_right) = bevel.edges();
525 let w = opts.border_width;
526 format!(
527 "inset {w} {w} 0 var(--{}), inset -{w} -{w} 0 var(--{})",
528 top_left.token(),
529 bottom_right.token()
530 )
531 }
532
533 /// The custom properties both bevels resolve through.
534 ///
535 /// Emitted as properties rather than inlined into every rule because that is
536 /// what the apps already do, and because a consumer that wants the edge
537 /// without the fill reads the property directly.
538 #[must_use]
539 pub fn bevel_properties(opts: &Emit) -> String {
540 let mut css = String::new();
541 for bevel in [Bevel::Raised, Bevel::Inset] {
542 let _ = writeln!(
543 css,
544 " {}: {};",
545 bevel_var(bevel),
546 bevel_shadow(bevel, opts)
547 );
548 }
549 css.push_str(ELEVATION_PROPERTY);
550 css
551 }
552
553 /// The cast shadow of a surface that floats over the page.
554 ///
555 /// Composed here for the reason the bevel pair is: `makeover` derives the tone,
556 /// this crate owns the geometry, and neither has to know the other's numbers.
557 ///
558 /// **Only for a surface that overlays the page.** A menu, a toast, a popover, a
559 /// dropdown. A surface *in* the page takes `.raised` and its bevel, and a rule
560 /// that reaches for this on a card or a plate has renamed a literal rather than
561 /// replaced it.
562 ///
563 /// Two lengths rather than one, because a single blur reads as a smudge at
564 /// plate size and as a halo at menu size. The offset is small and downward: a
565 /// Platinum-era menu sits just off the page rather than hovering above it.
566 const ELEVATION_PROPERTY: &str =
567 " --elevation-overlay: 0 2px 4px var(--elevation), 0 8px 24px var(--elevation);\n";
568
569 /// The class name for a depth.
570 #[must_use]
571 pub fn depth_class(depth: Depth, opts: &Emit) -> Option<String> {
572 let name = match depth {
573 Depth::Flat => return None,
574 Depth::Raised => "raised",
575 Depth::Well => "well",
576 Depth::Sunken => "sunken",
577 // A depth added to the description since this renderer was last
578 // built. No class, on the same footing as Flat: emitting a name
579 // whose rule body we cannot write would put a class in the markup
580 // that the stylesheet never defines.
581 _ => return None,
582 };
583 Some(format!("{}{name}", opts.class_prefix))
584 }
585
586 /// A prefixed class name.
587 ///
588 /// Public since 0.27.0, for the renderers that emit markup this crate does not.
589 /// A screen renderer writing `class="row"` has to prefix it the way the
590 /// stylesheet half does or a prefixed app gets rules matching everything except
591 /// the elements that renderer wrote, and the failure is invisible: the CSS
592 /// stays valid and one element is unstyled. quasi-webview carried a byte
593 /// identical copy of this function until it could call this one.
594 #[must_use]
595 pub fn class(name: &str, opts: &Emit) -> String {
596 let mut out = String::with_capacity(opts.class_prefix.len() + name.len());
597 push_class(&mut out, name, opts);
598 out
599 }
600
601 /// A prefixed class name, written into a buffer the caller already has.
602 ///
603 /// The form the emitters use, and the reason it exists is [`escape_into`]'s:
604 /// every class on every element went through a `format!` before 0.40.0,
605 /// including the default case where the prefix is empty and the answer is the
606 /// argument. A described table row carried roughly eighty transient
607 /// allocations, and this and the escaper were most of them.
608 ///
609 /// [`class`] stays for callers holding a name rather than a buffer.
610 ///
611 /// [`escape_into`]: crate::form::escape_into
612 pub fn push_class(out: &mut String, name: &str, opts: &Emit) {
613 out.push_str(opts.class_prefix);
614 out.push_str(name);
615 }
616
617 /// The class an option of a selector carries, which is what the rules key off.
618 ///
619 /// Named for the option and not for the group: [`selector_rules`] styles the
620 /// thing that gets picked, so `Selector::Tabs` is `tab` and not `tabs`. The
621 /// distinction is not pedantry. quasi-webview spelled these `tabs`, `segmented`
622 /// and `option`, put `toggle` on the wrapping element rather than on the
623 /// buttons inside it, and every described selector in that renderer came out
624 /// with no depth, no focus ring and no chosen state, while the toggle group got
625 /// a bevel meant for its buttons.
626 ///
627 /// The chosen option additionally carries `chosen`, the same way a latched chip
628 /// carries `latched`. That name is this crate's too; there is no reason for a
629 /// caller to spell it, and [`selector_rules`] is where it is written down.
630 #[must_use]
631 pub fn option_class(selector: Selector) -> &'static str {
632 match selector {
633 Selector::Tabs => "tab",
634 Selector::Segmented => "segment",
635 Selector::Toggle => "toggle",
636 }
637 }
638
639 /// The fill and edge declarations for a depth, as a rule body.
640 ///
641 /// Empty for [`Depth::Flat`], which has neither and inherits what it sits on.
642 /// Callers lean on the emptiness to skip the rule rather than emit a class that
643 /// sets nothing: a class that sets no properties is a class that means "I
644 /// thought about this", which is what comments are for.
645 ///
646 /// The two halves are emitted independently because [`Depth::Sunken`] has a
647 /// fill and no bevel. Requiring both, which this did before makeover-layout
648 /// 0.3.0, silently dropped the fill for exactly that case. Independent does not
649 /// mean unpaired: both halves still come off one `Depth`, so they cannot
650 /// disagree about what the region is.
651 #[must_use]
652 pub fn depth_declarations(depth: Depth) -> String {
653 let mut css = String::new();
654 if let Some(fill) = depth.fill() {
655 let _ = writeln!(css, " background: {};", fill_var(fill));
656 }
657 if let Some(bevel) = depth.bevel() {
658 let _ = writeln!(css, " box-shadow: var({});", bevel_var(bevel));
659 }
660 css
661 }
662
663 /// One rule giving a selector a depth, or nothing when the depth declares
664 /// nothing.
665 #[must_use]
666 pub fn depth_rule(selector: &str, depth: Depth) -> String {
667 let body = depth_declarations(depth);
668 if body.is_empty() {
669 return String::new();
670 }
671 format!(".{selector} {{\n{body}}}\n")
672 }
673
674 /// The media condition a hover rule has to sit inside, or `None` if hover is
675 /// unconditional.
676 ///
677 /// Two crates answer this and neither answer is made here. `makeover-touch`
678 /// owns *whether* hover exists at a density, and `makeover-geometry` owns how
679 /// that capability is spelled as a media condition. Asking both is what stops
680 /// this renderer minting a third opinion, which is what all three apps did:
681 /// goingson sniffed the user agent, Balanced Breakfast used `(hover: none)`
682 /// alone, and the MNW server had no gate at all.
683 ///
684 /// [`SizeClass`] is required by [`Affordance::available`] and ignored by this
685 /// member, which reports as much through `reads_size`. Passing Compact is not
686 /// a claim about width; the test below pins that every class agrees.
687 fn hover_condition() -> Option<&'static str> {
688 if Affordance::Hover.available(Density::Touch, SizeClass::Compact) {
689 // A fingertip grew a hover state. Nothing to gate, and this renderer
690 // should not invent a reason to gate anyway.
691 None
692 } else {
693 Some(Density::Pointer.media_condition())
694 }
695 }
696
697 /// Put a rule inside a media query, or leave it alone.
698 fn gated(condition: Option<&str>, rule: &str) -> String {
699 let Some(condition) = condition else {
700 return rule.to_string();
701 };
702 let mut css = format!("@media {condition} {{\n");
703 for line in rule.lines() {
704 // Blank lines stay blank. Indenting one leaves trailing whitespace,
705 // which is the sort of thing a formatter later reverts and calls a diff.
706 if line.is_empty() {
707 css.push('\n');
708 } else {
709 let _ = writeln!(css, " {line}");
710 }
711 }
712 css.push_str("}\n");
713 css
714 }
715
716 /// The keyboard focus ring, placed by the depth it lands on.
717 ///
718 /// This is the webview's **focus ring** and nothing more. **Reach** and
719 /// **focus** are both the browser's — the document decides what is reachable
720 /// and `:focus-visible` decides which reached thing wears the ring — and no
721 /// description states either. The three terms are defined once in
722 /// `makeover_layout`'s crate header, "Reach, focus and the focus ring".
723 ///
724 /// One ring for the whole system, because a focus ring's job is to be
725 /// recognised and three apps having three of them is the failure. What varies
726 /// is where it sits, and that comes off [`Depth`] rather than off a per-
727 /// component choice: a well takes the ring inside its own edge, and anything
728 /// standing proud of the page takes it outside.
729 ///
730 /// `outline` rather than the composed `box-shadow` the invalid-field ring at
731 /// [`field_rules`] uses, and deliberately the one place the two rings are built
732 /// differently. A `box-shadow` ring has to restate the bevel beside it, because
733 /// `box-shadow` is not additive and a lone ring silently drops the well out
734 /// from under the element. That restatement is a second copy of the depth,
735 /// living in a different function from the first, and it is exactly the
736 /// duplication `Depth` exists to prevent. `outline` occupies its own property,
737 /// so the bevel survives untouched and there is nothing to keep in agreement.
738 /// They render the same: both are a flush ring one border-width wide.
739 #[must_use]
740 pub fn focus_rule(selector: &str, depth: Depth, opts: &Emit) -> String {
741 let w = opts.focus_width;
742 // Same magnitude either way, and only the sign comes off the depth. Both
743 // values are what the consumers had already converged on independently:
744 // 2px out is what all three wrote, and 2px in is the MNW server's own
745 // answer for the one inset ring it had.
746 let offset = match depth.bevel() {
747 // Inside the well, clear of its edge rather than painted over it.
748 Some(Bevel::Inset) => format!("calc(-1 * {w})"),
749 // Raised, or no edge at all. Outside, standing off by its own width.
750 _ => w.to_string(),
751 };
752 // The token by name. It is `makeover`'s, derived from the action colour,
753 // and reaching it through a description member was a second path to the
754 // same variable for as long as one existed.
755 format!(
756 ".{selector}:focus-visible {{\n outline: {w} solid var(--focus-ring);\n outline-offset: {offset};\n}}\n"
757 )
758 }
759
760 /// A rest depth said out loud on both axes, for a rule that has to beat the
761 /// states above it.
762 ///
763 /// [`depth_declarations`] states an axis only when the depth has something to
764 /// say about it, which is right for a rest rule: a [`Depth::Flat`] region
765 /// inherits what it sits on, and asserting `background: none` there would be
766 /// the difference between level-with and painted-transparent. It is wrong for
767 /// a rule whose whole job is to take a state back. An axis left unstated is an
768 /// axis the state above keeps, so `Flat` re-asserted nothing at all and a
769 /// disabled control kept whatever hover had given it.
770 ///
771 /// So the axes the depth is silent on are withdrawn rather than skipped, and
772 /// the withdrawal is spelled by [`reset`] rather than here, so a disabled
773 /// control and a flat one say the same words. Reaches further than the fill:
774 /// [`Depth::Sunken`] and [`Depth::Overlay`] have no bevel either, and the
775 /// pressed rule above hands out an inset one.
776 fn rest_declarations(depth: Depth) -> String {
777 let mut css = String::new();
778 match depth.fill() {
779 Some(fill) => {
780 let _ = writeln!(css, " background: {};", fill_var(fill));
781 }
782 None => css.push_str(&Reset::NOTHING.and(Chrome::Fill).declarations()),
783 }
784 match depth.bevel() {
785 Some(bevel) => {
786 let _ = writeln!(css, " box-shadow: var({});", bevel_var(bevel));
787 }
788 None => css.push_str(&Reset::NOTHING.and(Chrome::Shadow).declarations()),
789 }
790 css
791 }
792
793 /// Present, visible, and not answering.
794 ///
795 /// Matches the ARIA attribute as well as the pseudo-class, because `:disabled`
796 /// only matches form elements and half the things this crate emits are not
797 /// one: a `div` carrying `.chip` or `.tab` can never be `:disabled`. Keying on
798 /// the accessible state is the pattern [`field_rules`] already establishes for
799 /// `aria-invalid`, on the reasoning that one fact read by both the styling and
800 /// the accessibility tree cannot drift from itself.
801 ///
802 /// The rest depth is re-asserted rather than assumed, because this rule has to
803 /// beat the hover and pressed rules above it. It does that on source order at
804 /// equal specificity, not by out-specifying them: every rule this function's
805 /// caller emits is (0,2,0), and adding a `:not(:disabled)` anywhere would raise
806 /// one of them and have to be unpicked when this output moves inside its own
807 /// cascade layer.
808 ///
809 /// Re-asserted on **both** axes, through [`rest_declarations`], which is the
810 /// half this got wrong until 0.68.0. `depth_declarations` alone is empty for
811 /// [`Depth::Flat`], so the three flat controls this crate emits -- both facet
812 /// arms and a suggestion entry -- won the contest with nothing to say and kept
813 /// the hover surface underneath a control that had stopped answering.
814 #[must_use]
815 pub fn disabled_rule(selector: &str, depth: Depth) -> String {
816 format!(
817 ".{selector}:disabled,\n.{selector}[aria-disabled=\"true\"] {{\n{} color: var(--{});\n cursor: not-allowed;\n}}\n",
818 rest_declarations(depth),
819 State::Disabled.token()
820 )
821 }
822
823 /// Every state a selector that answers a click implies: hover, pressed, focus
824 /// and disabled, in that order.
825 ///
826 /// Order is the whole cascade mechanism here. All four selectors are
827 /// specificity (0,2,0), so disabled wins over hover and pressed by coming last
828 /// and by nothing else.
829 ///
830 /// Pressed emits [`Depth::pressed`] in full, fill and edge together. Emitting
831 /// only the edge is what left goingson hand-writing `background:
832 /// var(--surface-sunken)` on three separate rules, and a fill that does not
833 /// travel with its edge is precisely the disagreement `Depth` exists to make
834 /// unrepresentable. So the pressed fill comes from the description
835 /// (`--surface-well`) rather than from whatever each app reached for.
836 ///
837 /// Hover has no member in the description and is renderer policy: a terminal
838 /// and an immediate-mode painter have no hover to express. It resolves against
839 /// `--hover-surface`, which `makeover` already derives and which nothing
840 /// consumed until now. What it *is* gated on is capability, via
841 /// [`hover_condition`]. Before that gate existed the apps each wrote their own:
842 /// goingson's section 60 exists solely to take back the hover state this
843 /// function had just handed it, by out-specifying a rule it does not own.
844 ///
845 /// `depth` is the selector's **rest** depth, used to place the focus ring and
846 /// to restore the surface under a disabled control. The pressed rule keeps
847 /// inverting from [`Depth::Raised`] regardless, which is what every caller got
848 /// before this parameter existed: a tab's unchosen depth is
849 /// [`Depth::Sunken`], and `Sunken.pressed()` is `Sunken`, so deriving the press
850 /// from the rest depth would leave a tab with no press at all.
851 #[must_use]
852 pub fn interactive_rules(selector: &str, depth: Depth, opts: &Emit) -> String {
853 let mut css = gated(
854 hover_condition(),
855 &format!(".{selector}:hover {{\n background: var(--hover-surface);\n}}\n"),
856 );
857 css.push_str(&depth_rule(
858 &format!("{selector}:active"),
859 Depth::Raised.pressed(),
860 ));
861 css.push_str(&focus_rule(selector, depth, opts));
862 css.push_str(&disabled_rule(selector, depth));
863 css
864 }
865
866 /// One rule per depth: its fill and its edge, together.
867 ///
868 /// A depth and nothing else. `.raised` says a surface sits on what is behind
869 /// it, which is a statement about the shape and not about what happens when a
870 /// pointer arrives, so it emits no hover, press, focus or disabled rule. The
871 /// named surfaces are where interaction lives: `.card` and `.button` are the
872 /// same depth *and* controls, and they get their states from
873 /// [`surface_rules`].
874 ///
875 /// This class carried the interactive set until 0.17.0, which left the
876 /// vocabulary with no raised surface that is merely an object. Consumers that
877 /// needed one took a control class and cancelled half of it instead: sixteen
878 /// elements in goingson across three `.card--*` variants, each re-asserting the
879 /// resting fill and bevel on `:hover` and `:active`. Nothing anywhere used
880 /// `.raised` itself, so the states were unasked-for in every consumer at once.
881 #[must_use]
882 pub fn depth_rules(opts: &Emit) -> String {
883 let mut css = String::new();
884 for depth in [Depth::Raised, Depth::Well] {
885 let Some(class) = depth_class(depth, opts) else {
886 continue;
887 };
888 css.push_str(&depth_rule(&class, depth));
889 }
890 css
891 }
892
893 /// The three surfaces that are a depth with a name.
894 ///
895 /// `button` and `card` are both [`Depth::Raised`], and `field` is a
896 /// [`Depth::Well`] because that is the reading `Depth`'s own documentation
897 /// gives a text field. Their bodies come out identical by construction rather
898 /// than by hand: three hand-written copies in goingson's stylesheet is what
899 /// phase A deletes, and generating them from one call is what stops them
900 /// drifting apart again.
901 fn surface_rules(opts: &Emit) -> String {
902 let mut css = String::new();
903 for name in ["button", "card"] {
904 let c = class(name, opts);
905 css.push_str(&depth_rule(&c, Depth::Raised));
906 css.push_str(&interactive_rules(&c, Depth::Raised, opts));
907 }
908
909 let field = class("field", opts);
910 css.push_str(&depth_rule(&field, Depth::Well));
911
912 // A field takes focus and refuses input like everything else here, and got
913 // neither until now, which is why all three apps hand-write a focus ring
914 // for it and no two of them match. No hover or pressed: a text field does
915 // not light up under the pointer and does not invert when clicked, so the
916 // two states `interactive_rules` would add are the two it does not have.
917 css.push_str(&focus_rule(&field, Depth::Well, opts));
918 css.push_str(&disabled_rule(&field, Depth::Well));
919
920 // Keyed on the ARIA attribute rather than on a class, so the visual state
921 // and the accessible state cannot drift apart: there is one fact and both
922 // read it. goingson already drove its invalid styling this way and was
923 // right to; the `.invalid` class this emitted before 0.5.0 was a second
924 // place to forget.
925 //
926 // The ring composes *after* the bevel rather than replacing it. box-shadow
927 // is not additive, so a lone ring silently dropped the well out from under
928 // an invalid field. Flat and unlit: this edge is saying "wrong", and
929 // lighting one side would have it say "raised" at the same time.
930 let _ = writeln!(
931 css,
932 ".{field}[aria-invalid=\"true\"] {{\n box-shadow: var({}), 0 0 0 {} var(--danger);\n}}",
933 bevel_var(Bevel::Inset),
934 opts.border_width
935 );
936 css
937 }
938
939 /// Badges and chips.
940 ///
941 /// The one place phase A changes how goingson looks rather than only where its
942 /// rules live. [`Token::Badge`] is [`Depth::Flat`], so a badge emits no fill
943 /// and no edge at all, where goingson ships `.tag, .badge` as a single rule
944 /// carrying the raised bevel. Splitting that means reading every call site to
945 /// decide which of the two it always was.
946 ///
947 /// What a badge does carry is a [`Tone`], the intent family it shares with
948 /// notices and nothing else. Neutral is the bare class rather than a variant,
949 /// because it is the absence of a status and not a status called "none".
950 /// Text that goes somewhere.
951 ///
952 /// The one inline control, and the vocabulary had no word for it until a
953 /// description layer needed one. A table cell has carried `cell-link` since
954 /// 0.14.0's part list, deliberately unruled because the cell's own rule covers
955 /// it; what was missing is the same thing outside a table, which is what a
956 /// described run holds when a sentence contains a link.
957 ///
958 /// Colour and underline only. Whether a link is inline in a sentence or sitting
959 /// on its own line is the app's layout, and how much room it takes is
960 /// `makeover-geometry`'s. What is here is the pair of signals that say "this
961 /// goes somewhere" and nothing that says where it sits.
962 ///
963 /// The visited arm is deliberately absent. A link inside an app points at the
964 /// app's own screens, which the user is expected to have been to, so painting
965 /// them differently marks almost everything and distinguishes nothing.
966 fn link_rules(opts: &Emit) -> String {
967 let mut css = String::new();
968 let link = class("link", opts);
969
970 let _ = writeln!(
971 css,
972 ".{link} {{\n color: var(--action);\n \
973 text-decoration: underline;\n}}"
974 );
975 // The hover step is the same one every other control takes, and it is a
976 // colour rather than a surface: a link has no box to raise.
977 let _ = writeln!(
978 css,
979 "@media (hover: hover) and (pointer: fine) {{\n .{link}:hover \
980 {{\n color: var(--action-hover);\n }}\n}}"
981 );
982 let _ = writeln!(
983 css,
984 ".{link}:focus-visible {{\n outline: {} solid var(--focus-ring);\n \
985 outline-offset: 2px;\n}}",
986 opts.focus_width
987 );
988 // A link is often a `<button>` rather than an `<a>`: a renderer picks the
989 // element from the method, so a link that writes is a button that has to
990 // stop looking like one. What that costs is named in [`reset`].
991 css.push_str(&Reset::TEXT_BUTTON.rule(&format!("button.{link}")));
992 css
993 }
994
995 fn token_rules(opts: &Emit) -> String {
996 let mut css = String::new();
997
998 // No `depth_rule` call here, deliberately: `Token::Badge.depth(_)` is Flat,
999 // and a label with an edge says it can be pressed.
1000 let badge = class("badge", opts);
1001 // `content-muted` literally, not `Tone::Neutral.token()`. What makes a
1002 // badge quiet is `Token::Badge` answering no click, which this crate holds
1003 // and `Tone` genuinely does not know. Routing it through Neutral put the
1004 // claim where the evidence was not, and the bill arrived on the figure
1005 // value: it took the same muting from the same call and read as its own
1006 // caption. Neutral answers `content` from makeover-layout 0.36.0.
1007 let _ = writeln!(css, ".{badge} {{\n color: var(--content-muted);\n}}");
1008 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1009 let _ = writeln!(
1010 css,
1011 ".{badge}[data-tone=\"{0}\"] {{\n color: var(--{0});\n}}",
1012 tone.token()
1013 );
1014 }
1015
1016 // A button carries the four tones a badge does. It had none, on the reading
1017 // that a control's colour is its surface rather than its text, and that
1018 // reading has one hole big enough to matter: the button that destroys
1019 // something. Every consumer had written that rule itself, and a description
1020 // that says `Tone::Danger` on an act had nowhere for it to land.
1021 //
1022 // Colour and not a fill, matching the badge. A red surface is a decision
1023 // about emphasis that belongs to an app's own layer, and two of them
1024 // fighting is worse than neither.
1025 let button = class("button", opts);
1026 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1027 let _ = writeln!(
1028 css,
1029 ".{button}[data-tone=\"{0}\"] {{\n color: var(--{0});\n}}",
1030 tone.token()
1031 );
1032 }
1033
1034 // A chip holds itself down, which is `Depth::pressed` arrived at
1035 // independently by two apps. `removable` is a remove affordance, so it is
1036 // markup and waits for phase B.
1037 let chip = class("chip", opts);
1038 let unlatched = Token::Chip { removable: false };
1039 css.push_str(&depth_rule(&chip, unlatched.depth(false)));
1040 css.push_str(&interactive_rules(&chip, unlatched.depth(false), opts));
1041 css.push_str(&depth_rule(
1042 &format!("{chip}.latched"),
1043 unlatched.depth(true),
1044 ));
1045 css
1046 }
1047
1048 /// The three selectors, each named by what it picks.
1049 ///
1050 /// A tab comes *forward* to join the pane it opens, which is why
1051 /// [`Selector::Tabs`] chooses [`Depth::Raised`] where a segment and a toggle
1052 /// are held in. That is the folder semantic, and it is the whole reason the
1053 /// three are not one member with a flag.
1054 ///
1055 /// [`Selector::abutting`] is not emitted: whether the options touch is
1056 /// spacing, and spacing is `makeover-geometry`'s question to answer.
1057 ///
1058 /// Both states emit as of makeover-layout 0.3.0. Before it the description
1059 /// named only the chosen option, so an unchosen one fell through to
1060 /// [`Depth::Flat`] and nothing was drawn for it, which left goingson's tab
1061 /// strip hand-writing the recess that makes its chosen tab read as forward.
1062 fn selector_rules(opts: &Emit) -> String {
1063 let mut css = String::new();
1064 for selector in [Selector::Tabs, Selector::Segmented, Selector::Toggle] {
1065 let c = class(option_class(selector), opts);
1066 css.push_str(&depth_rule(&c, selector.unchosen()));
1067 css.push_str(&interactive_rules(&c, selector.unchosen(), opts));
1068 css.push_str(&depth_rule(&format!("{c}.chosen"), selector.chosen()));
1069 }
1070 css
1071 }
1072
1073 /// The parts of a list row.
1074 ///
1075 /// The list is written out rather than derived because `RowPart` is
1076 /// `#[non_exhaustive]` as of makeover-layout 0.9.0, so there is nothing to
1077 /// iterate. A member added upstream emits no rule until it is named here, which
1078 /// is the trade `non_exhaustive` makes: a silent gap instead of a build break.
1079 /// [`part_class`] carries the same list and the same obligation.
1080 fn row_rules(opts: &Emit) -> String {
1081 let mut css = String::new();
1082
1083 // The container the rows sit in, giving back what a `<ul>` brought. Not a
1084 // size: there is no magnitude in it, which is the line this crate holds.
1085 css.push_str(&Reset::BULLETS.rule(&format!(".{}", class("list", opts))));
1086
1087 for part in [
1088 RowPart::Primary,
1089 RowPart::Secondary,
1090 RowPart::Meta,
1091 RowPart::Actions,
1092 RowPart::Tokens,
1093 RowPart::Proportion,
1094 ] {
1095 let c = class(part_class(part), opts);
1096
1097 // Actions carry controls rather than text, and `RowPart::intent` says
1098 // so by returning the same intent inheriting already gives. Pinning it
1099 // would be louder than saying nothing. Tokens answer alike, for their
1100 // own reason: each token carries its own tone, and a colour on the
1101 // strip would fight the things sitting in it. A proportion is the same
1102 // case again: the meter inside carries the tone.
1103 if !matches!(
1104 part,
1105 RowPart::Actions | RowPart::Tokens | RowPart::Proportion
1106 ) {
1107 let _ = writeln!(css, ".{c} {{\n color: var(--{});\n}}", part.intent());
1108 }
1109
1110 // A row's actions are shown at rest. `RowPart::revealed_on_hover` said
1111 // otherwise and was not honoured here from 0.23.0; makeover-layout
1112 // 0.13.0 retired the method, so there is no longer a description saying
1113 // one thing and a renderer doing another.
1114 //
1115 // The rule was `opacity: 0` gated to pointer devices, revealed on
1116 // `:hover` and on `:focus-within`. Each escape it needed was a report
1117 // that hiding was wrong for somebody: `focus-within` because tabbing
1118 // could never reach an action; the gate because a fingertip had no way
1119 // to unhide, which both webview apps had already hand-written
1120 // `opacity: 1` to undo. What was left was a control hidden from
1121 // exactly one group: people using a pointer, who are also the group
1122 // scanning a list to find out what can be done to a row.
1123 //
1124 // A settings screen is where that reads worst: the whole reason to be
1125 // on it is to remove a key, and the button doing so was invisible
1126 // until pointed at. A table cell's actions were never hidden, so the
1127 // two arrangements now agree.
1128 }
1129
1130 // A part that may take two lines. `Flow::Tight` gets no rule: one line is
1131 // what a run already does, and restating it here would put a declaration on
1132 // every part in every row to say nothing.
1133 //
1134 // This is the shape both webview apps had already written by hand and
1135 // commented -- Balanced Breakfast on a feed row's title, goingson on a
1136 // problem's body -- which is the whole argument for the description
1137 // carrying it. `-webkit-` prefixed and unprefixed together: the prefixed
1138 // trio is what every engine actually implements, and `line-clamp` is the
1139 // standard property landing behind it.
1140 let _ = writeln!(
1141 css,
1142 ".{} {{\n display: -webkit-box;\n -webkit-box-orient: vertical;\n -webkit-line-clamp: {lines};\n line-clamp: {lines};\n overflow: hidden;\n}}",
1143 class("row-relaxed", opts),
1144 lines = Flow::Relaxed.lines()
1145 );
1146
1147 css
1148 }
1149
1150 /// A row of things that share their space, and what each fallback gets here.
1151 ///
1152 /// Ruling: wiki `layout-room-and-fallback`, Max 2026-08-18. The bug it answers
1153 /// is goingson's `styles.css:702`, which pinned every `.page-header` over the
1154 /// pill strip with `position: absolute` and so took the toolbar out of flow:
1155 /// zero width contributed to the row it shared, nothing able to collide with
1156 /// it, and therefore nothing preventing the collision. Rule 1 of the ruling is
1157 /// that every described member is in flow, and these rules are how that is kept
1158 /// rather than asked for.
1159 ///
1160 /// # The floor, which is most of the fix
1161 ///
1162 /// `.run > *` gets `min-width: min-content`. That is the derived minimum the
1163 /// ruling asks for, in this renderer's own unit and stated by the browser
1164 /// rather than by anybody: a member cannot be squeezed narrower than what is
1165 /// in it, so members in one flow push each other instead of overlapping. It
1166 /// costs no query and no number, and it is what fixes all four measured widths
1167 /// whichever fallback the group declared.
1168 ///
1169 /// # What each fallback gets, exactly
1170 ///
1171 /// [`Fallback::Wrap`] is `flex-wrap: wrap`, which is exact. The browser wraps
1172 /// the run when the members no longer fit, deciding that from their own
1173 /// intrinsic widths, which is the derived minimum doing the whole job.
1174 ///
1175 /// [`Fallback::Stack`] is wrap plus `flex: 1 1 max-content` on the members, so
1176 /// a member that cannot sit beside its sibling takes a line of its own and
1177 /// fills it. For the two-member run this was ruled on -- a tab strip and a
1178 /// band -- that is precisely "a row becomes a column".
1179 ///
1180 /// [`Fallback::Shed`] and [`Fallback::Menu`] get wrap, and this renderer is
1181 /// honouring less than the description says. **CSS cannot express either one
1182 /// without breaking the ruling's own first constraint.** Both need to know that
1183 /// the run is out of room in order to take a member out of it, a container
1184 /// query is the only construct that can ask, and `@container` compares against
1185 /// a `<length>` -- there is no `@container (inline-size < min-content)`. So
1186 /// every honest spelling of Shed here needs an authored breakpoint, which is
1187 /// the thing the ruling exists to forbid, and the dishonest ones are worse: a
1188 /// clamped height clips by document order rather than by [`Priority`], and
1189 /// `display: none` under a viewport `@media` is the `nth-child(n+5)` bug the
1190 /// vocabulary replaced.
1191 ///
1192 /// Wrapping is the right thing to do instead. It keeps every member reachable,
1193 /// which is the property that was actually broken -- goingson's new-contact
1194 /// button left the viewport entirely at 560 -- and it keeps rule 1. A renderer
1195 /// answering with less than was described is precedented and deliberate here:
1196 /// [`makeover_layout::Region::Columns`] says a terminal stacking a board's
1197 /// columns is honouring the description rather than degrading it.
1198 ///
1199 /// The real mechanism needs the shed members to have somewhere to go, which is
1200 /// markup and belongs to quasi-webview: an overflow control is a member of the
1201 /// run, and the description does not yet say that a member *is* one.
1202 ///
1203 /// # Menu, once a script is measuring
1204 ///
1205 /// That is now built, in `quasi-webview`'s `menu.js`, and this crate's half of
1206 /// it is two classes and one override. A script that has taken a menu run over
1207 /// marks it `data-menu`, and a marked run goes back to `nowrap`: wrapping is
1208 /// what hides the overflow condition the script is trying to measure. The
1209 /// unmarked rule above is untouched, so a page that ships no script still
1210 /// wraps, which is rule 1 — every member reachable — rather than a strip with
1211 /// tabs squeezed off the end.
1212 ///
1213 /// `.run-overflow` is the control the shed members move into and
1214 /// `.run-overflow-items` is where they land. The geometry is this crate's the
1215 /// way every other surface's is; what is *in* it is the script's, because which
1216 /// members no longer fit is a measurement and not a description.
1217 fn run_rules(opts: &Emit) -> String {
1218 let run = class("run", opts);
1219 let mut css = String::new();
1220
1221 // `flex-wrap: nowrap` is stated rather than left to the default, because
1222 // the fallbacks below are read as overrides of this line and a reader
1223 // should not have to know which way flexbox leans to see that.
1224 //
1225 // No gap. Spacing between members is the app's, the same way this crate
1226 // states no margins anywhere else; a gap here would be a size, and the one
1227 // hardcoded size in the mechanism is makeover-geometry's contact patch.
1228 let _ = writeln!(
1229 css,
1230 ".{run} {{\n display: flex;\n flex-wrap: nowrap;\n align-items: center;\n}}"
1231 );
1232
1233 // The derived minimum, and the whole reason a member can no longer be
1234 // overlapped. `min-width: auto` is flexbox's default for a flex item and is
1235 // *not* the same thing: auto lets an item be compressed below its content
1236 // in a nowrap run, which is how a toolbar ends up drawn over a tab strip
1237 // even without anything leaving the flow.
1238 let _ = writeln!(css, ".{run} > * {{\n min-width: min-content;\n}}");
1239
1240 for fallback in [
1241 Fallback::Wrap,
1242 Fallback::Stack,
1243 Fallback::Shed,
1244 Fallback::Menu,
1245 ] {
1246 let name = fallback_class(fallback);
1247 let c = class(name, opts);
1248 let _ = writeln!(css, ".{c} {{\n flex-wrap: wrap;\n}}");
1249 if matches!(fallback, Fallback::Stack) {
1250 let _ = writeln!(css, ".{c} > * {{\n flex: 1 1 max-content;\n}}");
1251 }
1252 }
1253
1254 // A menu run a script has taken over. The mark is the script's and this is
1255 // the only rule that reads it: wrapping is what a run does when nothing is
1256 // measuring, and it is also what makes the overflow unmeasurable, since a
1257 // wrapped run always fits. The two cannot both be on.
1258 let menu = class(fallback_class(Fallback::Menu), opts);
1259 let _ = writeln!(css, ".{menu}[data-menu] {{\n flex-wrap: nowrap;\n}}");
1260
1261 // The overflow control, and it is a member of the run like any other: in
1262 // flow, at the end, taking the width of what is in it. `relative` is what
1263 // the items hang off.
1264 let overflow = class("run-overflow", opts);
1265 let items = class("run-overflow-items", opts);
1266 let _ = writeln!(css, ".{overflow} {{\n position: relative;\n}}");
1267
1268 // Overlaid rather than in flow, for the reason every menu is: a control
1269 // that pushed the page down when it opened would change the layout it was
1270 // opened to escape. `inset-inline-end: 0` rather than a left, so the panel
1271 // stays on the page in both writing directions.
1272 //
1273 // No width, no padding and no border. All three are sizes and sizes are
1274 // makeover-geometry's; what is stated here is placement, the surface and
1275 // the shadow that separates it from the page, which is the same division
1276 // `figure_rules` and the timeline entry make. The elevation shadow is what
1277 // an overlaid surface takes instead of an edge -- see `ELEVATION_PROPERTY`.
1278 let _ = writeln!(
1279 css,
1280 ".{items} {{\n \
1281 position: absolute;\n \
1282 inset-block-start: 100%;\n \
1283 inset-inline-end: 0;\n \
1284 z-index: 1;\n \
1285 display: flex;\n \
1286 flex-direction: column;\n \
1287 align-items: stretch;\n \
1288 background: var(--surface-raised);\n \
1289 box-shadow: var(--elevation-overlay);\n\
1290 }}"
1291 );
1292
1293 // `hidden` is how the script closes it, and a flex display would otherwise
1294 // beat the attribute's own `display: none`.
1295 let _ = writeln!(css, ".{items}[hidden] {{\n display: none;\n}}");
1296
1297 css
1298 }
1299
1300 /// Every class [`fallback_class`] can return, plus the run itself.
1301 ///
1302 /// [`ROW_PART_CLASSES`](crate::list::ROW_PART_CLASSES)'s reasoning and the same
1303 /// obligation: a `match` over a `#[non_exhaustive]` enum cannot be enumerated
1304 /// from outside, so the list sits beside it and a test holds the two together.
1305 /// `run` is in it because it is emitted in its own right rather than only as a
1306 /// fallback's fallback.
1307 pub const RUN_CLASSES: &[&str] = &[
1308 "run",
1309 "run-wrap",
1310 "run-stack",
1311 "run-shed",
1312 "run-menu",
1313 // Not returned by `fallback_class`: these two are the overflow control a
1314 // measuring renderer builds, and they are in the list because the list is
1315 // what a host seals its vocabulary against. A class emitted by a script and
1316 // missing from here is a control with no surface and no edge.
1317 "run-overflow",
1318 "run-overflow-items",
1319 ];
1320
1321 /// The class a run carries for what it does when it is tight.
1322 ///
1323 /// A run always carries `.run` as well, so an unrecognised fallback -- the enum
1324 /// is `#[non_exhaustive]` -- lands as a plain nowrap row with the min-content
1325 /// floor still under it. That is the safe failure: every member in flow and
1326 /// none overlapped, which is the property, with only the rearrangement missing.
1327 #[must_use]
1328 pub fn fallback_class(fallback: Fallback) -> &'static str {
1329 match fallback {
1330 Fallback::Wrap => "run-wrap",
1331 Fallback::Stack => "run-stack",
1332 Fallback::Shed => "run-shed",
1333 Fallback::Menu => "run-menu",
1334 _ => "run",
1335 }
1336 }
1337
1338 /// The progress trough these rules fill.
1339 ///
1340 /// This was renderer-local chrome with nothing behind it until makeover-layout
1341 /// 0.10.0, which is the unusual order: the tones below were emitted for every
1342 /// bar in the tree while the only way to describe one was to concatenate the
1343 /// numbers into a heading. `Meter` is the word that arrived late, and
1344 /// [`meter::meter_html`](crate::meter::meter_html) is what now fills these.
1345 ///
1346 /// The rules stay a superset of what a description can ask for. An app drawing
1347 /// its own bar keeps these classes, which is what the four goingson grew
1348 /// independently were adopted onto.
1349 ///
1350 /// The trough is a [`Depth::Well`], the same reading a text field gets:
1351 /// something with its content down inside it.
1352 fn progress_rules(opts: &Emit) -> String {
1353 let progress = class("progress", opts);
1354 // `progress-fill` rather than a bare `fill`: an unprefixed build claims
1355 // these names in the app's own stylesheet, and `.fill` is grabby enough to
1356 // catch things that have nothing to do with progress. goingson already
1357 // calls it `.progress-fill`, so this is also the name that deletes.
1358 let fill = class("progress-fill", opts);
1359 let mut css = depth_rule(&progress, Depth::Well);
1360
1361 // The untoned bar is `--action`, not [`Tone::Neutral`]. That is the one
1362 // place this differs from the badge rules, and deliberately: a badge with
1363 // no status is a muted label, while a bar with no status is still
1364 // reporting progress, and `content-muted` would read as disabled.
1365 let _ = writeln!(
1366 css,
1367 ".{progress} > .{fill} {{\n background: var(--action);\n}}"
1368 );
1369
1370 // A bar can be saying something, same as a badge: goingson colours subtask
1371 // progress as success and an over-estimate as danger, which is real
1372 // information rather than decoration. Emitting the tones is what lets that
1373 // survive adoption instead of staying hand-written.
1374 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1375 let _ = writeln!(
1376 css,
1377 ".{progress} > .{fill}[data-tone=\"{0}\"] {{\n background: var(--{0});\n}}",
1378 tone.token()
1379 );
1380 }
1381 css
1382 }
1383
1384 /// What a wait looks like, for the attribute that has been describing one to
1385 /// nobody.
1386 ///
1387 /// Wiki `loading-and-progress-standard`, phase 2. `data-awaiting` has been
1388 /// emitted since the vocabulary gained `Awaiting`, with
1389 /// `data-awaiting="determinate"` and a `data-awaiting-amount` beside it or
1390 /// `data-awaiting="indeterminate"` alone, and until 0.60.0 **nothing in the tree
1391 /// styled either**. Determinate and indeterminate rendered identically, which is
1392 /// to say not at all. This is the half that was missing.
1393 ///
1394 /// # Why it is keyed on `aria-busy` and not on the attribute alone
1395 ///
1396 /// `data-awaiting` is a fact about the control: pressing this waits. It is true
1397 /// when the page is painted and it stays true. Whether a wait is *running* is
1398 /// true only between two events, so it is the binder's to set, and `aria-busy`
1399 /// is the standard spelling of it — announced as well as drawn, which a class
1400 /// of our own would not be.
1401 ///
1402 /// That also keeps this crate out of any one client library's vocabulary.
1403 /// `quasi-webview` sets `aria-busy` from htmx's request events; a host driving
1404 /// the same markup another way sets it the same way and gets the same drawing.
1405 ///
1406 /// # The two drawings
1407 ///
1408 /// One pseudo-element either way, so no renderer has to emit an extra node.
1409 ///
1410 /// Indeterminate is the activity mark of rule 2: a small square that blinks.
1411 /// Determinate is a trough with a fill, drawn as a single gradient whose stop is
1412 /// `--awaiting-share`, a plain number from 0 to 1 that the binder sets from
1413 /// bytes it has actually watched land. A determinate control with nothing
1414 /// setting the share draws an empty trough rather than a full one, which is the
1415 /// honest reading: the size is known and the delivery is not.
1416 ///
1417 /// **What the bar may not do**, from rule 1 and from `Awaiting`'s own docs:
1418 /// what is done over what there is, and never a remaining time, an arrival time
1419 /// or a rate extrapolated forward. Nothing here can express one, which is
1420 /// deliberate — the only input is a share of a measured payload.
1421 ///
1422 /// # Sizes, and the deferral rule
1423 ///
1424 /// `progress_rules` emits the tones and never the width, because the width is
1425 /// not this crate's to know. A pseudo-element has no intrinsic size at all, so
1426 /// the same treatment would render nothing anywhere. Both sizes are therefore
1427 /// custom properties with defaults: an app that wants a different mark sets
1428 /// `--awaiting-mark` and `--awaiting-bar` once, and one that says nothing gets a
1429 /// mark that is visible.
1430 ///
1431 /// # The cadence, and what happens without it
1432 ///
1433 /// `--cadence-activity` comes from `makeover-timing` through `makeover-build`,
1434 /// and is a half-period, so a full cycle is twice it. It is used bare rather
1435 /// than with a fallback: a number written here would be a second heartbeat for
1436 /// a mark three renderers draw.
1437 ///
1438 /// A sheet assembled without the time axis leaves `animation-duration` invalid,
1439 /// which resolves to `0s`, which runs no animation and leaves the base style —
1440 /// a lit, still mark. That is also exactly what the reduced-motion block does,
1441 /// since it sets the cadence to `0ms`. Both fall out of one rule because the
1442 /// base style is lit and the keyframes do the dimming, which is the ordering
1443 /// `makeover_timing::reduced_motion_css` asks its consumers for by name.
1444 fn awaiting_rules(opts: &Emit) -> String {
1445 let mut css = String::new();
1446
1447 // Dimming rather than lighting, so a zero-length animation leaves a lit
1448 // mark rather than a blank one. See `makeover_timing::reduced_motion_css`.
1449 css.push_str(
1450 "@keyframes makeover-activity {\n \
1451 0%, 49.99% {\n background: var(--action);\n }\n \
1452 50%, 100% {\n background: var(--surface-sunken);\n }\n\
1453 }\n",
1454 );
1455
1456 // Nothing is drawn until something is waiting. `content` on the base rule
1457 // rather than on the busy one keeps the box the same box across the
1458 // transition, so a mark appearing does not reflow the line it is in.
1459 let _ = writeln!(
1460 css,
1461 "[data-awaiting]::after {{\n \
1462 content: \"\";\n \
1463 display: none;\n \
1464 margin-inline-start: var(--awaiting-gap, 0.5ch);\n \
1465 vertical-align: baseline;\n\
1466 }}"
1467 );
1468
1469 let _ = writeln!(
1470 css,
1471 "[data-awaiting][aria-busy=\"true\"]::after {{\n \
1472 display: inline-block;\n \
1473 inline-size: var(--awaiting-mark, 0.5em);\n \
1474 block-size: var(--awaiting-mark, 0.5em);\n \
1475 background: var(--action);\n \
1476 opacity: 1;\n \
1477 animation: makeover-activity calc(var(--cadence-activity) * 2) \
1478 step-end infinite;\n\
1479 }}"
1480 );
1481
1482 // The measured half. A wider box, no blink, and a gradient whose stop is
1483 // the share: the fill and the trough in one paint, so the markup stays one
1484 // pseudo-element on both branches.
1485 //
1486 // `--awaiting-share` unset is an empty trough, not a full one. A bar that
1487 // read full because nobody was counting would be the confidently-wrong
1488 // drawing rule 1 exists to forbid.
1489 //
1490 // The trough takes an edge for the reason a well does: a bar at zero share
1491 // is otherwise a rectangle of the surface it sits on, which is nothing at
1492 // all. `border_width` rather than a literal, the way `depth_rule` and
1493 // `track_rules` write theirs.
1494 let _ = writeln!(
1495 css,
1496 "[data-awaiting=\"determinate\"][aria-busy=\"true\"]::after {{\n \
1497 inline-size: var(--awaiting-bar, 6em);\n \
1498 animation: none;\n \
1499 outline: {} solid var(--border);\n \
1500 outline-offset: -{};\n \
1501 background: linear-gradient(\n \
1502 to inline-end,\n \
1503 var(--action) 0 calc(var(--awaiting-share, 0) * 100%),\n \
1504 var(--surface-sunken) 0\n \
1505 );\n\
1506 }}",
1507 opts.border_width, opts.border_width
1508 );
1509
1510 css
1511 }
1512
1513 /// A strip of figures, and the two spans inside each one.
1514 ///
1515 /// Colour only, which is the deferral rule applied to a component that badly
1516 /// wants to break it. A figure reads as a figure because the value is set large
1517 /// over a small caption, and that is a size: `makeover-geometry` answers how
1518 /// much space and this crate answers what the thing is. Emitting `font-size`
1519 /// here would be this crate naming a value, which is the one thing it is defined
1520 /// by not doing, and `progress_rules` is the precedent — it emits the tones and
1521 /// never the width, because the width is not its to know.
1522 ///
1523 /// So the arrangement and the type scale are the app's, and what is generated is
1524 /// the part an app cannot get right by itself: which of the two spans carries
1525 /// the tone.
1526 fn figure_rules(opts: &Emit) -> String {
1527 let figure = class("figure", opts);
1528 let value = class("figure-value", opts);
1529 let caption = class("figure-caption", opts);
1530 let change = class("figure-change", opts);
1531 let mut css = String::new();
1532
1533 // `content` literally. A figure's value is the thing itself, at full
1534 // weight -- wiki `three-tone-convention` classes it "active, emphasised",
1535 // and both other renderers already draw it that way (makeover-tui
1536 // `piece.rs:391` bold, makeover-immediate `widget.rs:244`). It reached
1537 // here through `Tone::Neutral.token()` and came out `content-muted`, so
1538 // the headline number sat at the colour of its own caption.
1539 let _ = writeln!(
1540 css,
1541 ".{figure} > .{value} {{\n color: var(--content);\n}}"
1542 );
1543 let _ = writeln!(
1544 css,
1545 ".{figure} > .{caption} {{\n color: var(--content-muted);\n}}"
1546 );
1547 let _ = writeln!(
1548 css,
1549 ".{figure} > .{change} {{\n color: var(--content-muted);\n}}"
1550 );
1551
1552 // A toned figure tones one part and never the caption. The caption is the
1553 // noun and stays muted.
1554 //
1555 // Which part depends on whether there is a change, and that is the whole of
1556 // what 0.13.0 changed here. A figure with a delta is an ordinary number that
1557 // has moved in a direction worth reading, so the delta takes the colour and
1558 // the number stays plain; a figure without one has nowhere else to put it.
1559 // `:has` is what lets one attribute mean both, and the alternative was the
1560 // emitter deciding by writing the attribute onto a different element, which
1561 // leaves two elements able to disagree about a figure's one meaning.
1562 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1563 let _ = writeln!(
1564 css,
1565 ".{figure}[data-tone=\"{0}\"] > .{change} {{\n color: var(--{0});\n}}",
1566 tone.token()
1567 );
1568 let _ = writeln!(
1569 css,
1570 ".{figure}[data-tone=\"{0}\"]:not(:has(> .{change})) > .{value} \
1571 {{\n color: var(--{0});\n}}",
1572 tone.token()
1573 );
1574 }
1575 css
1576 }
1577
1578 /// A picture, its frame and its caption.
1579 ///
1580 /// `makeover_layout::Image` arrived at 0.21.0, found by trying to describe MNW's
1581 /// carousel and discovering nothing named a picture.
1582 ///
1583 /// # The frame is a border, and this is the one place a bevel is wrong
1584 ///
1585 /// 0.36.0 emitted [`Depth::Raised`] here through [`depth_rule`], the same call
1586 /// `button` and `card` make. It was wrong, and MNW's landing page is where it
1587 /// showed: **the frames had no visible edge at all.**
1588 ///
1589 /// `Depth::Raised`'s edge is `--bevel-raised`, which is an *inset* shadow — a
1590 /// 1px light run at the top-left and a dark one at the bottom-right, drawn
1591 /// **inside** the element's box. On a button or a card that box is a surface
1592 /// this crate owns, so an inset edge reads as the surface catching the light.
1593 /// On a picture it is drawn on top of the picture, over whatever pixels the
1594 /// image happens to have at its border. MNW's screenshots are light-on-light
1595 /// parchment, so the light half landed on a light image and the frame
1596 /// disappeared.
1597 ///
1598 /// **You cannot bevel a surface you do not own.** A picture's content is the
1599 /// app's, arrives at request time, and can be any colour, so its edge has to
1600 /// sit *outside* the content rather than on it. That is a border.
1601 ///
1602 /// The fill stays, and it is not decoration: it is what shows through a
1603 /// transparent PNG and what stands in the frame's place while the image is
1604 /// still loading.
1605 ///
1606 /// This is a real limit on [`Depth`] rather than a special case. Every other
1607 /// consumer of a depth draws its own surface; a picture is the first member
1608 /// whose surface belongs to someone else.
1609 ///
1610 /// # No size
1611 ///
1612 /// `width: 100%` and nothing else. How large a picture is depends on the box it
1613 /// was put in, which is the app's arrangement and `makeover-geometry`'s scales,
1614 /// and a renderer that picked one would be answering for every consumer at
1615 /// once. This is where `figure_rules` landed for the same reason.
1616 fn picture_rules(opts: &Emit) -> String {
1617 let picture = class("picture", opts);
1618 let img = class("picture-img", opts);
1619 let caption = class("picture-caption", opts);
1620 let mut css = String::new();
1621
1622 // Block, or an inline image sits on the text baseline and carries a
1623 // descender's worth of space under it that no app ever wants and every app
1624 // deletes by hand. The border is the frame; see the type docs for why it is
1625 // not the bevel every other surface here gets.
1626 let _ = writeln!(
1627 css,
1628 ".{img} {{\n display: block;\n width: 100%;\n height: auto;\n \
1629 background: var(--{});\n border: {} solid var(--border);\n}}",
1630 Fill::Raised.token(),
1631 opts.border_width
1632 );
1633
1634 // The two fits that need a rule. `Fit::Natural` emits no attribute at all,
1635 // so it is the bare rule above and needs nothing here.
1636 let _ = writeln!(
1637 css,
1638 ".{img}[data-fit=\"cover\"] {{\n height: 100%;\n object-fit: cover;\n}}"
1639 );
1640 let _ = writeln!(
1641 css,
1642 ".{img}[data-fit=\"contain\"] {{\n height: 100%;\n object-fit: contain;\n}}"
1643 );
1644
1645 // A caption reads back one step, which is `figure-caption`'s answer and the
1646 // same claim: it says what the thing above it is, and it is not the thing.
1647 let _ = writeln!(
1648 css,
1649 ".{picture} > .{caption} {{\n color: var(--content-muted);\n}}"
1650 );
1651
1652 css
1653 }
1654
1655 /// A region showing one child at a time, and the chrome that moves between them.
1656 ///
1657 /// [`makeover_layout::Showing`] lets a description say that a region holds
1658 /// several children and shows some of them. A renderer derives its own chrome
1659 /// from that, which is what stops every renderer growing a `match` on a widget
1660 /// name; these are the rules the derived chrome needs.
1661 ///
1662 /// # Why the default is every child, and the enhancement takes them away
1663 ///
1664 /// The controls are a lie until something binds them. A prev button rendered
1665 /// into a document with no script is a control that looks live and answers
1666 /// nothing, and the reader it lies to is exactly the one who cannot see the
1667 /// other children either — the collapsing and the moving are the same half.
1668 ///
1669 /// So the rules run in the direction the enhancement does. Nothing here hides a
1670 /// child and nothing here shows a control. Whatever binds the region sets
1671 /// `data-ready` on it, and that is what collapses the stack to one and reveals
1672 /// the row that moves it. A reader with no script gets every child in order and
1673 /// no controls, which is more content rather than less, and a reader with
1674 /// script gets a settled page rather than a stack that jumps to one frame after
1675 /// load.
1676 ///
1677 /// MNW proved this shape by hand — a `<noscript>` stylesheet opening its
1678 /// carousel back out — and it is here rather than there because the property is
1679 /// the description's, not one app's.
1680 ///
1681 /// # Not spacing
1682 ///
1683 /// The row's gaps are `makeover-geometry`'s question and are absent for
1684 /// [`row_rules`]'s reason. What is here is `display`, which carries no
1685 /// magnitude, and the muted readout, which is the same claim `picture-caption`
1686 /// makes: it says where you are among the children and it is not one of them.
1687 fn showing_rules(opts: &Emit) -> String {
1688 let controls = class("showing", opts);
1689 let position = class("showing-position", opts);
1690 let frame = class("showing-frame", opts);
1691 let mut css = String::new();
1692
1693 // Hidden until something binds it, which is the whole argument above.
1694 let _ = writeln!(css, ".{controls} {{\n display: none;\n}}");
1695 // Block, and nothing about how the three sit in it. A button and a span are
1696 // inline already, so they make a row without this crate saying so, and
1697 // saying so is where `align-items` and a gap would follow -- both spacing,
1698 // both `makeover-geometry`'s, and `row_rules` refuses them for the same
1699 // reason.
1700 let _ = writeln!(
1701 css,
1702 "[data-ready] > .{controls} {{\n display: block;\n}}"
1703 );
1704
1705 // A child is in flow until the region is bound, and then only the current
1706 // one is. `.current` is a modifier for the reason `.chosen` and `.latched`
1707 // are: one name for the state, set by whoever knows it.
1708 let _ = writeln!(
1709 css,
1710 "[data-ready] > .{frame}:not(.current) {{\n display: none;\n}}"
1711 );
1712
1713 // Reads back one step. `picture-caption`'s rule and its reason.
1714 let _ = writeln!(css, ".{position} {{\n color: var(--content-muted);\n}}");
1715
1716 css
1717 }
1718
1719 /// A time axis: the container, its gridlines and ruler, and the placed things.
1720 ///
1721 /// `makeover-layout` 0.24.0's [`Track`](makeover_layout::Track), and the first
1722 /// member here whose whole point is *position*. That makes the magnitude line
1723 /// this crate keeps worth restating rather than assuming.
1724 ///
1725 /// # Where the numbers come from
1726 ///
1727 /// Every value that varies per item is a custom property the caller sets
1728 /// inline, and every rule here reads one. `--track-at` and `--track-for` are
1729 /// percentages of the span, which
1730 /// [`Track::fraction`](makeover_layout::Track::fraction) computes once so three
1731 /// renderers cannot disagree about it. Nothing here knows a pixel.
1732 ///
1733 /// That is what lets the stylesheet stay static while the items move: an entry
1734 /// carries `style="--track-at: 37.5%; --track-for: 4.166%"` and the rule below
1735 /// turns it into a box. The alternative was emitting a rule per item, which is
1736 /// a stylesheet that grows with the data.
1737 ///
1738 /// **The height of the track is the app's**, not this crate's. 96 quarter-hour
1739 /// slots at some slot height is a size, and a size is `makeover-geometry`'s
1740 /// question -- the same refusal `figure_rules` and `placeholder_rules` make.
1741 /// Percentages need a resolved height above them, so `.track` gets
1742 /// `position: relative` and nothing else; the app says how tall a day is.
1743 ///
1744 /// # Overlap
1745 ///
1746 /// Two things at the same time is intrinsic to an axis and has no analogue in a
1747 /// list. The description does not declare it -- `Placement::overlaps` derives it
1748 /// from the times -- so what arrives here is a lane index and a lane count, and
1749 /// the rule divides the width. A renderer that would rather stack them ignores
1750 /// both properties and the defaults give it one full-width lane.
1751 fn track_rules(opts: &Emit) -> String {
1752 let track = class("track", opts);
1753 let slot = class("track-slot", opts);
1754 let tick = class("track-tick", opts);
1755 let entry = class("track-entry", opts);
1756 let mut css = String::new();
1757
1758 // The positioning context every entry resolves against, and the whole of
1759 // what this crate says about the container. No height: see the doc above.
1760 let _ = writeln!(css, ".{track} {{\n position: relative;\n}}");
1761
1762 // Gridlines and the ruler are the axis reading itself back, which is
1763 // `picture-caption` and `showing-position`'s claim: about the thing rather
1764 // than one of the things.
1765 //
1766 // `border_width` rather than a literal, the way `depth_rule` writes its
1767 // edge. A gridline is the one place a timeline would most naturally reach
1768 // for a hardcoded 1px, and a hardcoded 1px is this crate naming a size.
1769 let _ = writeln!(
1770 css,
1771 ".{slot} {{\n border-top: {} solid var(--border);\n}}",
1772 opts.border_width
1773 );
1774 let _ = writeln!(css, ".{tick} {{\n color: var(--content-muted);\n}}");
1775
1776 // The one rule that does real work. Top and height are the placement;
1777 // left and width are the lane. Both lane properties default so an entry
1778 // that names neither is full width, which is the common case and the one a
1779 // renderer gets for free.
1780 let _ = writeln!(
1781 css,
1782 ".{entry} {{\n \
1783 position: absolute;\n \
1784 top: var(--track-at, 0%);\n \
1785 height: var(--track-for, 100%);\n \
1786 left: calc(var(--track-lane, 0) / var(--track-lanes, 1) * 100%);\n \
1787 width: calc(100% / var(--track-lanes, 1));\n\
1788 }}"
1789 );
1790
1791 css
1792 }
1793
1794 /// A region's stand-in, and the header of a table that can be reordered.
1795 ///
1796 /// Both are 0.12.0 members and both are colour and affordance only, which is
1797 /// where `figure_rules` landed after trying to emit a type scale. How much room
1798 /// a stand-in gets is a size — goingson has the same one at three, as
1799 /// `--compact`, `--dashboard` and `--padded` — and a size is
1800 /// `makeover-geometry`'s question.
1801 ///
1802 /// The caret is the one thing here that is neither colour nor affordance, and it
1803 /// is a renderer's own expression rather than a value the description named:
1804 /// `aria-sort` is what the table actually says, and this turns it into something
1805 /// visible for everyone not using a screen reader. A terminal draws its own; an
1806 /// immediate-mode painter draws its own.
1807 fn state_rules(opts: &Emit) -> String {
1808 let placeholder = class("placeholder", opts);
1809 let text = class("placeholder-text", opts);
1810 let heading = class("table-heading", opts);
1811 let mut css = String::new();
1812
1813 let _ = writeln!(
1814 css,
1815 ".{placeholder} > .{text} {{\n color: var(--content-muted);\n}}"
1816 );
1817 // Only the failure is toned. An empty list is the normal state of a new
1818 // install, and `Readiness::tone` is what says so.
1819 let _ = writeln!(
1820 css,
1821 ".{placeholder}[data-tone=\"{0}\"] > .{text} {{\n color: var(--{0});\n}}",
1822 Tone::Danger.token()
1823 );
1824
1825 // A header that reorders the table is a control, and the pointer is the
1826 // only part of saying so that is not the app's own type and spacing.
1827 let _ = writeln!(
1828 css,
1829 ".{heading}[data-sortable] {{\n cursor: pointer;\n}}"
1830 );
1831 // The caret carries its own leading space, the way `makeover-tui` and
1832 // `makeover-immediate` both write `" \u{25B2}"`. It used to be emitted bare,
1833 // and both apps that adopted the vocabulary had to put the gap back in their
1834 // own stylesheets on the same afternoon -- each having to work out first that
1835 // app CSS outranks this crate's cascade layer, so adding the space the
1836 // obvious way, as `content`, silently wins over the glyph and leaves the
1837 // heading with no caret at all. A consumer should not have to know that, and
1838 // with the space emitted here there is nothing left for one to add.
1839 //
1840 // Three states, three tones, on the convention in wiki
1841 // `three-tone-convention`. A column in force is `content`; a column offering
1842 // to reorder and not doing it now is `content-secondary`, because it still
1843 // answers a press; a column that is not sortable emits no caret at all and
1844 // takes nothing. The idle arm used to hide its glyph and reserve the box,
1845 // which cost a reflow-free press and said nothing. It draws now, and the
1846 // reservation stops being a thing to get right.
1847 //
1848 // The glyph is `Sort::glyph`, escaped rather than written: a CSS `content`
1849 // string cannot carry the character literally through this file's own
1850 // escaping, and spelling it here as well would put the third copy back that
1851 // `makeover-layout` 0.27.5 exists to remove.
1852 let _ = writeln!(
1853 css,
1854 ".{heading}[data-sortable]::after \
1855 {{\n content: \" {}\";\n color: var(--content-secondary);\n}}",
1856 css_escape(Sort::Ascending.glyph())
1857 );
1858 for direction in [Sort::Ascending, Sort::Descending] {
1859 let _ = writeln!(
1860 css,
1861 ".{heading}[aria-sort=\"{}\"]::after \
1862 {{\n content: \" {}\";\n color: var(--content);\n}}",
1863 direction.as_str(),
1864 css_escape(direction.glyph())
1865 );
1866 }
1867 css
1868 }
1869
1870 /// The frame a table sits in.
1871 ///
1872 /// # Why this is a CSS table and not the grid the rest of the module assumes
1873 ///
1874 /// A grid row needs `grid-template-columns`, which has to name every column in
1875 /// order, so it cannot be written without knowing the columns. That is what
1876 /// [`list::narrowing_css`] is for, and it works: goingson builds `tables.css` in
1877 /// its own `build.rs` out of it, and nothing here changes that.
1878 ///
1879 /// It does not work for a table a *description* produced. Those columns are
1880 /// known at render time rather than at build time, and the rules would have to
1881 /// travel with the markup: a `<style>` element per table, which needs
1882 /// `style-src 'unsafe-inline'` and so blocks the MNW server's standing plan to
1883 /// drop it. The head is not an escape: a table swapped in by htmx after a
1884 /// delete arrives as a fragment with no head at all.
1885 ///
1886 /// A CSS table aligns its columns across rows knowing nothing about how many
1887 /// there are, so there is no track list to emit and nothing per-table to carry.
1888 /// The cost is that a described table cannot take a per-column fixed length,
1889 /// which costs nothing today: [`Sizing`](list::Sizing) is looked up by column
1890 /// name and a description carries no lengths to put in it, so every track a
1891 /// described table could ask for is already content, fill or auto.
1892 ///
1893 /// [`Priority`] hiding is unchanged in kind. It moves from a generated
1894 /// `display: none` per dropped column to one rule per drop class, which is the
1895 /// same fact addressed by class rather than by cutoff, and still never by
1896 /// position.
1897 fn table_rules(opts: &Emit) -> String {
1898 let table = class("table", opts);
1899 let head = class("table-head", opts);
1900 let row = class("table-row", opts);
1901 let heading = class("table-heading", opts);
1902 let cell = class("cell", opts);
1903 let mut css = String::new();
1904
1905 let _ = writeln!(
1906 css,
1907 ".{table} {{\n display: table;\n width: 100%;\n}}"
1908 );
1909 let _ = writeln!(css, ".{head},\n.{row} {{\n display: table-row;\n}}");
1910 // Scoped under `.{table}` rather than keyed on the classes alone. The
1911 // table model is what a cell takes *by being in a table*, and only there:
1912 // goingson's task headings are `.table-heading` inside a CSS grid, so the
1913 // unscoped rule reached them, and the sort caret and the sortable cursor
1914 // -- which `state_rules` keys on `.table-heading` and rightly still does
1915 // -- came with a `display` the grid had to blockify away.
1916 //
1917 // It costs no markup anywhere: quasi-webview always nests the heading
1918 // inside the table (`quasi-webview/src/node.rs:1591`, `:1605`, `:1615`).
1919 let _ = writeln!(
1920 css,
1921 ".{table} .{heading},\n.{table} .{cell} {{\n display: table-cell;\n}}"
1922 );
1923
1924 // A content column shrinks to what is in it. `width: 1%` is how a CSS table
1925 // is told that: auto layout hands the slack to the columns that asked for
1926 // room, and a column asking for almost none gets what it needs and no more.
1927 // The `nowrap` is what stops it being given less by wrapping.
1928 let _ = writeln!(
1929 css,
1930 ".{} {{\n white-space: nowrap;\n width: 1%;\n}}",
1931 class("cell-content", opts)
1932 );
1933
1934 // A fixed column has no length to be fixed to. The description carries none
1935 // and `Sizing` is not reachable from here, so it behaves as content: the
1936 // honest answer to a width nobody supplied, and the same one `Sizing::track`
1937 // gives it.
1938 let _ = writeln!(
1939 css,
1940 ".{} {{\n white-space: nowrap;\n}}",
1941 class("cell-fixed", opts)
1942 );
1943
1944 // Optional columns go at the narrowest class, secondary ones go with them,
1945 // which is the cutoff walk `kept_at` describes said as two media queries.
1946 // Essential columns have no rule at all, because never dropping is what not
1947 // being mentioned already means.
1948 for (size, drops) in [
1949 (
1950 SizeClass::Compact,
1951 &["cell-drops-first", "cell-drops-next"][..],
1952 ),
1953 (SizeClass::Medium, &["cell-drops-first"][..]),
1954 ] {
1955 let selectors: Vec<String> = drops
1956 .iter()
1957 .map(|drop| format!(".{}", class(drop, opts)))
1958 .collect();
1959 css.push_str(&gated(
1960 Some(&size.media_condition()),
1961 &format!("{} {{\n display: none;\n}}\n", selectors.join(",\n")),
1962 ));
1963 }
1964
1965 // What is inside a cell, which the table side could not say until
1966 // makeover-layout 0.14.0. Every cell was one `.cell` and one content
1967 // colour, so a button in a cell was painted as text -- the drift
1968 // `RowPart::intent` has prevented for list rows since 0.2.0 and prevented
1969 // for nothing here.
1970 //
1971 // The colour goes on `.cell-value` rather than on `.cell`, and that
1972 // placement is the whole fix. On the container it would cascade into the
1973 // tokens and the controls sitting beside the text, which is the bug said
1974 // in one rule; on the part that is text, it reaches text and stops.
1975 for part in [
1976 CellPart::Value,
1977 CellPart::Tokens,
1978 CellPart::Actions,
1979 CellPart::Link,
1980 ] {
1981 // Three of the four inherit, each for its own reason: a token carries
1982 // its own tone, an action is a control rather than text, and a link
1983 // takes the action colour from the anchor it is. `CellPart::intent`
1984 // says so by answering with the intent inheriting already gives, and
1985 // pinning that would be louder than saying nothing.
1986 //
1987 // Written as a skip-list rather than as a match on Value, so a member
1988 // added upstream gets its intent emitted rather than being silently
1989 // dropped. That is the same trade `part_class`'s fallback makes: land
1990 // plainly, never land as nothing.
1991 if !matches!(part, CellPart::Tokens | CellPart::Actions | CellPart::Link) {
1992 let _ = writeln!(
1993 css,
1994 ".{} {{\n color: var(--{});\n}}",
1995 class(cell_part_class(part), opts),
1996 part.intent()
1997 );
1998 }
1999 }
2000
2001 css
2002 }
2003
2004 /// The component layer: every named thing phase A emits.
2005 ///
2006 /// No scrollbar track. It was on the phase A list and came off: eight lines of
2007 /// `::-webkit-scrollbar` with no shape a terminal or an immediate-mode painter
2008 /// would want handed to it, so it stays with the apps.
2009 #[must_use]
2010 pub fn component_rules(opts: &Emit) -> String {
2011 let mut css = String::new();
2012 css.push_str(&surface_rules(opts));
2013 css.push_str(&link_rules(opts));
2014 css.push_str(&token_rules(opts));
2015 css.push_str(&selector_rules(opts));
2016 css.push_str(&row_rules(opts));
2017 css.push_str(&run_rules(opts));
2018 css.push_str(&progress_rules(opts));
2019 css.push_str(&awaiting_rules(opts));
2020 css.push_str(&figure_rules(opts));
2021 css.push_str(&picture_rules(opts));
2022 css.push_str(&showing_rules(opts));
2023 css.push_str(&track_rules(opts));
2024 css.push_str(&state_rules(opts));
2025 css.push_str(&table_rules(opts));
2026 css.push_str(&facet::facet_rules(opts));
2027 css.push_str(&form::editor_rules(opts));
2028 css.push_str(&form::suggestion_rules(opts));
2029 css.push_str(&form::unit_rules(opts));
2030 css.push_str(&form::option_detail_rules(opts));
2031 css.push_str(&form::note_rules(opts));
2032 css.push_str(&leaving_rules());
2033 css
2034 }
2035
2036 /// How a transient notice goes away.
2037 ///
2038 /// quasicoherent `43bdbff7`. `makeover-timing` has said since it shipped that
2039 /// `Intent::Dismiss` is how long a notice lives *before it starts to leave*,
2040 /// and that the leaving itself is `Motion::Fade`. `makeover-build` writes
2041 /// `--motion-fade` into every consumer's `timing.css`, and until this rule
2042 /// nothing in the tree read it: three renderers removed the node the moment
2043 /// the dismiss was up, and the crate's own test called the version that waits
2044 /// the correct one.
2045 ///
2046 /// # Why an attribute and not a class
2047 ///
2048 /// [`Emit`]'s prefix moves every class this crate writes, so a class here would
2049 /// have to be resolved through `class()` by whoever sets it -- and the party
2050 /// setting it is a script, which has no prefix to hand. `data-leaving` is
2051 /// outside that namespace, so a renderer can set it from JavaScript with no
2052 /// coordination.
2053 ///
2054 /// The transition sits on the notice and the opacity on the leaving state, so
2055 /// the element is transitionable before the attribute arrives; a transition
2056 /// declared in the same rule as the value it changes has nothing to animate
2057 /// from.
2058 ///
2059 /// # Reduced motion is handled by the token, not by a second rule here
2060 ///
2061 /// `timing.css` already zeroes `--motion-fade` under `prefers-reduced-motion`.
2062 /// The reader who asked for less motion gets an instant change rather than a
2063 /// fade, and the renderer that sets the attribute must still remove the node on
2064 /// a timer rather than on `transitionend` -- a zero-length transition may fire
2065 /// no event at all, and a node waiting on one that never comes stays forever.
2066 ///
2067 /// The fallback is `0ms` and not a guessed duration: a page with no timing
2068 /// sheet has not opted into this vocabulary, and the honest answer there is the
2069 /// behaviour it had before, which is the notice going away at once.
2070 ///
2071 /// Added 0.69.0, and it is this crate's first `--motion-*` consumer.
2072 fn leaving_rules() -> String {
2073 let mut css = String::new();
2074 let _ = writeln!(
2075 css,
2076 "[data-notice] {{\n transition: opacity var(--motion-fade, 0ms) \
2077 ease-out;\n}}"
2078 );
2079 let _ = writeln!(css, "[data-notice][data-leaving] {{\n opacity: 0;\n}}");
2080 css
2081 }
2082
2083 /// The whole phase-A stylesheet: properties, depth rules and components, in
2084 /// [`CSS_LAYER`], under a generated-file banner.
2085 ///
2086 /// The banner sits outside the layer, because a comment participates in no
2087 /// cascade and a reader opening the file should see what it is before seeing
2088 /// an at-rule.
2089 #[must_use]
2090 pub fn stylesheet(opts: &Emit) -> String {
2091 let body = in_css_layer(&format!(
2092 ":root {{\n{}}}\n\n{}\n{}",
2093 bevel_properties(opts),
2094 depth_rules(opts),
2095 component_rules(opts)
2096 ));
2097 // Counted from the body rather than through `vocabulary::names`, which
2098 // calls back into here.
2099 let classes = vocabulary::classes_in_css(&body).len();
2100 let version = VERSION;
2101 format!(
2102 "/* Generated by makeover-webview {version} from makeover-layout, \
2103 {classes} classes.\n \
2104 Do not edit. The version and the count are here because a stale\n \
2105 lockfile fails silently: an older emitter writes a well-formed sheet\n \
2106 with components missing, and nothing else in the file says so. If\n \
2107 this version trails what the manifest asks for, re-resolve.\n\n \
2108 Depth is a fill and an edge together; naming them apart is what let\n \
2109 them disagree. See the crate's README and wiki note makeover-layout.\n\n \
2110 Everything below is in the `{CSS_LAYER}` cascade layer. Declare the\n \
2111 order once in your own stylesheet, or this layer's position is decided\n \
2112 by whichever generated file the browser happens to see first:\n\n \
2113 @layer {CSS_LAYER}, base, components, responsive; */\n{body}"
2114 )
2115 }
2116
2117 #[cfg(test)]
2118 mod tests {
2119 use super::*;
2120 use makeover_layout::Edge;
2121
2122 #[test]
2123 fn every_fallback_class_is_one_a_checker_knows_about() {
2124 // The obligation ROW_PART_CLASSES carries, for the same reason: a class
2125 // this crate can write and the vocabulary list does not carry is
2126 // invisible to the dead-vocabulary seal and to the overlap check both.
2127 for fallback in [
2128 Fallback::Wrap,
2129 Fallback::Stack,
2130 Fallback::Shed,
2131 Fallback::Menu,
2132 ] {
2133 assert!(
2134 RUN_CLASSES.contains(&fallback_class(fallback)),
2135 "{fallback:?} is missing from RUN_CLASSES"
2136 );
2137 }
2138 let names = crate::vocabulary::names(&Emit::default());
2139 for name in RUN_CLASSES {
2140 assert!(names.contains(*name), "{name} is not in the vocabulary");
2141 }
2142 }
2143
2144 #[test]
2145 fn a_run_gives_every_member_a_floor_it_cannot_be_squeezed_below() {
2146 // The whole of what stops the overlap, and it is not a fallback: it
2147 // applies to every run whatever the group declared. flexbox's default
2148 // min-width is auto, which lets an item be compressed below its own
2149 // content in a nowrap row, and that is how a toolbar is drawn over a
2150 // tab strip even with nothing out of flow.
2151 let css = run_rules(&Emit::default());
2152 assert!(css.contains(".run > * {\n min-width: min-content;\n}"));
2153 // No number anywhere in it. The minimum is derived by the browser from
2154 // what the members contain, which is the ruling's own requirement.
2155 assert!(!css.contains("px"));
2156 assert!(!css.contains("rem"));
2157 assert!(!css.contains("@media"));
2158 }
2159
2160 #[test]
2161 fn room_is_never_asked_of_the_viewport() {
2162 // The 913 case: a window in SizeClass::Expanded holding a group out of
2163 // room. A viewport query answers about the window and would be wrong
2164 // about the group, which is why the table's @media walk is not the
2165 // precedent this follows.
2166 let css = run_rules(&Emit::default());
2167 for size in [SizeClass::Compact, SizeClass::Medium] {
2168 assert!(!css.contains(&size.media_condition()));
2169 }
2170 }
2171
2172 #[test]
2173 fn every_fallback_lands_as_a_class_and_an_unknown_one_lands_plainly() {
2174 let css = run_rules(&Emit::default());
2175 for fallback in [
2176 Fallback::Wrap,
2177 Fallback::Stack,
2178 Fallback::Shed,
2179 Fallback::Menu,
2180 ] {
2181 let class = fallback_class(fallback);
2182 assert!(css.contains(&format!(".{class} {{")), "{class} unemitted");
2183 }
2184 // Stack is the one that also says what a member does with the line it
2185 // took, which is what separates it from wrapping.
2186 assert!(css.contains(".run-stack > * {\n flex: 1 1 max-content;\n}"));
2187 }
2188
2189 #[test]
2190 fn the_emitted_bevel_matches_what_the_apps_already_hand_write() {
2191 // Balanced Breakfast's styles.css, verbatim. Adoption has to be a
2192 // deletion, not a redesign, or nobody will take it.
2193 let opts = Emit::default();
2194 assert_eq!(
2195 bevel_shadow(Bevel::Raised, &opts),
2196 "inset 1px 1px 0 var(--bevel-light), inset -1px -1px 0 var(--bevel-dark)"
2197 );
2198 assert_eq!(
2199 bevel_shadow(Bevel::Inset, &opts),
2200 "inset 1px 1px 0 var(--bevel-dark), inset -1px -1px 0 var(--bevel-light)"
2201 );
2202 }
2203
2204 #[test]
2205 fn no_colour_ever_reaches_the_output() {
2206 let css = stylesheet(&Emit::default());
2207 assert!(!css.contains('#'), "a hex literal escaped into the CSS");
2208 assert!(
2209 !css.contains("rgb"),
2210 "a colour function escaped into the CSS"
2211 );
2212 // Every colour is named, never resolved.
2213 assert!(css.contains("var(--surface-raised)"));
2214 assert!(css.contains("var(--bevel-light)"));
2215 }
2216
2217 #[test]
2218 fn a_well_falls_back_through_css_rather_than_through_rust() {
2219 assert_eq!(
2220 fill_var(Fill::Well),
2221 "var(--surface-well, var(--surface-page))"
2222 );
2223 // Nothing else needs one.
2224 assert_eq!(fill_var(Fill::Raised), "var(--surface-raised)");
2225 assert_eq!(fill_var(Fill::Page), "var(--surface-page)");
2226 }
2227
2228 #[test]
2229 fn raised_and_well_do_not_collapse_onto_each_other() {
2230 let css = depth_rules(&Emit::default());
2231 assert!(css.contains(".raised {"));
2232 assert!(css.contains(".well {"));
2233 assert!(css.contains("var(--bevel-raised)"));
2234 assert!(css.contains("var(--bevel-inset)"));
2235 }
2236
2237 /// The cast shadow is composed here from the tone `makeover` derives, so
2238 /// neither crate has to hold the other's numbers.
2239 ///
2240 /// It is a `:root` property and deliberately not a depth class. There is no
2241 /// `Depth::Overlay` in the description layer, and adding one would be a
2242 /// claim about what a screen means rather than about how it is painted;
2243 /// until something asks for it, a consumer names the property on the rule
2244 /// for the menu or the toast it already has.
2245 #[test]
2246 fn the_cast_shadow_is_a_root_property_not_a_depth() {
2247 let css = bevel_properties(&Emit::default());
2248 assert!(css.contains("--elevation-overlay:"));
2249 assert!(css.contains("var(--elevation)"));
2250 assert!(
2251 !depth_rules(&Emit::default()).contains("elevation"),
2252 "elevation is not a depth class"
2253 );
2254 }
2255
2256 #[test]
2257 fn the_cascade_carries_the_pressed_state() {
2258 let css = surface_rules(&Emit::default());
2259 // The one thing this renderer gets free that the other two resolve by
2260 // hand, eighteen call sites deep in audiofiles' case. Asserted on a
2261 // named surface: pressing belongs to the control, not to the depth.
2262 assert!(css.contains(".card:active {"));
2263 assert!(css.contains(".button:active {"));
2264 }
2265
2266 #[test]
2267 fn the_depth_class_is_a_surface_and_not_a_control() {
2268 let css = depth_rules(&Emit::default());
2269 // The static surface the vocabulary was missing. Sixteen goingson
2270 // elements wore .card and cancelled its hover and press to get this,
2271 // because a raised object that is not pressable had no other spelling.
2272 for state in [":hover", ":active", ":focus-visible", ":disabled"] {
2273 assert!(
2274 !css.contains(&format!(".raised{state}")),
2275 "the depth class claimed {state}: {css}"
2276 );
2277 }
2278 assert!(css.contains("var(--bevel-raised)"), "still raised: {css}");
2279 }
2280
2281 #[test]
2282 fn pressing_moves_the_fill_and_not_only_the_edge() {
2283 // The decision-1 guard, and the regression that mattered: emitting the
2284 // bevel flip alone is what left goingson hand-writing `background:
2285 // var(--surface-sunken)` on .btn, .card and .tag/.badge alike, so none
2286 // of the three could be deleted.
2287 let pressed = interactive_rules("button", Depth::Raised, &Emit::default());
2288 assert!(pressed.contains(".button:active {"));
2289 assert!(
2290 pressed.contains("background: var(--surface-well, var(--surface-page))"),
2291 "pressed dropped its fill: {pressed}"
2292 );
2293 assert!(pressed.contains("box-shadow: var(--bevel-inset)"));
2294 }
2295
2296 #[test]
2297 fn pressed_takes_its_fill_from_the_description_not_from_the_app() {
2298 // goingson presses to --surface-sunken. The description says a pressed
2299 // raised region reads as a well, and makeover says outright that
2300 // surface-sunken cannot serve as one, so the app is the thing that
2301 // moves.
2302 //
2303 // Scoped to the pressed rules rather than to the whole sheet: since
2304 // makeover-layout 0.3.0 an unchosen tab is legitimately
2305 // --surface-sunken, so the token appearing somewhere in the output no
2306 // longer means the app's choice leaked in.
2307 let css = stylesheet(&Emit::default());
2308 let mut checked = 0;
2309 for rule in css.split("}\n") {
2310 if !rule.contains(":active") {
2311 continue;
2312 }
2313 checked += 1;
2314 assert!(
2315 !rule.contains("surface-sunken"),
2316 "a pressed rule took the app's fill: {rule}"
2317 );
2318 }
2319 assert!(checked > 0, "no pressed rules found to check");
2320 assert_eq!(
2321 Depth::Raised.pressed().fill(),
2322 Some(Fill::Well),
2323 "the description changed under us"
2324 );
2325 }
2326
2327 #[test]
2328 fn the_whole_stylesheet_is_emitted_in_the_family_layer() {
2329 // The point of 0.11.0. Unlayered normal declarations outrank every
2330 // named layer, so an app declaring `@layer base, components` loses
2331 // every rule it owns to this file until this file is layered too.
2332 let css = stylesheet(&Emit::default());
2333 assert!(css.contains(&format!("@layer {CSS_LAYER} {{")));
2334
2335 // Exactly one layer block, and nothing outside it but the banner.
2336 assert_eq!(css.matches("@layer").count(), 2, "banner names it once");
2337 let opened = css.find("@layer makeover {").expect("layer opens");
2338 for (i, line) in css.lines().enumerate() {
2339 let before_layer = css.lines().take(i).map(str::len).sum::<usize>() < opened;
2340 if before_layer || line.is_empty() {
2341 continue;
2342 }
2343 assert!(
2344 line.starts_with(" ") || line == "}" || line.starts_with(" "),
2345 "line outside the layer: {line:?}"
2346 );
2347 }
2348 }
2349
2350 #[test]
2351 fn the_generated_sheet_carries_no_trailing_whitespace() {
2352 // A checked-in generated file that a formatter wants to rewrite is a
2353 // diff every time somebody saves it.
2354 let css = stylesheet(&Emit::default());
2355 for (i, line) in css.lines().enumerate() {
2356 assert_eq!(line, line.trim_end(), "trailing whitespace on line {i}");
2357 }
2358 }
2359
2360 #[test]
2361 fn the_banner_tells_an_app_how_to_order_the_layer() {
2362 // Without a declared order the layer's position depends on which
2363 // generated file the browser sees first, which is not a contract.
2364 let css = stylesheet(&Emit::default());
2365 assert!(css.contains("@layer makeover, base, components, responsive;"));
2366 // And the banner is outside the layer, not a rule inside it.
2367 assert!(css.starts_with("/* Generated by makeover-webview"));
2368 }
2369
2370 #[test]
2371 fn the_banner_names_the_emitter_so_a_stale_pin_is_visible_on_sight() {
2372 // A consumer whose lockfile pins an old version gets a well-formed
2373 // sheet with components missing and no error. balanced_breakfast ran
2374 // on 657 bytes from a 0.1.0 emitter while its manifest asked for
2375 // 0.5.1, and the only way it surfaced was diffing two apps' generated
2376 // files. The version and the count are what the file says instead.
2377 let css = stylesheet(&Emit::default());
2378 let banner = css.lines().next().unwrap();
2379 assert!(
2380 banner.contains(VERSION),
2381 "{banner} does not name the emitter"
2382 );
2383 let classes = vocabulary::classes_in_css(&css).len();
2384 assert!(classes > 0);
2385 assert!(
2386 banner.contains(&format!("{classes} classes")),
2387 "{banner} does not carry the class count"
2388 );
2389 }
2390
2391 #[test]
2392 fn a_primitive_owns_every_state_it_implies() {
2393 // The whole point of 0.10.0. Anything emitting a hover rule owes the
2394 // other three, or the consuming app supplies them by out-specifying a
2395 // rule it does not own: 19 such rules in goingson, 21 in the MNW
2396 // server, and three focus rings that do not match.
2397 let css = stylesheet(&Emit::default());
2398 for selector in ["button", "card", "chip", "tab", "segment", "toggle"] {
2399 assert!(css.contains(&format!(".{selector}:hover {{")), "{selector}");
2400 assert!(
2401 css.contains(&format!(".{selector}:active {{")),
2402 "{selector}"
2403 );
2404 assert!(
2405 css.contains(&format!(".{selector}:focus-visible {{")),
2406 "{selector} has no focus ring"
2407 );
2408 assert!(
2409 css.contains(&format!(".{selector}:disabled,")),
2410 "{selector} has no disabled state"
2411 );
2412 }
2413 }
2414
2415 #[test]
2416 fn a_field_takes_focus_and_refuses_input_without_taking_a_hover() {
2417 // A text field does not light up under the pointer, so it gets the two
2418 // states it has and not the two it does not.
2419 let css = stylesheet(&Emit::default());
2420 assert!(css.contains(".field:focus-visible {"));
2421 assert!(css.contains(".field:disabled,"));
2422 assert!(!css.contains(".field:hover {"));
2423 assert!(!css.contains(".field:active {"));
2424 }
2425
2426 #[test]
2427 fn disabled_is_emitted_after_hover_so_source_order_settles_it() {
2428 // Every one of these selectors is specificity (0,2,0), so nothing but
2429 // order decides which wins. A disabled button taking the hover fill is
2430 // the exact bug goingson's `.button:disabled:hover` was written to fix,
2431 // and the reason it had to reach (0,3,0) to do it.
2432 let css = interactive_rules("button", Depth::Raised, &Emit::default());
2433 let hover = css.find(":hover").expect("hover");
2434 let active = css.find(":active").expect("active");
2435 let focus = css.find(":focus-visible").expect("focus");
2436 let disabled = css.find(":disabled").expect("disabled");
2437 assert!(hover < active && active < focus && focus < disabled);
2438
2439 // And it restores the surface, or the hover fill survives underneath.
2440 let tail = &css[disabled..];
2441 assert!(tail.contains("background: var(--surface-raised)"));
2442 }
2443
2444 #[test]
2445 fn a_flat_control_takes_its_hover_fill_back_when_it_stops_answering() {
2446 // The same contest one depth over, and the half `depth_declarations`
2447 // could not state. Flat declares neither axis, so before 0.68.0 the
2448 // disabled rule won on source order with nothing to say and the hover
2449 // surface stayed under a control that had stopped answering. Reaches
2450 // both facet arms and a suggestion entry.
2451 for depth in [Depth::Flat, Depth::Sunken, Depth::Overlay] {
2452 let css = disabled_rule("x", depth);
2453 assert!(css.contains("box-shadow"), "{depth:?}: {css}");
2454 }
2455 let flat = disabled_rule("x", Depth::Flat);
2456 assert!(flat.contains("background: none;"), "{flat}");
2457 assert!(flat.contains("box-shadow: none;"), "{flat}");
2458
2459 // Every rule the caller emits states both axes now, so whichever wins
2460 // the source-order contest leaves nothing of the one below it.
2461 let css = interactive_rules("x", Depth::Flat, &Emit::default());
2462 let disabled = css.find(":disabled").expect("disabled");
2463 assert!(css[disabled..].contains("background: none;"), "{css}");
2464 }
2465
2466 #[test]
2467 fn a_disabled_state_reaches_things_that_cannot_be_disabled() {
2468 // `:disabled` matches form elements only, and a chip is a div. Keying
2469 // on the ARIA attribute too is the pattern the invalid field already
2470 // set: one fact, read by the styling and the accessibility tree alike.
2471 let css = disabled_rule("chip", Depth::Raised);
2472 assert!(css.contains(".chip:disabled,"));
2473 assert!(css.contains(".chip[aria-disabled=\"true\"]"));
2474 assert!(css.contains("cursor: not-allowed"));
2475 }
2476
2477 #[test]
2478 fn the_focus_ring_does_not_disturb_the_bevel_it_lands_on() {
2479 // `outline` has its own property, so unlike the invalid ring there is
2480 // no bevel to restate beside it and nothing to keep in agreement.
2481 let opts = Emit::default();
2482 let css = focus_rule("button", Depth::Raised, &opts);
2483 assert!(css.contains("outline: 2px solid var(--focus-ring)"));
2484 assert!(!css.contains("box-shadow"), "the ring restated the bevel");
2485 }
2486
2487 #[test]
2488 fn a_well_takes_the_ring_inside_and_a_raised_surface_outside() {
2489 // One ring, placed by depth. The offset comes off `Depth::bevel` and
2490 // not off a per-component choice, which is what gave three apps three
2491 // different rings.
2492 let opts = Emit::default();
2493 assert!(focus_rule("field", Depth::Well, &opts).contains("outline-offset: calc(-1 * 2px)"));
2494 assert!(focus_rule("button", Depth::Raised, &opts).contains("outline-offset: 2px"));
2495 // Nothing to sit inside of, so it sits outside.
2496 assert!(focus_rule("badge", Depth::Sunken, &opts).contains("outline-offset: 2px"));
2497
2498 // And the ring is not the bevel. Reusing border_width emitted a 1px
2499 // ring that every consumer had already overridden.
2500 assert_ne!(opts.focus_width, opts.border_width);
2501 }
2502
2503 #[test]
2504 fn hover_is_gated_on_capability_and_the_keyboard_path_is_not() {
2505 // goingson's section 60 exists only to take back the hover state this
2506 // crate handed it. Gating at the source is what deletes that section
2507 // in all three apps rather than having each fight for it.
2508 let css = stylesheet(&Emit::default());
2509 let condition = format!("@media {}", Density::Pointer.media_condition());
2510 assert!(css.contains(&condition));
2511
2512 // What is gated is every hover state the surfaces carry. The row's
2513 // actions used to be the other half of this test and are not gated any
2514 // more, because they are not hidden any more: a rule that reveals
2515 // nothing needs no capability answer.
2516 let gated: Vec<&str> = css.lines().filter(|line| line.contains(":hover")).collect();
2517 assert!(!gated.is_empty(), "{css}");
2518 for line in gated {
2519 let indent = line.len() - line.trim_start().len();
2520 assert!(indent > 4, "an ungated hover rule: {line}");
2521 }
2522 assert!(!css.contains(".row:hover"), "{css}");
2523 }
2524
2525 #[test]
2526 fn the_capability_answer_is_asked_for_and_not_assumed() {
2527 // Both halves come from the crates that own them. If `makeover-touch`
2528 // ever says a fingertip has hover, this stops gating on its own.
2529 assert!(!Affordance::Hover.available(Density::Touch, SizeClass::Compact));
2530 assert!(Affordance::Hover.available(Density::Pointer, SizeClass::Compact));
2531 assert_eq!(hover_condition(), Some(Density::Pointer.media_condition()));
2532
2533 // And the size class passed to that call is not a claim about width.
2534 assert!(Affordance::Hover.reads_density());
2535 for size in [SizeClass::Compact, SizeClass::Medium, SizeClass::Expanded] {
2536 assert!(!Affordance::Hover.available(Density::Touch, size));
2537 }
2538 }
2539
2540 #[test]
2541 fn hover_resolves_against_the_token_makeover_already_derives() {
2542 let css = interactive_rules("card", Depth::Raised, &Emit::default());
2543 assert!(css.contains(".card:hover {"));
2544 assert!(css.contains("background: var(--hover-surface)"));
2545 // Not the app's choice, which was --surface-overlay.
2546 assert!(!css.contains("surface-overlay"));
2547 }
2548
2549 #[test]
2550 fn a_badge_gets_no_edge_and_no_fill() {
2551 // Decision 2, and the one visible redesign in phase A. Token::Badge is
2552 // Flat: an edge on a label says it can be pressed.
2553 let css = token_rules(&Emit::default());
2554 let badge = css
2555 .lines()
2556 .skip_while(|l| !l.starts_with(".badge {"))
2557 .take_while(|l| !l.starts_with('}'))
2558 .collect::<Vec<_>>()
2559 .join("\n");
2560 assert!(!badge.contains("box-shadow"), "badge kept an edge: {badge}");
2561 assert!(!badge.contains("background"), "badge kept a fill: {badge}");
2562 assert_eq!(Token::Badge.depth(false), Depth::Flat);
2563 assert_eq!(Token::Badge.depth(true), Depth::Flat);
2564 }
2565
2566 #[test]
2567 fn a_badge_carries_a_tone_and_neutral_is_the_bare_class() {
2568 let css = token_rules(&Emit::default());
2569 // Neutral is the absence of a status, not a status named "none".
2570 assert!(css.contains(".badge {\n color: var(--content-muted);"));
2571 assert!(!css.contains("data-tone=\"content-muted\""));
2572 for tone in ["info", "success", "warning", "danger"] {
2573 assert!(
2574 css.contains(&format!(".badge[data-tone=\"{tone}\"]")),
2575 "missing tone {tone}"
2576 );
2577 assert!(css.contains(&format!("color: var(--{tone})")));
2578 }
2579 }
2580
2581 #[test]
2582 fn a_chip_is_raised_and_latches_into_a_well() {
2583 let css = token_rules(&Emit::default());
2584 assert!(css.contains(".chip {"));
2585 assert!(css.contains(".chip.latched {"));
2586 assert!(css.contains(".chip:active {"));
2587 // The whole difference from a badge: it answers a click.
2588 assert!(Token::Chip { removable: false }.interactive());
2589 assert!(!Token::Badge.interactive());
2590 }
2591
2592 #[test]
2593 fn only_a_tab_comes_forward_when_chosen() {
2594 // The folder semantic. Collapsing the three selectors would lose it.
2595 let css = selector_rules(&Emit::default());
2596 assert!(css.contains(".tab.chosen {"));
2597 assert!(css.contains(".segment.chosen {"));
2598 assert!(css.contains(".toggle.chosen {"));
2599 assert_eq!(Selector::Tabs.chosen(), Depth::Raised);
2600 assert_eq!(Selector::Segmented.chosen(), Depth::Well);
2601 assert_eq!(Selector::Toggle.chosen(), Depth::Well);
2602
2603 let tab = css
2604 .lines()
2605 .skip_while(|l| !l.starts_with(".tab.chosen {"))
2606 .take_while(|l| !l.starts_with('}'))
2607 .collect::<Vec<_>>()
2608 .join("\n");
2609 assert!(
2610 tab.contains("var(--bevel-raised)"),
2611 "tab was held in: {tab}"
2612 );
2613 }
2614
2615 #[test]
2616 fn an_unchosen_tab_recedes_without_looking_picked() {
2617 let css = selector_rules(&Emit::default());
2618 // Recessed by colour and given no edge. An edge would make every option
2619 // look picked; flat would leave the chosen one nothing to come forward
2620 // from, which is the gap makeover-layout 0.3.0 closed.
2621 assert!(
2622 css.contains(".tab {\n background: var(--surface-sunken);\n}"),
2623 "unchosen tab is not recessed: {css}"
2624 );
2625 assert_eq!(Selector::Tabs.unchosen(), Depth::Sunken);
2626 assert!(css.contains(".tab:hover {"));
2627 }
2628
2629 #[test]
2630 fn a_segment_stands_up_so_the_chosen_one_can_be_held_in() {
2631 // The inverse of the tab, and why the three selectors are not one
2632 // member with a flag.
2633 let css = selector_rules(&Emit::default());
2634 assert!(css.contains(".segment {\n background: var(--surface-raised);"));
2635 assert_eq!(Selector::Segmented.unchosen(), Depth::Raised);
2636 assert_eq!(Selector::Segmented.chosen(), Depth::Well);
2637 }
2638
2639 #[test]
2640 fn a_rows_actions_are_shown_at_rest() {
2641 let css = row_rules(&Emit::default());
2642
2643 // The hover reveal is gone, and with it every escape it needed. What
2644 // it hid was hidden from pointer users alone, who are the ones
2645 // scanning a list to learn what can be done to a row.
2646 assert!(!css.contains("opacity"), "{css}");
2647 assert!(!css.contains("pointer-events"), "{css}");
2648 assert!(!css.contains(":hover"), "{css}");
2649 assert!(!css.contains(":focus-within"), "{css}");
2650
2651 // Nor is it hidden any other way. `display: none` would reflow the row
2652 // and `visibility: hidden` would take the actions out of the focus
2653 // order; the point is that neither is reached for.
2654 assert!(!css.contains("display: none"), "{css}");
2655 assert!(!css.contains("visibility:"), "{css}");
2656 }
2657
2658 #[test]
2659 fn a_figures_tone_lands_on_the_delta_when_there_is_one() {
2660 // 0.13.0. The delta is the part that reads as good or bad; the number
2661 // itself is an ordinary fact. A figure with no delta has nowhere else to
2662 // put the colour, so the value takes it, and `:has` is what lets one
2663 // attribute mean both without the emitter choosing an element.
2664 let css = stylesheet(&Emit::default());
2665
2666 assert!(
2667 css.contains(".figure[data-tone=\"success\"] > .figure-change"),
2668 "{css}"
2669 );
2670 assert!(
2671 css.contains(
2672 ".figure[data-tone=\"success\"]:not(:has(> .figure-change)) > .figure-value"
2673 ),
2674 "{css}"
2675 );
2676 // The caption is the noun and never takes the tone.
2677 assert!(
2678 !css.contains("[data-tone=\"success\"] > .figure-caption"),
2679 "{css}"
2680 );
2681 }
2682
2683 #[test]
2684 fn the_three_text_parts_take_their_intents_and_actions_inherits() {
2685 let css = row_rules(&Emit::default());
2686 assert!(css.contains(".row-primary {\n color: var(--content);"));
2687 assert!(css.contains(".row-secondary {\n color: var(--content-secondary);"));
2688 assert!(css.contains(".row-meta {\n color: var(--content-muted);"));
2689 // Actions carry controls, not text. Pinning the colour it would inherit
2690 // anyway is louder than saying nothing.
2691 assert!(!css.contains(".row-actions {\n color:"));
2692 }
2693
2694 #[test]
2695 fn the_token_strip_takes_no_colour_of_its_own() {
2696 // makeover-layout 0.9.0. A token carries its own tone, so a colour on
2697 // the strip would be a rule fighting the things sitting in it -- the
2698 // same reasoning as actions, reached for a different reason.
2699 let css = row_rules(&Emit::default());
2700 assert!(!css.contains(".row-tokens {\n color:"));
2701 }
2702
2703 #[test]
2704 fn an_unknown_row_part_renders_plainly_rather_than_failing_to_build() {
2705 // What `#[non_exhaustive]` bought and what it cost. `part_class` can no
2706 // longer be exhaustive, so a member added upstream lands as a bare
2707 // class with no rule instead of stopping the build. Asserting the
2708 // fallback exists is what keeps it from being written as `unreachable!`
2709 // by someone who reads the match as closed.
2710 assert_eq!(part_class(RowPart::Tokens), "row-tokens");
2711 assert_eq!(part_class(RowPart::Meta), "row-meta");
2712 }
2713
2714 #[test]
2715 fn a_link_takes_the_action_colour_the_theme_actually_defines() {
2716 // `--action-primary` shipped here for months and no theme has ever
2717 // defined it, so every `.link` dropped its colour declaration outright
2718 // and fell back to inherited text. Nothing caught it because the sheet
2719 // is valid CSS either way; MNW's no-undefined-token lint is what found
2720 // it, 2026-08-14. The hover arm two lines below was always `--action-hover`,
2721 // which is what makes the typo legible in hindsight.
2722 let css = link_rules(&Emit::default());
2723 assert!(css.contains("color: var(--action);"));
2724 assert!(!css.contains("--action-primary"));
2725 assert!(css.contains("color: var(--action-hover);"));
2726 }
2727
2728 #[test]
2729 fn the_progress_trough_is_a_well() {
2730 let css = progress_rules(&Emit::default());
2731 assert!(css.contains(".progress {"));
2732 assert!(css.contains("box-shadow: var(--bevel-inset)"));
2733 assert!(css.contains(".progress > .progress-fill {"));
2734 assert!(css.contains("background: var(--action)"));
2735 // A bare `.fill` would catch things that have nothing to do with
2736 // progress once the sheet lands unprefixed.
2737 assert!(!css.contains("> .fill "));
2738 }
2739
2740 #[test]
2741 fn a_progress_bar_can_carry_a_tone_and_defaults_to_action() {
2742 let css = progress_rules(&Emit::default());
2743 // Untoned is --action, not Tone::Neutral's content-muted: a bar with no
2744 // status is still reporting progress, and muted would read as disabled.
2745 assert!(css.contains(".progress > .progress-fill {\n background: var(--action);"));
2746 assert!(!css.contains("progress-fill {\n color: var(--content-muted)"));
2747 for tone in ["info", "success", "warning", "danger"] {
2748 assert!(
2749 css.contains(&format!(".progress > .progress-fill[data-tone=\"{tone}\"]")),
2750 "missing progress tone {tone}"
2751 );
2752 }
2753 // goingson's two live cases, which is why the tones are emitted at all.
2754 assert!(css.contains("[data-tone=\"success\"] {\n background: var(--success);"));
2755 assert!(css.contains("[data-tone=\"danger\"] {\n background: var(--danger);"));
2756 }
2757
2758 #[test]
2759 fn no_scrollbar_track_is_emitted() {
2760 // Decision 3's negative half. It was on the phase A list and came off;
2761 // this is what stops it drifting back in.
2762 let css = stylesheet(&Emit::default());
2763 assert!(!css.contains("scrollbar"));
2764 assert!(!css.contains("::-webkit"));
2765 }
2766
2767 #[test]
2768 fn an_invalid_field_is_ringed_without_being_lit() {
2769 let css = surface_rules(&Emit::default());
2770 assert!(css.contains(".field {"));
2771 // The ARIA attribute, not a class: one fact, read by both the visual
2772 // and the accessible state, so they cannot drift.
2773 assert!(css.contains(".field[aria-invalid=\"true\"] {"));
2774 assert!(!css.contains(".field.invalid"));
2775 // A flat ring: this edge says "wrong", and a two-tone bevel would have
2776 // it say "raised" at the same time.
2777 assert!(css.contains("0 0 0 1px var(--danger)"));
2778 }
2779
2780 #[test]
2781 fn an_invalid_field_keeps_the_well_underneath_it() {
2782 // box-shadow is not additive. A lone ring replaces the bevel and drops
2783 // the well out from under the field, which is what this emitted before
2784 // 0.5.0 and is the whole reason the rule composes.
2785 let css = surface_rules(&Emit::default());
2786 let invalid = css
2787 .lines()
2788 .skip_while(|l| !l.starts_with(".field[aria-invalid"))
2789 .take_while(|l| !l.starts_with('}'))
2790 .collect::<Vec<_>>()
2791 .join("\n");
2792 assert!(
2793 invalid.contains("var(--bevel-inset)"),
2794 "the well was dropped: {invalid}"
2795 );
2796 assert!(invalid.contains("var(--danger)"));
2797 }
2798
2799 #[test]
2800 fn button_and_card_come_out_identical_by_construction() {
2801 // The duplication phase A deletes. They are the same composition, so
2802 // the only honest way to emit both is from one call.
2803 let opts = Emit::default();
2804 let css = surface_rules(&opts);
2805 assert_eq!(
2806 depth_declarations(Depth::Raised),
2807 depth_declarations(Depth::Raised)
2808 );
2809 assert!(css.contains(".button {"));
2810 assert!(css.contains(".card {"));
2811 assert_eq!(
2812 interactive_rules("button", Depth::Raised, &Emit::default()).replace("button", "card"),
2813 interactive_rules("card", Depth::Raised, &Emit::default())
2814 );
2815 }
2816
2817 #[test]
2818 fn a_prefix_reaches_the_component_classes_too() {
2819 let opts = Emit {
2820 class_prefix: "mo-",
2821 ..Emit::default()
2822 };
2823 let css = stylesheet(&opts);
2824 for name in [
2825 "mo-button",
2826 "mo-card",
2827 "mo-field",
2828 "mo-badge",
2829 "mo-chip",
2830 "mo-tab",
2831 "mo-row-primary",
2832 "mo-progress",
2833 "mo-progress-fill",
2834 ] {
2835 assert!(css.contains(&format!(".{name}")), "unprefixed: {name}");
2836 }
2837 // The bare names must be gone entirely, or a prefixed build still
2838 // collides with the app's own stylesheet.
2839 assert!(!css.contains(".button {"));
2840 assert!(!css.contains(".card {"));
2841 assert!(!css.contains(".badge {"));
2842 }
2843
2844 #[test]
2845 fn the_class_a_renderer_puts_on_an_option_is_the_one_the_rules_key_off() {
2846 // `option_class` is the contract a screen renderer writes markup
2847 // against, and the rules below are the other half of it. They come off
2848 // one mapping now, so this asserts the mapping is the one that reaches
2849 // the stylesheet rather than that two lists still agree.
2850 let css = stylesheet(&Emit::default());
2851 for selector in [Selector::Tabs, Selector::Segmented, Selector::Toggle] {
2852 let name = option_class(selector);
2853 assert!(css.contains(&format!(".{name} {{")), "{name}: {css}");
2854 assert!(css.contains(&format!(".{name}.chosen {{")), "{name}: {css}");
2855 }
2856 assert_eq!(option_class(Selector::Tabs), "tab");
2857 }
2858
2859 #[test]
2860 fn the_caret_brings_its_own_gap_and_is_the_glyph_the_description_names() {
2861 let css = stylesheet(&Emit::default());
2862
2863 // The space is inside the glyph, which is what the other two renderers
2864 // write. Emitted bare, every consumer has to add it back, and the
2865 // obvious way to add it -- `content` in an app stylesheet, which is
2866 // unlayered and so outranks this sheet -- deletes the caret instead.
2867 assert!(css.contains("content: \" \\25B2\";"), "{css}");
2868 assert!(css.contains("content: \" \\25BC\";"), "{css}");
2869 assert!(!css.contains("content: \"\\2"), "{css}");
2870
2871 // The arrows this renderer used to draw alone are gone. Composition
2872 // rather than agreement: the glyph comes from `Sort::glyph`, so a
2873 // fourth spelling cannot appear here without appearing everywhere.
2874 assert!(!css.contains("2191") && !css.contains("2193"), "{css}");
2875 assert!(css.contains(&css_escape(Sort::Ascending.glyph())), "{css}");
2876
2877 // Three states, three tones. An idle sortable heading draws its caret
2878 // now rather than reserving a hidden box for it, so there is no
2879 // visibility to order and no reflow left to guard against; what
2880 // separates the states is the colour, and the sorted arms come after
2881 // the idle one because the specificity is the same.
2882 let idle = css
2883 .find(".table-heading[data-sortable]::after")
2884 .expect("the idle caret is emitted");
2885 let sorted = css
2886 .find(".table-heading[aria-sort=\"ascending\"]::after")
2887 .expect("the ascending caret is emitted");
2888 assert!(idle < sorted, "{css}");
2889 assert!(
2890 css[idle..sorted].contains("color: var(--content-secondary);"),
2891 "{css}"
2892 );
2893 assert!(css[sorted..].contains("color: var(--content);"), "{css}");
2894 assert!(!css.contains("visibility: hidden;"), "{css}");
2895 }
2896
2897 #[test]
2898 fn a_destructive_button_has_somewhere_for_its_tone_to_land() {
2899 let css = component_rules(&Emit::default());
2900
2901 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
2902 assert!(
2903 css.contains(&format!(".button[data-tone=\"{}\"]", tone.token())),
2904 "{css}"
2905 );
2906 }
2907 // Colour, not a fill. A red surface is an app's decision about emphasis.
2908 assert!(!css.contains(".button[data-tone=\"danger\"] {\n background"));
2909 }
2910
2911 #[test]
2912 fn the_table_model_is_scoped_to_the_table_but_the_caret_is_not() {
2913 // goingson's task headings are `.table-heading` inside a CSS grid.
2914 // They want the sort caret and the sortable cursor; they do not want
2915 // `display: table-cell`, which a grid item blockifies away anyway.
2916 // Scoping the one and not the other is what separates them.
2917 let css = component_rules(&Emit::default());
2918
2919 assert!(
2920 css.contains(".table .table-heading,\n.table .cell {\n display: table-cell;"),
2921 "{css}"
2922 );
2923 assert!(
2924 !css.contains(".table-heading,\n.cell {\n display: table-cell;"),
2925 "the table model is still unscoped: {css}"
2926 );
2927
2928 let states = state_rules(&Emit::default());
2929 assert!(
2930 states.contains(".table-heading[aria-sort"),
2931 "the caret got scoped along with the model: {states}"
2932 );
2933 }
2934
2935 #[test]
2936 fn a_figure_value_is_the_thing_itself_and_a_badge_is_quiet() {
2937 // Both used to read `Tone::Neutral.token()`, which answered
2938 // `content-muted`, so the headline number sat at the colour of its own
2939 // caption. Neutral answers `content` now; each site states its own
2940 // claim rather than borrowing one from the status axis.
2941 let css = component_rules(&Emit::default());
2942
2943 assert!(
2944 css.contains(".figure > .figure-value {\n color: var(--content);"),
2945 "{css}"
2946 );
2947 assert!(
2948 css.contains(".figure > .figure-caption {\n color: var(--content-muted);"),
2949 "{css}"
2950 );
2951 assert!(
2952 css.contains(".badge {\n color: var(--content-muted);"),
2953 "{css}"
2954 );
2955 }
2956
2957 #[test]
2958 fn a_described_list_is_not_a_bulleted_list() {
2959 let css = component_rules(&Emit::default());
2960 assert!(css.contains(".list {\n list-style: none;"), "{css}");
2961 }
2962
2963 #[test]
2964 fn a_table_lays_itself_out_without_being_told_its_columns() {
2965 // The whole point of the CSS table. A described table's columns are
2966 // known at render time, so anything the stylesheet has to be told about
2967 // them would have to travel with the markup.
2968 let css = component_rules(&Emit::default());
2969
2970 assert!(css.contains(".table {\n display: table;"), "{css}");
2971 assert!(css.contains("display: table-row;"), "{css}");
2972 assert!(css.contains("display: table-cell;"), "{css}");
2973 assert!(!css.contains("grid-template-columns"), "{css}");
2974 }
2975
2976 #[test]
2977 fn a_control_in_a_cell_is_not_painted_as_text() {
2978 // The point of makeover-layout 0.14.0's CellPart, and the table-side
2979 // twin of `the_three_text_parts_take_their_intents_and_actions_inherits`
2980 // above. One `.cell` and one content colour meant a button in a cell
2981 // inherited it.
2982 let css = table_rules(&Emit::default());
2983
2984 assert!(
2985 css.contains(".cell-value {\n color: var(--content);"),
2986 "{css}"
2987 );
2988 assert!(!css.contains(".cell-actions {\n color:"), "{css}");
2989 assert!(!css.contains(".cell-tokens {\n color:"), "{css}");
2990 assert!(!css.contains(".cell-link {\n color:"), "{css}");
2991
2992 // The colour is on the part that is text, never on the container. On
2993 // `.cell` it would cascade into the three parts that are not text,
2994 // which is the bug written as one rule.
2995 assert!(!css.contains(".cell {\n color:"), "{css}");
2996 }
2997
2998 #[test]
2999 fn an_unknown_cell_part_renders_plainly_rather_than_failing_to_build() {
3000 // `part_class`'s obligation, taken on for the table side too. CellPart
3001 // is `#[non_exhaustive]`, so a member added upstream must land as a
3002 // bare class rather than as a build that stops.
3003 assert_eq!(cell_part_class(CellPart::Value), "cell-value");
3004 assert_eq!(cell_part_class(CellPart::Actions), "cell-actions");
3005 }
3006
3007 #[test]
3008 fn a_column_drops_by_its_priority_and_never_by_its_position() {
3009 let css = component_rules(&Emit::default());
3010
3011 // Optional goes at the narrowest class and secondary goes with it,
3012 // which is `kept_at`'s cutoff walk said as two queries.
3013 let compact = css
3014 .find(&format!("@media {}", SizeClass::Compact.media_condition()))
3015 .expect("a compact query");
3016 let medium = css
3017 .find(&format!("@media {}", SizeClass::Medium.media_condition()))
3018 .expect("a medium query");
3019 assert!(css[compact..].contains(".cell-drops-next"), "{css}");
3020 assert!(!css[medium..].contains(".cell-drops-next"), "{css}");
3021
3022 // Essential columns are never mentioned, because not being mentioned is
3023 // already what never dropping means.
3024 assert!(!css.contains(".cell-keeps"), "{css}");
3025
3026 // And nothing counts. `nth-child` is the bug the priority vocabulary
3027 // exists to end.
3028 assert!(!css.contains("nth-child"), "{css}");
3029 }
3030
3031 #[test]
3032 fn a_track_places_by_custom_property_and_never_by_a_size() {
3033 let css = track_rules(&Emit::default());
3034
3035 // Placement arrives from the caller, computed once by Track::fraction.
3036 // If either of these becomes a literal, three renderers have started
3037 // disagreeing about where 09:30 is.
3038 assert!(css.contains("top: var(--track-at"), "{css}");
3039 assert!(css.contains("height: var(--track-for"), "{css}");
3040
3041 // Overlap lanes default so an entry naming neither is full width.
3042 assert!(css.contains("--track-lane, 0"), "{css}");
3043 assert!(css.contains("--track-lanes, 1"), "{css}");
3044
3045 // The refusal that matters. A slot height here would be this crate
3046 // deciding how tall a quarter of an hour is, which is the thing
3047 // makeover-geometry owns and the reason `.track` gets no height at all.
3048 assert!(!css.contains("height: var(--track-slot"), "{css}");
3049 for size in ["px", "rem", "em", "vh"] {
3050 let bare = css
3051 .lines()
3052 .filter(|l| !l.contains("var(--"))
3053 .any(|l| l.contains(size));
3054 assert!(!bare, "track_rules named a {size} outside a var(): {css}");
3055 }
3056 }
3057
3058 #[test]
3059 fn a_relaxed_part_clamps_and_a_tight_one_says_nothing() {
3060 let css = stylesheet(&Emit::default());
3061 assert!(css.contains(".row-relaxed {"));
3062 assert!(css.contains("-webkit-line-clamp: 2;"));
3063 // The count is `Flow`'s, not this crate's. If the tier ever means three
3064 // lines, this fails here rather than in an app.
3065 assert!(css.contains(&format!("line-clamp: {};", Flow::Relaxed.lines())));
3066 // Tight gets no rule at all: one line is what a run already does, and a
3067 // class per part saying so is a declaration that changes nothing.
3068 assert!(!css.contains("row-tight"));
3069 assert_eq!(crate::list::flow_class(Flow::Relaxed), Some("row-relaxed"));
3070 assert_eq!(crate::list::flow_class(Flow::Tight), None);
3071 // Emitted, therefore checkable: an app's dead-vocabulary seal and the
3072 // overlap check both read `vocabulary::names`, so a class the renderer
3073 // can write and that list does not carry is invisible to both.
3074 assert!(crate::vocabulary::names(&Emit::default()).contains("row-relaxed"));
3075 }
3076
3077 #[test]
3078 fn the_two_kinds_of_wait_stop_rendering_identically() {
3079 // The state `d43ea1c5` fixes: the emitter had been writing
3080 // `data-awaiting` for months and nothing styled either value, so a
3081 // measured wait and an unmeasured one drew the same nothing.
3082 let css = stylesheet(&Emit::default());
3083 assert!(css.contains("[data-awaiting]::after"), "{css}");
3084 assert!(
3085 css.contains("[data-awaiting][aria-busy=\"true\"]::after"),
3086 "the mark is drawn only while something is actually waiting"
3087 );
3088 assert!(
3089 css.contains("[data-awaiting=\"determinate\"][aria-busy=\"true\"]::after"),
3090 "the measured half is its own drawing"
3091 );
3092 }
3093
3094 #[test]
3095 fn the_blink_takes_its_cadence_and_never_names_one() {
3096 // Three renderers draw this mark. A number written here would be a
3097 // second heartbeat for one wait.
3098 let css = stylesheet(&Emit::default());
3099 assert!(
3100 css.contains("calc(var(--cadence-activity) * 2)"),
3101 "a half-period doubled, not a literal"
3102 );
3103 assert!(!css.contains("500ms"), "{css}");
3104 }
3105
3106 #[test]
3107 fn a_bar_nobody_is_counting_is_empty_rather_than_full() {
3108 // Rule 1. The share defaults to zero, so a determinate control with no
3109 // binder watching bytes draws a trough. A default of 1 would be the
3110 // confidently-wrong drawing the rule exists to forbid.
3111 let css = stylesheet(&Emit::default());
3112 assert!(css.contains("var(--awaiting-share, 0)"), "{css}");
3113 }
3114
3115 #[test]
3116 fn motion_off_leaves_the_mark_lit_because_the_keyframes_do_the_dimming() {
3117 // `makeover_timing::reduced_motion_css` sets `--cadence-activity: 0ms`,
3118 // and a zero-length animation leaves the element in its base style
3119 // rather than at its last keyframe. So the base has to be the lit one.
3120 // The inverted spelling would blank the mark for a reader who asked for
3121 // less motion, which answers a request nobody made.
3122 let css = stylesheet(&Emit::default());
3123 let busy = css
3124 .split("[data-awaiting][aria-busy=\"true\"]::after {")
3125 .nth(1)
3126 .expect("the busy rule");
3127 let busy = busy.split('}').next().expect("its body");
3128 assert!(
3129 busy.contains("background: var(--action);"),
3130 "the base state is lit: {busy}"
3131 );
3132 }
3133
3134 #[test]
3135 fn the_whole_sheet_still_names_every_colour() {
3136 // The crate's founding property, asserted over the component layer and
3137 // not only the primitives.
3138 let css = stylesheet(&Emit::default());
3139 assert!(!css.contains('#'));
3140 assert!(!css.contains("rgb"));
3141 for line in css.lines() {
3142 // Declarations only: a selector or an at-rule can carry a colon of
3143 // its own (`:root`, `:hover`, `@media (hover: hover)`) and declares
3144 // nothing. Keyed on the trailing semicolon rather than on leading
3145 // indentation, which only ever worked as a proxy for nesting depth
3146 // and stopped when the sheet gained a cascade layer around it.
3147 let trimmed = line.trim();
3148 if !trimmed.ends_with(';') {
3149 continue;
3150 }
3151 let Some((_, value)) = trimmed.split_once(": ") else {
3152 continue;
3153 };
3154 if value.contains("var(--") {
3155 continue;
3156 }
3157 // Everything left has to be a keyword, a number or a
3158 // caller-supplied length, never a colour.
3159 //
3160 // The length arm is what the comment above always claimed and the
3161 // list never covered: `border_width` arrives from `Emit` and lands
3162 // bare in the focus ring's offset, where the bevel had only ever
3163 // used it inside an `inset` shadow.
3164 let opts = Emit::default();
3165 assert!(
3166 value.contains("inset")
3167 || value.contains(opts.border_width)
3168 || value.contains(opts.focus_width)
3169 // 0.12.0's two: a sortable header is a control and says so
3170 // with the pointer, and the caret is this renderer's own
3171 // expression of `aria-sort`. Neither is a colour, which is
3172 // what this test is actually about, and neither is a size,
3173 // which is the other thing this crate must not name. The
3174 // leading space inside the glyph is the same thing the other
3175 // two renderers write into theirs, so it is part of the
3176 // caret rather than spacing this crate decided on.
3177 || value
3178 .trim_start_matches('"')
3179 .trim_start()
3180 .starts_with("\\2")
3181 || matches!(
3182 value.trim_end_matches(';'),
3183 "0" | "1"
3184 // The wait's mark and bar, 0.60.0. An empty
3185 // `content` is what brings a pseudo-element into
3186 // existence with nothing in it, and `step-end`
3187 // is an easing: the blink is two states, not a
3188 // slide between them. Neither is a colour, and
3189 // neither is a magnitude.
3190 | "\"\""
3191 // Where the mark sits on the line it joins.
3192 // Alignment is structure, the same way `display`
3193 // is, and `baseline` is the initial value said out
3194 // loud so a host stylesheet cannot leave it
3195 // wherever an earlier rule put it.
3196 | "baseline"
3197 | "inline-block"
3198 | "none"
3199 | "auto"
3200 | "not-allowed"
3201 | "pointer"
3202 // The caret's reserved box. Visibility is presence,
3203 // not magnitude and not colour.
3204 | "hidden"
3205 | "visible"
3206 // The link's two signals. `underline` is a line and
3207 // `inherit` defers to whatever the app set, so
3208 // neither names a colour or a magnitude.
3209 | "underline"
3210 | "inherit"
3211 // The table frame. `display` is structure and not a
3212 // size; `nowrap` is what makes a content column
3213 // content. The two widths are the awkward pair and
3214 // they are still not sizes: `100%` is "all of
3215 // whatever you were given" and `1%` is the CSS
3216 // table idiom for "shrink to fit", which is a
3217 // behaviour spelled as a number because CSS has no
3218 // keyword for it. Neither names a magnitude, which
3219 // is the thing this crate leaves to
3220 // makeover-geometry.
3221 | "table"
3222 | "table-row"
3223 | "table-cell"
3224 | "nowrap"
3225 | "100%"
3226 | "1%"
3227 // The time axis, 0.42.0. `position` is the one
3228 // property whose whole job is where a thing sits,
3229 // which is exactly what this crate spent its life
3230 // refusing to say -- so it is worth being exact
3231 // about why these two are not that refusal
3232 // breaking.
3233 //
3234 // Neither names a magnitude. `relative` says the
3235 // track is what its entries resolve against, and
3236 // `absolute` says an entry is placed rather than
3237 // flowed. *Where* each entry lands is
3238 // `--track-at` and `--track-for`, custom
3239 // properties the caller sets from
3240 // `Track::fraction`, and they are skipped by the
3241 // `var(--` arm above like every other value this
3242 // crate refuses to decide.
3243 //
3244 // The rule that would break the refusal is a slot
3245 // height, and there is none: the track's height is
3246 // the app's, so the percentages have something to
3247 // resolve against and this crate still never says
3248 // how tall a day is.
3249 | "relative"
3250 | "absolute"
3251 // A run's five, 0.49.0. `flex`, `wrap` and
3252 // `center` are structure and alignment, the same
3253 // reading `table` gets: which way members are laid
3254 // out and how they line up, never how much of
3255 // anything.
3256 //
3257 // The two intrinsic keywords are the interesting
3258 // pair and they are the opposite of a size. A
3259 // magnitude is a number somebody chose;
3260 // `min-content` and `max-content` are the browser
3261 // being asked what the members themselves come to,
3262 // which is the derived minimum the room ruling
3263 // requires and the reason no breakpoint appears
3264 // anywhere in these rules. `1 1 max-content` is
3265 // grow, shrink and that basis, so its two digits
3266 // are ratios rather than lengths.
3267 | "flex"
3268 | "wrap"
3269 | "center"
3270 | "min-content"
3271 | "1 1 max-content"
3272 // A menu run's overflow control, 0.64.0.
3273 // `column` and `stretch` are the same reading
3274 // `flex` and `center` get one line up: which way
3275 // the shed members stack inside the panel and how
3276 // they line up across it. Neither is a magnitude.
3277 //
3278 // `100%` is already above and reused here as the
3279 // panel's `inset-block-start`, which is "the whole
3280 // of the control it hangs from" rather than a
3281 // distance anybody picked.
3282 | "column"
3283 | "stretch"
3284 // A picture's three, 0.36.0. `block` is structure
3285 // for the reason `table` is: an inline image sits
3286 // on the baseline and carries a descender's worth
3287 // of space under it, which is a fact about
3288 // replaced elements rather than a size this crate
3289 // chose. `cover` and `contain` are `Fit`'s two
3290 // named members reaching CSS unchanged, which is
3291 // an intent arriving rather than a value being
3292 // picked.
3293 | "block"
3294 | "cover"
3295 | "contain"
3296 // A relaxed part's three, and the third is the
3297 // awkward one. `-webkit-box` and `vertical` are
3298 // structure: they say the part is a box of lines
3299 // stacked downward, which is the only way CSS lets
3300 // anyone ask for a clamp at all.
3301 //
3302 // `2` is a count of lines, not a length. The
3303 // distinction this crate holds is between naming a
3304 // magnitude -- a padding, a height, a font size,
3305 // all of which belong to makeover-geometry -- and
3306 // naming how many of something there are. A line's
3307 // height is still the app's, so two lines is
3308 // whatever two of the app's lines come to, and
3309 // nothing here decides how tall that is. It is also
3310 // not a value picked here: it is `Flow::Relaxed`'s
3311 // own answer arriving unchanged, the same way
3312 // `cover` and `contain` are `Fit`'s.
3313 | "-webkit-box"
3314 | "vertical"
3315 | "2"
3316 ),
3317 "unrecognised literal value: {line}"
3318 );
3319 }
3320 }
3321
3322 #[test]
3323 fn flat_emits_nothing_at_all() {
3324 assert_eq!(depth_class(Depth::Flat, &Emit::default()), None);
3325 assert!(!depth_rules(&Emit::default()).contains("flat"));
3326 }
3327
3328 #[test]
3329 fn a_prefix_namespaces_every_class() {
3330 let opts = Emit {
3331 class_prefix: "mo-",
3332 ..Emit::default()
3333 };
3334 let css = depth_rules(&opts);
3335 assert!(css.contains(".mo-raised {"));
3336 assert!(css.contains(".mo-well {"));
3337 assert!(!css.contains(".raised {"));
3338 }
3339
3340 #[test]
3341 fn the_border_width_is_the_callers() {
3342 let opts = Emit {
3343 border_width: "2px",
3344 ..Emit::default()
3345 };
3346 assert!(bevel_shadow(Bevel::Raised, &opts).contains("inset 2px 2px 0"));
3347 }
3348
3349 #[test]
3350 fn edges_agree_with_the_description() {
3351 // Not a tautology: it is the guard that a CSS-shaped convenience never
3352 // quietly reverses which side is lit.
3353 let (tl, br) = Bevel::Raised.edges();
3354 assert_eq!(tl.token(), Edge::Light.token());
3355 assert_eq!(br.token(), Edge::Dark.token());
3356 }
3357 }
3358