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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::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 /// Present, visible, and not answering.
761 ///
762 /// Matches the ARIA attribute as well as the pseudo-class, because `:disabled`
763 /// only matches form elements and half the things this crate emits are not
764 /// one: a `div` carrying `.chip` or `.tab` can never be `:disabled`. Keying on
765 /// the accessible state is the pattern [`field_rules`] already establishes for
766 /// `aria-invalid`, on the reasoning that one fact read by both the styling and
767 /// the accessibility tree cannot drift from itself.
768 ///
769 /// The rest depth is re-asserted rather than assumed, because this rule has to
770 /// beat the hover and pressed rules above it. It does that on source order at
771 /// equal specificity, not by out-specifying them: every rule this function's
772 /// caller emits is (0,2,0), and adding a `:not(:disabled)` anywhere would raise
773 /// one of them and have to be unpicked when this output moves inside its own
774 /// cascade layer.
775 #[must_use]
776 pub fn disabled_rule(selector: &str, depth: Depth) -> String {
777 format!(
778 ".{selector}:disabled,\n.{selector}[aria-disabled=\"true\"] {{\n{} color: var(--{});\n cursor: not-allowed;\n}}\n",
779 depth_declarations(depth),
780 State::Disabled.token()
781 )
782 }
783
784 /// Every state a selector that answers a click implies: hover, pressed, focus
785 /// and disabled, in that order.
786 ///
787 /// Order is the whole cascade mechanism here. All four selectors are
788 /// specificity (0,2,0), so disabled wins over hover and pressed by coming last
789 /// and by nothing else.
790 ///
791 /// Pressed emits [`Depth::pressed`] in full, fill and edge together. Emitting
792 /// only the edge is what left goingson hand-writing `background:
793 /// var(--surface-sunken)` on three separate rules, and a fill that does not
794 /// travel with its edge is precisely the disagreement `Depth` exists to make
795 /// unrepresentable. So the pressed fill comes from the description
796 /// (`--surface-well`) rather than from whatever each app reached for.
797 ///
798 /// Hover has no member in the description and is renderer policy: a terminal
799 /// and an immediate-mode painter have no hover to express. It resolves against
800 /// `--hover-surface`, which `makeover` already derives and which nothing
801 /// consumed until now. What it *is* gated on is capability, via
802 /// [`hover_condition`]. Before that gate existed the apps each wrote their own:
803 /// goingson's section 60 exists solely to take back the hover state this
804 /// function had just handed it, by out-specifying a rule it does not own.
805 ///
806 /// `depth` is the selector's **rest** depth, used to place the focus ring and
807 /// to restore the surface under a disabled control. The pressed rule keeps
808 /// inverting from [`Depth::Raised`] regardless, which is what every caller got
809 /// before this parameter existed: a tab's unchosen depth is
810 /// [`Depth::Sunken`], and `Sunken.pressed()` is `Sunken`, so deriving the press
811 /// from the rest depth would leave a tab with no press at all.
812 #[must_use]
813 pub fn interactive_rules(selector: &str, depth: Depth, opts: &Emit) -> String {
814 let mut css = gated(
815 hover_condition(),
816 &format!(".{selector}:hover {{\n background: var(--hover-surface);\n}}\n"),
817 );
818 css.push_str(&depth_rule(
819 &format!("{selector}:active"),
820 Depth::Raised.pressed(),
821 ));
822 css.push_str(&focus_rule(selector, depth, opts));
823 css.push_str(&disabled_rule(selector, depth));
824 css
825 }
826
827 /// One rule per depth: its fill and its edge, together.
828 ///
829 /// A depth and nothing else. `.raised` says a surface sits on what is behind
830 /// it, which is a statement about the shape and not about what happens when a
831 /// pointer arrives, so it emits no hover, press, focus or disabled rule. The
832 /// named surfaces are where interaction lives: `.card` and `.button` are the
833 /// same depth *and* controls, and they get their states from
834 /// [`surface_rules`].
835 ///
836 /// This class carried the interactive set until 0.17.0, which left the
837 /// vocabulary with no raised surface that is merely an object. Consumers that
838 /// needed one took a control class and cancelled half of it instead: sixteen
839 /// elements in goingson across three `.card--*` variants, each re-asserting the
840 /// resting fill and bevel on `:hover` and `:active`. Nothing anywhere used
841 /// `.raised` itself, so the states were unasked-for in every consumer at once.
842 #[must_use]
843 pub fn depth_rules(opts: &Emit) -> String {
844 let mut css = String::new();
845 for depth in [Depth::Raised, Depth::Well] {
846 let Some(class) = depth_class(depth, opts) else {
847 continue;
848 };
849 css.push_str(&depth_rule(&class, depth));
850 }
851 css
852 }
853
854 /// The three surfaces that are a depth with a name.
855 ///
856 /// `button` and `card` are both [`Depth::Raised`], and `field` is a
857 /// [`Depth::Well`] because that is the reading `Depth`'s own documentation
858 /// gives a text field. Their bodies come out identical by construction rather
859 /// than by hand: three hand-written copies in goingson's stylesheet is what
860 /// phase A deletes, and generating them from one call is what stops them
861 /// drifting apart again.
862 fn surface_rules(opts: &Emit) -> String {
863 let mut css = String::new();
864 for name in ["button", "card"] {
865 let c = class(name, opts);
866 css.push_str(&depth_rule(&c, Depth::Raised));
867 css.push_str(&interactive_rules(&c, Depth::Raised, opts));
868 }
869
870 let field = class("field", opts);
871 css.push_str(&depth_rule(&field, Depth::Well));
872
873 // A field takes focus and refuses input like everything else here, and got
874 // neither until now, which is why all three apps hand-write a focus ring
875 // for it and no two of them match. No hover or pressed: a text field does
876 // not light up under the pointer and does not invert when clicked, so the
877 // two states `interactive_rules` would add are the two it does not have.
878 css.push_str(&focus_rule(&field, Depth::Well, opts));
879 css.push_str(&disabled_rule(&field, Depth::Well));
880
881 // Keyed on the ARIA attribute rather than on a class, so the visual state
882 // and the accessible state cannot drift apart: there is one fact and both
883 // read it. goingson already drove its invalid styling this way and was
884 // right to; the `.invalid` class this emitted before 0.5.0 was a second
885 // place to forget.
886 //
887 // The ring composes *after* the bevel rather than replacing it. box-shadow
888 // is not additive, so a lone ring silently dropped the well out from under
889 // an invalid field. Flat and unlit: this edge is saying "wrong", and
890 // lighting one side would have it say "raised" at the same time.
891 let _ = writeln!(
892 css,
893 ".{field}[aria-invalid=\"true\"] {{\n box-shadow: var({}), 0 0 0 {} var(--danger);\n}}",
894 bevel_var(Bevel::Inset),
895 opts.border_width
896 );
897 css
898 }
899
900 /// Badges and chips.
901 ///
902 /// The one place phase A changes how goingson looks rather than only where its
903 /// rules live. [`Token::Badge`] is [`Depth::Flat`], so a badge emits no fill
904 /// and no edge at all, where goingson ships `.tag, .badge` as a single rule
905 /// carrying the raised bevel. Splitting that means reading every call site to
906 /// decide which of the two it always was.
907 ///
908 /// What a badge does carry is a [`Tone`], the intent family it shares with
909 /// notices and nothing else. Neutral is the bare class rather than a variant,
910 /// because it is the absence of a status and not a status called "none".
911 /// Text that goes somewhere.
912 ///
913 /// The one inline control, and the vocabulary had no word for it until a
914 /// description layer needed one. A table cell has carried `cell-link` since
915 /// 0.14.0's part list, deliberately unruled because the cell's own rule covers
916 /// it; what was missing is the same thing outside a table, which is what a
917 /// described run holds when a sentence contains a link.
918 ///
919 /// Colour and underline only. Whether a link is inline in a sentence or sitting
920 /// on its own line is the app's layout, and how much room it takes is
921 /// `makeover-geometry`'s. What is here is the pair of signals that say "this
922 /// goes somewhere" and nothing that says where it sits.
923 ///
924 /// The visited arm is deliberately absent. A link inside an app points at the
925 /// app's own screens, which the user is expected to have been to, so painting
926 /// them differently marks almost everything and distinguishes nothing.
927 fn link_rules(opts: &Emit) -> String {
928 let mut css = String::new();
929 let link = class("link", opts);
930
931 let _ = writeln!(
932 css,
933 ".{link} {{\n color: var(--action);\n \
934 text-decoration: underline;\n}}"
935 );
936 // The hover step is the same one every other control takes, and it is a
937 // colour rather than a surface: a link has no box to raise.
938 let _ = writeln!(
939 css,
940 "@media (hover: hover) and (pointer: fine) {{\n .{link}:hover \
941 {{\n color: var(--action-hover);\n }}\n}}"
942 );
943 let _ = writeln!(
944 css,
945 ".{link}:focus-visible {{\n outline: {} solid var(--focus-ring);\n \
946 outline-offset: 2px;\n}}",
947 opts.focus_width
948 );
949 // A link is often a `<button>` rather than an `<a>`: a renderer picks the
950 // element from the method, so a link that writes is a button that has to
951 // stop looking like one. What that costs is named in [`reset`].
952 css.push_str(&Reset::TEXT_BUTTON.rule(&format!("button.{link}")));
953 css
954 }
955
956 fn token_rules(opts: &Emit) -> String {
957 let mut css = String::new();
958
959 // No `depth_rule` call here, deliberately: `Token::Badge.depth(_)` is Flat,
960 // and a label with an edge says it can be pressed.
961 let badge = class("badge", opts);
962 // `content-muted` literally, not `Tone::Neutral.token()`. What makes a
963 // badge quiet is `Token::Badge` answering no click, which this crate holds
964 // and `Tone` genuinely does not know. Routing it through Neutral put the
965 // claim where the evidence was not, and the bill arrived on the figure
966 // value: it took the same muting from the same call and read as its own
967 // caption. Neutral answers `content` from makeover-layout 0.36.0.
968 let _ = writeln!(css, ".{badge} {{\n color: var(--content-muted);\n}}");
969 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
970 let _ = writeln!(
971 css,
972 ".{badge}[data-tone=\"{0}\"] {{\n color: var(--{0});\n}}",
973 tone.token()
974 );
975 }
976
977 // A button carries the four tones a badge does. It had none, on the reading
978 // that a control's colour is its surface rather than its text, and that
979 // reading has one hole big enough to matter: the button that destroys
980 // something. Every consumer had written that rule itself, and a description
981 // that says `Tone::Danger` on an act had nowhere for it to land.
982 //
983 // Colour and not a fill, matching the badge. A red surface is a decision
984 // about emphasis that belongs to an app's own layer, and two of them
985 // fighting is worse than neither.
986 let button = class("button", opts);
987 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
988 let _ = writeln!(
989 css,
990 ".{button}[data-tone=\"{0}\"] {{\n color: var(--{0});\n}}",
991 tone.token()
992 );
993 }
994
995 // A chip holds itself down, which is `Depth::pressed` arrived at
996 // independently by two apps. `removable` is a remove affordance, so it is
997 // markup and waits for phase B.
998 let chip = class("chip", opts);
999 let unlatched = Token::Chip { removable: false };
1000 css.push_str(&depth_rule(&chip, unlatched.depth(false)));
1001 css.push_str(&interactive_rules(&chip, unlatched.depth(false), opts));
1002 css.push_str(&depth_rule(
1003 &format!("{chip}.latched"),
1004 unlatched.depth(true),
1005 ));
1006 css
1007 }
1008
1009 /// The three selectors, each named by what it picks.
1010 ///
1011 /// A tab comes *forward* to join the pane it opens, which is why
1012 /// [`Selector::Tabs`] chooses [`Depth::Raised`] where a segment and a toggle
1013 /// are held in. That is the folder semantic, and it is the whole reason the
1014 /// three are not one member with a flag.
1015 ///
1016 /// [`Selector::abutting`] is not emitted: whether the options touch is
1017 /// spacing, and spacing is `makeover-geometry`'s question to answer.
1018 ///
1019 /// Both states emit as of makeover-layout 0.3.0. Before it the description
1020 /// named only the chosen option, so an unchosen one fell through to
1021 /// [`Depth::Flat`] and nothing was drawn for it, which left goingson's tab
1022 /// strip hand-writing the recess that makes its chosen tab read as forward.
1023 fn selector_rules(opts: &Emit) -> String {
1024 let mut css = String::new();
1025 for selector in [Selector::Tabs, Selector::Segmented, Selector::Toggle] {
1026 let c = class(option_class(selector), opts);
1027 css.push_str(&depth_rule(&c, selector.unchosen()));
1028 css.push_str(&interactive_rules(&c, selector.unchosen(), opts));
1029 css.push_str(&depth_rule(&format!("{c}.chosen"), selector.chosen()));
1030 }
1031 css
1032 }
1033
1034 /// The parts of a list row.
1035 ///
1036 /// The list is written out rather than derived because `RowPart` is
1037 /// `#[non_exhaustive]` as of makeover-layout 0.9.0, so there is nothing to
1038 /// iterate. A member added upstream emits no rule until it is named here, which
1039 /// is the trade `non_exhaustive` makes: a silent gap instead of a build break.
1040 /// [`part_class`] carries the same list and the same obligation.
1041 fn row_rules(opts: &Emit) -> String {
1042 let mut css = String::new();
1043
1044 // The container the rows sit in, giving back what a `<ul>` brought. Not a
1045 // size: there is no magnitude in it, which is the line this crate holds.
1046 css.push_str(&Reset::BULLETS.rule(&format!(".{}", class("list", opts))));
1047
1048 for part in [
1049 RowPart::Primary,
1050 RowPart::Secondary,
1051 RowPart::Meta,
1052 RowPart::Actions,
1053 RowPart::Tokens,
1054 RowPart::Proportion,
1055 ] {
1056 let c = class(part_class(part), opts);
1057
1058 // Actions carry controls rather than text, and `RowPart::intent` says
1059 // so by returning the same intent inheriting already gives. Pinning it
1060 // would be louder than saying nothing. Tokens answer alike, for their
1061 // own reason: each token carries its own tone, and a colour on the
1062 // strip would fight the things sitting in it. A proportion is the same
1063 // case again: the meter inside carries the tone.
1064 if !matches!(
1065 part,
1066 RowPart::Actions | RowPart::Tokens | RowPart::Proportion
1067 ) {
1068 let _ = writeln!(css, ".{c} {{\n color: var(--{});\n}}", part.intent());
1069 }
1070
1071 // A row's actions are shown at rest. `RowPart::revealed_on_hover` said
1072 // otherwise and was not honoured here from 0.23.0; makeover-layout
1073 // 0.13.0 retired the method, so there is no longer a description saying
1074 // one thing and a renderer doing another.
1075 //
1076 // The rule was `opacity: 0` gated to pointer devices, revealed on
1077 // `:hover` and on `:focus-within`. Each escape it needed was a report
1078 // that hiding was wrong for somebody: `focus-within` because tabbing
1079 // could never reach an action; the gate because a fingertip had no way
1080 // to unhide, which both webview apps had already hand-written
1081 // `opacity: 1` to undo. What was left was a control hidden from
1082 // exactly one group: people using a pointer, who are also the group
1083 // scanning a list to find out what can be done to a row.
1084 //
1085 // A settings screen is where that reads worst: the whole reason to be
1086 // on it is to remove a key, and the button doing so was invisible
1087 // until pointed at. A table cell's actions were never hidden, so the
1088 // two arrangements now agree.
1089 }
1090
1091 // A part that may take two lines. `Flow::Tight` gets no rule: one line is
1092 // what a run already does, and restating it here would put a declaration on
1093 // every part in every row to say nothing.
1094 //
1095 // This is the shape both webview apps had already written by hand and
1096 // commented -- Balanced Breakfast on a feed row's title, goingson on a
1097 // problem's body -- which is the whole argument for the description
1098 // carrying it. `-webkit-` prefixed and unprefixed together: the prefixed
1099 // trio is what every engine actually implements, and `line-clamp` is the
1100 // standard property landing behind it.
1101 let _ = writeln!(
1102 css,
1103 ".{} {{\n display: -webkit-box;\n -webkit-box-orient: vertical;\n -webkit-line-clamp: {lines};\n line-clamp: {lines};\n overflow: hidden;\n}}",
1104 class("row-relaxed", opts),
1105 lines = Flow::Relaxed.lines()
1106 );
1107
1108 css
1109 }
1110
1111 /// A row of things that share their space, and what each fallback gets here.
1112 ///
1113 /// Ruling: wiki `layout-room-and-fallback`, Max 2026-08-18. The bug it answers
1114 /// is goingson's `styles.css:702`, which pinned every `.page-header` over the
1115 /// pill strip with `position: absolute` and so took the toolbar out of flow:
1116 /// zero width contributed to the row it shared, nothing able to collide with
1117 /// it, and therefore nothing preventing the collision. Rule 1 of the ruling is
1118 /// that every described member is in flow, and these rules are how that is kept
1119 /// rather than asked for.
1120 ///
1121 /// # The floor, which is most of the fix
1122 ///
1123 /// `.run > *` gets `min-width: min-content`. That is the derived minimum the
1124 /// ruling asks for, in this renderer's own unit and stated by the browser
1125 /// rather than by anybody: a member cannot be squeezed narrower than what is
1126 /// in it, so members in one flow push each other instead of overlapping. It
1127 /// costs no query and no number, and it is what fixes all four measured widths
1128 /// whichever fallback the group declared.
1129 ///
1130 /// # What each fallback gets, exactly
1131 ///
1132 /// [`Fallback::Wrap`] is `flex-wrap: wrap`, which is exact. The browser wraps
1133 /// the run when the members no longer fit, deciding that from their own
1134 /// intrinsic widths, which is the derived minimum doing the whole job.
1135 ///
1136 /// [`Fallback::Stack`] is wrap plus `flex: 1 1 max-content` on the members, so
1137 /// a member that cannot sit beside its sibling takes a line of its own and
1138 /// fills it. For the two-member run this was ruled on -- a tab strip and a
1139 /// band -- that is precisely "a row becomes a column".
1140 ///
1141 /// [`Fallback::Shed`] and [`Fallback::Menu`] get wrap, and this renderer is
1142 /// honouring less than the description says. **CSS cannot express either one
1143 /// without breaking the ruling's own first constraint.** Both need to know that
1144 /// the run is out of room in order to take a member out of it, a container
1145 /// query is the only construct that can ask, and `@container` compares against
1146 /// a `<length>` -- there is no `@container (inline-size < min-content)`. So
1147 /// every honest spelling of Shed here needs an authored breakpoint, which is
1148 /// the thing the ruling exists to forbid, and the dishonest ones are worse: a
1149 /// clamped height clips by document order rather than by [`Priority`], and
1150 /// `display: none` under a viewport `@media` is the `nth-child(n+5)` bug the
1151 /// vocabulary replaced.
1152 ///
1153 /// Wrapping is the right thing to do instead. It keeps every member reachable,
1154 /// which is the property that was actually broken -- goingson's new-contact
1155 /// button left the viewport entirely at 560 -- and it keeps rule 1. A renderer
1156 /// answering with less than was described is precedented and deliberate here:
1157 /// [`makeover_layout::Region::Columns`] says a terminal stacking a board's
1158 /// columns is honouring the description rather than degrading it.
1159 ///
1160 /// The real mechanism needs the shed members to have somewhere to go, which is
1161 /// markup and belongs to quasi-webview: an overflow control is a member of the
1162 /// run, and the description does not yet say that a member *is* one.
1163 ///
1164 /// # Menu, once a script is measuring
1165 ///
1166 /// That is now built, in `quasi-webview`'s `menu.js`, and this crate's half of
1167 /// it is two classes and one override. A script that has taken a menu run over
1168 /// marks it `data-menu`, and a marked run goes back to `nowrap`: wrapping is
1169 /// what hides the overflow condition the script is trying to measure. The
1170 /// unmarked rule above is untouched, so a page that ships no script still
1171 /// wraps, which is rule 1 — every member reachable — rather than a strip with
1172 /// tabs squeezed off the end.
1173 ///
1174 /// `.run-overflow` is the control the shed members move into and
1175 /// `.run-overflow-items` is where they land. The geometry is this crate's the
1176 /// way every other surface's is; what is *in* it is the script's, because which
1177 /// members no longer fit is a measurement and not a description.
1178 fn run_rules(opts: &Emit) -> String {
1179 let run = class("run", opts);
1180 let mut css = String::new();
1181
1182 // `flex-wrap: nowrap` is stated rather than left to the default, because
1183 // the fallbacks below are read as overrides of this line and a reader
1184 // should not have to know which way flexbox leans to see that.
1185 //
1186 // No gap. Spacing between members is the app's, the same way this crate
1187 // states no margins anywhere else; a gap here would be a size, and the one
1188 // hardcoded size in the mechanism is makeover-geometry's contact patch.
1189 let _ = writeln!(
1190 css,
1191 ".{run} {{\n display: flex;\n flex-wrap: nowrap;\n align-items: center;\n}}"
1192 );
1193
1194 // The derived minimum, and the whole reason a member can no longer be
1195 // overlapped. `min-width: auto` is flexbox's default for a flex item and is
1196 // *not* the same thing: auto lets an item be compressed below its content
1197 // in a nowrap run, which is how a toolbar ends up drawn over a tab strip
1198 // even without anything leaving the flow.
1199 let _ = writeln!(css, ".{run} > * {{\n min-width: min-content;\n}}");
1200
1201 for fallback in [
1202 Fallback::Wrap,
1203 Fallback::Stack,
1204 Fallback::Shed,
1205 Fallback::Menu,
1206 ] {
1207 let name = fallback_class(fallback);
1208 let c = class(name, opts);
1209 let _ = writeln!(css, ".{c} {{\n flex-wrap: wrap;\n}}");
1210 if matches!(fallback, Fallback::Stack) {
1211 let _ = writeln!(css, ".{c} > * {{\n flex: 1 1 max-content;\n}}");
1212 }
1213 }
1214
1215 // A menu run a script has taken over. The mark is the script's and this is
1216 // the only rule that reads it: wrapping is what a run does when nothing is
1217 // measuring, and it is also what makes the overflow unmeasurable, since a
1218 // wrapped run always fits. The two cannot both be on.
1219 let menu = class(fallback_class(Fallback::Menu), opts);
1220 let _ = writeln!(css, ".{menu}[data-menu] {{\n flex-wrap: nowrap;\n}}");
1221
1222 // The overflow control, and it is a member of the run like any other: in
1223 // flow, at the end, taking the width of what is in it. `relative` is what
1224 // the items hang off.
1225 let overflow = class("run-overflow", opts);
1226 let items = class("run-overflow-items", opts);
1227 let _ = writeln!(css, ".{overflow} {{\n position: relative;\n}}");
1228
1229 // Overlaid rather than in flow, for the reason every menu is: a control
1230 // that pushed the page down when it opened would change the layout it was
1231 // opened to escape. `inset-inline-end: 0` rather than a left, so the panel
1232 // stays on the page in both writing directions.
1233 //
1234 // No width, no padding and no border. All three are sizes and sizes are
1235 // makeover-geometry's; what is stated here is placement, the surface and
1236 // the shadow that separates it from the page, which is the same division
1237 // `figure_rules` and the timeline entry make. The elevation shadow is what
1238 // an overlaid surface takes instead of an edge -- see `ELEVATION_PROPERTY`.
1239 let _ = writeln!(
1240 css,
1241 ".{items} {{\n \
1242 position: absolute;\n \
1243 inset-block-start: 100%;\n \
1244 inset-inline-end: 0;\n \
1245 z-index: 1;\n \
1246 display: flex;\n \
1247 flex-direction: column;\n \
1248 align-items: stretch;\n \
1249 background: var(--surface-raised);\n \
1250 box-shadow: var(--elevation-overlay);\n\
1251 }}"
1252 );
1253
1254 // `hidden` is how the script closes it, and a flex display would otherwise
1255 // beat the attribute's own `display: none`.
1256 let _ = writeln!(css, ".{items}[hidden] {{\n display: none;\n}}");
1257
1258 css
1259 }
1260
1261 /// Every class [`fallback_class`] can return, plus the run itself.
1262 ///
1263 /// [`ROW_PART_CLASSES`](crate::list::ROW_PART_CLASSES)'s reasoning and the same
1264 /// obligation: a `match` over a `#[non_exhaustive]` enum cannot be enumerated
1265 /// from outside, so the list sits beside it and a test holds the two together.
1266 /// `run` is in it because it is emitted in its own right rather than only as a
1267 /// fallback's fallback.
1268 pub const RUN_CLASSES: &[&str] = &[
1269 "run",
1270 "run-wrap",
1271 "run-stack",
1272 "run-shed",
1273 "run-menu",
1274 // Not returned by `fallback_class`: these two are the overflow control a
1275 // measuring renderer builds, and they are in the list because the list is
1276 // what a host seals its vocabulary against. A class emitted by a script and
1277 // missing from here is a control with no surface and no edge.
1278 "run-overflow",
1279 "run-overflow-items",
1280 ];
1281
1282 /// The class a run carries for what it does when it is tight.
1283 ///
1284 /// A run always carries `.run` as well, so an unrecognised fallback -- the enum
1285 /// is `#[non_exhaustive]` -- lands as a plain nowrap row with the min-content
1286 /// floor still under it. That is the safe failure: every member in flow and
1287 /// none overlapped, which is the property, with only the rearrangement missing.
1288 #[must_use]
1289 pub fn fallback_class(fallback: Fallback) -> &'static str {
1290 match fallback {
1291 Fallback::Wrap => "run-wrap",
1292 Fallback::Stack => "run-stack",
1293 Fallback::Shed => "run-shed",
1294 Fallback::Menu => "run-menu",
1295 _ => "run",
1296 }
1297 }
1298
1299 /// The progress trough these rules fill.
1300 ///
1301 /// This was renderer-local chrome with nothing behind it until makeover-layout
1302 /// 0.10.0, which is the unusual order: the tones below were emitted for every
1303 /// bar in the tree while the only way to describe one was to concatenate the
1304 /// numbers into a heading. `Meter` is the word that arrived late, and
1305 /// [`meter::meter_html`](crate::meter::meter_html) is what now fills these.
1306 ///
1307 /// The rules stay a superset of what a description can ask for. An app drawing
1308 /// its own bar keeps these classes, which is what the four goingson grew
1309 /// independently were adopted onto.
1310 ///
1311 /// The trough is a [`Depth::Well`], the same reading a text field gets:
1312 /// something with its content down inside it.
1313 fn progress_rules(opts: &Emit) -> String {
1314 let progress = class("progress", opts);
1315 // `progress-fill` rather than a bare `fill`: an unprefixed build claims
1316 // these names in the app's own stylesheet, and `.fill` is grabby enough to
1317 // catch things that have nothing to do with progress. goingson already
1318 // calls it `.progress-fill`, so this is also the name that deletes.
1319 let fill = class("progress-fill", opts);
1320 let mut css = depth_rule(&progress, Depth::Well);
1321
1322 // The untoned bar is `--action`, not [`Tone::Neutral`]. That is the one
1323 // place this differs from the badge rules, and deliberately: a badge with
1324 // no status is a muted label, while a bar with no status is still
1325 // reporting progress, and `content-muted` would read as disabled.
1326 let _ = writeln!(
1327 css,
1328 ".{progress} > .{fill} {{\n background: var(--action);\n}}"
1329 );
1330
1331 // A bar can be saying something, same as a badge: goingson colours subtask
1332 // progress as success and an over-estimate as danger, which is real
1333 // information rather than decoration. Emitting the tones is what lets that
1334 // survive adoption instead of staying hand-written.
1335 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1336 let _ = writeln!(
1337 css,
1338 ".{progress} > .{fill}[data-tone=\"{0}\"] {{\n background: var(--{0});\n}}",
1339 tone.token()
1340 );
1341 }
1342 css
1343 }
1344
1345 /// What a wait looks like, for the attribute that has been describing one to
1346 /// nobody.
1347 ///
1348 /// Wiki `loading-and-progress-standard`, phase 2. `data-awaiting` has been
1349 /// emitted since the vocabulary gained `Awaiting`, with
1350 /// `data-awaiting="determinate"` and a `data-awaiting-amount` beside it or
1351 /// `data-awaiting="indeterminate"` alone, and until 0.60.0 **nothing in the tree
1352 /// styled either**. Determinate and indeterminate rendered identically, which is
1353 /// to say not at all. This is the half that was missing.
1354 ///
1355 /// # Why it is keyed on `aria-busy` and not on the attribute alone
1356 ///
1357 /// `data-awaiting` is a fact about the control: pressing this waits. It is true
1358 /// when the page is painted and it stays true. Whether a wait is *running* is
1359 /// true only between two events, so it is the binder's to set, and `aria-busy`
1360 /// is the standard spelling of it — announced as well as drawn, which a class
1361 /// of our own would not be.
1362 ///
1363 /// That also keeps this crate out of any one client library's vocabulary.
1364 /// `quasi-webview` sets `aria-busy` from htmx's request events; a host driving
1365 /// the same markup another way sets it the same way and gets the same drawing.
1366 ///
1367 /// # The two drawings
1368 ///
1369 /// One pseudo-element either way, so no renderer has to emit an extra node.
1370 ///
1371 /// Indeterminate is the activity mark of rule 2: a small square that blinks.
1372 /// Determinate is a trough with a fill, drawn as a single gradient whose stop is
1373 /// `--awaiting-share`, a plain number from 0 to 1 that the binder sets from
1374 /// bytes it has actually watched land. A determinate control with nothing
1375 /// setting the share draws an empty trough rather than a full one, which is the
1376 /// honest reading: the size is known and the delivery is not.
1377 ///
1378 /// **What the bar may not do**, from rule 1 and from `Awaiting`'s own docs:
1379 /// what is done over what there is, and never a remaining time, an arrival time
1380 /// or a rate extrapolated forward. Nothing here can express one, which is
1381 /// deliberate — the only input is a share of a measured payload.
1382 ///
1383 /// # Sizes, and the deferral rule
1384 ///
1385 /// `progress_rules` emits the tones and never the width, because the width is
1386 /// not this crate's to know. A pseudo-element has no intrinsic size at all, so
1387 /// the same treatment would render nothing anywhere. Both sizes are therefore
1388 /// custom properties with defaults: an app that wants a different mark sets
1389 /// `--awaiting-mark` and `--awaiting-bar` once, and one that says nothing gets a
1390 /// mark that is visible.
1391 ///
1392 /// # The cadence, and what happens without it
1393 ///
1394 /// `--cadence-activity` comes from `makeover-timing` through `makeover-build`,
1395 /// and is a half-period, so a full cycle is twice it. It is used bare rather
1396 /// than with a fallback: a number written here would be a second heartbeat for
1397 /// a mark three renderers draw.
1398 ///
1399 /// A sheet assembled without the time axis leaves `animation-duration` invalid,
1400 /// which resolves to `0s`, which runs no animation and leaves the base style —
1401 /// a lit, still mark. That is also exactly what the reduced-motion block does,
1402 /// since it sets the cadence to `0ms`. Both fall out of one rule because the
1403 /// base style is lit and the keyframes do the dimming, which is the ordering
1404 /// `makeover_timing::reduced_motion_css` asks its consumers for by name.
1405 fn awaiting_rules(opts: &Emit) -> String {
1406 let mut css = String::new();
1407
1408 // Dimming rather than lighting, so a zero-length animation leaves a lit
1409 // mark rather than a blank one. See `makeover_timing::reduced_motion_css`.
1410 css.push_str(
1411 "@keyframes makeover-activity {\n \
1412 0%, 49.99% {\n background: var(--action);\n }\n \
1413 50%, 100% {\n background: var(--surface-sunken);\n }\n\
1414 }\n",
1415 );
1416
1417 // Nothing is drawn until something is waiting. `content` on the base rule
1418 // rather than on the busy one keeps the box the same box across the
1419 // transition, so a mark appearing does not reflow the line it is in.
1420 let _ = writeln!(
1421 css,
1422 "[data-awaiting]::after {{\n \
1423 content: \"\";\n \
1424 display: none;\n \
1425 margin-inline-start: var(--awaiting-gap, 0.5ch);\n \
1426 vertical-align: baseline;\n\
1427 }}"
1428 );
1429
1430 let _ = writeln!(
1431 css,
1432 "[data-awaiting][aria-busy=\"true\"]::after {{\n \
1433 display: inline-block;\n \
1434 inline-size: var(--awaiting-mark, 0.5em);\n \
1435 block-size: var(--awaiting-mark, 0.5em);\n \
1436 background: var(--action);\n \
1437 opacity: 1;\n \
1438 animation: makeover-activity calc(var(--cadence-activity) * 2) \
1439 step-end infinite;\n\
1440 }}"
1441 );
1442
1443 // The measured half. A wider box, no blink, and a gradient whose stop is
1444 // the share: the fill and the trough in one paint, so the markup stays one
1445 // pseudo-element on both branches.
1446 //
1447 // `--awaiting-share` unset is an empty trough, not a full one. A bar that
1448 // read full because nobody was counting would be the confidently-wrong
1449 // drawing rule 1 exists to forbid.
1450 //
1451 // The trough takes an edge for the reason a well does: a bar at zero share
1452 // is otherwise a rectangle of the surface it sits on, which is nothing at
1453 // all. `border_width` rather than a literal, the way `depth_rule` and
1454 // `track_rules` write theirs.
1455 let _ = writeln!(
1456 css,
1457 "[data-awaiting=\"determinate\"][aria-busy=\"true\"]::after {{\n \
1458 inline-size: var(--awaiting-bar, 6em);\n \
1459 animation: none;\n \
1460 outline: {} solid var(--border);\n \
1461 outline-offset: -{};\n \
1462 background: linear-gradient(\n \
1463 to inline-end,\n \
1464 var(--action) 0 calc(var(--awaiting-share, 0) * 100%),\n \
1465 var(--surface-sunken) 0\n \
1466 );\n\
1467 }}",
1468 opts.border_width, opts.border_width
1469 );
1470
1471 css
1472 }
1473
1474 /// A strip of figures, and the two spans inside each one.
1475 ///
1476 /// Colour only, which is the deferral rule applied to a component that badly
1477 /// wants to break it. A figure reads as a figure because the value is set large
1478 /// over a small caption, and that is a size: `makeover-geometry` answers how
1479 /// much space and this crate answers what the thing is. Emitting `font-size`
1480 /// here would be this crate naming a value, which is the one thing it is defined
1481 /// by not doing, and `progress_rules` is the precedent — it emits the tones and
1482 /// never the width, because the width is not its to know.
1483 ///
1484 /// So the arrangement and the type scale are the app's, and what is generated is
1485 /// the part an app cannot get right by itself: which of the two spans carries
1486 /// the tone.
1487 fn figure_rules(opts: &Emit) -> String {
1488 let figure = class("figure", opts);
1489 let value = class("figure-value", opts);
1490 let caption = class("figure-caption", opts);
1491 let change = class("figure-change", opts);
1492 let mut css = String::new();
1493
1494 // `content` literally. A figure's value is the thing itself, at full
1495 // weight -- wiki `three-tone-convention` classes it "active, emphasised",
1496 // and both other renderers already draw it that way (makeover-tui
1497 // `piece.rs:391` bold, makeover-immediate `widget.rs:244`). It reached
1498 // here through `Tone::Neutral.token()` and came out `content-muted`, so
1499 // the headline number sat at the colour of its own caption.
1500 let _ = writeln!(
1501 css,
1502 ".{figure} > .{value} {{\n color: var(--content);\n}}"
1503 );
1504 let _ = writeln!(
1505 css,
1506 ".{figure} > .{caption} {{\n color: var(--content-muted);\n}}"
1507 );
1508 let _ = writeln!(
1509 css,
1510 ".{figure} > .{change} {{\n color: var(--content-muted);\n}}"
1511 );
1512
1513 // A toned figure tones one part and never the caption. The caption is the
1514 // noun and stays muted.
1515 //
1516 // Which part depends on whether there is a change, and that is the whole of
1517 // what 0.13.0 changed here. A figure with a delta is an ordinary number that
1518 // has moved in a direction worth reading, so the delta takes the colour and
1519 // the number stays plain; a figure without one has nowhere else to put it.
1520 // `:has` is what lets one attribute mean both, and the alternative was the
1521 // emitter deciding by writing the attribute onto a different element, which
1522 // leaves two elements able to disagree about a figure's one meaning.
1523 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
1524 let _ = writeln!(
1525 css,
1526 ".{figure}[data-tone=\"{0}\"] > .{change} {{\n color: var(--{0});\n}}",
1527 tone.token()
1528 );
1529 let _ = writeln!(
1530 css,
1531 ".{figure}[data-tone=\"{0}\"]:not(:has(> .{change})) > .{value} \
1532 {{\n color: var(--{0});\n}}",
1533 tone.token()
1534 );
1535 }
1536 css
1537 }
1538
1539 /// A picture, its frame and its caption.
1540 ///
1541 /// `makeover_layout::Image` arrived at 0.21.0, found by trying to describe MNW's
1542 /// carousel and discovering nothing named a picture.
1543 ///
1544 /// # The frame is a border, and this is the one place a bevel is wrong
1545 ///
1546 /// 0.36.0 emitted [`Depth::Raised`] here through [`depth_rule`], the same call
1547 /// `button` and `card` make. It was wrong, and MNW's landing page is where it
1548 /// showed: **the frames had no visible edge at all.**
1549 ///
1550 /// `Depth::Raised`'s edge is `--bevel-raised`, which is an *inset* shadow — a
1551 /// 1px light run at the top-left and a dark one at the bottom-right, drawn
1552 /// **inside** the element's box. On a button or a card that box is a surface
1553 /// this crate owns, so an inset edge reads as the surface catching the light.
1554 /// On a picture it is drawn on top of the picture, over whatever pixels the
1555 /// image happens to have at its border. MNW's screenshots are light-on-light
1556 /// parchment, so the light half landed on a light image and the frame
1557 /// disappeared.
1558 ///
1559 /// **You cannot bevel a surface you do not own.** A picture's content is the
1560 /// app's, arrives at request time, and can be any colour, so its edge has to
1561 /// sit *outside* the content rather than on it. That is a border.
1562 ///
1563 /// The fill stays, and it is not decoration: it is what shows through a
1564 /// transparent PNG and what stands in the frame's place while the image is
1565 /// still loading.
1566 ///
1567 /// This is a real limit on [`Depth`] rather than a special case. Every other
1568 /// consumer of a depth draws its own surface; a picture is the first member
1569 /// whose surface belongs to someone else.
1570 ///
1571 /// # No size
1572 ///
1573 /// `width: 100%` and nothing else. How large a picture is depends on the box it
1574 /// was put in, which is the app's arrangement and `makeover-geometry`'s scales,
1575 /// and a renderer that picked one would be answering for every consumer at
1576 /// once. This is where `figure_rules` landed for the same reason.
1577 fn picture_rules(opts: &Emit) -> String {
1578 let picture = class("picture", opts);
1579 let img = class("picture-img", opts);
1580 let caption = class("picture-caption", opts);
1581 let mut css = String::new();
1582
1583 // Block, or an inline image sits on the text baseline and carries a
1584 // descender's worth of space under it that no app ever wants and every app
1585 // deletes by hand. The border is the frame; see the type docs for why it is
1586 // not the bevel every other surface here gets.
1587 let _ = writeln!(
1588 css,
1589 ".{img} {{\n display: block;\n width: 100%;\n height: auto;\n \
1590 background: var(--{});\n border: {} solid var(--border);\n}}",
1591 Fill::Raised.token(),
1592 opts.border_width
1593 );
1594
1595 // The two fits that need a rule. `Fit::Natural` emits no attribute at all,
1596 // so it is the bare rule above and needs nothing here.
1597 let _ = writeln!(
1598 css,
1599 ".{img}[data-fit=\"cover\"] {{\n height: 100%;\n object-fit: cover;\n}}"
1600 );
1601 let _ = writeln!(
1602 css,
1603 ".{img}[data-fit=\"contain\"] {{\n height: 100%;\n object-fit: contain;\n}}"
1604 );
1605
1606 // A caption reads back one step, which is `figure-caption`'s answer and the
1607 // same claim: it says what the thing above it is, and it is not the thing.
1608 let _ = writeln!(
1609 css,
1610 ".{picture} > .{caption} {{\n color: var(--content-muted);\n}}"
1611 );
1612
1613 css
1614 }
1615
1616 /// A region showing one child at a time, and the chrome that moves between them.
1617 ///
1618 /// [`makeover_layout::Showing`] lets a description say that a region holds
1619 /// several children and shows some of them. A renderer derives its own chrome
1620 /// from that, which is what stops every renderer growing a `match` on a widget
1621 /// name; these are the rules the derived chrome needs.
1622 ///
1623 /// # Why the default is every child, and the enhancement takes them away
1624 ///
1625 /// The controls are a lie until something binds them. A prev button rendered
1626 /// into a document with no script is a control that looks live and answers
1627 /// nothing, and the reader it lies to is exactly the one who cannot see the
1628 /// other children either — the collapsing and the moving are the same half.
1629 ///
1630 /// So the rules run in the direction the enhancement does. Nothing here hides a
1631 /// child and nothing here shows a control. Whatever binds the region sets
1632 /// `data-ready` on it, and that is what collapses the stack to one and reveals
1633 /// the row that moves it. A reader with no script gets every child in order and
1634 /// no controls, which is more content rather than less, and a reader with
1635 /// script gets a settled page rather than a stack that jumps to one frame after
1636 /// load.
1637 ///
1638 /// MNW proved this shape by hand — a `<noscript>` stylesheet opening its
1639 /// carousel back out — and it is here rather than there because the property is
1640 /// the description's, not one app's.
1641 ///
1642 /// # Not spacing
1643 ///
1644 /// The row's gaps are `makeover-geometry`'s question and are absent for
1645 /// [`row_rules`]'s reason. What is here is `display`, which carries no
1646 /// magnitude, and the muted readout, which is the same claim `picture-caption`
1647 /// makes: it says where you are among the children and it is not one of them.
1648 fn showing_rules(opts: &Emit) -> String {
1649 let controls = class("showing", opts);
1650 let position = class("showing-position", opts);
1651 let frame = class("showing-frame", opts);
1652 let mut css = String::new();
1653
1654 // Hidden until something binds it, which is the whole argument above.
1655 let _ = writeln!(css, ".{controls} {{\n display: none;\n}}");
1656 // Block, and nothing about how the three sit in it. A button and a span are
1657 // inline already, so they make a row without this crate saying so, and
1658 // saying so is where `align-items` and a gap would follow -- both spacing,
1659 // both `makeover-geometry`'s, and `row_rules` refuses them for the same
1660 // reason.
1661 let _ = writeln!(
1662 css,
1663 "[data-ready] > .{controls} {{\n display: block;\n}}"
1664 );
1665
1666 // A child is in flow until the region is bound, and then only the current
1667 // one is. `.current` is a modifier for the reason `.chosen` and `.latched`
1668 // are: one name for the state, set by whoever knows it.
1669 let _ = writeln!(
1670 css,
1671 "[data-ready] > .{frame}:not(.current) {{\n display: none;\n}}"
1672 );
1673
1674 // Reads back one step. `picture-caption`'s rule and its reason.
1675 let _ = writeln!(css, ".{position} {{\n color: var(--content-muted);\n}}");
1676
1677 css
1678 }
1679
1680 /// A time axis: the container, its gridlines and ruler, and the placed things.
1681 ///
1682 /// `makeover-layout` 0.24.0's [`Track`](makeover_layout::Track), and the first
1683 /// member here whose whole point is *position*. That makes the magnitude line
1684 /// this crate keeps worth restating rather than assuming.
1685 ///
1686 /// # Where the numbers come from
1687 ///
1688 /// Every value that varies per item is a custom property the caller sets
1689 /// inline, and every rule here reads one. `--track-at` and `--track-for` are
1690 /// percentages of the span, which
1691 /// [`Track::fraction`](makeover_layout::Track::fraction) computes once so three
1692 /// renderers cannot disagree about it. Nothing here knows a pixel.
1693 ///
1694 /// That is what lets the stylesheet stay static while the items move: an entry
1695 /// carries `style="--track-at: 37.5%; --track-for: 4.166%"` and the rule below
1696 /// turns it into a box. The alternative was emitting a rule per item, which is
1697 /// a stylesheet that grows with the data.
1698 ///
1699 /// **The height of the track is the app's**, not this crate's. 96 quarter-hour
1700 /// slots at some slot height is a size, and a size is `makeover-geometry`'s
1701 /// question -- the same refusal `figure_rules` and `placeholder_rules` make.
1702 /// Percentages need a resolved height above them, so `.track` gets
1703 /// `position: relative` and nothing else; the app says how tall a day is.
1704 ///
1705 /// # Overlap
1706 ///
1707 /// Two things at the same time is intrinsic to an axis and has no analogue in a
1708 /// list. The description does not declare it -- `Placement::overlaps` derives it
1709 /// from the times -- so what arrives here is a lane index and a lane count, and
1710 /// the rule divides the width. A renderer that would rather stack them ignores
1711 /// both properties and the defaults give it one full-width lane.
1712 fn track_rules(opts: &Emit) -> String {
1713 let track = class("track", opts);
1714 let slot = class("track-slot", opts);
1715 let tick = class("track-tick", opts);
1716 let entry = class("track-entry", opts);
1717 let mut css = String::new();
1718
1719 // The positioning context every entry resolves against, and the whole of
1720 // what this crate says about the container. No height: see the doc above.
1721 let _ = writeln!(css, ".{track} {{\n position: relative;\n}}");
1722
1723 // Gridlines and the ruler are the axis reading itself back, which is
1724 // `picture-caption` and `showing-position`'s claim: about the thing rather
1725 // than one of the things.
1726 //
1727 // `border_width` rather than a literal, the way `depth_rule` writes its
1728 // edge. A gridline is the one place a timeline would most naturally reach
1729 // for a hardcoded 1px, and a hardcoded 1px is this crate naming a size.
1730 let _ = writeln!(
1731 css,
1732 ".{slot} {{\n border-top: {} solid var(--border);\n}}",
1733 opts.border_width
1734 );
1735 let _ = writeln!(css, ".{tick} {{\n color: var(--content-muted);\n}}");
1736
1737 // The one rule that does real work. Top and height are the placement;
1738 // left and width are the lane. Both lane properties default so an entry
1739 // that names neither is full width, which is the common case and the one a
1740 // renderer gets for free.
1741 let _ = writeln!(
1742 css,
1743 ".{entry} {{\n \
1744 position: absolute;\n \
1745 top: var(--track-at, 0%);\n \
1746 height: var(--track-for, 100%);\n \
1747 left: calc(var(--track-lane, 0) / var(--track-lanes, 1) * 100%);\n \
1748 width: calc(100% / var(--track-lanes, 1));\n\
1749 }}"
1750 );
1751
1752 css
1753 }
1754
1755 /// A region's stand-in, and the header of a table that can be reordered.
1756 ///
1757 /// Both are 0.12.0 members and both are colour and affordance only, which is
1758 /// where `figure_rules` landed after trying to emit a type scale. How much room
1759 /// a stand-in gets is a size — goingson has the same one at three, as
1760 /// `--compact`, `--dashboard` and `--padded` — and a size is
1761 /// `makeover-geometry`'s question.
1762 ///
1763 /// The caret is the one thing here that is neither colour nor affordance, and it
1764 /// is a renderer's own expression rather than a value the description named:
1765 /// `aria-sort` is what the table actually says, and this turns it into something
1766 /// visible for everyone not using a screen reader. A terminal draws its own; an
1767 /// immediate-mode painter draws its own.
1768 fn state_rules(opts: &Emit) -> String {
1769 let placeholder = class("placeholder", opts);
1770 let text = class("placeholder-text", opts);
1771 let heading = class("table-heading", opts);
1772 let mut css = String::new();
1773
1774 let _ = writeln!(
1775 css,
1776 ".{placeholder} > .{text} {{\n color: var(--content-muted);\n}}"
1777 );
1778 // Only the failure is toned. An empty list is the normal state of a new
1779 // install, and `Readiness::tone` is what says so.
1780 let _ = writeln!(
1781 css,
1782 ".{placeholder}[data-tone=\"{0}\"] > .{text} {{\n color: var(--{0});\n}}",
1783 Tone::Danger.token()
1784 );
1785
1786 // A header that reorders the table is a control, and the pointer is the
1787 // only part of saying so that is not the app's own type and spacing.
1788 let _ = writeln!(
1789 css,
1790 ".{heading}[data-sortable] {{\n cursor: pointer;\n}}"
1791 );
1792 // The caret carries its own leading space, the way `makeover-tui` and
1793 // `makeover-immediate` both write `" \u{25B2}"`. It used to be emitted bare,
1794 // and both apps that adopted the vocabulary had to put the gap back in their
1795 // own stylesheets on the same afternoon -- each having to work out first that
1796 // app CSS outranks this crate's cascade layer, so adding the space the
1797 // obvious way, as `content`, silently wins over the glyph and leaves the
1798 // heading with no caret at all. A consumer should not have to know that, and
1799 // with the space emitted here there is nothing left for one to add.
1800 //
1801 // Three states, three tones, on the convention in wiki
1802 // `three-tone-convention`. A column in force is `content`; a column offering
1803 // to reorder and not doing it now is `content-secondary`, because it still
1804 // answers a press; a column that is not sortable emits no caret at all and
1805 // takes nothing. The idle arm used to hide its glyph and reserve the box,
1806 // which cost a reflow-free press and said nothing. It draws now, and the
1807 // reservation stops being a thing to get right.
1808 //
1809 // The glyph is `Sort::glyph`, escaped rather than written: a CSS `content`
1810 // string cannot carry the character literally through this file's own
1811 // escaping, and spelling it here as well would put the third copy back that
1812 // `makeover-layout` 0.27.5 exists to remove.
1813 let _ = writeln!(
1814 css,
1815 ".{heading}[data-sortable]::after \
1816 {{\n content: \" {}\";\n color: var(--content-secondary);\n}}",
1817 css_escape(Sort::Ascending.glyph())
1818 );
1819 for direction in [Sort::Ascending, Sort::Descending] {
1820 let _ = writeln!(
1821 css,
1822 ".{heading}[aria-sort=\"{}\"]::after \
1823 {{\n content: \" {}\";\n color: var(--content);\n}}",
1824 direction.as_str(),
1825 css_escape(direction.glyph())
1826 );
1827 }
1828 css
1829 }
1830
1831 /// The frame a table sits in.
1832 ///
1833 /// # Why this is a CSS table and not the grid the rest of the module assumes
1834 ///
1835 /// A grid row needs `grid-template-columns`, which has to name every column in
1836 /// order, so it cannot be written without knowing the columns. That is what
1837 /// [`list::narrowing_css`] is for, and it works: goingson builds `tables.css` in
1838 /// its own `build.rs` out of it, and nothing here changes that.
1839 ///
1840 /// It does not work for a table a *description* produced. Those columns are
1841 /// known at render time rather than at build time, and the rules would have to
1842 /// travel with the markup: a `<style>` element per table, which needs
1843 /// `style-src 'unsafe-inline'` and so blocks the MNW server's standing plan to
1844 /// drop it. The head is not an escape: a table swapped in by htmx after a
1845 /// delete arrives as a fragment with no head at all.
1846 ///
1847 /// A CSS table aligns its columns across rows knowing nothing about how many
1848 /// there are, so there is no track list to emit and nothing per-table to carry.
1849 /// The cost is that a described table cannot take a per-column fixed length,
1850 /// which costs nothing today: [`Sizing`](list::Sizing) is looked up by column
1851 /// name and a description carries no lengths to put in it, so every track a
1852 /// described table could ask for is already content, fill or auto.
1853 ///
1854 /// [`Priority`] hiding is unchanged in kind. It moves from a generated
1855 /// `display: none` per dropped column to one rule per drop class, which is the
1856 /// same fact addressed by class rather than by cutoff, and still never by
1857 /// position.
1858 fn table_rules(opts: &Emit) -> String {
1859 let table = class("table", opts);
1860 let head = class("table-head", opts);
1861 let row = class("table-row", opts);
1862 let heading = class("table-heading", opts);
1863 let cell = class("cell", opts);
1864 let mut css = String::new();
1865
1866 let _ = writeln!(
1867 css,
1868 ".{table} {{\n display: table;\n width: 100%;\n}}"
1869 );
1870 let _ = writeln!(css, ".{head},\n.{row} {{\n display: table-row;\n}}");
1871 // Scoped under `.{table}` rather than keyed on the classes alone. The
1872 // table model is what a cell takes *by being in a table*, and only there:
1873 // goingson's task headings are `.table-heading` inside a CSS grid, so the
1874 // unscoped rule reached them, and the sort caret and the sortable cursor
1875 // -- which `state_rules` keys on `.table-heading` and rightly still does
1876 // -- came with a `display` the grid had to blockify away.
1877 //
1878 // It costs no markup anywhere: quasi-webview always nests the heading
1879 // inside the table (`quasi-webview/src/node.rs:1591`, `:1605`, `:1615`).
1880 let _ = writeln!(
1881 css,
1882 ".{table} .{heading},\n.{table} .{cell} {{\n display: table-cell;\n}}"
1883 );
1884
1885 // A content column shrinks to what is in it. `width: 1%` is how a CSS table
1886 // is told that: auto layout hands the slack to the columns that asked for
1887 // room, and a column asking for almost none gets what it needs and no more.
1888 // The `nowrap` is what stops it being given less by wrapping.
1889 let _ = writeln!(
1890 css,
1891 ".{} {{\n white-space: nowrap;\n width: 1%;\n}}",
1892 class("cell-content", opts)
1893 );
1894
1895 // A fixed column has no length to be fixed to. The description carries none
1896 // and `Sizing` is not reachable from here, so it behaves as content: the
1897 // honest answer to a width nobody supplied, and the same one `Sizing::track`
1898 // gives it.
1899 let _ = writeln!(
1900 css,
1901 ".{} {{\n white-space: nowrap;\n}}",
1902 class("cell-fixed", opts)
1903 );
1904
1905 // Optional columns go at the narrowest class, secondary ones go with them,
1906 // which is the cutoff walk `kept_at` describes said as two media queries.
1907 // Essential columns have no rule at all, because never dropping is what not
1908 // being mentioned already means.
1909 for (size, drops) in [
1910 (
1911 SizeClass::Compact,
1912 &["cell-drops-first", "cell-drops-next"][..],
1913 ),
1914 (SizeClass::Medium, &["cell-drops-first"][..]),
1915 ] {
1916 let selectors: Vec<String> = drops
1917 .iter()
1918 .map(|drop| format!(".{}", class(drop, opts)))
1919 .collect();
1920 css.push_str(&gated(
1921 Some(&size.media_condition()),
1922 &format!("{} {{\n display: none;\n}}\n", selectors.join(",\n")),
1923 ));
1924 }
1925
1926 // What is inside a cell, which the table side could not say until
1927 // makeover-layout 0.14.0. Every cell was one `.cell` and one content
1928 // colour, so a button in a cell was painted as text -- the drift
1929 // `RowPart::intent` has prevented for list rows since 0.2.0 and prevented
1930 // for nothing here.
1931 //
1932 // The colour goes on `.cell-value` rather than on `.cell`, and that
1933 // placement is the whole fix. On the container it would cascade into the
1934 // tokens and the controls sitting beside the text, which is the bug said
1935 // in one rule; on the part that is text, it reaches text and stops.
1936 for part in [
1937 CellPart::Value,
1938 CellPart::Tokens,
1939 CellPart::Actions,
1940 CellPart::Link,
1941 ] {
1942 // Three of the four inherit, each for its own reason: a token carries
1943 // its own tone, an action is a control rather than text, and a link
1944 // takes the action colour from the anchor it is. `CellPart::intent`
1945 // says so by answering with the intent inheriting already gives, and
1946 // pinning that would be louder than saying nothing.
1947 //
1948 // Written as a skip-list rather than as a match on Value, so a member
1949 // added upstream gets its intent emitted rather than being silently
1950 // dropped. That is the same trade `part_class`'s fallback makes: land
1951 // plainly, never land as nothing.
1952 if !matches!(part, CellPart::Tokens | CellPart::Actions | CellPart::Link) {
1953 let _ = writeln!(
1954 css,
1955 ".{} {{\n color: var(--{});\n}}",
1956 class(cell_part_class(part), opts),
1957 part.intent()
1958 );
1959 }
1960 }
1961
1962 css
1963 }
1964
1965 /// The component layer: every named thing phase A emits.
1966 ///
1967 /// No scrollbar track. It was on the phase A list and came off: eight lines of
1968 /// `::-webkit-scrollbar` with no shape a terminal or an immediate-mode painter
1969 /// would want handed to it, so it stays with the apps.
1970 #[must_use]
1971 pub fn component_rules(opts: &Emit) -> String {
1972 let mut css = String::new();
1973 css.push_str(&surface_rules(opts));
1974 css.push_str(&link_rules(opts));
1975 css.push_str(&token_rules(opts));
1976 css.push_str(&selector_rules(opts));
1977 css.push_str(&row_rules(opts));
1978 css.push_str(&run_rules(opts));
1979 css.push_str(&progress_rules(opts));
1980 css.push_str(&awaiting_rules(opts));
1981 css.push_str(&figure_rules(opts));
1982 css.push_str(&picture_rules(opts));
1983 css.push_str(&showing_rules(opts));
1984 css.push_str(&track_rules(opts));
1985 css.push_str(&state_rules(opts));
1986 css.push_str(&table_rules(opts));
1987 css.push_str(&facet::facet_rules(opts));
1988 css.push_str(&form::editor_rules(opts));
1989 css.push_str(&form::suggestion_rules(opts));
1990 css.push_str(&form::unit_rules(opts));
1991 css.push_str(&form::option_detail_rules(opts));
1992 css.push_str(&form::note_rules(opts));
1993 css
1994 }
1995
1996 /// The whole phase-A stylesheet: properties, depth rules and components, in
1997 /// [`CSS_LAYER`], under a generated-file banner.
1998 ///
1999 /// The banner sits outside the layer, because a comment participates in no
2000 /// cascade and a reader opening the file should see what it is before seeing
2001 /// an at-rule.
2002 #[must_use]
2003 pub fn stylesheet(opts: &Emit) -> String {
2004 let body = in_css_layer(&format!(
2005 ":root {{\n{}}}\n\n{}\n{}",
2006 bevel_properties(opts),
2007 depth_rules(opts),
2008 component_rules(opts)
2009 ));
2010 // Counted from the body rather than through `vocabulary::names`, which
2011 // calls back into here.
2012 let classes = vocabulary::classes_in_css(&body).len();
2013 let version = VERSION;
2014 format!(
2015 "/* Generated by makeover-webview {version} from makeover-layout, \
2016 {classes} classes.\n \
2017 Do not edit. The version and the count are here because a stale\n \
2018 lockfile fails silently: an older emitter writes a well-formed sheet\n \
2019 with components missing, and nothing else in the file says so. If\n \
2020 this version trails what the manifest asks for, re-resolve.\n\n \
2021 Depth is a fill and an edge together; naming them apart is what let\n \
2022 them disagree. See the crate's README and wiki note makeover-layout.\n\n \
2023 Everything below is in the `{CSS_LAYER}` cascade layer. Declare the\n \
2024 order once in your own stylesheet, or this layer's position is decided\n \
2025 by whichever generated file the browser happens to see first:\n\n \
2026 @layer {CSS_LAYER}, base, components, responsive; */\n{body}"
2027 )
2028 }
2029
2030 #[cfg(test)]
2031 mod tests {
2032 use super::*;
2033 use makeover_layout::Edge;
2034
2035 #[test]
2036 fn every_fallback_class_is_one_a_checker_knows_about() {
2037 // The obligation ROW_PART_CLASSES carries, for the same reason: a class
2038 // this crate can write and the vocabulary list does not carry is
2039 // invisible to the dead-vocabulary seal and to the overlap check both.
2040 for fallback in [
2041 Fallback::Wrap,
2042 Fallback::Stack,
2043 Fallback::Shed,
2044 Fallback::Menu,
2045 ] {
2046 assert!(
2047 RUN_CLASSES.contains(&fallback_class(fallback)),
2048 "{fallback:?} is missing from RUN_CLASSES"
2049 );
2050 }
2051 let names = crate::vocabulary::names(&Emit::default());
2052 for name in RUN_CLASSES {
2053 assert!(names.contains(*name), "{name} is not in the vocabulary");
2054 }
2055 }
2056
2057 #[test]
2058 fn a_run_gives_every_member_a_floor_it_cannot_be_squeezed_below() {
2059 // The whole of what stops the overlap, and it is not a fallback: it
2060 // applies to every run whatever the group declared. flexbox's default
2061 // min-width is auto, which lets an item be compressed below its own
2062 // content in a nowrap row, and that is how a toolbar is drawn over a
2063 // tab strip even with nothing out of flow.
2064 let css = run_rules(&Emit::default());
2065 assert!(css.contains(".run > * {\n min-width: min-content;\n}"));
2066 // No number anywhere in it. The minimum is derived by the browser from
2067 // what the members contain, which is the ruling's own requirement.
2068 assert!(!css.contains("px"));
2069 assert!(!css.contains("rem"));
2070 assert!(!css.contains("@media"));
2071 }
2072
2073 #[test]
2074 fn room_is_never_asked_of_the_viewport() {
2075 // The 913 case: a window in SizeClass::Expanded holding a group out of
2076 // room. A viewport query answers about the window and would be wrong
2077 // about the group, which is why the table's @media walk is not the
2078 // precedent this follows.
2079 let css = run_rules(&Emit::default());
2080 for size in [SizeClass::Compact, SizeClass::Medium] {
2081 assert!(!css.contains(&size.media_condition()));
2082 }
2083 }
2084
2085 #[test]
2086 fn every_fallback_lands_as_a_class_and_an_unknown_one_lands_plainly() {
2087 let css = run_rules(&Emit::default());
2088 for fallback in [
2089 Fallback::Wrap,
2090 Fallback::Stack,
2091 Fallback::Shed,
2092 Fallback::Menu,
2093 ] {
2094 let class = fallback_class(fallback);
2095 assert!(css.contains(&format!(".{class} {{")), "{class} unemitted");
2096 }
2097 // Stack is the one that also says what a member does with the line it
2098 // took, which is what separates it from wrapping.
2099 assert!(css.contains(".run-stack > * {\n flex: 1 1 max-content;\n}"));
2100 }
2101
2102 #[test]
2103 fn the_emitted_bevel_matches_what_the_apps_already_hand_write() {
2104 // Balanced Breakfast's styles.css, verbatim. Adoption has to be a
2105 // deletion, not a redesign, or nobody will take it.
2106 let opts = Emit::default();
2107 assert_eq!(
2108 bevel_shadow(Bevel::Raised, &opts),
2109 "inset 1px 1px 0 var(--bevel-light), inset -1px -1px 0 var(--bevel-dark)"
2110 );
2111 assert_eq!(
2112 bevel_shadow(Bevel::Inset, &opts),
2113 "inset 1px 1px 0 var(--bevel-dark), inset -1px -1px 0 var(--bevel-light)"
2114 );
2115 }
2116
2117 #[test]
2118 fn no_colour_ever_reaches_the_output() {
2119 let css = stylesheet(&Emit::default());
2120 assert!(!css.contains('#'), "a hex literal escaped into the CSS");
2121 assert!(
2122 !css.contains("rgb"),
2123 "a colour function escaped into the CSS"
2124 );
2125 // Every colour is named, never resolved.
2126 assert!(css.contains("var(--surface-raised)"));
2127 assert!(css.contains("var(--bevel-light)"));
2128 }
2129
2130 #[test]
2131 fn a_well_falls_back_through_css_rather_than_through_rust() {
2132 assert_eq!(
2133 fill_var(Fill::Well),
2134 "var(--surface-well, var(--surface-page))"
2135 );
2136 // Nothing else needs one.
2137 assert_eq!(fill_var(Fill::Raised), "var(--surface-raised)");
2138 assert_eq!(fill_var(Fill::Page), "var(--surface-page)");
2139 }
2140
2141 #[test]
2142 fn raised_and_well_do_not_collapse_onto_each_other() {
2143 let css = depth_rules(&Emit::default());
2144 assert!(css.contains(".raised {"));
2145 assert!(css.contains(".well {"));
2146 assert!(css.contains("var(--bevel-raised)"));
2147 assert!(css.contains("var(--bevel-inset)"));
2148 }
2149
2150 /// The cast shadow is composed here from the tone `makeover` derives, so
2151 /// neither crate has to hold the other's numbers.
2152 ///
2153 /// It is a `:root` property and deliberately not a depth class. There is no
2154 /// `Depth::Overlay` in the description layer, and adding one would be a
2155 /// claim about what a screen means rather than about how it is painted;
2156 /// until something asks for it, a consumer names the property on the rule
2157 /// for the menu or the toast it already has.
2158 #[test]
2159 fn the_cast_shadow_is_a_root_property_not_a_depth() {
2160 let css = bevel_properties(&Emit::default());
2161 assert!(css.contains("--elevation-overlay:"));
2162 assert!(css.contains("var(--elevation)"));
2163 assert!(
2164 !depth_rules(&Emit::default()).contains("elevation"),
2165 "elevation is not a depth class"
2166 );
2167 }
2168
2169 #[test]
2170 fn the_cascade_carries_the_pressed_state() {
2171 let css = surface_rules(&Emit::default());
2172 // The one thing this renderer gets free that the other two resolve by
2173 // hand, eighteen call sites deep in audiofiles' case. Asserted on a
2174 // named surface: pressing belongs to the control, not to the depth.
2175 assert!(css.contains(".card:active {"));
2176 assert!(css.contains(".button:active {"));
2177 }
2178
2179 #[test]
2180 fn the_depth_class_is_a_surface_and_not_a_control() {
2181 let css = depth_rules(&Emit::default());
2182 // The static surface the vocabulary was missing. Sixteen goingson
2183 // elements wore .card and cancelled its hover and press to get this,
2184 // because a raised object that is not pressable had no other spelling.
2185 for state in [":hover", ":active", ":focus-visible", ":disabled"] {
2186 assert!(
2187 !css.contains(&format!(".raised{state}")),
2188 "the depth class claimed {state}: {css}"
2189 );
2190 }
2191 assert!(css.contains("var(--bevel-raised)"), "still raised: {css}");
2192 }
2193
2194 #[test]
2195 fn pressing_moves_the_fill_and_not_only_the_edge() {
2196 // The decision-1 guard, and the regression that mattered: emitting the
2197 // bevel flip alone is what left goingson hand-writing `background:
2198 // var(--surface-sunken)` on .btn, .card and .tag/.badge alike, so none
2199 // of the three could be deleted.
2200 let pressed = interactive_rules("button", Depth::Raised, &Emit::default());
2201 assert!(pressed.contains(".button:active {"));
2202 assert!(
2203 pressed.contains("background: var(--surface-well, var(--surface-page))"),
2204 "pressed dropped its fill: {pressed}"
2205 );
2206 assert!(pressed.contains("box-shadow: var(--bevel-inset)"));
2207 }
2208
2209 #[test]
2210 fn pressed_takes_its_fill_from_the_description_not_from_the_app() {
2211 // goingson presses to --surface-sunken. The description says a pressed
2212 // raised region reads as a well, and makeover says outright that
2213 // surface-sunken cannot serve as one, so the app is the thing that
2214 // moves.
2215 //
2216 // Scoped to the pressed rules rather than to the whole sheet: since
2217 // makeover-layout 0.3.0 an unchosen tab is legitimately
2218 // --surface-sunken, so the token appearing somewhere in the output no
2219 // longer means the app's choice leaked in.
2220 let css = stylesheet(&Emit::default());
2221 let mut checked = 0;
2222 for rule in css.split("}\n") {
2223 if !rule.contains(":active") {
2224 continue;
2225 }
2226 checked += 1;
2227 assert!(
2228 !rule.contains("surface-sunken"),
2229 "a pressed rule took the app's fill: {rule}"
2230 );
2231 }
2232 assert!(checked > 0, "no pressed rules found to check");
2233 assert_eq!(
2234 Depth::Raised.pressed().fill(),
2235 Some(Fill::Well),
2236 "the description changed under us"
2237 );
2238 }
2239
2240 #[test]
2241 fn the_whole_stylesheet_is_emitted_in_the_family_layer() {
2242 // The point of 0.11.0. Unlayered normal declarations outrank every
2243 // named layer, so an app declaring `@layer base, components` loses
2244 // every rule it owns to this file until this file is layered too.
2245 let css = stylesheet(&Emit::default());
2246 assert!(css.contains(&format!("@layer {CSS_LAYER} {{")));
2247
2248 // Exactly one layer block, and nothing outside it but the banner.
2249 assert_eq!(css.matches("@layer").count(), 2, "banner names it once");
2250 let opened = css.find("@layer makeover {").expect("layer opens");
2251 for (i, line) in css.lines().enumerate() {
2252 let before_layer = css.lines().take(i).map(str::len).sum::<usize>() < opened;
2253 if before_layer || line.is_empty() {
2254 continue;
2255 }
2256 assert!(
2257 line.starts_with(" ") || line == "}" || line.starts_with(" "),
2258 "line outside the layer: {line:?}"
2259 );
2260 }
2261 }
2262
2263 #[test]
2264 fn the_generated_sheet_carries_no_trailing_whitespace() {
2265 // A checked-in generated file that a formatter wants to rewrite is a
2266 // diff every time somebody saves it.
2267 let css = stylesheet(&Emit::default());
2268 for (i, line) in css.lines().enumerate() {
2269 assert_eq!(line, line.trim_end(), "trailing whitespace on line {i}");
2270 }
2271 }
2272
2273 #[test]
2274 fn the_banner_tells_an_app_how_to_order_the_layer() {
2275 // Without a declared order the layer's position depends on which
2276 // generated file the browser sees first, which is not a contract.
2277 let css = stylesheet(&Emit::default());
2278 assert!(css.contains("@layer makeover, base, components, responsive;"));
2279 // And the banner is outside the layer, not a rule inside it.
2280 assert!(css.starts_with("/* Generated by makeover-webview"));
2281 }
2282
2283 #[test]
2284 fn the_banner_names_the_emitter_so_a_stale_pin_is_visible_on_sight() {
2285 // A consumer whose lockfile pins an old version gets a well-formed
2286 // sheet with components missing and no error. balanced_breakfast ran
2287 // on 657 bytes from a 0.1.0 emitter while its manifest asked for
2288 // 0.5.1, and the only way it surfaced was diffing two apps' generated
2289 // files. The version and the count are what the file says instead.
2290 let css = stylesheet(&Emit::default());
2291 let banner = css.lines().next().unwrap();
2292 assert!(
2293 banner.contains(VERSION),
2294 "{banner} does not name the emitter"
2295 );
2296 let classes = vocabulary::classes_in_css(&css).len();
2297 assert!(classes > 0);
2298 assert!(
2299 banner.contains(&format!("{classes} classes")),
2300 "{banner} does not carry the class count"
2301 );
2302 }
2303
2304 #[test]
2305 fn a_primitive_owns_every_state_it_implies() {
2306 // The whole point of 0.10.0. Anything emitting a hover rule owes the
2307 // other three, or the consuming app supplies them by out-specifying a
2308 // rule it does not own: 19 such rules in goingson, 21 in the MNW
2309 // server, and three focus rings that do not match.
2310 let css = stylesheet(&Emit::default());
2311 for selector in ["button", "card", "chip", "tab", "segment", "toggle"] {
2312 assert!(css.contains(&format!(".{selector}:hover {{")), "{selector}");
2313 assert!(
2314 css.contains(&format!(".{selector}:active {{")),
2315 "{selector}"
2316 );
2317 assert!(
2318 css.contains(&format!(".{selector}:focus-visible {{")),
2319 "{selector} has no focus ring"
2320 );
2321 assert!(
2322 css.contains(&format!(".{selector}:disabled,")),
2323 "{selector} has no disabled state"
2324 );
2325 }
2326 }
2327
2328 #[test]
2329 fn a_field_takes_focus_and_refuses_input_without_taking_a_hover() {
2330 // A text field does not light up under the pointer, so it gets the two
2331 // states it has and not the two it does not.
2332 let css = stylesheet(&Emit::default());
2333 assert!(css.contains(".field:focus-visible {"));
2334 assert!(css.contains(".field:disabled,"));
2335 assert!(!css.contains(".field:hover {"));
2336 assert!(!css.contains(".field:active {"));
2337 }
2338
2339 #[test]
2340 fn disabled_is_emitted_after_hover_so_source_order_settles_it() {
2341 // Every one of these selectors is specificity (0,2,0), so nothing but
2342 // order decides which wins. A disabled button taking the hover fill is
2343 // the exact bug goingson's `.button:disabled:hover` was written to fix,
2344 // and the reason it had to reach (0,3,0) to do it.
2345 let css = interactive_rules("button", Depth::Raised, &Emit::default());
2346 let hover = css.find(":hover").expect("hover");
2347 let active = css.find(":active").expect("active");
2348 let focus = css.find(":focus-visible").expect("focus");
2349 let disabled = css.find(":disabled").expect("disabled");
2350 assert!(hover < active && active < focus && focus < disabled);
2351
2352 // And it restores the surface, or the hover fill survives underneath.
2353 let tail = &css[disabled..];
2354 assert!(tail.contains("background: var(--surface-raised)"));
2355 }
2356
2357 #[test]
2358 fn a_disabled_state_reaches_things_that_cannot_be_disabled() {
2359 // `:disabled` matches form elements only, and a chip is a div. Keying
2360 // on the ARIA attribute too is the pattern the invalid field already
2361 // set: one fact, read by the styling and the accessibility tree alike.
2362 let css = disabled_rule("chip", Depth::Raised);
2363 assert!(css.contains(".chip:disabled,"));
2364 assert!(css.contains(".chip[aria-disabled=\"true\"]"));
2365 assert!(css.contains("cursor: not-allowed"));
2366 }
2367
2368 #[test]
2369 fn the_focus_ring_does_not_disturb_the_bevel_it_lands_on() {
2370 // `outline` has its own property, so unlike the invalid ring there is
2371 // no bevel to restate beside it and nothing to keep in agreement.
2372 let opts = Emit::default();
2373 let css = focus_rule("button", Depth::Raised, &opts);
2374 assert!(css.contains("outline: 2px solid var(--focus-ring)"));
2375 assert!(!css.contains("box-shadow"), "the ring restated the bevel");
2376 }
2377
2378 #[test]
2379 fn a_well_takes_the_ring_inside_and_a_raised_surface_outside() {
2380 // One ring, placed by depth. The offset comes off `Depth::bevel` and
2381 // not off a per-component choice, which is what gave three apps three
2382 // different rings.
2383 let opts = Emit::default();
2384 assert!(focus_rule("field", Depth::Well, &opts).contains("outline-offset: calc(-1 * 2px)"));
2385 assert!(focus_rule("button", Depth::Raised, &opts).contains("outline-offset: 2px"));
2386 // Nothing to sit inside of, so it sits outside.
2387 assert!(focus_rule("badge", Depth::Sunken, &opts).contains("outline-offset: 2px"));
2388
2389 // And the ring is not the bevel. Reusing border_width emitted a 1px
2390 // ring that every consumer had already overridden.
2391 assert_ne!(opts.focus_width, opts.border_width);
2392 }
2393
2394 #[test]
2395 fn hover_is_gated_on_capability_and_the_keyboard_path_is_not() {
2396 // goingson's section 60 exists only to take back the hover state this
2397 // crate handed it. Gating at the source is what deletes that section
2398 // in all three apps rather than having each fight for it.
2399 let css = stylesheet(&Emit::default());
2400 let condition = format!("@media {}", Density::Pointer.media_condition());
2401 assert!(css.contains(&condition));
2402
2403 // What is gated is every hover state the surfaces carry. The row's
2404 // actions used to be the other half of this test and are not gated any
2405 // more, because they are not hidden any more: a rule that reveals
2406 // nothing needs no capability answer.
2407 let gated: Vec<&str> = css.lines().filter(|line| line.contains(":hover")).collect();
2408 assert!(!gated.is_empty(), "{css}");
2409 for line in gated {
2410 let indent = line.len() - line.trim_start().len();
2411 assert!(indent > 4, "an ungated hover rule: {line}");
2412 }
2413 assert!(!css.contains(".row:hover"), "{css}");
2414 }
2415
2416 #[test]
2417 fn the_capability_answer_is_asked_for_and_not_assumed() {
2418 // Both halves come from the crates that own them. If `makeover-touch`
2419 // ever says a fingertip has hover, this stops gating on its own.
2420 assert!(!Affordance::Hover.available(Density::Touch, SizeClass::Compact));
2421 assert!(Affordance::Hover.available(Density::Pointer, SizeClass::Compact));
2422 assert_eq!(hover_condition(), Some(Density::Pointer.media_condition()));
2423
2424 // And the size class passed to that call is not a claim about width.
2425 assert!(Affordance::Hover.reads_density());
2426 for size in [SizeClass::Compact, SizeClass::Medium, SizeClass::Expanded] {
2427 assert!(!Affordance::Hover.available(Density::Touch, size));
2428 }
2429 }
2430
2431 #[test]
2432 fn hover_resolves_against_the_token_makeover_already_derives() {
2433 let css = interactive_rules("card", Depth::Raised, &Emit::default());
2434 assert!(css.contains(".card:hover {"));
2435 assert!(css.contains("background: var(--hover-surface)"));
2436 // Not the app's choice, which was --surface-overlay.
2437 assert!(!css.contains("surface-overlay"));
2438 }
2439
2440 #[test]
2441 fn a_badge_gets_no_edge_and_no_fill() {
2442 // Decision 2, and the one visible redesign in phase A. Token::Badge is
2443 // Flat: an edge on a label says it can be pressed.
2444 let css = token_rules(&Emit::default());
2445 let badge = css
2446 .lines()
2447 .skip_while(|l| !l.starts_with(".badge {"))
2448 .take_while(|l| !l.starts_with('}'))
2449 .collect::<Vec<_>>()
2450 .join("\n");
2451 assert!(!badge.contains("box-shadow"), "badge kept an edge: {badge}");
2452 assert!(!badge.contains("background"), "badge kept a fill: {badge}");
2453 assert_eq!(Token::Badge.depth(false), Depth::Flat);
2454 assert_eq!(Token::Badge.depth(true), Depth::Flat);
2455 }
2456
2457 #[test]
2458 fn a_badge_carries_a_tone_and_neutral_is_the_bare_class() {
2459 let css = token_rules(&Emit::default());
2460 // Neutral is the absence of a status, not a status named "none".
2461 assert!(css.contains(".badge {\n color: var(--content-muted);"));
2462 assert!(!css.contains("data-tone=\"content-muted\""));
2463 for tone in ["info", "success", "warning", "danger"] {
2464 assert!(
2465 css.contains(&format!(".badge[data-tone=\"{tone}\"]")),
2466 "missing tone {tone}"
2467 );
2468 assert!(css.contains(&format!("color: var(--{tone})")));
2469 }
2470 }
2471
2472 #[test]
2473 fn a_chip_is_raised_and_latches_into_a_well() {
2474 let css = token_rules(&Emit::default());
2475 assert!(css.contains(".chip {"));
2476 assert!(css.contains(".chip.latched {"));
2477 assert!(css.contains(".chip:active {"));
2478 // The whole difference from a badge: it answers a click.
2479 assert!(Token::Chip { removable: false }.interactive());
2480 assert!(!Token::Badge.interactive());
2481 }
2482
2483 #[test]
2484 fn only_a_tab_comes_forward_when_chosen() {
2485 // The folder semantic. Collapsing the three selectors would lose it.
2486 let css = selector_rules(&Emit::default());
2487 assert!(css.contains(".tab.chosen {"));
2488 assert!(css.contains(".segment.chosen {"));
2489 assert!(css.contains(".toggle.chosen {"));
2490 assert_eq!(Selector::Tabs.chosen(), Depth::Raised);
2491 assert_eq!(Selector::Segmented.chosen(), Depth::Well);
2492 assert_eq!(Selector::Toggle.chosen(), Depth::Well);
2493
2494 let tab = css
2495 .lines()
2496 .skip_while(|l| !l.starts_with(".tab.chosen {"))
2497 .take_while(|l| !l.starts_with('}'))
2498 .collect::<Vec<_>>()
2499 .join("\n");
2500 assert!(
2501 tab.contains("var(--bevel-raised)"),
2502 "tab was held in: {tab}"
2503 );
2504 }
2505
2506 #[test]
2507 fn an_unchosen_tab_recedes_without_looking_picked() {
2508 let css = selector_rules(&Emit::default());
2509 // Recessed by colour and given no edge. An edge would make every option
2510 // look picked; flat would leave the chosen one nothing to come forward
2511 // from, which is the gap makeover-layout 0.3.0 closed.
2512 assert!(
2513 css.contains(".tab {\n background: var(--surface-sunken);\n}"),
2514 "unchosen tab is not recessed: {css}"
2515 );
2516 assert_eq!(Selector::Tabs.unchosen(), Depth::Sunken);
2517 assert!(css.contains(".tab:hover {"));
2518 }
2519
2520 #[test]
2521 fn a_segment_stands_up_so_the_chosen_one_can_be_held_in() {
2522 // The inverse of the tab, and why the three selectors are not one
2523 // member with a flag.
2524 let css = selector_rules(&Emit::default());
2525 assert!(css.contains(".segment {\n background: var(--surface-raised);"));
2526 assert_eq!(Selector::Segmented.unchosen(), Depth::Raised);
2527 assert_eq!(Selector::Segmented.chosen(), Depth::Well);
2528 }
2529
2530 #[test]
2531 fn a_rows_actions_are_shown_at_rest() {
2532 let css = row_rules(&Emit::default());
2533
2534 // The hover reveal is gone, and with it every escape it needed. What
2535 // it hid was hidden from pointer users alone, who are the ones
2536 // scanning a list to learn what can be done to a row.
2537 assert!(!css.contains("opacity"), "{css}");
2538 assert!(!css.contains("pointer-events"), "{css}");
2539 assert!(!css.contains(":hover"), "{css}");
2540 assert!(!css.contains(":focus-within"), "{css}");
2541
2542 // Nor is it hidden any other way. `display: none` would reflow the row
2543 // and `visibility: hidden` would take the actions out of the focus
2544 // order; the point is that neither is reached for.
2545 assert!(!css.contains("display: none"), "{css}");
2546 assert!(!css.contains("visibility:"), "{css}");
2547 }
2548
2549 #[test]
2550 fn a_figures_tone_lands_on_the_delta_when_there_is_one() {
2551 // 0.13.0. The delta is the part that reads as good or bad; the number
2552 // itself is an ordinary fact. A figure with no delta has nowhere else to
2553 // put the colour, so the value takes it, and `:has` is what lets one
2554 // attribute mean both without the emitter choosing an element.
2555 let css = stylesheet(&Emit::default());
2556
2557 assert!(
2558 css.contains(".figure[data-tone=\"success\"] > .figure-change"),
2559 "{css}"
2560 );
2561 assert!(
2562 css.contains(
2563 ".figure[data-tone=\"success\"]:not(:has(> .figure-change)) > .figure-value"
2564 ),
2565 "{css}"
2566 );
2567 // The caption is the noun and never takes the tone.
2568 assert!(
2569 !css.contains("[data-tone=\"success\"] > .figure-caption"),
2570 "{css}"
2571 );
2572 }
2573
2574 #[test]
2575 fn the_three_text_parts_take_their_intents_and_actions_inherits() {
2576 let css = row_rules(&Emit::default());
2577 assert!(css.contains(".row-primary {\n color: var(--content);"));
2578 assert!(css.contains(".row-secondary {\n color: var(--content-secondary);"));
2579 assert!(css.contains(".row-meta {\n color: var(--content-muted);"));
2580 // Actions carry controls, not text. Pinning the colour it would inherit
2581 // anyway is louder than saying nothing.
2582 assert!(!css.contains(".row-actions {\n color:"));
2583 }
2584
2585 #[test]
2586 fn the_token_strip_takes_no_colour_of_its_own() {
2587 // makeover-layout 0.9.0. A token carries its own tone, so a colour on
2588 // the strip would be a rule fighting the things sitting in it -- the
2589 // same reasoning as actions, reached for a different reason.
2590 let css = row_rules(&Emit::default());
2591 assert!(!css.contains(".row-tokens {\n color:"));
2592 }
2593
2594 #[test]
2595 fn an_unknown_row_part_renders_plainly_rather_than_failing_to_build() {
2596 // What `#[non_exhaustive]` bought and what it cost. `part_class` can no
2597 // longer be exhaustive, so a member added upstream lands as a bare
2598 // class with no rule instead of stopping the build. Asserting the
2599 // fallback exists is what keeps it from being written as `unreachable!`
2600 // by someone who reads the match as closed.
2601 assert_eq!(part_class(RowPart::Tokens), "row-tokens");
2602 assert_eq!(part_class(RowPart::Meta), "row-meta");
2603 }
2604
2605 #[test]
2606 fn a_link_takes_the_action_colour_the_theme_actually_defines() {
2607 // `--action-primary` shipped here for months and no theme has ever
2608 // defined it, so every `.link` dropped its colour declaration outright
2609 // and fell back to inherited text. Nothing caught it because the sheet
2610 // is valid CSS either way; MNW's no-undefined-token lint is what found
2611 // it, 2026-08-14. The hover arm two lines below was always `--action-hover`,
2612 // which is what makes the typo legible in hindsight.
2613 let css = link_rules(&Emit::default());
2614 assert!(css.contains("color: var(--action);"));
2615 assert!(!css.contains("--action-primary"));
2616 assert!(css.contains("color: var(--action-hover);"));
2617 }
2618
2619 #[test]
2620 fn the_progress_trough_is_a_well() {
2621 let css = progress_rules(&Emit::default());
2622 assert!(css.contains(".progress {"));
2623 assert!(css.contains("box-shadow: var(--bevel-inset)"));
2624 assert!(css.contains(".progress > .progress-fill {"));
2625 assert!(css.contains("background: var(--action)"));
2626 // A bare `.fill` would catch things that have nothing to do with
2627 // progress once the sheet lands unprefixed.
2628 assert!(!css.contains("> .fill "));
2629 }
2630
2631 #[test]
2632 fn a_progress_bar_can_carry_a_tone_and_defaults_to_action() {
2633 let css = progress_rules(&Emit::default());
2634 // Untoned is --action, not Tone::Neutral's content-muted: a bar with no
2635 // status is still reporting progress, and muted would read as disabled.
2636 assert!(css.contains(".progress > .progress-fill {\n background: var(--action);"));
2637 assert!(!css.contains("progress-fill {\n color: var(--content-muted)"));
2638 for tone in ["info", "success", "warning", "danger"] {
2639 assert!(
2640 css.contains(&format!(".progress > .progress-fill[data-tone=\"{tone}\"]")),
2641 "missing progress tone {tone}"
2642 );
2643 }
2644 // goingson's two live cases, which is why the tones are emitted at all.
2645 assert!(css.contains("[data-tone=\"success\"] {\n background: var(--success);"));
2646 assert!(css.contains("[data-tone=\"danger\"] {\n background: var(--danger);"));
2647 }
2648
2649 #[test]
2650 fn no_scrollbar_track_is_emitted() {
2651 // Decision 3's negative half. It was on the phase A list and came off;
2652 // this is what stops it drifting back in.
2653 let css = stylesheet(&Emit::default());
2654 assert!(!css.contains("scrollbar"));
2655 assert!(!css.contains("::-webkit"));
2656 }
2657
2658 #[test]
2659 fn an_invalid_field_is_ringed_without_being_lit() {
2660 let css = surface_rules(&Emit::default());
2661 assert!(css.contains(".field {"));
2662 // The ARIA attribute, not a class: one fact, read by both the visual
2663 // and the accessible state, so they cannot drift.
2664 assert!(css.contains(".field[aria-invalid=\"true\"] {"));
2665 assert!(!css.contains(".field.invalid"));
2666 // A flat ring: this edge says "wrong", and a two-tone bevel would have
2667 // it say "raised" at the same time.
2668 assert!(css.contains("0 0 0 1px var(--danger)"));
2669 }
2670
2671 #[test]
2672 fn an_invalid_field_keeps_the_well_underneath_it() {
2673 // box-shadow is not additive. A lone ring replaces the bevel and drops
2674 // the well out from under the field, which is what this emitted before
2675 // 0.5.0 and is the whole reason the rule composes.
2676 let css = surface_rules(&Emit::default());
2677 let invalid = css
2678 .lines()
2679 .skip_while(|l| !l.starts_with(".field[aria-invalid"))
2680 .take_while(|l| !l.starts_with('}'))
2681 .collect::<Vec<_>>()
2682 .join("\n");
2683 assert!(
2684 invalid.contains("var(--bevel-inset)"),
2685 "the well was dropped: {invalid}"
2686 );
2687 assert!(invalid.contains("var(--danger)"));
2688 }
2689
2690 #[test]
2691 fn button_and_card_come_out_identical_by_construction() {
2692 // The duplication phase A deletes. They are the same composition, so
2693 // the only honest way to emit both is from one call.
2694 let opts = Emit::default();
2695 let css = surface_rules(&opts);
2696 assert_eq!(
2697 depth_declarations(Depth::Raised),
2698 depth_declarations(Depth::Raised)
2699 );
2700 assert!(css.contains(".button {"));
2701 assert!(css.contains(".card {"));
2702 assert_eq!(
2703 interactive_rules("button", Depth::Raised, &Emit::default()).replace("button", "card"),
2704 interactive_rules("card", Depth::Raised, &Emit::default())
2705 );
2706 }
2707
2708 #[test]
2709 fn a_prefix_reaches_the_component_classes_too() {
2710 let opts = Emit {
2711 class_prefix: "mo-",
2712 ..Emit::default()
2713 };
2714 let css = stylesheet(&opts);
2715 for name in [
2716 "mo-button",
2717 "mo-card",
2718 "mo-field",
2719 "mo-badge",
2720 "mo-chip",
2721 "mo-tab",
2722 "mo-row-primary",
2723 "mo-progress",
2724 "mo-progress-fill",
2725 ] {
2726 assert!(css.contains(&format!(".{name}")), "unprefixed: {name}");
2727 }
2728 // The bare names must be gone entirely, or a prefixed build still
2729 // collides with the app's own stylesheet.
2730 assert!(!css.contains(".button {"));
2731 assert!(!css.contains(".card {"));
2732 assert!(!css.contains(".badge {"));
2733 }
2734
2735 #[test]
2736 fn the_class_a_renderer_puts_on_an_option_is_the_one_the_rules_key_off() {
2737 // `option_class` is the contract a screen renderer writes markup
2738 // against, and the rules below are the other half of it. They come off
2739 // one mapping now, so this asserts the mapping is the one that reaches
2740 // the stylesheet rather than that two lists still agree.
2741 let css = stylesheet(&Emit::default());
2742 for selector in [Selector::Tabs, Selector::Segmented, Selector::Toggle] {
2743 let name = option_class(selector);
2744 assert!(css.contains(&format!(".{name} {{")), "{name}: {css}");
2745 assert!(css.contains(&format!(".{name}.chosen {{")), "{name}: {css}");
2746 }
2747 assert_eq!(option_class(Selector::Tabs), "tab");
2748 }
2749
2750 #[test]
2751 fn the_caret_brings_its_own_gap_and_is_the_glyph_the_description_names() {
2752 let css = stylesheet(&Emit::default());
2753
2754 // The space is inside the glyph, which is what the other two renderers
2755 // write. Emitted bare, every consumer has to add it back, and the
2756 // obvious way to add it -- `content` in an app stylesheet, which is
2757 // unlayered and so outranks this sheet -- deletes the caret instead.
2758 assert!(css.contains("content: \" \\25B2\";"), "{css}");
2759 assert!(css.contains("content: \" \\25BC\";"), "{css}");
2760 assert!(!css.contains("content: \"\\2"), "{css}");
2761
2762 // The arrows this renderer used to draw alone are gone. Composition
2763 // rather than agreement: the glyph comes from `Sort::glyph`, so a
2764 // fourth spelling cannot appear here without appearing everywhere.
2765 assert!(!css.contains("2191") && !css.contains("2193"), "{css}");
2766 assert!(css.contains(&css_escape(Sort::Ascending.glyph())), "{css}");
2767
2768 // Three states, three tones. An idle sortable heading draws its caret
2769 // now rather than reserving a hidden box for it, so there is no
2770 // visibility to order and no reflow left to guard against; what
2771 // separates the states is the colour, and the sorted arms come after
2772 // the idle one because the specificity is the same.
2773 let idle = css
2774 .find(".table-heading[data-sortable]::after")
2775 .expect("the idle caret is emitted");
2776 let sorted = css
2777 .find(".table-heading[aria-sort=\"ascending\"]::after")
2778 .expect("the ascending caret is emitted");
2779 assert!(idle < sorted, "{css}");
2780 assert!(
2781 css[idle..sorted].contains("color: var(--content-secondary);"),
2782 "{css}"
2783 );
2784 assert!(css[sorted..].contains("color: var(--content);"), "{css}");
2785 assert!(!css.contains("visibility: hidden;"), "{css}");
2786 }
2787
2788 #[test]
2789 fn a_destructive_button_has_somewhere_for_its_tone_to_land() {
2790 let css = component_rules(&Emit::default());
2791
2792 for tone in [Tone::Info, Tone::Success, Tone::Warning, Tone::Danger] {
2793 assert!(
2794 css.contains(&format!(".button[data-tone=\"{}\"]", tone.token())),
2795 "{css}"
2796 );
2797 }
2798 // Colour, not a fill. A red surface is an app's decision about emphasis.
2799 assert!(!css.contains(".button[data-tone=\"danger\"] {\n background"));
2800 }
2801
2802 #[test]
2803 fn the_table_model_is_scoped_to_the_table_but_the_caret_is_not() {
2804 // goingson's task headings are `.table-heading` inside a CSS grid.
2805 // They want the sort caret and the sortable cursor; they do not want
2806 // `display: table-cell`, which a grid item blockifies away anyway.
2807 // Scoping the one and not the other is what separates them.
2808 let css = component_rules(&Emit::default());
2809
2810 assert!(
2811 css.contains(".table .table-heading,\n.table .cell {\n display: table-cell;"),
2812 "{css}"
2813 );
2814 assert!(
2815 !css.contains(".table-heading,\n.cell {\n display: table-cell;"),
2816 "the table model is still unscoped: {css}"
2817 );
2818
2819 let states = state_rules(&Emit::default());
2820 assert!(
2821 states.contains(".table-heading[aria-sort"),
2822 "the caret got scoped along with the model: {states}"
2823 );
2824 }
2825
2826 #[test]
2827 fn a_figure_value_is_the_thing_itself_and_a_badge_is_quiet() {
2828 // Both used to read `Tone::Neutral.token()`, which answered
2829 // `content-muted`, so the headline number sat at the colour of its own
2830 // caption. Neutral answers `content` now; each site states its own
2831 // claim rather than borrowing one from the status axis.
2832 let css = component_rules(&Emit::default());
2833
2834 assert!(
2835 css.contains(".figure > .figure-value {\n color: var(--content);"),
2836 "{css}"
2837 );
2838 assert!(
2839 css.contains(".figure > .figure-caption {\n color: var(--content-muted);"),
2840 "{css}"
2841 );
2842 assert!(
2843 css.contains(".badge {\n color: var(--content-muted);"),
2844 "{css}"
2845 );
2846 }
2847
2848 #[test]
2849 fn a_described_list_is_not_a_bulleted_list() {
2850 let css = component_rules(&Emit::default());
2851 assert!(css.contains(".list {\n list-style: none;"), "{css}");
2852 }
2853
2854 #[test]
2855 fn a_table_lays_itself_out_without_being_told_its_columns() {
2856 // The whole point of the CSS table. A described table's columns are
2857 // known at render time, so anything the stylesheet has to be told about
2858 // them would have to travel with the markup.
2859 let css = component_rules(&Emit::default());
2860
2861 assert!(css.contains(".table {\n display: table;"), "{css}");
2862 assert!(css.contains("display: table-row;"), "{css}");
2863 assert!(css.contains("display: table-cell;"), "{css}");
2864 assert!(!css.contains("grid-template-columns"), "{css}");
2865 }
2866
2867 #[test]
2868 fn a_control_in_a_cell_is_not_painted_as_text() {
2869 // The point of makeover-layout 0.14.0's CellPart, and the table-side
2870 // twin of `the_three_text_parts_take_their_intents_and_actions_inherits`
2871 // above. One `.cell` and one content colour meant a button in a cell
2872 // inherited it.
2873 let css = table_rules(&Emit::default());
2874
2875 assert!(
2876 css.contains(".cell-value {\n color: var(--content);"),
2877 "{css}"
2878 );
2879 assert!(!css.contains(".cell-actions {\n color:"), "{css}");
2880 assert!(!css.contains(".cell-tokens {\n color:"), "{css}");
2881 assert!(!css.contains(".cell-link {\n color:"), "{css}");
2882
2883 // The colour is on the part that is text, never on the container. On
2884 // `.cell` it would cascade into the three parts that are not text,
2885 // which is the bug written as one rule.
2886 assert!(!css.contains(".cell {\n color:"), "{css}");
2887 }
2888
2889 #[test]
2890 fn an_unknown_cell_part_renders_plainly_rather_than_failing_to_build() {
2891 // `part_class`'s obligation, taken on for the table side too. CellPart
2892 // is `#[non_exhaustive]`, so a member added upstream must land as a
2893 // bare class rather than as a build that stops.
2894 assert_eq!(cell_part_class(CellPart::Value), "cell-value");
2895 assert_eq!(cell_part_class(CellPart::Actions), "cell-actions");
2896 }
2897
2898 #[test]
2899 fn a_column_drops_by_its_priority_and_never_by_its_position() {
2900 let css = component_rules(&Emit::default());
2901
2902 // Optional goes at the narrowest class and secondary goes with it,
2903 // which is `kept_at`'s cutoff walk said as two queries.
2904 let compact = css
2905 .find(&format!("@media {}", SizeClass::Compact.media_condition()))
2906 .expect("a compact query");
2907 let medium = css
2908 .find(&format!("@media {}", SizeClass::Medium.media_condition()))
2909 .expect("a medium query");
2910 assert!(css[compact..].contains(".cell-drops-next"), "{css}");
2911 assert!(!css[medium..].contains(".cell-drops-next"), "{css}");
2912
2913 // Essential columns are never mentioned, because not being mentioned is
2914 // already what never dropping means.
2915 assert!(!css.contains(".cell-keeps"), "{css}");
2916
2917 // And nothing counts. `nth-child` is the bug the priority vocabulary
2918 // exists to end.
2919 assert!(!css.contains("nth-child"), "{css}");
2920 }
2921
2922 #[test]
2923 fn a_track_places_by_custom_property_and_never_by_a_size() {
2924 let css = track_rules(&Emit::default());
2925
2926 // Placement arrives from the caller, computed once by Track::fraction.
2927 // If either of these becomes a literal, three renderers have started
2928 // disagreeing about where 09:30 is.
2929 assert!(css.contains("top: var(--track-at"), "{css}");
2930 assert!(css.contains("height: var(--track-for"), "{css}");
2931
2932 // Overlap lanes default so an entry naming neither is full width.
2933 assert!(css.contains("--track-lane, 0"), "{css}");
2934 assert!(css.contains("--track-lanes, 1"), "{css}");
2935
2936 // The refusal that matters. A slot height here would be this crate
2937 // deciding how tall a quarter of an hour is, which is the thing
2938 // makeover-geometry owns and the reason `.track` gets no height at all.
2939 assert!(!css.contains("height: var(--track-slot"), "{css}");
2940 for size in ["px", "rem", "em", "vh"] {
2941 let bare = css
2942 .lines()
2943 .filter(|l| !l.contains("var(--"))
2944 .any(|l| l.contains(size));
2945 assert!(!bare, "track_rules named a {size} outside a var(): {css}");
2946 }
2947 }
2948
2949 #[test]
2950 fn a_relaxed_part_clamps_and_a_tight_one_says_nothing() {
2951 let css = stylesheet(&Emit::default());
2952 assert!(css.contains(".row-relaxed {"));
2953 assert!(css.contains("-webkit-line-clamp: 2;"));
2954 // The count is `Flow`'s, not this crate's. If the tier ever means three
2955 // lines, this fails here rather than in an app.
2956 assert!(css.contains(&format!("line-clamp: {};", Flow::Relaxed.lines())));
2957 // Tight gets no rule at all: one line is what a run already does, and a
2958 // class per part saying so is a declaration that changes nothing.
2959 assert!(!css.contains("row-tight"));
2960 assert_eq!(crate::list::flow_class(Flow::Relaxed), Some("row-relaxed"));
2961 assert_eq!(crate::list::flow_class(Flow::Tight), None);
2962 // Emitted, therefore checkable: an app's dead-vocabulary seal and the
2963 // overlap check both read `vocabulary::names`, so a class the renderer
2964 // can write and that list does not carry is invisible to both.
2965 assert!(crate::vocabulary::names(&Emit::default()).contains("row-relaxed"));
2966 }
2967
2968 #[test]
2969 fn the_two_kinds_of_wait_stop_rendering_identically() {
2970 // The state `d43ea1c5` fixes: the emitter had been writing
2971 // `data-awaiting` for months and nothing styled either value, so a
2972 // measured wait and an unmeasured one drew the same nothing.
2973 let css = stylesheet(&Emit::default());
2974 assert!(css.contains("[data-awaiting]::after"), "{css}");
2975 assert!(
2976 css.contains("[data-awaiting][aria-busy=\"true\"]::after"),
2977 "the mark is drawn only while something is actually waiting"
2978 );
2979 assert!(
2980 css.contains("[data-awaiting=\"determinate\"][aria-busy=\"true\"]::after"),
2981 "the measured half is its own drawing"
2982 );
2983 }
2984
2985 #[test]
2986 fn the_blink_takes_its_cadence_and_never_names_one() {
2987 // Three renderers draw this mark. A number written here would be a
2988 // second heartbeat for one wait.
2989 let css = stylesheet(&Emit::default());
2990 assert!(
2991 css.contains("calc(var(--cadence-activity) * 2)"),
2992 "a half-period doubled, not a literal"
2993 );
2994 assert!(!css.contains("500ms"), "{css}");
2995 }
2996
2997 #[test]
2998 fn a_bar_nobody_is_counting_is_empty_rather_than_full() {
2999 // Rule 1. The share defaults to zero, so a determinate control with no
3000 // binder watching bytes draws a trough. A default of 1 would be the
3001 // confidently-wrong drawing the rule exists to forbid.
3002 let css = stylesheet(&Emit::default());
3003 assert!(css.contains("var(--awaiting-share, 0)"), "{css}");
3004 }
3005
3006 #[test]
3007 fn motion_off_leaves_the_mark_lit_because_the_keyframes_do_the_dimming() {
3008 // `makeover_timing::reduced_motion_css` sets `--cadence-activity: 0ms`,
3009 // and a zero-length animation leaves the element in its base style
3010 // rather than at its last keyframe. So the base has to be the lit one.
3011 // The inverted spelling would blank the mark for a reader who asked for
3012 // less motion, which answers a request nobody made.
3013 let css = stylesheet(&Emit::default());
3014 let busy = css
3015 .split("[data-awaiting][aria-busy=\"true\"]::after {")
3016 .nth(1)
3017 .expect("the busy rule");
3018 let busy = busy.split('}').next().expect("its body");
3019 assert!(
3020 busy.contains("background: var(--action);"),
3021 "the base state is lit: {busy}"
3022 );
3023 }
3024
3025 #[test]
3026 fn the_whole_sheet_still_names_every_colour() {
3027 // The crate's founding property, asserted over the component layer and
3028 // not only the primitives.
3029 let css = stylesheet(&Emit::default());
3030 assert!(!css.contains('#'));
3031 assert!(!css.contains("rgb"));
3032 for line in css.lines() {
3033 // Declarations only: a selector or an at-rule can carry a colon of
3034 // its own (`:root`, `:hover`, `@media (hover: hover)`) and declares
3035 // nothing. Keyed on the trailing semicolon rather than on leading
3036 // indentation, which only ever worked as a proxy for nesting depth
3037 // and stopped when the sheet gained a cascade layer around it.
3038 let trimmed = line.trim();
3039 if !trimmed.ends_with(';') {
3040 continue;
3041 }
3042 let Some((_, value)) = trimmed.split_once(": ") else {
3043 continue;
3044 };
3045 if value.contains("var(--") {
3046 continue;
3047 }
3048 // Everything left has to be a keyword, a number or a
3049 // caller-supplied length, never a colour.
3050 //
3051 // The length arm is what the comment above always claimed and the
3052 // list never covered: `border_width` arrives from `Emit` and lands
3053 // bare in the focus ring's offset, where the bevel had only ever
3054 // used it inside an `inset` shadow.
3055 let opts = Emit::default();
3056 assert!(
3057 value.contains("inset")
3058 || value.contains(opts.border_width)
3059 || value.contains(opts.focus_width)
3060 // 0.12.0's two: a sortable header is a control and says so
3061 // with the pointer, and the caret is this renderer's own
3062 // expression of `aria-sort`. Neither is a colour, which is
3063 // what this test is actually about, and neither is a size,
3064 // which is the other thing this crate must not name. The
3065 // leading space inside the glyph is the same thing the other
3066 // two renderers write into theirs, so it is part of the
3067 // caret rather than spacing this crate decided on.
3068 || value
3069 .trim_start_matches('"')
3070 .trim_start()
3071 .starts_with("\\2")
3072 || matches!(
3073 value.trim_end_matches(';'),
3074 "0" | "1"
3075 // The wait's mark and bar, 0.60.0. An empty
3076 // `content` is what brings a pseudo-element into
3077 // existence with nothing in it, and `step-end`
3078 // is an easing: the blink is two states, not a
3079 // slide between them. Neither is a colour, and
3080 // neither is a magnitude.
3081 | "\"\""
3082 // Where the mark sits on the line it joins.
3083 // Alignment is structure, the same way `display`
3084 // is, and `baseline` is the initial value said out
3085 // loud so a host stylesheet cannot leave it
3086 // wherever an earlier rule put it.
3087 | "baseline"
3088 | "inline-block"
3089 | "none"
3090 | "auto"
3091 | "not-allowed"
3092 | "pointer"
3093 // The caret's reserved box. Visibility is presence,
3094 // not magnitude and not colour.
3095 | "hidden"
3096 | "visible"
3097 // The link's two signals. `underline` is a line and
3098 // `inherit` defers to whatever the app set, so
3099 // neither names a colour or a magnitude.
3100 | "underline"
3101 | "inherit"
3102 // The table frame. `display` is structure and not a
3103 // size; `nowrap` is what makes a content column
3104 // content. The two widths are the awkward pair and
3105 // they are still not sizes: `100%` is "all of
3106 // whatever you were given" and `1%` is the CSS
3107 // table idiom for "shrink to fit", which is a
3108 // behaviour spelled as a number because CSS has no
3109 // keyword for it. Neither names a magnitude, which
3110 // is the thing this crate leaves to
3111 // makeover-geometry.
3112 | "table"
3113 | "table-row"
3114 | "table-cell"
3115 | "nowrap"
3116 | "100%"
3117 | "1%"
3118 // The time axis, 0.42.0. `position` is the one
3119 // property whose whole job is where a thing sits,
3120 // which is exactly what this crate spent its life
3121 // refusing to say -- so it is worth being exact
3122 // about why these two are not that refusal
3123 // breaking.
3124 //
3125 // Neither names a magnitude. `relative` says the
3126 // track is what its entries resolve against, and
3127 // `absolute` says an entry is placed rather than
3128 // flowed. *Where* each entry lands is
3129 // `--track-at` and `--track-for`, custom
3130 // properties the caller sets from
3131 // `Track::fraction`, and they are skipped by the
3132 // `var(--` arm above like every other value this
3133 // crate refuses to decide.
3134 //
3135 // The rule that would break the refusal is a slot
3136 // height, and there is none: the track's height is
3137 // the app's, so the percentages have something to
3138 // resolve against and this crate still never says
3139 // how tall a day is.
3140 | "relative"
3141 | "absolute"
3142 // A run's five, 0.49.0. `flex`, `wrap` and
3143 // `center` are structure and alignment, the same
3144 // reading `table` gets: which way members are laid
3145 // out and how they line up, never how much of
3146 // anything.
3147 //
3148 // The two intrinsic keywords are the interesting
3149 // pair and they are the opposite of a size. A
3150 // magnitude is a number somebody chose;
3151 // `min-content` and `max-content` are the browser
3152 // being asked what the members themselves come to,
3153 // which is the derived minimum the room ruling
3154 // requires and the reason no breakpoint appears
3155 // anywhere in these rules. `1 1 max-content` is
3156 // grow, shrink and that basis, so its two digits
3157 // are ratios rather than lengths.
3158 | "flex"
3159 | "wrap"
3160 | "center"
3161 | "min-content"
3162 | "1 1 max-content"
3163 // A menu run's overflow control, 0.64.0.
3164 // `column` and `stretch` are the same reading
3165 // `flex` and `center` get one line up: which way
3166 // the shed members stack inside the panel and how
3167 // they line up across it. Neither is a magnitude.
3168 //
3169 // `100%` is already above and reused here as the
3170 // panel's `inset-block-start`, which is "the whole
3171 // of the control it hangs from" rather than a
3172 // distance anybody picked.
3173 | "column"
3174 | "stretch"
3175 // A picture's three, 0.36.0. `block` is structure
3176 // for the reason `table` is: an inline image sits
3177 // on the baseline and carries a descender's worth
3178 // of space under it, which is a fact about
3179 // replaced elements rather than a size this crate
3180 // chose. `cover` and `contain` are `Fit`'s two
3181 // named members reaching CSS unchanged, which is
3182 // an intent arriving rather than a value being
3183 // picked.
3184 | "block"
3185 | "cover"
3186 | "contain"
3187 // A relaxed part's three, and the third is the
3188 // awkward one. `-webkit-box` and `vertical` are
3189 // structure: they say the part is a box of lines
3190 // stacked downward, which is the only way CSS lets
3191 // anyone ask for a clamp at all.
3192 //
3193 // `2` is a count of lines, not a length. The
3194 // distinction this crate holds is between naming a
3195 // magnitude -- a padding, a height, a font size,
3196 // all of which belong to makeover-geometry -- and
3197 // naming how many of something there are. A line's
3198 // height is still the app's, so two lines is
3199 // whatever two of the app's lines come to, and
3200 // nothing here decides how tall that is. It is also
3201 // not a value picked here: it is `Flow::Relaxed`'s
3202 // own answer arriving unchanged, the same way
3203 // `cover` and `contain` are `Fit`'s.
3204 | "-webkit-box"
3205 | "vertical"
3206 | "2"
3207 ),
3208 "unrecognised literal value: {line}"
3209 );
3210 }
3211 }
3212
3213 #[test]
3214 fn flat_emits_nothing_at_all() {
3215 assert_eq!(depth_class(Depth::Flat, &Emit::default()), None);
3216 assert!(!depth_rules(&Emit::default()).contains("flat"));
3217 }
3218
3219 #[test]
3220 fn a_prefix_namespaces_every_class() {
3221 let opts = Emit {
3222 class_prefix: "mo-",
3223 ..Emit::default()
3224 };
3225 let css = depth_rules(&opts);
3226 assert!(css.contains(".mo-raised {"));
3227 assert!(css.contains(".mo-well {"));
3228 assert!(!css.contains(".raised {"));
3229 }
3230
3231 #[test]
3232 fn the_border_width_is_the_callers() {
3233 let opts = Emit {
3234 border_width: "2px",
3235 ..Emit::default()
3236 };
3237 assert!(bevel_shadow(Bevel::Raised, &opts).contains("inset 2px 2px 0"));
3238 }
3239
3240 #[test]
3241 fn edges_agree_with_the_description() {
3242 // Not a tautology: it is the guard that a CSS-shaped convenience never
3243 // quietly reverses which side is lit.
3244 let (tl, br) = Bevel::Raised.edges();
3245 assert_eq!(tl.token(), Edge::Light.token());
3246 assert_eq!(br.token(), Edge::Dark.token());
3247 }
3248 }
3249