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