Phase 6, steps 1 and 2. The app had no notion of window width at all -- two
`BoxWithConstraints` in 30,000 lines of UI, both inside a view model -- so every
layout decision in it was made once, for a phone, and then rendered unchanged
into a 1800dp desktop window.
**The dependency question the plan asked to settle first.** `material3-adaptive`
publishes multiplatform under `org.jetbrains.compose.material3.adaptive`, with
android, desktop and ios variants; the ios ones carry `ios_arm64` and
`ios_simulator_arm64` attributes despite the `uikit*` artifact names, so the
targets this project declares on a mac resolve. Version **1.2.0**, not the newer
1.3.0-beta02, because that is the version the pinned material3 itself resolves:
`material3-adaptive-navigation-suite:1.10.0-alpha05` names `adaptive:1.2.0` in
its pom, and 1.3.0 would pull window-core 1.5.0 in beside the 1.4.0 the pinned
material3 compiled against. Nothing is lost by staying: 1.2.0 already computes
the large and extra-large breakpoints through `supportLargeAndXLargeWidth`, and
carries `ListDetailPaneScaffold` for the pane work. So steps 3-4 can use the
library scaffolds rather than a hand-rolled equivalent.
**`Breakpoint`** is the five-value enum -- compact / medium / expanded / large /
extra-large at 0 / 600 / 840 / 1200 / 1600dp -- with `ofWidth` as a pure function
so the thresholds are assertable without a Compose runtime. `TorchTheme`
classifies once and provides `LocalBreakpoint`, so no two screens can disagree
about the window they are both in.
It reads `currentWindowDpSize()` rather than `currentWindowAdaptiveInfo()`.
The latter also computes a `Posture` from the platform's fold state, which on
android reaches for `WindowInfoTracker` and an activity; this call sits in
`TorchTheme`, which wraps all 51 `@Preview` bodies in the tree, and a preview
context is not an activity. The pane scaffolds ask for posture themselves, at
the one place a fold changes the answer.
**Spacing now adapts, and exactly one value moves.** M3 publishes a margin per
breakpoint -- 16dp compact, 24dp everywhere wider -- and publishes nothing else
that varies with window width. The scale itself is absolute: `space200` is 16dp
on a phone and 16dp on a desktop, and what adapts is which token a job reaches
for, not the token. So `screenMargin` goes 16 -> 24 at medium and holds there,
and `containerPadding`, `itemGap` and the rest do not move -- a card does not
become a different component because the window grew. Widening all of them is
the "everything breathes on a big screen" instinct, and it reads as a zoomed
phone rather than as a layout. A test asserts the non-movement, because that is
the edit a later reviewer would wave through.
Mechanically this made the eight semantic names constructor parameters instead
of `get()`s over the scale, so a breakpoint can reassign one without moving the
stop underneath it. Kotlin resolves a default expression against the parameters
before it, so each still reads its stop by name and still follows it when the
scale is overridden -- phase 2's `Spacing(space200 = 24.dp)` assertion holds
unchanged. The two instances are singletons because `LocalSpacing` is a
`staticCompositionLocalOf` and invalidates on identity, not equality.
**A test found a real defect while being written.** `ofWidth` was
`entries.last { width >= it.minWidth }`, which throws `NoSuchElementException`
below 0dp. A desktop window reports a zero size for the frame before its first
layout pass, and this is called from the theme on every composition, so the
crash would have arrived on a resize rather than on anything a user did. Now
total.
`:composeApp:compileDebugKotlinAndroid` and `:composeApp:compileKotlinJvm` both
green; 28 theme tests pass.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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