Skill Claude CodeCodex
A custom window title bar, splash, or crash dialog composed as a sibling of the app theme rather than inside it reads MaterialTheme's framework DEFAULT scheme — light, always, no matter what the user picked — and nothing errors. Covers extracting the stored-mode-to-boolean decision as one shared composable function so…
Skill Claude CodeCodex
Find and fix CI steps that only ever passed by timing luck — an asynchronous detach of a same-name mounted volume colliding with the next iteration's mount, and a downloader that quietly saves an error page as the artifact; reach for it when a step that ran green for months starts failing after a runner image update…
Skill Claude CodeCodex
Lay out a Kotlin Multiplatform app in layers that actually hold — a domain module carrying interfaces and models, repository implementations kept internal to the data module, and one module per external integration so a breaking service cannot spread — plus how to verify each boundary with a grep instead of trusting…
Skill Claude CodeCodex
Deleting the dependent rows that exist only to serve a state at the exact transition that ends that state — rather than leaving them to a later bulk sweep — and why a foreign key cannot do this for you when only a flag changes. Reach for it when tables grow without bound and nothing ever deletes from them, when rows…
Skill Claude CodeCodex
Build a collapsing header from five siblings in one box — four sharing a single scroll state, one driven by a boolean instead — with artwork moved by a graphics layer at half the scroll rate, a title interpolated along a two-segment curve into the pinned bar, and a derived flip point that swaps the floating back…
Skill Claude CodeCodex
Turn several independent condition flows into one on/off gate with combine + distinctUntilChanged + collectLatest, make both the start and the teardown branch idempotent, and run teardown uncancellably. Use when a subsystem starts before it is fully configured, keeps running after one of its preconditions is…
Skill Claude CodeCodex
A Devanagari, Gurmukhi, or other diacritic-marked letter that looks like one glyph in the editor fails to compile as a 'x' character literal with "Too many characters in a character literal," because it is a base letter plus a separate combining mark — two Chars, not one. Use when a lookup table keyed by Char needs an…
Skill Claude CodeCodex
An editable value that is written on focus loss stores whatever was half-typed when a dialog, a rotation or a stray tap took the focus away; keep the draft in its own state keyed on the stored value and write only when the user asks for it. Covers why the dirty check that shows the confirm button gets stuck when the…
Skill Claude CodeCodex
Mine a repository's history without being misled by it — an empty-bodied commit's file statistics are its real abstract, a nested-repository bump hides its entire content behind a one-line pointer change, and a merge flattens a branch's decision trail into a single subject. Use when reconstructing why something is the…
Skill Claude CodeCodex
Render a composable off-screen into an ImageBitmap so a button can save or share it as a picture — a capture primitive ported into common code rather than pulled in as a platform-only dependency, a max-width ceiling standing in for a fixed output size, artwork that has to already be resolved before the button is even…
Skill Claude CodeCodex
The ordered list of probes, system properties and platform gates a Compose desktop entry point must run before its first window exists. Covers warming the JDK's desktop-integration API ahead of any native load, renderer and interop properties that are read once at start-up, turning off vsync where the wait can park…
Skill Claude CodeCodex
Rendering video frames from a native media engine in Compose Desktop without embedding a heavyweight AWT panel — publish finished frames as immutable snapshots on a StateFlow and draw them with a plain Image, convert off the UI thread, match the engine's pixel byte order, and let the engine decide the fit. Reach for…
Skill Claude CodeCodex
A shared ViewModel base class for Compose Multiplatform — container-aware so subclasses can pull extra dependencies without constructor threading, with one loading/error surface for every screen — and the blocking resource-lookup hazard that such a base almost always grows. Use when every screen is re-implementing its…
Skill Claude CodeCodex
Verifying a config-driven feature against the generated artifact instead of against the config, for formats that fail open and ignore unknown keys — the two-build A/B diff, the artifact fingerprint to grep for, and the CI assertion that keeps it from regressing. Reach for it when a config key looks correct, the build…
Skill Claude CodeCodex
Model an endpoint that returns a page plus a next-token as Flow >> — a null token means the end, the caller stores only the token, and a bounded prefetch primes the first pages before anything is shown. Use when wiring an opaque-cursor API into a repository, or when a list stops loading after one failed request and…
Skill Claude CodeCodex
Size a slider's range from the real distribution of values it will be handed — stored, imported, migrated — rather than from a neighbouring control's range, because a value outside the range parks the thumb at the end of the track while your readout shows a different number, and the first touch silently rewrites it.…
Skill Claude CodeCodex
Packaging a JVM desktop app with a config-driven packager whose HOCON config silently ignores unknown keys — which keys bind at the app level versus a per-OS section versus a nested group, command-line key overrides, pinning the packaging JDK, and the environment block that quietly pins PATH. Reach for it when a key…
Skill Claude CodeCodex
A crossfade's container is a Box aligned to the top-start corner and sized to the largest child currently composed, so swapping a thin child for a taller one pins the thin one to the top mid-transition and drops it when the tall one leaves. Covers boxing both branches into one fixed frame with an explicit alignment…
Skill Claude CodeCodex
Build a crossfade between two media items with one player instance per item and a second live instance during the blend, then keep transport commands and playback settings correct while two players are audible. Use when adding a fade to a player, or when pausing mid-fade leaves the old track playing underneath, a seek…
Skill Claude CodeCodex
Decide when a crossfade must NOT run — the item plays as video, the item is too short for the fade, or two consecutive items belong to the same album — and encode each rule so it survives shuffle, an auto-length fade and a queue that keeps growing. Use when a fade cuts a song short, a video jumps to its first frame…
Skill Claude CodeCodex
A client plugin that logs every outgoing request as one paste-ready curl command — POSIX single-quoting so a body full of quotes, dollars or newlines survives the shell, the whole command in a single log call, a redaction list, and a body read that does not consume a one-shot channel. Use when you want to replay a…
Skill Claude CodeCodex
A house style over Material3's ModalBottomSheet — transparent container plus your own surface, zeroed window insets with an explicit end spacer, a hand-rolled drag handle, and hide-then-dismiss so the sheet animates closed before it leaves composition. Use when a sheet snaps shut instead of sliding, when its last row…
Skill Claude CodeCodex
Replacing a media engine's default shuffle order so that tracks added mid-playback land contiguously after the current one instead of being scattered through the rest of the queue. Use when "play next" or an appended continuation page ends up in random positions while shuffle is on, or when writing any custom shuffle…
Skill Claude CodeCodex
A slim seek bar with a buffered-progress track behind it, built from Material3's Slider with custom track and thumb slots — including the fraction-not-your-own-scale rule that keeps the thumb from pinning at the end, and the state gate that stops incoming playback position from fighting the drag. Use when a seek bar…