Implements Phase 4 of CARD_PLAN.md — the runtime hook that loads the
default theme on startup and refreshes the card-rendering pipeline
whenever the active theme changes.
solitaire_engine/src/theme/plugin.rs
ThemePlugin
init_asset::<CardTheme>, register_asset_loader for SvgLoader and
CardThemeLoader, Startup load_default_theme, and Update
sync_card_image_set_with_active_theme.
ActiveTheme(Handle<CardTheme>)
Resource pointing at the currently-loaded theme.
set_theme(commands, asset_server, theme_id)
Public API for switching themes — formats the URL as
`themes://<theme_id>/theme.ron` and updates the resource.
Integration approach: rather than refactor every `card_plugin.rs`
spawn site to read from `Assets<CardTheme>` directly, the sync system
writes the theme's face/back image handles into the existing
`CardImageSet` resource on `AssetEvent::LoadedWithDependencies` /
`Modified`, then fires `StateChangedEvent`. The existing
`sync_cards_on_change` pipeline rebuilds card sprites from the new
handles on the next tick — observable behaviour matches the plan's
intent (theme switches propagate immediately) while keeping
card_plugin's 1929-line surface area untouched.
Theme.back is mapped onto `CardImageSet.backs[0]` (the default-back
slot xCards previously occupied); `backs[1..=4]` are the
asset-generator patterns and remain user-selectable independent of
the active theme.
Added to solitaire_app/main.rs as `add_plugins(ThemePlugin)` after
`AssetSourcesPlugin` so the asset sources are registered before the
default-theme load is dispatched.
6 new tests covering suit/rank index mapping (matching the
`card_plugin` doc-commented `[suit][rank]` layout), empty-theme
no-panic, back-slot overwrite, and the URL format from `set_theme`.
cargo build / clippy --workspace --all-targets -- -D warnings / test
--workspace all green (950 passed, 0 failed, 9 ignored).
funman300
7f477b4ad8