3.0 KiB
UI ownership and compatibility
| Surface | Long-term backend | Compatibility scope |
|---|---|---|
| Candidate, floating toolbar, tray menu | msimeui native Direct2D/DirectWrite | appearance.ui_backend=webview2 explicitly selects existing WebView skins |
| Settings | UiHtml hosted by the separate native settings application | Small-window backend settings never change this host |
| Keyboard, handwriting, emoji and voice panels | Their existing native application/presenter | Shared actions/configuration stay in Server; panels do not own input sessions |
window/ui_backend_policy.h owns backend selection. D2D is the default; existing
WebView aliases remain readable. Unknown/retired stored values migrate to D2D,
while new invalid configuration writes fail. A backend setting applies at process
startup, preserving the existing controller lifetime and restart behavior.
The candidate worker resolves output text, auxiliary codes, source badges and
translations once into CandidateViewItem. Both native and Web renderers consume
these values. HTML escaping and the legacy comma framing are confined to the Web
adapter; native rendering receives plain text. Both click paths enter the existing
EnqueueCandidateUiAction queue with the same focus owner checks and action policy.
The ten-entry mouse range is distinct from the 1–9 keyboard shortcuts.
WebView small windows remain a compatibility backend for existing skins. Their removal requires: a supported conversion path for CSS-dependent external skins; parity for candidate/context-menu actions, translations and accessibility; and recorded mixed-DPI, cold-start and signed/uiAccess host validation of the native replacement. Until those conditions are met, keep compatibility tests and do not silently reinterpret a configured WebView skin as a native skin. New business behavior belongs in shared actions/session/view models, not either renderer.
Sciter is not an active product backend. The old unreferenced handwritten D2D prototype is removed; native small windows use msimeui presenters. The msimeui library owns generic controls and rendering, never Server configuration, pipe sessions, dictionary access, or global input state.
v2 皮肤在两个后端下的渲染
schema_version = 2 的皮肤（九宫格贴图面板、自由锚定挂件、面板外空白）两个后端都支持，但走的是不同的实现：
- WebView2 把面板翻成 CSS：
border-image铺九宫格，content_insets_dip落成容器内边距，挂件用.containerParent的伪元素绝对定位。 - D2D 用
CandidatePresenter的本地场景：面板由msimeui::Card::SetBackgroundImageNineSlice画成九宫格，挂件由CandidateSkinOverlay这一层浮在卡片上，outer_insets_dip换成窗口在卡片四边多留的空白。
两侧读同一份 skin.toml，字段语义必须一致，尤其是 anchor 与 offset_*_dip：正数向右、向下。改一侧的定位规则要同时改另一侧。
content_insets_dip 在两个后端都从面板外缘量起，D2D 侧由卡片内边距承担，不需要再扣边框。