Fluent controls and retained docking presentation

Defaults and scope

The Gallery starts in Fluent Light with the existing classic docking arrangement and Comfortable density. Light/Dark use native Uno/WinUI controls and optional WorkbenchResources. Generic remains explicitly selectable and restores the independently authored compact docking palette, custom legacy button/menu templates and original pane metrics. The library's null Theme behavior is not changed.

This increment changes presentation, not the ownership tree, drag transactions, geometry adapters, splitter allocator, serialization or source-binding semantics. No public API is removed. Native floating-window chrome continues to use its existing lifetime and input protocol.

Platform-owned controls

Fluent docking buttons and context-menu rows now derive their styles from the platform DefaultButtonStyle, DefaultMenuFlyoutItemStyle and DefaultMenuFlyoutPresenterStyle. Their real ControlTemplates, CommonStates, keyboard processing, automation peers and two-tone system focus visuals remain platform-owned. No Uno template source is copied. Generic keeps the original compiled templates for comparison.

DockChromeButton observes ButtonBase.IsPressed instead of maintaining an unrelated pointer-only pressed flag. Space/Enter and pointer capture therefore share the native press lifecycle. The legacy painter also observes that authoritative state. Right-button and already-handled input cannot invent a second pressed state. Disabled Fluent glyph/text uses a semantic disabled brush rather than fading the entire subtree. Inactive tab labels have secondary text; selected labels and tool captions use semibold text.

Scoped HoverBrush/PressedBrush/ForegroundBrush/DisabledForegroundBrush values are forwarded by identity to the native Button state-resource keys. MenuHoverBrush, MenuPressedBrush and menu text/disabled overrides likewise feed native menu states. The forwarding dictionaries apply only to Light/Dark and do not replace the platform's HighContrast state dictionaries. Native focus visuals replace the legacy menu gutter/highlight border in Fluent mode; legacy MenuGutterBrush and MenuHoverBorderBrush still apply to Generic's original template.

Theme-family changes can replace templates. Light-to-Dark updates within Fluent retain template and control identities. Application-supplied ContextFlyout objects are not restyled. Normal resource replacement still requires the documented manager Refresh; this is not a new general observable dictionary mechanism.

The Gallery toolbar uses native Button/ComboBox templates, 28-DIP minimum control heights and compiled FontIcon content. It retains command IDs, tooltips, keyboard focus and handlers. SampleButton remains only where existing diagnostic examples specifically use it; not every custom diagnostic control is claimed migrated.

The property inspector's styles explicitly use the platform default Button, ToggleButton, ListViewItem and TextBox styles as their bases. A style without that base fell back to the pinned host's older control template despite using the right CLR control type. Category disclosure headers now use neutral checked surfaces instead of the accent-filled toggle appearance; actual mode buttons keep the normal native checked accent. Parsing, conflict detection, retained editors, selection epochs and column resizing are unchanged.

Surfaces and metrics

WorkbenchResources now supplies neutral light/dark pane surfaces and borders, primary/secondary/disabled text, restrained active-title shading and distinct selection accents. Existing density sizes are unchanged. New scoped keys:

The workbench retains its 3-DIP button corners and 2-DIP non-hit-testable selected tab indicator. Tabs, their header/editor presenters, context menus and pane views survive theme and metric refreshes. Pane rounding is presentation, not a promise of rounded clipping for arbitrary application content.

The Gallery changes its surface/status styles only when changing style families. Clearing their values on every theme refresh would also clear installed resource bindings, producing a dark document under an incorrectly light toolbar. Regression coverage includes repeated themes and a Generic-to-Fluent round trip.

The workbench HighContrast dictionary supplies all eleven semantic chrome slots using system colors. Inspector category state resources also have a HighContrast branch. Dictionary construction is tested; real operating-system contrast-theme transitions and hardware rendering remain separate acceptance work.

Verification

The actual-host fluent-presentation suite contains 24 common cases plus two opt-in Linux XTEST keyboard cases. It checks native templates/states, semantic text, retained control/editor identities, scoped brushes reaching native state parts without cloning, resource binding retention, Generic restoration, shape metrics and five rendered scenes: light, dark, RTL, large text and narrow.

The state-brush tests explicitly drive native VisualStateManager presentation; they are not physical input tests. The two XTEST cases inject actual Space press and release, require zero early Click events, observe ButtonBase.IsPressed and require one activation on release. On a bare Xvfb server PointerRoot keyboard focus follows the native window under the mouse: the fixture first places the real pointer over that host, then assigns XAML keyboard focus. No synthetic routed event or direct command invocation replaces those assertions.

Existing sample, presentation, inspector, menu, theme, docking, sizing and XAML suites remain enabled without relaxed assertions. Dedicated desktop CI requires complete JUnit/native-process agreement and all five captures. Exact final-head results are recorded in the PR, not predicted in this document.

Windows runtime acceptance uses Uno Skia Win32; native WinUI is compiled/packaged. Browser runtime, pure Wayland, physical AppKit input, mixed-DPI hardware and full WPF/binary/pixel equivalence are not established here. No release version change or package publication is part of this work.

Live visual-state resources and application ownership

Palette changes also refresh a button or menu row that is already in PointerOver, Pressed or Disabled. Merely replacing a dictionary entry does not invalidate an already-entered native state setter in the pinned host; without refresh, a hovered tab could retain its previous light brush in a dark workspace. UnoDock replays that control's existing CommonStates transition with animations disabled when its resolved brush identities change. It does not inject input, execute a command, replace the template, change native IsPressed or replace the focus-state group. Applications can observe the visual-state transitions. A callback which chooses another state, changes the palette or replaces/unloads the template revokes the old replay instead of being overwritten by it. Temporary observation ends in a finally block. Observer errors are not swallowed.

The forwarded brushes occupy one low-priority merged resource dictionary with separate Light and Dark dictionaries. No application ThemeDictionaries entry is replaced, including HighContrast. Direct values, merged dictionaries and explicit same-scope theme overrides retain precedence and brush identity. Replacing the control's Resources detaches the old fallback and installs one in the new scope; returning to Generic removes only the owned fallback. Repeated theme changes do not accumulate dictionaries. Updating a resource still requires the existing manager Refresh contract; this is not automatic observation of arbitrary ResourceDictionary edits. Mutable application brushes are not cloned or recolored.

Fourteen additional common cases exercise active button/menu states during palette and theme changes, resource ownership, replacements, Generic round trips and application-controlled state changes. One Linux XTEST case holds a real Space press during a live palette change and requires zero early clicks and exactly one on key release. These supplement the original 24 common/two Linux input cases: final focused coverage is 38 cases on Windows/AppKit and 41 on Linux. VSM-only cases are presentation tests, not claims of physical pointer automation.

The source contract now separately verifies the seven original compiled templates and all three native-based Fluent styles by exact key and TargetType. It rejects copied ControlTemplates or Template setters inside those styles. The previous flat resource-count check incorrectly rejected the added styles; the original template identities remain required rather than weakening that contract.