Owner request (docs/plans/2026-09-06-plugin-shelf-and-dat-icons.md, Slice A):
the plugin shelf was pinned to the right screen edge every tick, had no drag
or hide affordance, and never persisted position. It is now a registered
retained window ("plugin-shelf") that gets drag, the UI lock, and
RetailWindowLayoutPersistence position/visibility/collapsed persistence for
free, the same way every other retained window does.
Design decisions where the plan left room:
- Grip + collapse toggle are drawn, not child elements. A real child for the
toggle would have to live outside any WindowMoveHandle grip subtree (nesting
it inside lets UiRoot's drag-handle promotion swallow the press before the
button ever sees a click - `handleWindow is not null` outranks
`HandlesClick` in UiRoot.OnMouseDown), and a grip element as a plain sibling
changes UiElement.Children's shape, which the pre-existing single-button
shelf tests assert directly (`Assert.Single(shelf.Children)`). Keeping the
whole shelf Draggable=true and excluding just the toggle's pixel rect from
an overridden HandlesClick (computed live from UiRoot.MouseX/MouseY, the
only call site) gets grip-drags/buttons-and-toggle-don't without adding any
child or touching the existing tests' shape assumptions.
- Availability (has plugin windows) vs the user's requested-visible intent
are split the same way PluginWindowVisibilityController already splits it
for individual plugin windows, but applied SYNCHRONOUSLY (not via
VisibleSource) so Visible updates immediately after Add()/unregister with
no dependency on a Tick ever running - required to keep the pre-Slice-A
unregistered-shelf test (ShelfAndMinimizeButtonsHideAndRestoreWithoutUnregisteringWindow)
green, since it never calls root.Tick().
- "The shelf was moved" (drag or a differing restored layout) is tracked via
the shelf's own RetailWindowHandle.Moved event, captured through
WindowManager.WindowRegistered the moment MountPlugins registers it - so
unregistered/legacy use (the two other pre-existing tests) never sets this
and behaves exactly as before.
- The one-time right-edge dock (no saved layout) fires on the first OnTick
with a real parent width, replacing the old per-tick pin; Reflow's
anchor math then preserves the top-right corner while still docked or the
top-left corner once positioned, on any width change (entry add/remove,
collapse, or a parent-height-driven column rewrap).
Caption finding: the Configure Keyboard row for InputAction.TogglePluginManager
resolves its label live from the installed DAT's action-map string table
(KeyboardConfigController.BuildActionRow, RetailActionMapRow.LabelHash) -
there is no "Plugin Manager" string literal anywhere in our code to rename to
"Plugin Shelf". The row keeps showing retail's own authored name; only the
acdream-side action semantics changed.
Tests added to PluginSidePanelTests.cs (all 7 fail to even compile against
the pre-Slice-A PluginSidePanel, verified by temporarily reverting the source
files and re-running): default right-edge dock; top-right corner preserved
across a Reflow-driven width change while docked; grip drag moves the shelf
and top-left survives the next reflow once positioned; drag refused under
UiLocked; collapse via the real toggle click round-trips through
CaptureWindowState/RestoreWindowState; Show/Hide toggle sequence and a hidden
shelf staying hidden when a new plugin window registers; a full
RetailWindowLayoutPersistence round trip of X/Y/Visible/Collapsed onto a
fresh shelf instance. All 3 pre-existing tests remain green unmodified.
Verified: dotnet build src/AcDream.App (Release) green; the full App test
suite passes 7294/97 skipped/36 pre-existing unrelated failures (identical
failure set confirmed present on HEAD before this change - installed-DAT
live-mount probes, Linux-only pacing/credential tests, and known alpha-flush
COUNT-only conformance divergences, none touching plugin UI).
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>