feat(ui): port retained widget foundations

src/AcDream.App/UI/UiRoot.cs

@@ -9,24 +9,15 @@ namespace AcDream.App.UI;
 public enum ResizeEdges { None = 0, Left = 1, Right = 2, Top = 4, Bottom = 8 }
 
 /// <summary>
-/// Top-level UI container. Implements the retail "Device" responsibilities
+/// Top-level UI container. Implements the retail <c>UIElementManager</c> responsibilities
 /// (mouse cursor tracking, keyboard focus, modal overlay, mouse capture,
 /// drag-drop state machine, tooltip timer). Routes Silk.NET input events
 /// into the widget tree with retail-faithful <see cref="UiEvent"/>
 /// semantics.
 ///
-/// Retail analog: the <c>DAT_00837ff4</c> Device object (see
-/// <c>docs/research/retail-ui/04-input-events.md §2</c>). That object has
-/// a ~20-slot vtable; the methods we emulate here are:
-///
-/// <list type="bullet">
-///   <item>+0x18 / +0x1C : <see cref="MouseX"/> / <see cref="MouseY"/></item>
-///   <item>+0x34 : <see cref="RegisterTimerEvent"/> (tooltip delay)</item>
-///   <item>+0x38 : <see cref="FireEvent"/></item>
-///   <item>+0x44 : <see cref="KeyboardFocus"/></item>
-///   <item>+0x48 / +0x4C : <see cref="SetCapture"/> / <see cref="ReleaseCapture"/></item>
-///   <item>+0x74 / +0x78 : drag cursor set / reset</item>
-/// </list>
+/// Retail analog: <c>UIElementManager::UseTime @ 0x0045CFD0</c>. Tooltip
+/// deadlines are polled before global time message 3; there is no generic Device
+/// timer queue in the named client.
 ///
 /// When no widget consumes an event, the <see cref="WorldMouseFallThrough"/>
 /// or <see cref="WorldKeyFallThrough"/> event fires so the game world
@@ -125,8 +116,10 @@ public sealed class UiRoot : UiElement
     // Hover / tooltip tracking.
     private UiElement? _hoverWidget;
     private long _hoverStartedMs;
-    private const int TooltipDelayMs = 1000;       // retail typical
+    public int TooltipDelayMs { get; set; } = 250;
+    public int TooltipDurationMs { get; set; } = 10_000;
     private bool _tooltipFired;
+    private long _tooltipShownMs;
 
     private long _nowMs;
 
@@ -152,10 +145,92 @@ public sealed class UiRoot : UiElement
 
     public override void AddChild(UiElement child)
     {
-        if (child.EventId == 0) child.EventId = _nextEventId++;
+        AssignEventIds(child);
         base.AddChild(child);
     }
 
+    private void AssignEventIds(UiElement element)
+    {
+        if (element.EventId == 0)
+            element.EventId = _nextEventId++;
+        foreach (var child in element.Children)
+            AssignEventIds(child);
+    }
+
+    private static void BroadcastGlobalUiTime(UiElement element, double nowSeconds)
+    {
+        if (element is IUiGlobalTimeListener listener)
+            listener.OnGlobalUiTime(nowSeconds);
+
+        // A listener may synchronously close/remove a window. Snapshot the walk,
+        // then skip children no longer owned by this parent so a deleted subtree
+        // cannot receive a stale pulse and collection mutation cannot invalidate it.
+        foreach (var child in element.Children.ToArray())
+            if (ReferenceEquals(child.Parent, element))
+                BroadcastGlobalUiTime(child, nowSeconds);
+    }
+
+    internal void OnSubtreeRemoving(UiElement subtree)
+    {
+        if (IsWithinSubtree(KeyboardFocus, subtree))
+            SetKeyboardFocus(null);
+        if (IsWithinSubtree(Captured, subtree))
+        {
+            ReleaseCapture();
+            _dragCandidate = false;
+        }
+        if (IsWithinSubtree(DefaultTextInput, subtree))
+            DefaultTextInput = null;
+        if (IsWithinSubtree(Modal, subtree))
+            Modal = null;
+        if (IsWithinSubtree(DragSource, subtree))
+        {
+            DragSource = null;
+            DragPayload = null;
+            _dragGhost = null;
+            _dragCandidate = false;
+        }
+        if (IsWithinSubtree(_hoverWidget, subtree))
+        {
+            var leave = new UiEvent(_hoverWidget!.EventId, _hoverWidget, UiEventType.HoverLeave);
+            _hoverWidget.OnEvent(in leave);
+            _hoverWidget = null;
+            _tooltipFired = false;
+        }
+        if (IsWithinSubtree(_lastDragHoverTarget, subtree))
+            _lastDragHoverTarget = null;
+        if (IsWithinSubtree(_lastClickTarget, subtree))
+            _lastClickTarget = null;
+        if (IsWithinSubtree(_windowDragTarget, subtree))
+        {
+            _windowDragTarget = null;
+            _dragCandidate = false;
+        }
+        if (IsWithinSubtree(_resizeTarget, subtree))
+        {
+            _resizeTarget = null;
+            _dragCandidate = false;
+        }
+
+        foreach (string name in _windows
+            .Where(pair => IsWithinSubtree(pair.Value, subtree))
+            .Select(pair => pair.Key)
+            .ToArray())
+        {
+            _windows.Remove(name);
+        }
+    }
+
+    private static bool IsWithinSubtree(UiElement? element, UiElement subtree)
+    {
+        while (element is not null)
+        {
+            if (ReferenceEquals(element, subtree)) return true;
+            element = element.Parent;
+        }
+        return false;
+    }
+
     // ── Per-frame pumping ────────────────────────────────────────────────
 
     public void Tick(double dt, long nowMs)
@@ -170,8 +245,18 @@ public sealed class UiRoot : UiElement
             var e = new UiEvent(_hoverWidget.EventId, _hoverWidget, UiEventType.Tooltip);
             _hoverWidget.OnEvent(in e);
             _tooltipFired = true;
+            _tooltipShownMs = _nowMs;
+        }
+        else if (_hoverWidget is not null && _tooltipFired
+            && _nowMs - _tooltipShownMs >= TooltipDurationMs)
+        {
+            var leave = new UiEvent(_hoverWidget.EventId, _hoverWidget, UiEventType.HoverLeave);
+            _hoverWidget.OnEvent(in leave);
+            _hoverWidget = null;
+            _tooltipFired = false;
         }
 
+        BroadcastGlobalUiTime(this, nowMs / 1000d);
         TickSelfAndChildren(dt);
     }
 
@@ -550,7 +635,13 @@ public sealed class UiRoot : UiElement
     }
 
     public void SetCapture(UiElement e) => Captured = e;
-    public void ReleaseCapture() => Captured = null;
+    public void ReleaseCapture()
+    {
+        Captured = null;
+        // Retail restarts the tooltip idle deadline when capture is released.
+        _hoverStartedMs = _nowMs;
+        _tooltipFired = false;
+    }
 
     // ── Window manager (named top-level windows: Show / Hide / Toggle) ───
 
@@ -694,14 +785,6 @@ public sealed class UiRoot : UiElement
         target.OnEvent(in e);
     }
 
-    public void RegisterTimerEvent(int type, UiElement target, int delayMs,
-        object? payload = null)
-    {
-        _timers.Add((_nowMs + delayMs, new UiEvent(target.EventId, target, type, Payload: payload)));
-    }
-
-    private readonly List<(long fireAt, UiEvent e)> _timers = new();
-
     private void UpdateButtonFlag(UiMouseButton b, bool down)
     {
         switch (b)