feat(ui): unify retained window mounts

src/AcDream.App/UI/Layout/ChatWindowController.cs

@@ -40,14 +40,6 @@ public sealed class ChatWindowController
     private const uint SendId         = 0x10000019u;
     private const uint MaxMinId       = 0x1000046Fu;
 
-    // Scrollbar sprite ids from base layout 0x2100003E (confirmed in Task D).
-    private const uint TrackSprite    = 0x06004C5Fu;
-    private const uint ThumbSprite    = 0x06004C63u;   // 3-slice middle tile
-    private const uint ThumbTopSprite = 0x06004C60u;   // 3-slice top cap
-    private const uint ThumbBotSprite = 0x06004C66u;   // 3-slice bottom cap
-    private const uint UpSprite       = 0x06004C6Cu;   // up arrow (top button)
-    private const uint DownSprite     = 0x06004C69u;   // down arrow (bottom button)
-
     // Channel menu sprite ids (confirmed in chat element dump).
     private const uint MenuNormal       = 0x06004D65u;   // button face
     private const uint MenuPressed      = 0x06004D66u;   // button pressed
@@ -72,6 +64,12 @@ public sealed class ChatWindowController
     /// <summary>Channel-selector menu widget.</summary>
     public UiMenu Menu { get; private set; } = null!;
 
+    /// <summary>Resolved gmMainChatUI root metadata, including DAT size constraints.</summary>
+    public ElementInfo DatWindowInfo { get; private set; } = null!;
+
+    public RetailWindowHandle? WindowHandle { get; private set; }
+    public bool IsMaximized => _maximized;
+
     // ── Private state ──────────────────────────────────────────────────────
 
     private ChatChannelKind _activeChannel = ChatChannelKind.Say;
@@ -121,6 +119,7 @@ public sealed class ChatWindowController
     /// <summary>Window top before maximize.</summary>
     private float _normalTop;
     private bool _maximized;
+    private UiButton? _maxMinButton;
 
     // ── Factory ────────────────────────────────────────────────────────────
 
@@ -181,7 +180,11 @@ public sealed class ChatWindowController
         // GameWindow adds this to the host, which re-parents it out of the synthetic wrapper,
         // orphaning the strays so they never draw.
         var window = layout.FindElement(RootId) ?? layout.Root;
-        var c = new ChatWindowController { Root = window };
+        var c = new ChatWindowController
+        {
+            Root = window,
+            DatWindowInfo = FindInfo(rootInfo, RootId) ?? rootInfo,
+        };
 
         // Drop the dat top resize bar (0x1000000F): it is authored 800px wide and
         // juts out of the content-width window. The host wraps this content in the
@@ -234,13 +237,7 @@ public sealed class ChatWindowController
             bar.Height = bar.Height + oldTop;
             bar.ResetAnchorCapture();
             bar.Model         = c.Transcript.Scroll;
-            bar.SpriteResolve = resolve;
-            bar.TrackSprite    = TrackSprite;
-            bar.ThumbSprite    = ThumbSprite;
-            bar.ThumbTopSprite = ThumbTopSprite;
-            bar.ThumbBotSprite = ThumbBotSprite;
-            bar.UpSprite       = UpSprite;
-            bar.DownSprite     = DownSprite;
+            bar.SpriteResolve ??= resolve;
             c.Scrollbar = bar;
         }
 
@@ -301,7 +298,7 @@ public sealed class ChatWindowController
             ReflowInputRow();
         }
 
-        // ── Max/min toggle — simplified gmMainChatUI::HandleMaximizeButton ──
+        // ── Max/min toggle — gmMainChatUI::HandleMaximizeButton ──
         if (layout.FindElement(MaxMinId) is UiButton maxMinEl)
         {
             // The dat puts max/min and the scrollbar up-button at the SAME X (both
@@ -310,6 +307,7 @@ public sealed class ChatWindowController
             if (track is not null)
                 maxMinEl.Left = track.Left - maxMinEl.Width;
             maxMinEl.ResetAnchorCapture();
+            c._maxMinButton = maxMinEl;
             maxMinEl.OnClick = c.ToggleMaximize;
         }
 
@@ -319,28 +317,76 @@ public sealed class ChatWindowController
     // ── Max/min implementation ─────────────────────────────────────────────
 
     /// <summary>
-    /// Toggle between the normal chat window height and an expanded 320px height.
-    /// Simplified port of retail <c>gmMainChatUI::HandleMaximizeButton @0x4cddb0</c>:
-    /// retail stores the pre-maximize height and restores it on a second click.
-    /// The 320px expanded size is the approximate retail maximized chat height.
+    /// Attach the typed outer-frame handle after the controller's imported content
+    /// has been mounted. Maximize/restore must resize this frame, not the child root.
+    /// </summary>
+    public void AttachWindow(RetailWindowHandle handle)
+    {
+        ArgumentNullException.ThrowIfNull(handle);
+        if (!ReferenceEquals(handle.ContentRoot, Root))
+            throw new ArgumentException("Chat handle content root does not match the bound layout.", nameof(handle));
+        if (WindowHandle is not null && !ReferenceEquals(WindowHandle, handle))
+            throw new InvalidOperationException("Chat controller is already attached to another window.");
+        WindowHandle = handle;
+    }
+
+    /// <summary>
+    /// Exact control flow from <c>gmMainChatUI::HandleMaximizeButton @0x004CCE50</c>:
+    /// save/restore Y+height, expand by half the parent, choose up/down growth from
+    /// available space, clamp through the mounted frame's DAT constraints, and set
+    /// the imported max/min button state.
     /// </summary>
     private void ToggleMaximize()
     {
-        if (!_maximized)
+        if (WindowHandle is not { IsRegistered: true } handle)
+            return;
+
+        UiElement frame = handle.OuterFrame;
+        float parentHeight = frame.Parent?.Height ?? 0f;
+        if (parentHeight <= 0f)
+            return;
+
+        if (_maximized)
         {
-            _normalHeight = Root.Height;
-            _normalTop    = Root.Top;
-            // Expand upward: move the top edge up so the bottom stays anchored.
-            Root.Top    = MathF.Max(0f, Root.Top + Root.Height - 320f);
-            Root.Height = 320f;
-            _maximized  = true;
+            float restoredHeight = Math.Clamp(_normalHeight, frame.MinHeight, frame.MaxHeight);
+            float restoredTop = Math.Clamp(
+                _normalTop,
+                0f,
+                MathF.Max(0f, parentHeight - frame.MinHeight));
+            _maximized = false;
+            _maxMinButton?.TrySetRetailState(RetailUiStateIds.Minimized);
+            handle.ResizeTo(frame.Width, restoredHeight);
+            handle.MoveTo(frame.Left, restoredTop);
+            return;
         }
-        else
+
+        _normalTop = frame.Top;
+        _normalHeight = frame.Height;
+
+        float expansion = parentHeight / 2f;
+        float targetTop = frame.Top;
+        float targetHeight = frame.Height + expansion;
+        if (frame.Top + targetHeight > parentHeight || frame.Top >= parentHeight / 2f)
+            targetTop = MathF.Max(0f, frame.Top - expansion);
+
+        targetHeight = MathF.Min(targetHeight, parentHeight - targetTop);
+        targetHeight = Math.Clamp(targetHeight, frame.MinHeight, frame.MaxHeight);
+
+        _maximized = true;
+        _maxMinButton?.TrySetRetailState(RetailUiStateIds.Maximized);
+        handle.ResizeTo(frame.Width, targetHeight);
+        handle.MoveTo(frame.Left, targetTop);
+    }
+
+    private static ElementInfo? FindInfo(ElementInfo node, uint id)
+    {
+        if (node.Id == id) return node;
+        foreach (ElementInfo child in node.Children)
         {
-            Root.Top    = _normalTop;
-            Root.Height = _normalHeight;
-            _maximized  = false;
+            ElementInfo? found = FindInfo(child, id);
+            if (found is not null) return found;
         }
+        return null;
     }
 
     // ── Helpers ────────────────────────────────────────────────────────────