feat(ui): port retained widget foundations

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

@@ -10,11 +10,10 @@ namespace AcDream.App.UI.Layout;
 /// <see cref="UiDatElement"/>.
 ///
 /// <para>
-/// Type 12 = UIElement_Text — a scrollable colored-line text view. Every Type-12
-/// element is now built as a <see cref="UiText"/>. Elements that carry their own
-/// dat sprite media keep it as the <see cref="UiText.BackgroundSprite"/>. Pure
-/// prototype elements (no state media, no controller binding) draw nothing because
-/// <see cref="UiText.BackgroundColor"/> defaults to transparent.
+/// Type 12 = UIElement_Text. Editable `0x16` elements become <see cref="UiField"/>
+/// in place; other elements become display/selectable <see cref="UiText"/> widgets.
+/// Elements that carry their own DAT sprite media keep it as widget background art.
+/// Pure prototype elements draw nothing because text backgrounds default transparent.
 /// </para>
 ///
 /// <para>
@@ -102,9 +101,31 @@ public static class DatWidgetFactory
         e.ZOrder = (int)info.ReadOrder - (int)info.ZLevel * 10000;
 
         // Map the four raw edge-anchor values to the AnchorEdges bit-flag that the
-        // UI layout engine uses for reflow.
+        // compatibility layout engine uses for programmatic overrides.
         e.Anchors = ElementReader.ToAnchors(info.Left, info.Top, info.Right, info.Bottom);
 
+        // Imported descendants use the exact four-mode retail policy. Roots have no
+        // design parent and intentionally remain on the compatibility path until a
+        // window mount assigns its own outer-frame policy.
+        if (info.HasOriginalParentSize)
+        {
+            e.LayoutPolicy = new UiLayoutPolicy(
+                info.Left,
+                info.Top,
+                info.Right,
+                info.Bottom,
+                UiPixelRect.FromPositionAndSize(
+                    (int)info.X,
+                    (int)info.Y,
+                    (int)info.Width,
+                    (int)info.Height),
+                UiPixelRect.FromPositionAndSize(
+                    0,
+                    0,
+                    (int)info.OriginalParentWidth,
+                    (int)info.OriginalParentHeight));
+        }
+
         return e;
     }
 
@@ -253,7 +274,8 @@ public static class DatWidgetFactory
 
     // ── Text ─────────────────────────────────────────────────────────────────
 
-    /// <summary>Type-12 UIElement_Text: a scrollable colored-line text view. The element's
+    /// <summary>Type-12 UIElement_Text: an editable field or colored-line text view,
+    /// selected from the canonical property bag. The element's
     /// own Direct/Normal media (if any) becomes the background sprite, drawn under the text —
     /// so a Type-12 element that previously rendered via UiDatElement keeps its sprite. Lines
     /// are bound later by the controller (LinesProvider). An unbound UiText draws nothing
@@ -273,7 +295,7 @@ public static class DatWidgetFactory
     /// font; otherwise it is the shared global fallback. Controllers that call
     /// <see cref="ImportedLayout.FindElement"/> and set <see cref="UiText.DatFont"/> afterward
     /// still override this — the build-time value is just the starting point.</param>
-    private static UiText BuildText(ElementInfo info, Func<uint, (uint, int, int)> resolve,
+    private static UiElement BuildText(ElementInfo info, Func<uint, (uint, int, int)> resolve,
         UiDatFont? elementFont = null)
     {
         uint bg = info.StateMedia.TryGetValue(
@@ -281,6 +303,35 @@ public static class DatWidgetFactory
                     : info.StateMedia.ContainsKey("Normal") ? "Normal" : "", out var m)
                   ? m.File : 0u;
 
+        bool editable = info.TryGetEffectiveBool(0x16u, out var editableValue)
+            && editableValue;
+        bool selectable = info.TryGetEffectiveBool(0x27u, out var selectableValue)
+            && selectableValue;
+        bool oneLine = info.TryGetEffectiveBool(0x20u, out var oneLineValue)
+            && oneLineValue;
+
+        if (editable)
+        {
+            uint focusSprite = info.StateMedia.TryGetValue("Normal_focussed", out var focus)
+                ? focus.File
+                : 0u;
+            var field = new UiField
+            {
+                ElementId = info.Id,
+                DatFont = elementFont,
+                SpriteResolve = resolve,
+                BackgroundSprite = bg,
+                FocusFieldSprite = focusSprite,
+                Selectable = selectable,
+                OneLine = oneLine,
+            };
+            if (info.TryGetEffectiveInteger(0x1Eu, out int maxCharacters))
+                field.MaxCharacters = maxCharacters;
+            if (info.FontColor.HasValue)
+                field.TextColor = info.FontColor.Value;
+            return field;
+        }
+
         // Apply horizontal + vertical justification from the dat at build time.
         // Controllers that call FindElement and set Centered/RightAligned/VerticalJustify
         // afterward will override these — this is only the dat-driven default.
@@ -301,6 +352,8 @@ public static class DatWidgetFactory
             Centered         = centered,
             RightAligned     = rightAligned,
             VerticalJustify  = vJustify,
+            OneLine          = oneLine,
+            Selectable       = selectable,
             // Seed the dat-driven font.  When a font resolver was supplied and the element
             // carries a non-zero FontDid, elementFont is the element-specific dat font; otherwise
             // it is the shared global fallback.  Controllers that call FindElement and explicitly