fix: Adjust window sizes and snapping logic for better alignment and docking

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

lib/main.dart

@@ -490,6 +490,10 @@ class _WinampRootState extends State<WinampRoot> {
     final saved = _savedSubPositions[type];
     if (saved != null) {
       rect = Rect.fromLTWH(saved.$1, saved.$2, size.width, size.height);
+      // If the saved position is near the main window's bottom edge within
+      // the snap tolerance, snap it exactly so the window restores docked
+      // rather than merely appearing visually aligned but detached.
+      rect = DockLogic.snapWindowBelow(rect, mainRect, snapLen: _dock.snapLen);
     } else if (_pendingSubBounds.containsKey(window)) {
       rect = _pendingSubBounds[window]!;
     }

lib/src/docking/dock_controller.dart

@@ -10,13 +10,13 @@ import "dock_logic.dart";
 const Map<DockWindow, Size> _mainSizes = {
   DockWindow.main: Size(275, 116),
   DockWindow.eq: Size(275, 116),
-  DockWindow.pl: Size(280, 290),
+  DockWindow.pl: Size(275, 290),
 };
 
 const Map<DockWindow, Size> _shadeSizes = {
   DockWindow.main: Size(275, 14),
   DockWindow.eq: Size(275, 14),
-  DockWindow.pl: Size(280, 14),
+  DockWindow.pl: Size(275, 14),
 };
 
 /// How a moved window rect is applied natively.
@@ -104,7 +104,13 @@ class DockController {
     _attached = DockLogic.dockedBelow(
       rects: _rects,
       dragged: DockWindow.main,
-      snapLen: snapLen,
+      // When beginning a main-window drag we must snapshot only windows
+      // that are truly attached (exactly sitting on the main window's
+      // bottom). Using the configured snapLen here would pick up nearby
+      // windows and cause the main window to "initiate" docking while
+      // dragging, which is incorrect. Use zero tolerance to require exact
+      // edge equality.
+      snapLen: 0.0,
     );
     debugPrint(
       "dock beginMainDrag ptr=${pointer.dx.toStringAsFixed(1)},"
@@ -127,9 +133,22 @@ class DockController {
     Rect target, {
     Set<DockWindow>? attached,
   }) {
-    attached =
-        attached ??
-        DockLogic.dockedBelow(rects: _rects, dragged: driven, snapLen: snapLen);
+    // Prefer an explicit attached set when provided. During an active main
+    // drag prefer the snapshot taken at `beginMainDrag` (`_attached`) so we
+    // never pick up nearby windows via snap tolerance and accidentally make
+    // the main window initiate docking. Otherwise compute the attached set
+    // from current rects using the configured `snapLen`.
+    if (attached == null) {
+      if (_grab != null && _attached != null && driven == DockWindow.main) {
+        attached = _attached!;
+      } else {
+        attached = DockLogic.dockedBelow(
+          rects: _rects,
+          dragged: driven,
+          snapLen: snapLen,
+        );
+      }
+    }
     final prevDriven = _rects[driven];
     if (prevDriven == null) {
       _rects[driven] = target;

lib/src/docking/dock_logic.dart

@@ -127,7 +127,19 @@ abstract final class DockLogic {
   }) {
     if (!_overlaps1(dest.left, dest.right, src.left, src.right)) return src;
     if (!_closeTo(src.top, dest.bottom, snapLen)) return src;
-    return Rect.fromLTWH(src.left, dest.bottom, src.width, src.height);
+    // Snap vertically below `dest`. Additionally, if the src's left edge is
+    // near either of `dest`'s vertical edges (left or right minus src.width),
+    // snap horizontally to the nearest vertical edge so the restored docked
+    // position is aligned both vertically and horizontally.
+    var left = src.left;
+    final leftEdge = dest.left;
+    final rightEdge = dest.right - src.width;
+    final leftDist = (src.left - leftEdge).abs();
+    final rightDist = (src.left - rightEdge).abs();
+    if (leftDist <= snapLen || rightDist <= snapLen) {
+      left = leftDist <= rightDist ? leftEdge : rightEdge;
+    }
+    return Rect.fromLTWH(left, dest.bottom, src.width, src.height);
   }
 
   /// Port of `MoveRect` (DOCK.cpp:81).

lib/src/main_window/playlist_window.dart

@@ -9,13 +9,13 @@ import "../player/player_state.dart";
 import "../skin/skin_cursors.dart";
 import "../windows/sub_window_channel.dart";
 
-const Size _plMainSize = Size(280, 290);
-const Size _plShadeSize = Size(280, 14);
+const Size _plMainSize = Size(275, 290);
+const Size _plShadeSize = Size(275, 14);
 
-const double _plWidth = 280;
+const double _plWidth = 275;
 const double _plShadeHeight = 14;
 const double _listLeft = 12;
-const double _listRight = 260;
+const double _listRight = 255;
 
 /// Visible rows for a 290-tall window: `(290 - 58) / pe_fontheight(13)`.
 const int _numSongs = 17;

lib/src/windows/sub_window_app.dart

@@ -17,8 +17,8 @@ import "window_args.dart";
 
 const Size _eqMainSize = Size(275, 116);
 const Size _eqShadeSize = Size(275, 14);
-const Size _plMainSize = Size(280, 290);
-const Size _plShadeSize = Size(280, 14);
+const Size _plMainSize = Size(275, 290);
+const Size _plShadeSize = Size(275, 14);
 
 /// The root of an Equalizer or Playlist sub-window.
 ///

test/dock_controller_test.dart

@@ -278,7 +278,7 @@ void main() {
     );
     expect(
       DockController.scaledSize(DockWindow.pl, false, 1.2),
-      const Size(336, 348),
+      const Size(330, 348),
     );
   });
 }