FlatLaf window decorations on Windows: fixed possible application fre…

…eze when using custom component that overrides `Component.contains(int x, int y)` and invokes `SwingUtilities.convertPoint()` (or similar) from the overridden method (issue #878)

CHANGELOG.md

@@ -1,6 +1,16 @@
 FlatLaf Change Log
 ==================
 
+## 3.6-SNAPSHOT
+
+#### Fixed bugs
+
+- FlatLaf window decorations on Windows: Fixed possible application freeze when
+  using custom component that overrides `Component.contains(int x, int y)` and
+  invokes `SwingUtilities.convertPoint()` (or similar) from the overridden
+  method. (issue #878)
+
+
 ## 3.5.1
 
 #### Fixed bugs

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatTitlePane.java

@@ -1079,7 +1079,7 @@ private boolean captionHitTest( Point pt ) {
 	}
 
 	private boolean isTitleBarCaptionAt( Component c, int x, int y ) {
-		if( !c.isDisplayable() || !c.isVisible() || !c.contains( x, y ) || c == mouseLayer )
+		if( !c.isDisplayable() || !c.isVisible() || !contains( c, x, y ) || c == mouseLayer )
 			return true; // continue checking with next component
 
 		if( c.isEnabled() &&
@@ -1131,6 +1131,16 @@ private boolean isTitleBarCaptionAt( Component c, int x, int y ) {
 		return true;
 	}
 
+	/**
+	 * Same as {@link Component#contains(int, int)}, but not using that method
+	 * because it may be overridden by custom components and invoke code that
+	 * tries to request AWT tree lock on 'AWT-Windows' thread.
+	 * This could freeze the application if AWT tree is already locked on 'AWT-EventQueue' thread.
+	 */
+	private boolean contains( Component c, int x, int y ) {
+		return x >= 0 && y >= 0 && x < c.getWidth() && y < c.getHeight();
+	}
+
 	private int lastCaptionHitTestX;
 	private int lastCaptionHitTestY;
 	private long lastCaptionHitTestTime;