Linux with FlatLaf window decorations: fixed occasional maximizing of window when single-clicking the window's title bar (issue #637)

CHANGELOG.md

@@ -27,9 +27,11 @@ FlatLaf Change Log
 - PopupFactory: Fixed NPE on Windows 10 when `owner` is `null`. (issue #952)
 - Popup: On Windows 10, drop shadow of heavy-weight popup was not updated if
   popup moved/resized. (issue #942)
-- FlatLaf window decorations: Minimize and maximize icons were not shown for
+- FlatLaf window decorations:
-  custom scale factors less than 100% (e.g. `-Dflatlaf.uiScale=75%`). (issue
+  - Minimize and maximize icons were not shown for custom scale factors less
-  #951)
+    than 100% (e.g. `-Dflatlaf.uiScale=75%`). (issue #951)
+  - Linux: Fixed occasional maximizing of window when single-clicking the
+    window's title bar. (issue #637)
 - Linux: Popups (menus and combobox lists) were not hidden when window is moved,
   resized, maximized, restored, iconified or switched to another window. (issue
   #962)

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

@@ -33,7 +33,6 @@ import java.awt.Image;
 import java.awt.Insets;
 import java.awt.Point;
 import java.awt.Rectangle;
-import java.awt.Toolkit;
 import java.awt.Window;
 import java.awt.event.ActionListener;
 import java.awt.event.ComponentAdapter;
@@ -1417,22 +1416,9 @@ debug*/
 
 		private Point dragOffset;
 		private boolean linuxNativeMove;
-		private long lastSingleClickWhen;
 
 		@Override
 		public void mouseClicked( MouseEvent e ) {
-			// on Linux, when using native library, the mouse clicked event
-			// is usually not sent and maximize/restore is done in mouse pressed event
-			// this check is here for the case that a mouse clicked event comes through for some reason
-			if( linuxNativeMove && SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
-				// see comment in mousePressed()
-				if( lastSingleClickWhen != 0 && (e.getWhen() - lastSingleClickWhen) <= getMultiClickInterval() ) {
-					lastSingleClickWhen = 0;
-					maximizeOrRestore();
-				}
-				return;
-			}
-
 			if( e.getClickCount() == 2 && SwingUtilities.isLeftMouseButton( e ) ) {
 				if( SwingUtilities.getDeepestComponentAt( FlatTitlePane.this, e.getX(), e.getY() ) == iconLabel ) {
 					// double-click on icon closes window
@@ -1463,42 +1449,6 @@ debug*/
 
 			dragOffset = SwingUtilities.convertPoint( mouseLayer, e.getPoint(), window );
 			linuxNativeMove = false;
-
-			// on Linux, move or maximize/restore window
-			if( SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
-				// The fired Java mouse events, when doing a double-click and the first click
-				// sends a _NET_WM_MOVERESIZE message, are different for various Linux distributions:
-				//   CentOS 7      (GNOME 3.28.2, X11):   PRESSED(clickCount=1) PRESSED(clickCount=2) RELEASED(clickCount=2)
-				//   Ubuntu 20.04  (GNOME 3.36.1, X11):   PRESSED(clickCount=1) PRESSED(clickCount=2) RELEASED(clickCount=2)
-				//   Ubuntu 22.04  (GNOME 42.2, Wayland): PRESSED(clickCount=1)                       RELEASED(clickCount=1) CLICKED(clickCount=1)
-				//   Kubuntu 22.04 (KDE 5.24.4, X11):     PRESSED(clickCount=1) PRESSED(clickCount=1) RELEASED(clickCount=1)
-
-				// double-click is not always recognized in Java when using _NET_WM_MOVERESIZE message
-				int clickCount = e.getClickCount();
-				if( clickCount == 1 && lastSingleClickWhen != 0 && (e.getWhen() - lastSingleClickWhen) <= getMultiClickInterval() )
-					clickCount = 2;
-
-				switch( clickCount ) {
-					case 1:
-						// move window via _NET_WM_MOVERESIZE message
-						e.consume();
-						linuxNativeMove = FlatNativeLinuxLibrary.moveOrResizeWindow( window, e, FlatNativeLinuxLibrary.MOVE );
-						lastSingleClickWhen = e.getWhen();
-						break;
-
-					case 2:
-						// maximize/restore on double-click
-						// also done here because no mouse clicked event is sent when using _NET_WM_MOVERESIZE message
-						lastSingleClickWhen = 0;
-						maximizeOrRestore();
-						break;
-				}
-			}
-		}
-
-		private int getMultiClickInterval() {
-			Object value = Toolkit.getDefaultToolkit().getDesktopProperty( "awt.multiClickInterval" );
-			return (value instanceof Integer) ? (Integer) value : 500;
 		}
 
 		@Override public void mouseReleased( MouseEvent e ) {}
@@ -1521,6 +1471,13 @@ debug*/
 			if( hasNativeCustomDecoration() )
 				return; // do nothing if having native window border
 
+			// on Linux, move window using window manager
+			if( SystemInfo.isLinux && FlatNativeLinuxLibrary.isWMUtilsSupported( window ) ) {
+				linuxNativeMove = FlatNativeLinuxLibrary.moveOrResizeWindow( window, e, FlatNativeLinuxLibrary.MOVE );
+				if( linuxNativeMove )
+					return;
+			}
+
 			// restore window if it is maximized
 			if( window instanceof Frame ) {
 				Frame frame = (Frame) window;