Window decorations: do not overwrite maximized bounds if controlled from the application

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

@@ -43,6 +43,7 @@ import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 import javax.accessibility.AccessibleContext;
 import javax.swing.BorderFactory;
 import javax.swing.BoxLayout;
@@ -367,7 +368,11 @@ class FlatTitlePane
 		Frame frame = (Frame) window;
 
 		// set maximized bounds to avoid that maximized window overlaps Windows task bar
-		if( !hasJBRCustomDecoration() ) {
+		// (if not running in JBR and if not modified from the application)
+		if( !hasJBRCustomDecoration() &&
+			(frame.getMaximizedBounds() == null ||
+			 Objects.equals( frame.getMaximizedBounds(), rootPane.getClientProperty( "flatlaf.maximizedBounds" ) )) )
+		{
 			GraphicsConfiguration gc = window.getGraphicsConfiguration();
 
 			// Screen bounds, which may be smaller than physical size on Java 9+.
@@ -415,6 +420,10 @@ class FlatTitlePane
 
 			// change maximized bounds
 			frame.setMaximizedBounds( maximizedBounds );
+
+			// remember maximized bounds in client property to be able to detect
+			// whether maximized bounds are modified from the application
+			rootPane.putClientProperty( "flatlaf.maximizedBounds", maximizedBounds );
 		}
 
 		// maximize window

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatWindowDecorationsTest.java

@@ -73,6 +73,8 @@ public class FlatWindowDecorationsTest
 
 		Window window = SwingUtilities.windowForComponent( this );
 		menuBarCheckBox.setEnabled( window instanceof JFrame );
+		menuBarEmbeddedCheckBox.setEnabled( window instanceof JFrame );
+		maximizedBoundsCheckBox.setEnabled( window instanceof Frame );
 
 		boolean windowHasIcons = (window != null && !window.getIconImages().isEmpty());
 		iconNoneRadioButton.setEnabled( windowHasIcons );
@@ -118,6 +120,15 @@ public class FlatWindowDecorationsTest
 			((Dialog)window).setResizable( resizableCheckBox.isSelected() );
 	}
 
+	private void maximizedBoundsChanged() {
+		Window window = SwingUtilities.windowForComponent( this );
+		if( window instanceof Frame ) {
+			((Frame)window).setMaximizedBounds( maximizedBoundsCheckBox.isSelected()
+				? new Rectangle( 50, 100, 1000, 700 )
+				: null );
+		}
+	}
+
 	private void menuItemActionPerformed(ActionEvent e) {
 		SwingUtilities.invokeLater( () -> {
 			JOptionPane.showMessageDialog( this, e.getActionCommand(), "Menu Item", JOptionPane.PLAIN_MESSAGE );
@@ -189,6 +200,7 @@ public class FlatWindowDecorationsTest
 		menuBarCheckBox = new JCheckBox();
 		menuBarEmbeddedCheckBox = new JCheckBox();
 		resizableCheckBox = new JCheckBox();
+		maximizedBoundsCheckBox = new JCheckBox();
 		JLabel label1 = new JLabel();
 		JLabel label2 = new JLabel();
 		JPanel panel1 = new JPanel();
@@ -265,6 +277,11 @@ public class FlatWindowDecorationsTest
 		resizableCheckBox.addActionListener(e -> resizableChanged());
 		add(resizableCheckBox, "cell 0 2");
 
+		//---- maximizedBoundsCheckBox ----
+		maximizedBoundsCheckBox.setText("maximized bounds (50,100, 1000,700)");
+		maximizedBoundsCheckBox.addActionListener(e -> maximizedBoundsChanged());
+		add(maximizedBoundsCheckBox, "cell 1 2");
+
 		//---- label1 ----
 		label1.setText("Style:");
 		add(label1, "cell 0 3");
@@ -564,6 +581,7 @@ public class FlatWindowDecorationsTest
 	private JCheckBox menuBarCheckBox;
 	private JCheckBox menuBarEmbeddedCheckBox;
 	private JCheckBox resizableCheckBox;
+	private JCheckBox maximizedBoundsCheckBox;
 	private JRadioButton styleNoneRadioButton;
 	private JRadioButton styleFrameRadioButton;
 	private JRadioButton stylePlainRadioButton;

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatWindowDecorationsTest.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.1.0.272" Java: "13.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.2.0.298" Java: "13.0.2" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -45,6 +45,16 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 0 2"
 			} )
+			add( new FormComponent( "javax.swing.JCheckBox" ) {
+				name: "maximizedBoundsCheckBox"
+				"text": "maximized bounds (50,100, 1000,700)"
+				auxiliary() {
+					"JavaCodeGenerator.variableLocal": false
+				}
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "maximizedBoundsChanged", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 2"
+			} )
 			add( new FormComponent( "javax.swing.JLabel" ) {
 				name: "label1"
 				"text": "Style:"