InternalFrame: use default icon in internal frames (issue #122)

CHANGELOG.md

@@ -6,6 +6,8 @@ FlatLaf Change Log
 - Hide focus indicator when window is inactive.
 - Custom window decorations: Improved/fixed window border color in dark themes.
 - Custom window decorations: Hide window border if window is maximized.
+- Custom window decorations: Center title if menu bar is embedded.
+- InternalFrame: Use default icon in internal frames. (issue #122)
 
 
 ## 0.37

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

@@ -26,13 +26,14 @@ import java.beans.PropertyChangeListener;
 import javax.swing.BorderFactory;
 import javax.swing.BoxLayout;
 import javax.swing.Icon;
+import javax.swing.ImageIcon;
 import javax.swing.JInternalFrame;
 import javax.swing.JLabel;
 import javax.swing.JPanel;
 import javax.swing.LookAndFeel;
-import javax.swing.UIManager;
 import javax.swing.border.Border;
 import javax.swing.plaf.basic.BasicInternalFrameTitlePane;
+import com.formdev.flatlaf.util.ScaledImageIcon;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -103,14 +104,16 @@ public class FlatInternalFrameTitlePane
 		add( buttonPanel, BorderLayout.LINE_END );
 	}
 
-	private void updateFrameIcon() {
+	protected void updateFrameIcon() {
 		Icon frameIcon = frame.getFrameIcon();
-		if( frameIcon == UIManager.getIcon( "InternalFrame.icon" ) )
+		if( frameIcon != null && (frameIcon.getIconWidth() == 0 || frameIcon.getIconHeight() == 0) )
 			frameIcon = null;
+		else if( frameIcon instanceof ImageIcon )
+			frameIcon = new ScaledImageIcon( (ImageIcon) frameIcon );
 		titleLabel.setIcon( frameIcon );
 	}
 
-	private void updateColors() {
+	protected void updateColors() {
 		Color background = FlatUIUtils.nonUIResource( frame.isSelected() ? selectedTitleColor : notSelectedTitleColor );
 		Color foreground = FlatUIUtils.nonUIResource( frame.isSelected() ? selectedTextColor : notSelectedTextColor );
 
@@ -123,7 +126,7 @@ public class FlatInternalFrameTitlePane
 		closeButton.setForeground( foreground );
 	}
 
-	private void updateButtonsVisibility() {
+	protected void updateButtonsVisibility() {
 		iconButton.setVisible( frame.isIconifiable() );
 		maxButton.setVisible( frame.isMaximizable() );
 		closeButton.setVisible( frame.isClosable() );

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

@@ -7,6 +7,7 @@ package com.formdev.flatlaf.testing;
 import java.awt.*;
 import java.beans.PropertyVetoException;
 import javax.swing.*;
+import com.formdev.flatlaf.extras.TriStateCheckBox;
 import com.formdev.flatlaf.icons.FlatFileViewFloppyDriveIcon;
 import com.formdev.flatlaf.util.UIScale;
 import net.miginfocom.swing.*;
@@ -50,8 +51,10 @@ public class FlatInternalFrameTest
 			maximizableCheckBox.isSelected(),
 			iconifiableCheckBox.isSelected() );
 
-		if( iconCheckBox.isSelected() )
+		if( iconCheckBox.getState() == TriStateCheckBox.State.SELECTED )
 			internalFrame.setFrameIcon( new FlatFileViewFloppyDriveIcon() );
+		else if( iconCheckBox.getState() == TriStateCheckBox.State.UNSELECTED )
+			internalFrame.setFrameIcon( null );
 
 		if( menuBarCheckBox.isSelected() ) {
 			JMenuBar menuBar = new JMenuBar();
@@ -100,7 +103,7 @@ public class FlatInternalFrameTest
 		closableCheckBox = new JCheckBox();
 		iconifiableCheckBox = new JCheckBox();
 		maximizableCheckBox = new JCheckBox();
-		iconCheckBox = new JCheckBox();
+		iconCheckBox = new TriStateCheckBox();
 		menuBarCheckBox = new JCheckBox();
 		titleLabel = new JLabel();
 		titleField = new JTextField();
@@ -192,7 +195,7 @@ public class FlatInternalFrameTest
 	private JCheckBox closableCheckBox;
 	private JCheckBox iconifiableCheckBox;
 	private JCheckBox maximizableCheckBox;
-	private JCheckBox iconCheckBox;
+	private TriStateCheckBox iconCheckBox;
 	private JCheckBox menuBarCheckBox;
 	private JLabel titleLabel;
 	private JTextField titleField;

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

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.0.0.194" Java: "13.0.1" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.2.0.298" Java: "14" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -50,7 +50,7 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 1 1,alignx left,growx 0"
 					} )
-					add( new FormComponent( "javax.swing.JCheckBox" ) {
+					add( new FormComponent( "com.formdev.flatlaf.extras.TriStateCheckBox" ) {
 						name: "iconCheckBox"
 						"text": "Frame icon"
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {