Window decorations: support toolbox-style "small" window title bar (issue #659)

CHANGELOG.md

@@ -5,6 +5,8 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- FlatLaf window decorations: Support toolbox-style "small" window title bar.
+  (issue #659)
 - Extras: Class `FlatSVGIcon` now uses [JSVG](https://github.com/weisJ/jsvg)
   library (instead of svgSalamander) for rendering. JSVG provides improved SVG
   rendering and uses less memory compared to svgSalamander. (PR #684)

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatClientProperties.java

@@ -17,6 +17,8 @@
 package com.formdev.flatlaf;
 
 import java.awt.Color;
+import java.awt.IllegalComponentStateException;
+import java.awt.Window;
 import java.util.Objects;
 import javax.swing.JComponent;
 import javax.swing.SwingConstants;
@@ -124,6 +126,7 @@ public interface FlatClientProperties
 	 */
 	String SQUARE_SIZE = "JButton.squareSize";
 
+
 	//---- JComponent ---------------------------------------------------------
 
 	/**
@@ -266,6 +269,7 @@ public interface FlatClientProperties
 	 */
 	String COMPONENT_TITLE_BAR_CAPTION = "JComponent.titleBarCaption";
 
+
 	//---- Popup --------------------------------------------------------------
 
 	/**
@@ -305,6 +309,7 @@ public interface FlatClientProperties
 	 */
 	String POPUP_FORCE_HEAVY_WEIGHT = "Popup.forceHeavyWeight";
 
+
 	//---- JProgressBar -------------------------------------------------------
 
 	/**
@@ -323,6 +328,7 @@ public interface FlatClientProperties
 	 */
 	String PROGRESS_BAR_SQUARE = "JProgressBar.square";
 
+
 	//---- JRootPane ----------------------------------------------------------
 
 	/**
@@ -472,6 +478,37 @@ public interface FlatClientProperties
 	 */
 	String GLASS_PANE_FULL_HEIGHT = "JRootPane.glassPaneFullHeight";
 
+	/**
+	 * Specifies the style of the window title bar.
+	 * Besides the default title bar style, you can use a Utility-style title bar,
+	 * which is smaller than the default title bar.
+	 * <p>
+	 * On Windows 10/11, this requires FlatLaf window decorations.
+	 * On macOS, Java supports this out of the box.
+	 * <p>
+	 * Note that this client property must be set before the window becomes displayable.
+	 * Otherwise an {@link IllegalComponentStateException} is thrown.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JRootPane}<br>
+	 * <strong>Value type</strong> {@link java.lang.String}<br>
+	 * <strong>Allowed Values</strong>
+	 *     {@link #WINDOW_STYLE_SMALL}
+	 *
+	 * @since 3.2
+	 */
+	String WINDOW_STYLE = "Window.style";
+
+	/**
+	 * The window has Utility-style title bar, which is smaller than default title bar.
+	 * <p>
+	 * This is the same as using {@link Window#setType}( {@link Window.Type#UTILITY} ).
+	 *
+	 * @see #WINDOW_STYLE
+	 * @since 3.2
+	 */
+	String WINDOW_STYLE_SMALL = "small";
+
+
 	//---- JScrollBar / JScrollPane -------------------------------------------
 
 	/**
@@ -490,6 +527,7 @@ public interface FlatClientProperties
 	 */
 	String SCROLL_PANE_SMOOTH_SCROLLING = "JScrollPane.smoothScrolling";
 
+
 	//---- JSplitPane ---------------------------------------------------------
 
 	/**
@@ -524,6 +562,7 @@ public interface FlatClientProperties
 	 */
 	String SPLIT_PANE_EXPANDABLE_SIDE_RIGHT = "right";
 
+
 	//---- JTabbedPane --------------------------------------------------------
 
 	/**
@@ -919,6 +958,7 @@ public interface FlatClientProperties
 	 */
 	String TABBED_PANE_TRAILING_COMPONENT = "JTabbedPane.trailingComponent";
 
+
 	//---- JTextField ---------------------------------------------------------
 
 	/**
@@ -1088,6 +1128,7 @@ public interface FlatClientProperties
 	 */
 	String TEXT_FIELD_CLEAR_CALLBACK = "JTextField.clearCallback";
 
+
 	//---- JToggleButton ------------------------------------------------------
 
 	/**
@@ -1129,6 +1170,7 @@ public interface FlatClientProperties
 	 */
 	String TAB_BUTTON_SELECTED_BACKGROUND = "JToggleButton.tab.selectedBackground";
 
+
 	//---- JTree --------------------------------------------------------------
 
 	/**
@@ -1148,6 +1190,7 @@ public interface FlatClientProperties
 	 */
 	String TREE_PAINT_SELECTION = "JTree.paintSelection";
 
+
 	//---- helper methods -----------------------------------------------------
 
 	/**

flatlaf-core/src/main/java/com/formdev/flatlaf/UIDefaultsLoader.java

@@ -27,8 +27,12 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.StreamTokenizer;
 import java.io.StringReader;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
+import java.lang.reflect.Method;
 import java.net.URL;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -548,7 +552,7 @@ class UIDefaultsLoader
 			case INTEGERORFLOAT:return parseIntegerOrFloat( value );
 			case FLOAT:			return parseFloat( value );
 			case BORDER:		return parseBorder( value, resolver, addonClassLoaders );
-			case ICON:			return parseInstance( value, addonClassLoaders );
+			case ICON:			return parseInstance( value, resolver, addonClassLoaders );
 			case INSETS:		return parseInsets( value );
 			case DIMENSION:		return parseDimension( value );
 			case COLOR:			return parseColorOrFunction( value, resolver );
@@ -557,7 +561,7 @@ class UIDefaultsLoader
 			case SCALEDFLOAT:	return parseScaledFloat( value );
 			case SCALEDINSETS:	return parseScaledInsets( value );
 			case SCALEDDIMENSION:return parseScaledDimension( value );
-			case INSTANCE:		return parseInstance( value, addonClassLoaders );
+			case INSTANCE:		return parseInstance( value, resolver, addonClassLoaders );
 			case CLASS:			return parseClass( value, addonClassLoaders );
 			case GRAYFILTER:	return parseGrayFilter( value );
 			case UNKNOWN:
@@ -623,7 +627,7 @@ class UIDefaultsLoader
 		throws IllegalArgumentException
 	{
 		if( value.indexOf( ',' ) >= 0 ) {
-			// top,left,bottom,right[,lineColor[,lineThickness[,arc]]]
+			// Syntax: top,left,bottom,right[,lineColor[,lineThickness[,arc]]]
 			List<String> parts = splitFunctionParams( value, ',' );
 			Insets insets = parseInsets( value );
 			ColorUIResource lineColor = (parts.size() >= 5)
@@ -638,12 +642,28 @@ class UIDefaultsLoader
 					: new FlatEmptyBorder( insets );
 			};
 		} else
-			return parseInstance( value, addonClassLoaders );
+			return parseInstance( value, resolver, addonClassLoaders );
 	}
 
-	private static Object parseInstance( String value, List<ClassLoader> addonClassLoaders ) {
+	private static Object parseInstance( String value, Function<String, String> resolver, List<ClassLoader> addonClassLoaders ) {
 		return (LazyValue) t -> {
 			try {
+				if( value.indexOf( ',' ) >= 0 ) {
+					// Syntax: className,param1,param2,...
+					List<String> parts = splitFunctionParams( value, ',' );
+					String className = parts.get( 0 );
+					Class<?> cls = findClass( className, addonClassLoaders );
+
+					Constructor<?>[] constructors = cls.getDeclaredConstructors();
+					Object result = invokeConstructorOrStaticMethod( constructors, parts, resolver );
+					if( result != null )
+						return result;
+
+					LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to instantiate '" + className
+						+ "': no constructor found for parameters '"
+						+ value.substring( value.indexOf( ',' + 1 ) ) + "'.", null );
+					return null;
+				} else
 					return findClass( value, addonClassLoaders ).getDeclaredConstructor().newInstance();
 			} catch( Exception ex ) {
 				LoggingFacade.INSTANCE.logSevere( "FlatLaf: Failed to instantiate '" + value + "'.", ex );
@@ -1466,6 +1486,86 @@ class UIDefaultsLoader
 		return strs;
 	}
 
+	private static Object invokeConstructorOrStaticMethod( Executable[] constructorsOrMethods,
+			List<String> parts, Function<String, String> resolver )
+		throws Exception
+	{
+		// order constructors/methods by parameter types:
+		// - String parameters to the end
+		// - int before float parameters
+		constructorsOrMethods = constructorsOrMethods.clone();
+		Arrays.sort( constructorsOrMethods, (c1, c2) -> {
+			Class<?>[] ptypes1 = c1.getParameterTypes();
+			Class<?>[] ptypes2 = c2.getParameterTypes();
+			if( ptypes1.length != ptypes2.length )
+				return ptypes1.length - ptypes2.length;
+
+			for( int i = 0; i < ptypes1.length; i++ ) {
+				Class<?> pt1 = ptypes1[i];
+				Class<?> pt2 = ptypes2[i];
+
+				if( pt1 == pt2 )
+					continue;
+
+				// order methods with String parameters to the end
+				if( pt1 == String.class )
+					return 2;
+				if( pt2 == String.class )
+					return -2;
+
+				// order int before float
+				if( pt1 == int.class )
+					return -1;
+				if( pt2 == int.class )
+					return 1;
+			}
+			return 0;
+		} );
+
+		// search for best constructor/method for given parameter values
+		for( Executable cm : constructorsOrMethods ) {
+			if( cm.getParameterCount() != parts.size() - 1 )
+				continue;
+
+			Object[] params = parseMethodParams( cm.getParameterTypes(), parts, resolver );
+			if( params == null )
+				continue;
+
+			// invoke constructor or static method
+			if( cm instanceof Constructor )
+				return ((Constructor<?>)cm).newInstance( params );
+			else
+				return ((Method)cm).invoke( null, params );
+		}
+
+		return null;
+	}
+
+	private static Object[] parseMethodParams( Class<?>[] paramTypes, List<String> parts, Function<String, String> resolver ) {
+		Object[] params = new Object[paramTypes.length];
+		try {
+			for( int i = 0; i < params.length; i++ ) {
+				Class<?> paramType = paramTypes[i];
+				String paramValue = parts.get( i + 1 );
+				if( paramType == String.class )
+					params[i] = paramValue;
+				else if( paramType == boolean.class )
+					params[i] = parseBoolean( paramValue );
+				else if( paramType == int.class )
+					params[i] = parseInteger( paramValue );
+				else if( paramType == float.class )
+					params[i] = parseFloat( paramValue );
+				else if( paramType == Color.class )
+					params[i] = parseColorOrFunction( resolver.apply( paramValue ), resolver );
+				else
+					return null; // unsupported parameter type
+			}
+		} catch( IllegalArgumentException ex ) {
+			return null; // failed to parse parameter for expected parameter type
+		}
+		return params;
+	}
+
 	/**
 	 * For use in LazyValue to get value for given key from UIManager and report error
 	 * if not found. If key is prefixed by '?', then no error is reported.

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowAbstractIcon.java

@@ -21,7 +21,6 @@ import java.awt.Component;
 import java.awt.Dimension;
 import java.awt.Graphics2D;
 import java.awt.RenderingHints;
-import javax.swing.UIManager;
 import com.formdev.flatlaf.ui.FlatButtonUI;
 import com.formdev.flatlaf.ui.FlatUIUtils;
 import com.formdev.flatlaf.util.HiDPIUtils;
@@ -30,6 +29,7 @@ import com.formdev.flatlaf.util.HiDPIUtils;
  * Base class for window icons.
  *
  * @uiDefault TitlePane.buttonSize						Dimension
+ * @uiDefault TitlePane.buttonSymbolHeight				int
  * @uiDefault TitlePane.buttonHoverBackground			Color
  * @uiDefault TitlePane.buttonPressedBackground			Color
  *
@@ -38,17 +38,22 @@ import com.formdev.flatlaf.util.HiDPIUtils;
 public abstract class FlatWindowAbstractIcon
 	extends FlatAbstractIcon
 {
+	private final int symbolHeight;
 	private final Color hoverBackground;
 	private final Color pressedBackground;
 
-	public FlatWindowAbstractIcon() {
+	/** @since 3.2 */
-		this( UIManager.getDimension( "TitlePane.buttonSize" ),
+	protected FlatWindowAbstractIcon( String windowStyle ) {
-			UIManager.getColor( "TitlePane.buttonHoverBackground" ),
+		this( FlatUIUtils.getSubUIDimension( "TitlePane.buttonSize", windowStyle ),
-			UIManager.getColor( "TitlePane.buttonPressedBackground" ) );
+			FlatUIUtils.getSubUIInt( "TitlePane.buttonSymbolHeight", windowStyle, 10 ),
+			FlatUIUtils.getSubUIColor( "TitlePane.buttonHoverBackground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.buttonPressedBackground", windowStyle ) );
 	}
 
-	public FlatWindowAbstractIcon( Dimension size, Color hoverBackground, Color pressedBackground ) {
+	/** @since 3.2 */
+	protected FlatWindowAbstractIcon( Dimension size, int symbolHeight, Color hoverBackground, Color pressedBackground ) {
 		super( size.width, size.height, null );
+		this.symbolHeight = symbolHeight;
 		this.hoverBackground = hoverBackground;
 		this.pressedBackground = pressedBackground;
 	}
@@ -80,4 +85,9 @@ public abstract class FlatWindowAbstractIcon
 	protected Color getForeground( Component c ) {
 		return c.getForeground();
 	}
+
+	/** @since 3.2 */
+	protected int getSymbolHeight() {
+		return symbolHeight;
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowCloseIcon.java

@@ -21,8 +21,8 @@ import java.awt.Color;
 import java.awt.Component;
 import java.awt.Graphics2D;
 import java.awt.geom.Path2D;
-import javax.swing.UIManager;
 import com.formdev.flatlaf.ui.FlatButtonUI;
+import com.formdev.flatlaf.ui.FlatUIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
@@ -38,18 +38,27 @@ import com.formdev.flatlaf.util.SystemInfo;
 public class FlatWindowCloseIcon
 	extends FlatWindowAbstractIcon
 {
-	private final Color hoverForeground = UIManager.getColor( "TitlePane.closeHoverForeground" );
+	private final Color hoverForeground;
-	private final Color pressedForeground = UIManager.getColor( "TitlePane.closePressedForeground" );
+	private final Color pressedForeground;
 
 	public FlatWindowCloseIcon() {
-		super( UIManager.getDimension( "TitlePane.buttonSize" ),
+		this( null );
-			UIManager.getColor( "TitlePane.closeHoverBackground" ),
+	}
-			UIManager.getColor( "TitlePane.closePressedBackground" ) );
+
+	/** @since 3.2 */
+	public FlatWindowCloseIcon( String windowStyle ) {
+		super( FlatUIUtils.getSubUIDimension( "TitlePane.buttonSize", windowStyle ),
+			FlatUIUtils.getSubUIInt( "TitlePane.buttonSymbolHeight", windowStyle, 10 ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closeHoverBackground", windowStyle ),
+			FlatUIUtils.getSubUIColor( "TitlePane.closePressedBackground", windowStyle ) );
+
+		hoverForeground = FlatUIUtils.getSubUIColor( "TitlePane.closeHoverForeground", windowStyle );
+		pressedForeground = FlatUIUtils.getSubUIColor( "TitlePane.closePressedForeground", windowStyle );
 	}
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (10 * scaleFactor);
+		int iwh = (int) (getSymbolHeight() * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
 		int ix2 = ix + iwh - 1;

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowIconifyIcon.java

@@ -27,11 +27,17 @@ public class FlatWindowIconifyIcon
 	extends FlatWindowAbstractIcon
 {
 	public FlatWindowIconifyIcon() {
+		this( null );
+	}
+
+	/** @since 3.2 */
+	public FlatWindowIconifyIcon( String windowStyle ) {
+		super( windowStyle );
 	}
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iw = (int) (10 * scaleFactor);
+		int iw = (int) (getSymbolHeight() * scaleFactor);
 		int ih = (int) scaleFactor;
 		int ix = x + ((width - iw) / 2);
 		int iy = y + ((height - ih) / 2);

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowMaximizeIcon.java

@@ -29,11 +29,17 @@ public class FlatWindowMaximizeIcon
 	extends FlatWindowAbstractIcon
 {
 	public FlatWindowMaximizeIcon() {
+		this( null );
+	}
+
+	/** @since 3.2 */
+	public FlatWindowMaximizeIcon( String windowStyle ) {
+		super( windowStyle );
 	}
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (10 * scaleFactor);
+		int iwh = (int) (getSymbolHeight() * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
 		float thickness = SystemInfo.isWindows_11_orLater ? (float) scaleFactor : (int) scaleFactor;

flatlaf-core/src/main/java/com/formdev/flatlaf/icons/FlatWindowRestoreIcon.java

@@ -32,18 +32,24 @@ public class FlatWindowRestoreIcon
 	extends FlatWindowAbstractIcon
 {
 	public FlatWindowRestoreIcon() {
+		this( null );
+	}
+
+	/** @since 3.2 */
+	public FlatWindowRestoreIcon( String windowStyle ) {
+		super( windowStyle );
 	}
 
 	@Override
 	protected void paintIconAt1x( Graphics2D g, int x, int y, int width, int height, double scaleFactor ) {
-		int iwh = (int) (10 * scaleFactor);
+		int iwh = (int) (getSymbolHeight() * scaleFactor);
 		int ix = x + ((width - iwh) / 2);
 		int iy = y + ((height - iwh) / 2);
 		float thickness = SystemInfo.isWindows_11_orLater ? (float) scaleFactor : (int) scaleFactor;
 		int arc = Math.max( (int) (1.5 * scaleFactor), 2 );
 		int arcOuter = (int) (arc + (1.5 * scaleFactor));
 
-		int rwh = (int) (8 * scaleFactor);
+		int rwh = (int) ((getSymbolHeight() - 2) * scaleFactor);
 		int ro2 = iwh - rwh;
 
 		// upper-right rectangle

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

@@ -23,6 +23,7 @@ import java.awt.Dimension;
 import java.awt.Frame;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
+import java.awt.IllegalComponentStateException;
 import java.awt.Insets;
 import java.awt.LayoutManager;
 import java.awt.LayoutManager2;
@@ -366,6 +367,11 @@ public class FlatRootPaneUI
 			case FlatClientProperties.GLASS_PANE_FULL_HEIGHT:
 				rootPane.revalidate();
 				break;
+
+			case FlatClientProperties.WINDOW_STYLE:
+				if( rootPane.isDisplayable() )
+					throw new IllegalComponentStateException( "The client property 'Window.style' must be set before the window becomes displayable." );
+				break;
 		}
 	}
 

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

@@ -97,6 +97,7 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault TitlePane.centerTitleIfMenuBarEmbedded		boolean
  * @uiDefault TitlePane.showIconBesideTitle					boolean
  * @uiDefault TitlePane.menuBarTitleGap						int
+ * @uiDefault TitlePane.menuBarTitleMinimumGap				int
  * @uiDefault TitlePane.menuBarResizeHeight					int
  * @uiDefault TitlePane.closeIcon							Icon
  * @uiDefault TitlePane.iconifyIcon							Icon
@@ -110,29 +111,30 @@ public class FlatTitlePane
 {
 	private static final String KEY_DEBUG_SHOW_RECTANGLES = "FlatLaf.debug.titlebar.showRectangles";
 
-	/** @since 2.5 */ protected final Font titleFont = UIManager.getFont( "TitlePane.font" );
+	/** @since 2.5 */ protected final Font titleFont;
-	protected final Color activeBackground = UIManager.getColor( "TitlePane.background" );
+	protected final Color activeBackground;
-	protected final Color inactiveBackground = UIManager.getColor( "TitlePane.inactiveBackground" );
+	protected final Color inactiveBackground;
-	protected final Color activeForeground = UIManager.getColor( "TitlePane.foreground" );
+	protected final Color activeForeground;
-	protected final Color inactiveForeground = UIManager.getColor( "TitlePane.inactiveForeground" );
+	protected final Color inactiveForeground;
-	protected final Color embeddedForeground = UIManager.getColor( "TitlePane.embeddedForeground" );
+	protected final Color embeddedForeground;
-	protected final Color borderColor = UIManager.getColor( "TitlePane.borderColor" );
+	protected final Color borderColor;
 
-	/** @since 2 */ protected final boolean showIcon = FlatUIUtils.getUIBoolean( "TitlePane.showIcon", true );
+	/** @since 2 */ protected final boolean showIcon;
-	/** @since 2.5 */ protected final boolean showIconInDialogs = FlatUIUtils.getUIBoolean( "TitlePane.showIconInDialogs", true );
+	/** @since 2.5 */ protected final boolean showIconInDialogs;
-	/** @since 2 */ protected final int noIconLeftGap = FlatUIUtils.getUIInt( "TitlePane.noIconLeftGap", 8 );
+	/** @since 2 */ protected final int noIconLeftGap;
-	protected final Dimension iconSize = UIManager.getDimension( "TitlePane.iconSize" );
+	protected final Dimension iconSize;
-	/** @since 2.4 */ protected final int titleMinimumWidth = FlatUIUtils.getUIInt( "TitlePane.titleMinimumWidth", 60 );
+	/** @since 2.4 */ protected final int titleMinimumWidth;
-	/** @since 2.4 */ protected final int buttonMinimumWidth = FlatUIUtils.getUIInt( "TitlePane.buttonMinimumWidth", 30 );
+	/** @since 2.4 */ protected final int buttonMinimumWidth;
-	protected final int buttonMaximizedHeight = UIManager.getInt( "TitlePane.buttonMaximizedHeight" );
+	protected final int buttonMaximizedHeight;
-	protected final boolean centerTitle = UIManager.getBoolean( "TitlePane.centerTitle" );
+	protected final boolean centerTitle;
-	protected final boolean centerTitleIfMenuBarEmbedded = FlatUIUtils.getUIBoolean( "TitlePane.centerTitleIfMenuBarEmbedded", true );
+	protected final boolean centerTitleIfMenuBarEmbedded;
-	/** @since 2.4 */ protected final boolean showIconBesideTitle = UIManager.getBoolean( "TitlePane.showIconBesideTitle" );
+	/** @since 2.4 */ protected final boolean showIconBesideTitle;
-	protected final int menuBarTitleGap = FlatUIUtils.getUIInt( "TitlePane.menuBarTitleGap", 40 );
+	protected final int menuBarTitleGap;
-	/** @since 2.4 */ protected final int menuBarTitleMinimumGap = FlatUIUtils.getUIInt( "TitlePane.menuBarTitleMinimumGap", 12 );
+	/** @since 2.4 */ protected final int menuBarTitleMinimumGap;
-	/** @since 2.4 */ protected final int menuBarResizeHeight = FlatUIUtils.getUIInt( "TitlePane.menuBarResizeHeight", 4 );
+	/** @since 2.4 */ protected final int menuBarResizeHeight;
 
 	protected final JRootPane rootPane;
+	protected final String windowStyle;
 
 	protected JPanel leftPanel;
 	protected JLabel iconLabel;
@@ -151,6 +153,34 @@ public class FlatTitlePane
 	public FlatTitlePane( JRootPane rootPane ) {
 		this.rootPane = rootPane;
 
+		Window w = SwingUtilities.getWindowAncestor( rootPane );
+		String defaultWindowStyle = (w != null && w.getType() == Window.Type.UTILITY) ? WINDOW_STYLE_SMALL : null;
+		windowStyle = clientProperty( rootPane, WINDOW_STYLE, defaultWindowStyle, String.class );
+
+		titleFont = FlatUIUtils.getSubUIFont( "TitlePane.font", windowStyle );
+		activeBackground = FlatUIUtils.getSubUIColor( "TitlePane.background", windowStyle );
+		inactiveBackground = FlatUIUtils.getSubUIColor( "TitlePane.inactiveBackground", windowStyle );
+		activeForeground = FlatUIUtils.getSubUIColor( "TitlePane.foreground", windowStyle );
+		inactiveForeground = FlatUIUtils.getSubUIColor( "TitlePane.inactiveForeground", windowStyle );
+		embeddedForeground = FlatUIUtils.getSubUIColor( "TitlePane.embeddedForeground", windowStyle );
+		// not using windowStyle here because TitlePane.borderColor is also used in FlatRootPaneUI
+		borderColor = UIManager.getColor( "TitlePane.borderColor" );
+
+		showIcon = FlatUIUtils.getSubUIBoolean( "TitlePane.showIcon", windowStyle, true );
+		showIconInDialogs = FlatUIUtils.getSubUIBoolean( "TitlePane.showIconInDialogs", windowStyle, true );
+		noIconLeftGap = FlatUIUtils.getSubUIInt( "TitlePane.noIconLeftGap", windowStyle, 8 );
+		iconSize = FlatUIUtils.getSubUIDimension( "TitlePane.iconSize", windowStyle );
+		titleMinimumWidth = FlatUIUtils.getSubUIInt( "TitlePane.titleMinimumWidth", windowStyle, 60 );
+		buttonMinimumWidth = FlatUIUtils.getSubUIInt( "TitlePane.buttonMinimumWidth", windowStyle, 30 );
+		buttonMaximizedHeight = FlatUIUtils.getSubUIInt( "TitlePane.buttonMaximizedHeight", windowStyle, 0 );
+		centerTitle = FlatUIUtils.getSubUIBoolean( "TitlePane.centerTitle", windowStyle, false );
+		centerTitleIfMenuBarEmbedded = FlatUIUtils.getSubUIBoolean( "TitlePane.centerTitleIfMenuBarEmbedded", windowStyle, true );
+		showIconBesideTitle = FlatUIUtils.getSubUIBoolean( "TitlePane.showIconBesideTitle", windowStyle, false );
+		menuBarTitleGap = FlatUIUtils.getSubUIInt( "TitlePane.menuBarTitleGap", windowStyle, 40 );
+		menuBarTitleMinimumGap = FlatUIUtils.getSubUIInt( "TitlePane.menuBarTitleMinimumGap", windowStyle, 12 );
+		menuBarResizeHeight = FlatUIUtils.getSubUIInt( "TitlePane.menuBarResizeHeight", windowStyle, 4 );
+
+
 		handler = createHandler();
 		setBorder( createTitlePaneBorder() );
 
@@ -183,8 +213,8 @@ public class FlatTitlePane
 				setUI( new FlatTitleLabelUI() );
 			}
 		};
-		iconLabel.setBorder( new FlatEmptyBorder( UIManager.getInsets( "TitlePane.iconMargins" ) ) );
+		iconLabel.setBorder( new FlatEmptyBorder( FlatUIUtils.getSubUIInsets( "TitlePane.iconMargins", windowStyle ) ) );
-		titleLabel.setBorder( new FlatEmptyBorder( UIManager.getInsets( "TitlePane.titleMargins" ) ) );
+		titleLabel.setBorder( new FlatEmptyBorder( FlatUIUtils.getSubUIInsets( "TitlePane.titleMargins", windowStyle ) ) );
 
 		leftPanel.setLayout( new BoxLayout( leftPanel, BoxLayout.LINE_AXIS ) );
 		leftPanel.setOpaque( false );
@@ -311,7 +341,7 @@ public class FlatTitlePane
 	}
 
 	protected JButton createButton( String iconKey, String accessibleName, ActionListener action ) {
-		JButton button = new JButton( UIManager.getIcon( iconKey ) ) {
+		JButton button = new JButton( FlatUIUtils.getSubUIIcon( iconKey, windowStyle ) ) {
 			@Override
 			public Dimension getMinimumSize() {
 				// allow the button to shrink if space is rare

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

@@ -39,10 +39,12 @@ import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JToolBar;
 import javax.swing.LayoutFocusTraversalPolicy;
+import javax.swing.RootPaneContainer;
 import javax.swing.UIManager;
 import javax.swing.border.Border;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicToolBarUI;
+import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.LoggingFacade;
@@ -156,6 +158,13 @@ public class FlatToolBarUI
 		}
 	}
 
+	@Override
+	protected RootPaneContainer createFloatingWindow( JToolBar toolbar ) {
+		RootPaneContainer floatingWindow = super.createFloatingWindow( toolbar );
+		floatingWindow.getRootPane().putClientProperty( FlatClientProperties.WINDOW_STYLE, FlatClientProperties.WINDOW_STYLE_SMALL );
+		return floatingWindow;
+	}
+
 	@Override
 	protected ContainerListener createToolBarContListener() {
 		return new ToolBarContListener() {

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

@@ -46,6 +46,7 @@ import java.util.IdentityHashMap;
 import java.util.WeakHashMap;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
+import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
 import javax.swing.JTable;
@@ -166,6 +167,88 @@ public class FlatUIUtils
 		return defaultValue;
 	}
 
+	/** @since 3.2 */
+	public static Color getSubUIColor( String key, String subKey ) {
+		if( subKey != null ) {
+			Color value = UIManager.getColor( buildSubKey( key, subKey ) );
+			if( value != null )
+				return value;
+		}
+		return UIManager.getColor( key );
+	}
+
+	/** @since 3.2 */
+	public static boolean getSubUIBoolean( String key, String subKey, boolean defaultValue ) {
+		if( subKey != null ) {
+			Object value = UIManager.get( buildSubKey( key, subKey ) );
+			if( value instanceof Boolean )
+				return (Boolean) value;
+		}
+		return getUIBoolean( key, defaultValue );
+	}
+
+	/** @since 3.2 */
+	public static int getSubUIInt( String key, String subKey, int defaultValue ) {
+		if( subKey != null ) {
+			Object value = UIManager.get( buildSubKey( key, subKey ) );
+			if( value instanceof Integer )
+				return (Integer) value;
+		}
+		return getUIInt( key, defaultValue );
+	}
+
+	/** @since 3.2 */
+	public static Insets getSubUIInsets( String key, String subKey ) {
+		if( subKey != null ) {
+			Insets value = UIManager.getInsets( buildSubKey( key, subKey ) );
+			if( value != null )
+				return value;
+		}
+		return UIManager.getInsets( key );
+	}
+
+	/** @since 3.2 */
+	public static Dimension getSubUIDimension( String key, String subKey ) {
+		if( subKey != null ) {
+			Dimension value = UIManager.getDimension( buildSubKey( key, subKey ) );
+			if( value != null )
+				return value;
+		}
+		return UIManager.getDimension( key );
+	}
+
+	/** @since 3.2 */
+	public static Icon getSubUIIcon( String key, String subKey ) {
+		if( subKey != null ) {
+			Icon value = UIManager.getIcon( buildSubKey( key, subKey ) );
+			if( value != null )
+				return value;
+		}
+		return UIManager.getIcon( key );
+	}
+
+	/** @since 3.2 */
+	public static Font getSubUIFont( String key, String subKey ) {
+		if( subKey != null ) {
+			Font value = UIManager.getFont( buildSubKey( key, subKey ) );
+			if( value != null )
+				return value;
+		}
+		return UIManager.getFont( key );
+	}
+
+	/**
+	 * Inserts {@code subKey} at last dot in {@code key}.
+	 * <p>
+	 * E.g. {@code buildSubKey( "TitlePane.font", "small" )} returns {@code "TitlePane.small.font"}.
+	 */
+	private static String buildSubKey( String key, String subKey ) {
+		int dot = key.lastIndexOf( '.' );
+		return (dot >= 0)
+			? key.substring( 0, dot ) + '.' + subKey + '.' + key.substring( dot + 1 )
+			: key;
+	}
+
 	/** @since 1.1.2 */
 	public static boolean getBoolean( JComponent c, String systemPropertyKey,
 		String clientPropertyKey, String uiKey, boolean defaultValue )

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -808,6 +808,7 @@ TitlePane.titleMinimumWidth = 60
 TitlePane.buttonSize = 44,30
 TitlePane.buttonMinimumWidth = 30
 TitlePane.buttonMaximizedHeight = 22
+TitlePane.buttonSymbolHeight = 10
 TitlePane.centerTitle = false
 TitlePane.centerTitleIfMenuBarEmbedded = true
 TitlePane.showIconBesideTitle = false
@@ -829,6 +830,16 @@ TitlePane.closePressedBackground = fade($TitlePane.closeHoverBackground,90%)
 TitlePane.closeHoverForeground = #fff
 TitlePane.closePressedForeground = #fff
 
+# window style "small"
+TitlePane.small.font = -1
+TitlePane.small.showIcon = false
+TitlePane.small.buttonSize = 30,20
+TitlePane.small.buttonSymbolHeight = 8
+TitlePane.small.closeIcon = com.formdev.flatlaf.icons.FlatWindowCloseIcon, small
+TitlePane.small.iconifyIcon = com.formdev.flatlaf.icons.FlatWindowIconifyIcon, small
+TitlePane.small.maximizeIcon = com.formdev.flatlaf.icons.FlatWindowMaximizeIcon, small
+TitlePane.small.restoreIcon = com.formdev.flatlaf.icons.FlatWindowRestoreIcon, small
+
 
 #---- ToggleButton ----
 

flatlaf-core/src/test/java/com/formdev/flatlaf/TestUIDefaultsLoader.java

@@ -21,6 +21,7 @@ import java.awt.Color;
 import java.awt.Dimension;
 import java.awt.Font;
 import java.awt.Insets;
+import java.util.Objects;
 import javax.swing.UIManager;
 import javax.swing.border.Border;
 import javax.swing.UIDefaults.ActiveValue;
@@ -153,4 +154,102 @@ public class TestUIDefaultsLoader
 			new Font( name, style, size ),
 			((ActiveValue)UIDefaultsLoader.parseValue( "dummyFont", actualStyle, null )).createValue( null ) );
 	}
+
+	@Test
+	void parseInstance() {
+		String className = TestInstance.class.getName();
+		assertEquals( new TestInstance(), ((LazyValue)UIDefaultsLoader.parseValue( "dummyIcon", className, null )).createValue( null ) );
+		assertInstanceEquals( new TestInstance(), null );
+		assertInstanceEquals( new TestInstance( "some string" ), "some string" );
+		assertInstanceEquals( new TestInstance( false ), "false" );
+		assertInstanceEquals( new TestInstance( true ), "true" );
+		assertInstanceEquals( new TestInstance( 123 ), "123" );
+		assertInstanceEquals( new TestInstance( 123.456f ), "123.456" );
+		assertInstanceEquals( new TestInstance( Color.red ), "#f00" );
+		assertInstanceEquals( new TestInstance( "some string", true ), "some string, true" );
+		assertInstanceEquals( new TestInstance( "some string", true, 123 ), "some string, true, 123" );
+		assertInstanceEquals( new TestInstance( "some string", 123, true ), "some string, 123, true" );
+		assertInstanceEquals( new TestInstance( "some string", 123.456f, true ), "some string, 123.456, true" );
+		assertInstanceEquals( new TestInstance( 123, "some string" ), "123, some string" );
+	}
+
+	private void assertInstanceEquals( TestInstance expected, String params ) {
+		String value = TestInstance.class.getName() + (params != null ? "," + params : "");
+		assertEquals( expected, ((LazyValue)UIDefaultsLoader.parseValue( "dummyIcon", value, null )).createValue( null ) );
+	}
+
+	//---- class TestInstance -------------------------------------------------
+
+	public static class TestInstance
+	{
+		private String s;
+		private boolean b;
+		private int i;
+		private float f;
+		private Color color;
+
+		public TestInstance() {
+		}
+
+		public TestInstance( String s ) {
+			this.s = s;
+		}
+
+		public TestInstance( boolean b ) {
+			this.b = b;
+		}
+
+		public TestInstance( int i ) {
+			this.i = i;
+		}
+
+		public TestInstance( float f ) {
+			this.f = f;
+		}
+
+		public TestInstance( Color color ) {
+			this.color = color;
+		}
+
+		public TestInstance( String s, boolean b ) {
+			this.s = s;
+			this.b = b;
+		}
+
+		public TestInstance( String s, boolean b, int i ) {
+			this.s = s;
+			this.b = b;
+			this.i = i;
+		}
+
+		public TestInstance( String s, int i, boolean b ) {
+			this.s = s;
+			this.b = b;
+			this.i = i;
+		}
+
+		public TestInstance( String s, float f, boolean b ) {
+			this.s = s;
+			this.b = b;
+			this.f = f;
+		}
+
+		protected TestInstance( int i, String s ) {
+			this.s = s;
+			this.i = i;
+		}
+
+		@Override
+		public boolean equals( Object obj ) {
+			if( !(obj instanceof TestInstance) )
+				return false;
+
+			TestInstance inst = (TestInstance) obj;
+			return Objects.equals( s, inst.s ) &&
+				b == inst.b &&
+				i == inst.i &&
+				f == inst.f &&
+				Objects.equals( color, inst.color );
+		}
+	}
 }

flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0.txt

@@ -1238,6 +1238,7 @@ TitlePane.buttonMaximizedHeight 22
 TitlePane.buttonMinimumWidth   30
 TitlePane.buttonPressedBackground #484c4f  HSL 206   5  30    com.formdev.flatlaf.util.DerivedColor [UI]    lighten(10% autoInverse)
 TitlePane.buttonSize           44,30    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.buttonSymbolHeight   10
 TitlePane.centerTitle          false
 TitlePane.centerTitleIfMenuBarEmbedded true
 TitlePane.closeHoverBackground #c42b1c  HSL   5  75  44    javax.swing.plaf.ColorUIResource [UI]
@@ -1264,6 +1265,14 @@ TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWin
 TitlePane.showIcon             true
 TitlePane.showIconBesideTitle  false
 TitlePane.showIconInDialogs    true
+TitlePane.small.buttonSize     30,20    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.small.buttonSymbolHeight 8
+TitlePane.small.closeIcon      [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowCloseIcon [UI]
+TitlePane.small.font           [active] Segoe UI plain 11    javax.swing.plaf.FontUIResource [UI]
+TitlePane.small.iconifyIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowIconifyIcon [UI]
+TitlePane.small.maximizeIcon   [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowMaximizeIcon [UI]
+TitlePane.small.restoreIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
+TitlePane.small.showIcon       false
 TitlePane.titleMargins         3,0,3,0    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.titleMinimumWidth    60
 TitlePane.unifiedBackground    true

flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0.txt

@@ -1243,6 +1243,7 @@ TitlePane.buttonMaximizedHeight 22
 TitlePane.buttonMinimumWidth   30
 TitlePane.buttonPressedBackground #ebebeb  HSL   0   0  92    com.formdev.flatlaf.util.DerivedColor [UI]    darken(8% autoInverse)
 TitlePane.buttonSize           44,30    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.buttonSymbolHeight   10
 TitlePane.centerTitle          false
 TitlePane.centerTitleIfMenuBarEmbedded true
 TitlePane.closeHoverBackground #c42b1c  HSL   5  75  44    javax.swing.plaf.ColorUIResource [UI]
@@ -1269,6 +1270,14 @@ TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWin
 TitlePane.showIcon             true
 TitlePane.showIconBesideTitle  false
 TitlePane.showIconInDialogs    true
+TitlePane.small.buttonSize     30,20    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.small.buttonSymbolHeight 8
+TitlePane.small.closeIcon      [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowCloseIcon [UI]
+TitlePane.small.font           [active] Segoe UI plain 11    javax.swing.plaf.FontUIResource [UI]
+TitlePane.small.iconifyIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowIconifyIcon [UI]
+TitlePane.small.maximizeIcon   [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowMaximizeIcon [UI]
+TitlePane.small.restoreIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
+TitlePane.small.showIcon       false
 TitlePane.titleMargins         3,0,3,0    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.titleMinimumWidth    60
 TitlePane.unifiedBackground    true

flatlaf-testing/dumps/uidefaults/FlatMacDarkLaf_1.8.0.txt

@@ -1248,6 +1248,7 @@ TitlePane.buttonMaximizedHeight 22
 TitlePane.buttonMinimumWidth   30
 TitlePane.buttonPressedBackground #4c4c4c  HSL   0   0  30    com.formdev.flatlaf.util.DerivedColor [UI]    lighten(10% autoInverse)
 TitlePane.buttonSize           44,30    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.buttonSymbolHeight   10
 TitlePane.centerTitle          false
 TitlePane.centerTitleIfMenuBarEmbedded true
 TitlePane.closeHoverBackground #c42b1c  HSL   5  75  44    javax.swing.plaf.ColorUIResource [UI]
@@ -1274,6 +1275,14 @@ TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWin
 TitlePane.showIcon             true
 TitlePane.showIconBesideTitle  false
 TitlePane.showIconInDialogs    true
+TitlePane.small.buttonSize     30,20    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.small.buttonSymbolHeight 8
+TitlePane.small.closeIcon      [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowCloseIcon [UI]
+TitlePane.small.font           [active] Segoe UI plain 11    javax.swing.plaf.FontUIResource [UI]
+TitlePane.small.iconifyIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowIconifyIcon [UI]
+TitlePane.small.maximizeIcon   [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowMaximizeIcon [UI]
+TitlePane.small.restoreIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
+TitlePane.small.showIcon       false
 TitlePane.titleMargins         3,0,3,0    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.titleMinimumWidth    60
 TitlePane.unifiedBackground    true

flatlaf-testing/dumps/uidefaults/FlatMacLightLaf_1.8.0.txt

@@ -1252,6 +1252,7 @@ TitlePane.buttonMaximizedHeight 22
 TitlePane.buttonMinimumWidth   30
 TitlePane.buttonPressedBackground #d8d8d8  HSL   0   0  85    com.formdev.flatlaf.util.DerivedColor [UI]    darken(8% autoInverse)
 TitlePane.buttonSize           44,30    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.buttonSymbolHeight   10
 TitlePane.centerTitle          false
 TitlePane.centerTitleIfMenuBarEmbedded true
 TitlePane.closeHoverBackground #c42b1c  HSL   5  75  44    javax.swing.plaf.ColorUIResource [UI]
@@ -1278,6 +1279,14 @@ TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWin
 TitlePane.showIcon             true
 TitlePane.showIconBesideTitle  false
 TitlePane.showIconInDialogs    true
+TitlePane.small.buttonSize     30,20    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.small.buttonSymbolHeight 8
+TitlePane.small.closeIcon      [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowCloseIcon [UI]
+TitlePane.small.font           [active] Segoe UI plain 11    javax.swing.plaf.FontUIResource [UI]
+TitlePane.small.iconifyIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowIconifyIcon [UI]
+TitlePane.small.maximizeIcon   [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowMaximizeIcon [UI]
+TitlePane.small.restoreIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
+TitlePane.small.showIcon       false
 TitlePane.titleMargins         3,0,3,0    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.titleMinimumWidth    60
 TitlePane.unifiedBackground    true

flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0.txt

@@ -1278,6 +1278,7 @@ TitlePane.borderColor          #ff0000  HSL   0 100  50    javax.swing.plaf.Colo
 TitlePane.buttonMaximizedHeight 22
 TitlePane.buttonMinimumWidth   30
 TitlePane.buttonSize           44,30    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.buttonSymbolHeight   10
 TitlePane.centerTitle          false
 TitlePane.centerTitleIfMenuBarEmbedded true
 TitlePane.closeHoverBackground #c42b1c  HSL   5  75  44    javax.swing.plaf.ColorUIResource [UI]
@@ -1303,6 +1304,14 @@ TitlePane.restoreIcon          [lazy] 44,30    com.formdev.flatlaf.icons.FlatWin
 TitlePane.showIcon             true
 TitlePane.showIconBesideTitle  false
 TitlePane.showIconInDialogs    true
+TitlePane.small.buttonSize     30,20    javax.swing.plaf.DimensionUIResource [UI]
+TitlePane.small.buttonSymbolHeight 8
+TitlePane.small.closeIcon      [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowCloseIcon [UI]
+TitlePane.small.font           [active] Segoe UI plain 11    javax.swing.plaf.FontUIResource [UI]
+TitlePane.small.iconifyIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowIconifyIcon [UI]
+TitlePane.small.maximizeIcon   [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowMaximizeIcon [UI]
+TitlePane.small.restoreIcon    [lazy] 30,20    com.formdev.flatlaf.icons.FlatWindowRestoreIcon [UI]
+TitlePane.small.showIcon       false
 TitlePane.titleMargins         3,0,3,0    javax.swing.plaf.InsetsUIResource [UI]
 TitlePane.titleMinimumWidth    60
 TitlePane.unifiedBackground    true

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

@@ -361,6 +361,7 @@ debug*/
 	private void openDialog() {
 		Window owner = SwingUtilities.windowForComponent( this );
 		JDialog dialog = new JDialog( owner, "Dialog", ModalityType.DOCUMENT_MODAL );
+		initWindowType( dialog );
 		dialog.setDefaultCloseOperation( JDialog.DISPOSE_ON_CLOSE );
 		dialog.add( new FlatWindowDecorationsTest() );
 		dialog.pack();
@@ -371,6 +372,7 @@ debug*/
 	private void openFrame() {
 		FlatWindowDecorationsTest comp = new FlatWindowDecorationsTest();
 		JFrame frame = new JFrame( "Frame" );
+		initWindowType( frame );
 		frame.setDefaultCloseOperation( JFrame.DISPOSE_ON_CLOSE );
 		frame.add( comp );
 		frame.setJMenuBar( comp.menuBar );
@@ -379,6 +381,13 @@ debug*/
 		frame.setVisible( true );
 	}
 
+	private void initWindowType( Window window ) {
+		if( typeUtilityRadioButton.isSelected() )
+			window.setType( Window.Type.UTILITY );
+		else if( typeSmallRadioButton.isSelected() )
+			((RootPaneContainer)window).getRootPane().putClientProperty( "Window.style", "small" );
+	}
+
 	private void decorationStyleChanged() {
 		int style;
 		if( styleFrameRadioButton.isSelected() )
@@ -536,6 +545,9 @@ debug*/
 		colorizeMenusCheckBox = new JCheckBox();
 		JButton openDialogButton = new JButton();
 		JButton openFrameButton = new JButton();
+		typeNormalRadioButton = new JRadioButton();
+		typeUtilityRadioButton = new JRadioButton();
+		typeSmallRadioButton = new JRadioButton();
 		menuBar = new JMenuBar();
 		JMenu fileMenu = new JMenu();
 		JMenuItem newMenuItem = new JMenuItem();
@@ -567,7 +579,7 @@ debug*/
 		setLayout(new MigLayout(
 			"ltr,insets dialog,hidemode 3",
 			// columns
-			"[fill]" +
+			"[left]" +
 			"[fill]" +
 			"[fill]" +
 			"[fill]",
@@ -617,7 +629,7 @@ debug*/
 			maximizedBoundsCheckBox.addActionListener(e -> maximizedBoundsChanged());
 			panel7.add(maximizedBoundsCheckBox, "cell 0 4");
 		}
-		add(panel7, "cell 0 0");
+		add(panel7, "cell 0 0,growx");
 
 		//======== panel4 ========
 		{
@@ -818,7 +830,7 @@ debug*/
 			styleFileChooserRadioButton.addActionListener(e -> decorationStyleChanged());
 			panel1.add(styleFileChooserRadioButton, "cell 0 8");
 		}
-		add(panel1, "cell 0 1");
+		add(panel1, "cell 0 1,growx");
 
 		//======== panel2 ========
 		{
@@ -900,13 +912,26 @@ debug*/
 		//---- openDialogButton ----
 		openDialogButton.setText("Open Dialog");
 		openDialogButton.addActionListener(e -> openDialog());
-		add(openDialogButton, "cell 0 2");
+		add(openDialogButton, "cell 0 2 3 1");
 
 		//---- openFrameButton ----
 		openFrameButton.setText("Open Frame");
 		openFrameButton.setMnemonic('A');
 		openFrameButton.addActionListener(e -> openFrame());
-		add(openFrameButton, "cell 0 2");
+		add(openFrameButton, "cell 0 2 3 1");
+
+		//---- typeNormalRadioButton ----
+		typeNormalRadioButton.setText("Normal");
+		typeNormalRadioButton.setSelected(true);
+		add(typeNormalRadioButton, "cell 0 2 3 1");
+
+		//---- typeUtilityRadioButton ----
+		typeUtilityRadioButton.setText("Utility");
+		add(typeUtilityRadioButton, "cell 0 2 3 1");
+
+		//---- typeSmallRadioButton ----
+		typeSmallRadioButton.setText("Small");
+		add(typeSmallRadioButton, "cell 0 2 3 1");
 
 		//======== menuBar ========
 		{
@@ -1095,6 +1120,12 @@ debug*/
 		iconButtonGroup.add(iconTestRandomRadioButton);
 		iconButtonGroup.add(iconTestMRIRadioButton);
 		iconButtonGroup.add(iconTestDynMRIRadioButton);
+
+		//---- typeButtonGroup ----
+		ButtonGroup typeButtonGroup = new ButtonGroup();
+		typeButtonGroup.add(typeNormalRadioButton);
+		typeButtonGroup.add(typeUtilityRadioButton);
+		typeButtonGroup.add(typeSmallRadioButton);
 		// JFormDesigner - End of component initialization  //GEN-END:initComponents
 	}
 
@@ -1138,6 +1169,9 @@ debug*/
 	private JCheckBox colorizeTitleBarCheckBox;
 	private JCheckBox colorizeMenuBarCheckBox;
 	private JCheckBox colorizeMenusCheckBox;
+	private JRadioButton typeNormalRadioButton;
+	private JRadioButton typeUtilityRadioButton;
+	private JRadioButton typeSmallRadioButton;
 	private JMenuBar menuBar;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 }

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

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "8.0.0.0.194" Java: "17.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "8.1.0.0.283" Java: "19.0.2" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -8,7 +8,7 @@ new FormModel {
 		}
 		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
-			"$columnConstraints": "[fill][fill][fill][fill]"
+			"$columnConstraints": "[left][fill][fill][fill]"
 			"$rowConstraints": "[fill][fill][]"
 		} ) {
 			name: "this"
@@ -72,7 +72,7 @@ new FormModel {
 					"value": "cell 0 4"
 				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-				"value": "cell 0 0"
+				"value": "cell 0 0,growx"
 			} )
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "ltr,hidemode 3,gap 0 0"
@@ -378,7 +378,7 @@ new FormModel {
 					"value": "cell 0 8"
 				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-				"value": "cell 0 1"
+				"value": "cell 0 1,growx"
 			} )
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[left]"
@@ -501,7 +501,7 @@ new FormModel {
 				"text": "Open Dialog"
 				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "openDialog", false ) )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-				"value": "cell 0 2"
+				"value": "cell 0 2 3 1"
 			} )
 			add( new FormComponent( "javax.swing.JButton" ) {
 				name: "openFrameButton"
@@ -509,7 +509,38 @@ new FormModel {
 				"mnemonic": 65
 				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "openFrame", false ) )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-				"value": "cell 0 2"
+				"value": "cell 0 2 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JRadioButton" ) {
+				name: "typeNormalRadioButton"
+				"text": "Normal"
+				"selected": true
+				"$buttonGroup": new FormReference( "typeButtonGroup" )
+				auxiliary() {
+					"JavaCodeGenerator.variableLocal": false
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 2 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JRadioButton" ) {
+				name: "typeUtilityRadioButton"
+				"text": "Utility"
+				"$buttonGroup": new FormReference( "typeButtonGroup" )
+				auxiliary() {
+					"JavaCodeGenerator.variableLocal": false
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 2 3 1"
+			} )
+			add( new FormComponent( "javax.swing.JRadioButton" ) {
+				name: "typeSmallRadioButton"
+				"text": "Small"
+				"$buttonGroup": new FormReference( "typeButtonGroup" )
+				auxiliary() {
+					"JavaCodeGenerator.variableLocal": false
+				}
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 2 3 1"
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
@@ -692,5 +723,10 @@ new FormModel {
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 615 )
 		} )
+		add( new FormNonVisual( "javax.swing.ButtonGroup" ) {
+			name: "typeButtonGroup"
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 669 )
+		} )
 	}
 }

flatlaf-theme-editor/src/main/resources/com/formdev/flatlaf/themeeditor/FlatLafUIKeys.txt

@@ -1012,6 +1012,7 @@ TitlePane.buttonMaximizedHeight
 TitlePane.buttonMinimumWidth
 TitlePane.buttonPressedBackground
 TitlePane.buttonSize
+TitlePane.buttonSymbolHeight
 TitlePane.centerTitle
 TitlePane.centerTitleIfMenuBarEmbedded
 TitlePane.closeHoverBackground
@@ -1038,6 +1039,40 @@ TitlePane.restoreIcon
 TitlePane.showIcon
 TitlePane.showIconBesideTitle
 TitlePane.showIconInDialogs
+TitlePane.small.background
+TitlePane.small.buttonHoverBackground
+TitlePane.small.buttonMaximizedHeight
+TitlePane.small.buttonMinimumWidth
+TitlePane.small.buttonPressedBackground
+TitlePane.small.buttonSize
+TitlePane.small.buttonSymbolHeight
+TitlePane.small.centerTitle
+TitlePane.small.centerTitleIfMenuBarEmbedded
+TitlePane.small.closeHoverBackground
+TitlePane.small.closeHoverForeground
+TitlePane.small.closeIcon
+TitlePane.small.closePressedBackground
+TitlePane.small.closePressedForeground
+TitlePane.small.embeddedForeground
+TitlePane.small.font
+TitlePane.small.foreground
+TitlePane.small.icon
+TitlePane.small.iconMargins
+TitlePane.small.iconSize
+TitlePane.small.iconifyIcon
+TitlePane.small.inactiveBackground
+TitlePane.small.inactiveForeground
+TitlePane.small.maximizeIcon
+TitlePane.small.menuBarResizeHeight
+TitlePane.small.menuBarTitleGap
+TitlePane.small.menuBarTitleMinimumGap
+TitlePane.small.noIconLeftGap
+TitlePane.small.restoreIcon
+TitlePane.small.showIcon
+TitlePane.small.showIconBesideTitle
+TitlePane.small.showIconInDialogs
+TitlePane.small.titleMargins
+TitlePane.small.titleMinimumWidth
 TitlePane.titleMargins
 TitlePane.titleMinimumWidth
 TitlePane.unifiedBackground