release 0.17

- make child components explicitly non-opaque
- paint parent background only if necessary

CHANGELOG.md

@@ -1,6 +1,21 @@
 FlatLaf Change Log
 ==================
 
+## 0.17
+
+- CheckBox: Support painting a third state (set client property
+  "JButton.selectedState" to "indeterminate").
+- `TriStateCheckBox` component added (see [FlatLaf Extras](flatlaf-extras)).
+- Made `JComboBox`, `JProgressBar`, `JSpinner` and `JXDatePicker` non-opaque.
+  `JPasswordField`, `JScrollPane` and `JTextField` are non-opaque if they have
+  an outside focus border (e.g. IntelliJ and Darcula themes). (issues #20 and
+  #17)
+- Button: Hover and pressed background colors are now derived from actual button
+  background color. (issue #21)
+- Table: Fixed missing upper right corner (e.g. in SwingX JXTable with column
+  control visible).
+
+
 ## 0.16
 
 - Made some fixes for right-to-left support in ComboBox, Slider and ToolTip.

README.md

@@ -35,7 +35,7 @@ build script:
 
     groupId:     com.formdev
     artifactId:  flatlaf
-    version:     0.16
+    version:     0.17
 
 Otherwise download `flatlaf-<version>.jar` here:
 

build.gradle.kts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-version = "0.16"
+version = "0.17"
 
 allprojects {
 	repositories {

flatlaf-core/build.gradle.kts

@@ -34,17 +34,19 @@ if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
 	}
 }
 
-dependencies {
-	testImplementation( "com.miglayout:miglayout-swing:5.2" )
-	testImplementation( "com.jgoodies:jgoodies-forms:1.9.0" )
-}
-
 java {
     sourceCompatibility = JavaVersion.VERSION_1_8
     targetCompatibility = JavaVersion.VERSION_1_8
 }
 
 tasks {
+	assemble {
+		dependsOn(
+			"sourcesJar",
+			"javadocJar"
+		)
+	}
+
 	if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
 		named<JavaCompile>( "compileModuleInfoJava" ) {
 			sourceCompatibility = "9"
@@ -88,19 +90,6 @@ tasks {
 
 		from( javadoc )
 	}
-
-	register( "testJar", Jar::class ) {
-		archiveBaseName.set( "flatlaf-test" )
-		from( sourceSets.test.get().output )
-	}
-}
-
-configurations {
-	create( "testArtifacts" )
-}
-
-artifacts {
-	add( "testArtifacts", tasks.getByPath( "testJar" ) )
 }
 
 publishing {

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

@@ -27,6 +27,9 @@ public interface FlatClientProperties
 	String BUTTON_TYPE = "JButton.buttonType";
 	String BUTTON_TYPE_HELP = "help";
 
+	String SELECTED_STATE = "JButton.selectedState";
+	String SELECTED_STATE_INDETERMINATE = "indeterminate";
+
 	/**
 	 * Checks whether a client property of a component has the given value.
 	 */

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

@@ -19,10 +19,8 @@ package com.formdev.flatlaf;
 import java.awt.Color;
 import java.awt.Component;
 import java.awt.Container;
-import java.awt.Dimension;
 import java.awt.EventQueue;
 import java.awt.Font;
-import java.awt.Insets;
 import java.awt.KeyEventPostProcessor;
 import java.awt.KeyboardFocusManager;
 import java.awt.Toolkit;
@@ -30,16 +28,7 @@ import java.awt.Window;
 import java.awt.event.KeyEvent;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Locale;
-import java.util.Map;
-import java.util.Properties;
-import java.util.ServiceLoader;
-import java.util.function.Function;
 import javax.swing.AbstractButton;
 import javax.swing.JLabel;
 import javax.swing.JTabbedPane;
@@ -48,16 +37,9 @@ import javax.swing.SwingUtilities;
 import javax.swing.UIDefaults;
 import javax.swing.UIManager;
 import javax.swing.UnsupportedLookAndFeelException;
-import javax.swing.UIDefaults.LazyValue;
-import javax.swing.plaf.ColorUIResource;
-import javax.swing.plaf.DimensionUIResource;
 import javax.swing.plaf.FontUIResource;
-import javax.swing.plaf.InsetsUIResource;
 import javax.swing.plaf.basic.BasicLookAndFeel;
 import javax.swing.plaf.metal.MetalLookAndFeel;
-import com.formdev.flatlaf.ui.FlatEmptyBorder;
-import com.formdev.flatlaf.ui.FlatLineBorder;
-import com.formdev.flatlaf.util.ScaledNumber;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -69,13 +51,6 @@ import com.formdev.flatlaf.util.UIScale;
 public abstract class FlatLaf
 	extends BasicLookAndFeel
 {
-	private static final String TYPE_PREFIX = "{";
-	private static final String TYPE_PREFIX_END = "}";
-	private static final String VARIABLE_PREFIX = "@";
-	private static final String REF_PREFIX = VARIABLE_PREFIX + "@";
-	private static final String OPTIONAL_PREFIX = "?";
-	private static final String GLOBAL_PREFIX = "*.";
-
 	private BasicLookAndFeel base;
 
 	private String desktopPropertyName;
@@ -209,7 +184,7 @@ public abstract class FlatLaf
 		Object aquaMenuBarUI = useScreenMenuBar ? defaults.get( "MenuBarUI" ) : null;
 
 		initFonts( defaults );
-		loadDefaultsFromProperties( defaults );
+		UIDefaultsLoader.loadDefaultsFromProperties( getClass(), defaults );
 
 		// use Aqua MenuBarUI if Mac screen menubar is enabled
 		if( useScreenMenuBar )
@@ -254,291 +229,8 @@ public abstract class FlatLaf
 		defaults.put( "MenuItem.acceleratorFont", uiFont );
 	}
 
-	/**
-	 * Load properties associated to Flat LaF classes and add to UI defaults.
-	 *
-	 * Each class that extend this class may have its own .properties file
-	 * in the same package as the class. Properties from superclasses are loaded
-	 * first to give subclasses a chance to override defaults.
-	 * E.g. if running FlatDarkLaf, then the FlatLaf.properties is loaded first
-	 * and FlatDarkLaf.properties loaded second.
-	 */
-	private void loadDefaultsFromProperties( UIDefaults defaults ) {
-		// determine classes in class hierarchy in reverse order
-		ArrayList<Class<?>> lafClasses = new ArrayList<>();
-		for( Class<?> lafClass = getClass();
-			FlatLaf.class.isAssignableFrom( lafClass );
-			lafClass = lafClass.getSuperclass() )
-		{
-			lafClasses.add( 0, lafClass );
-		}
-
-		try {
-			// load properties files
-			Properties properties = new Properties();
-			ServiceLoader<FlatDefaultsAddon> addonLoader = ServiceLoader.load( FlatDefaultsAddon.class );
-			for( Class<?> lafClass : lafClasses ) {
-				// load core properties
-				String propertiesName = "/" + lafClass.getName().replace( '.', '/' ) + ".properties";
-				try( InputStream in = lafClass.getResourceAsStream( propertiesName ) ) {
-					if( in != null )
-						properties.load( in );
-				}
-
-				// load properties from addons
-				for( FlatDefaultsAddon addon : addonLoader ) {
-					try( InputStream in = addon.getDefaults( lafClass ) ) {
-						if( in != null )
-							properties.load( in );
-					}
-				}
-			}
-
-			Function<String, String> resolver = value -> {
-				return resolveValue( properties, value );
-			};
-
-			// get globals, which override all other defaults that end with same suffix
-			HashMap<String, Object> globals = new HashMap<>();
-			for( Map.Entry<Object, Object> e : properties.entrySet() ) {
-				String key = (String) e.getKey();
-				if( !key.startsWith( GLOBAL_PREFIX ) )
-					continue;
-
-				String value = resolveValue( properties, (String) e.getValue() );
-				globals.put( key.substring( GLOBAL_PREFIX.length() ), parseValue( key, value, resolver ) );
-			}
-
-			// override UI defaults with globals
-			for( Object key : defaults.keySet() ) {
-				if( key instanceof String && ((String)key).contains( "." ) ) {
-					String skey = (String) key;
-					String globalKey = skey.substring( skey.lastIndexOf( '.' ) + 1 );
-					Object globalValue = globals.get( globalKey );
-					if( globalValue != null )
-						defaults.put( key, globalValue );
-				}
-			}
-
-			// add non-global properties to UI defaults
-			for( Map.Entry<Object, Object> e : properties.entrySet() ) {
-				String key = (String) e.getKey();
-				if( key.startsWith( VARIABLE_PREFIX ) || key.startsWith( GLOBAL_PREFIX ) )
-					continue;
-
-				String value = resolveValue( properties, (String) e.getValue() );
-				defaults.put( key, parseValue( key, value, resolver ) );
-			}
-		} catch( IOException ex ) {
-			ex.printStackTrace();
-		}
-	}
-
-	private String resolveValue( Properties properties, String value ) {
-		if( !value.startsWith( VARIABLE_PREFIX ) )
-			return value;
-
-		if( value.startsWith( REF_PREFIX ) )
-			value = value.substring( REF_PREFIX.length() );
-
-		boolean optional = false;
-		if( value.startsWith( OPTIONAL_PREFIX ) ) {
-			value = value.substring( OPTIONAL_PREFIX.length() );
-			optional = true;
-		}
-
-		String newValue = properties.getProperty( value );
-		if( newValue == null ) {
-			if( optional )
-				return "null";
-
-			System.err.println( "variable or reference '" + value + "' not found" );
-			throw new IllegalArgumentException( value );
-		}
-
-		return resolveValue( properties, newValue );
-	}
-
-	private enum ValueType { UNKNOWN, STRING, INTEGER, BORDER, ICON, INSETS, SIZE, COLOR, SCALEDNUMBER }
-
-	private Object parseValue( String key, String value, Function<String, String> resolver ) {
-		value = value.trim();
-
-		// null, false, true
-		switch( value ) {
-			case "null":	return null;
-			case "false":	return false;
-			case "true":	return true;
-		}
-
-		ValueType valueType = ValueType.UNKNOWN;
-
-		// check whether value type is specified in the value
-		if( value.startsWith( TYPE_PREFIX ) ) {
-			int end = value.indexOf( TYPE_PREFIX_END );
-			if( end != -1 ) {
-				try {
-					String typeStr = value.substring( TYPE_PREFIX.length(), end );
-					valueType = ValueType.valueOf( typeStr.toUpperCase( Locale.ENGLISH ) );
-
-					// remove type from value
-					value = value.substring( end + TYPE_PREFIX_END.length() );
-				} catch( IllegalArgumentException ex ) {
-					// ignore
-				}
-			}
-		}
-
-		// determine value type from key
-		if( valueType == ValueType.UNKNOWN ) {
-			if( key.endsWith( ".border" ) || key.endsWith( "Border" ) )
-				valueType = ValueType.BORDER;
-			else if( key.endsWith( ".icon" ) || key.endsWith( "Icon" ) )
-				valueType = ValueType.ICON;
-			else if( key.endsWith( ".margin" ) || key.endsWith( ".padding" ) ||
-					 key.endsWith( "Margins" ) || key.endsWith( "Insets" ) )
-				valueType = ValueType.INSETS;
-			else if( key.endsWith( "Size" ) )
-				valueType = ValueType.SIZE;
-			else if( key.endsWith( "Width" ) || key.endsWith( "Height" ) )
-				valueType = ValueType.INTEGER;
-		}
-
-		// parse value
-		switch( valueType ) {
-			case STRING:		return value;
-			case INTEGER:		return parseInteger( value, true );
-			case BORDER:		return parseBorder( value, resolver );
-			case ICON:			return parseInstance( value );
-			case INSETS:		return parseInsets( value );
-			case SIZE:			return parseSize( value );
-			case COLOR:			return parseColor( value, true );
-			case SCALEDNUMBER:	return parseScaledNumber( value );
-			case UNKNOWN:
-			default:
-				// colors
-				ColorUIResource color = parseColor( value, false );
-				if( color != null )
-					return color;
-
-				// integer
-				Integer integer = parseInteger( value, false );
-				if( integer != null )
-					return integer;
-
-				// string
-				return value;
-		}
-	}
-
-	private Object parseBorder( String value, Function<String, String> resolver ) {
-		if( value.indexOf( ',' ) >= 0 ) {
-			// top,left,bottom,right[,lineColor]
-			List<String> parts = split( value, ',' );
-			Insets insets = parseInsets( value );
-			ColorUIResource lineColor = (parts.size() == 5)
-				? parseColor( resolver.apply( parts.get( 4 ) ), true )
-				: null;
-
-			return (LazyValue) t -> {
-				return (lineColor != null)
-					? new FlatLineBorder( insets, lineColor )
-					: new FlatEmptyBorder( insets );
-			};
-		} else
-			return parseInstance( value );
-	}
-
-	private Object parseInstance( String value ) {
-		return (LazyValue) t -> {
-			try {
-				return Class.forName( value ).newInstance();
-			} catch( InstantiationException | IllegalAccessException | ClassNotFoundException ex ) {
-				ex.printStackTrace();
-				return null;
-			}
-		};
-	}
-
-	private Insets parseInsets( String value ) {
-		List<String> numbers = split( value, ',' );
-		try {
-			return new InsetsUIResource(
-				Integer.parseInt( numbers.get( 0 ) ),
-				Integer.parseInt( numbers.get( 1 ) ),
-				Integer.parseInt( numbers.get( 2 ) ),
-				Integer.parseInt( numbers.get( 3 ) ) );
-		} catch( NumberFormatException ex ) {
-			System.err.println( "invalid insets '" + value + "'" );
-			throw ex;
-		}
-	}
-
-	private Dimension parseSize( String value ) {
-		List<String> numbers = split( value, ',' );
-		try {
-			return new DimensionUIResource(
-				Integer.parseInt( numbers.get( 0 ) ),
-				Integer.parseInt( numbers.get( 1 ) ) );
-		} catch( NumberFormatException ex ) {
-			System.err.println( "invalid size '" + value + "'" );
-			throw ex;
-		}
-	}
-
-	private ColorUIResource parseColor( String value, boolean reportError ) {
-		try {
-			int rgb = Integer.parseInt( value, 16 );
-			if( value.length() == 6 )
-				return new ColorUIResource( rgb );
-			if( value.length() == 8 )
-				return new ColorUIResource( new Color( rgb, true ) );
-
-			if( reportError )
-				throw new NumberFormatException( value );
-		} catch( NumberFormatException ex ) {
-			if( reportError ) {
-				System.err.println( "invalid color '" + value + "'" );
-				throw ex;
-			}
-			// not a color --> ignore
-		}
-		return null;
-	}
-
-	private Integer parseInteger( String value, boolean reportError ) {
-		try {
-			return Integer.parseInt( value );
-		} catch( NumberFormatException ex ) {
-			if( reportError ) {
-				System.err.println( "invalid integer '" + value + "'" );
-				throw ex;
-			}
-		}
-		return null;
-	}
-
-	private ScaledNumber parseScaledNumber( String value ) {
-		try {
-			return new ScaledNumber( Integer.parseInt( value ) );
-		} catch( NumberFormatException ex ) {
-			System.err.println( "invalid integer '" + value + "'" );
-			throw ex;
-		}
-	}
-
 	public static List<String> split( String str, char delim ) {
-		ArrayList<String> strs = new ArrayList<>();
+		return UIDefaultsLoader.split( str, delim );
-		int delimIndex = str.indexOf( delim );
-		int index = 0;
-		while( delimIndex >= 0 ) {
-			strs.add( str.substring( index, delimIndex ) );
-			index = delimIndex + 1;
-			delimIndex = str.indexOf( delim, index );
-		}
-		strs.add( str.substring( index ) );
-
-		return strs;
 	}
 
 	private static void reSetLookAndFeel() {

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

@@ -0,0 +1,407 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Insets;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Properties;
+import java.util.ServiceLoader;
+import java.util.function.Function;
+import javax.swing.UIDefaults;
+import javax.swing.UIDefaults.LazyValue;
+import javax.swing.plaf.ColorUIResource;
+import javax.swing.plaf.DimensionUIResource;
+import javax.swing.plaf.InsetsUIResource;
+import com.formdev.flatlaf.ui.FlatEmptyBorder;
+import com.formdev.flatlaf.ui.FlatLineBorder;
+import com.formdev.flatlaf.util.ColorFunctions;
+import com.formdev.flatlaf.util.DerivedColor;
+import com.formdev.flatlaf.util.ScaledNumber;
+
+/**
+ * Load UI defaults from properties files associated to Flat LaF classes and add to UI defaults.
+ *
+ * Each class that extend the LaF class may have its own .properties file
+ * in the same package as the class. Properties from superclasses are loaded
+ * first to give subclasses a chance to override defaults.
+ * E.g. if running FlatDarkLaf, then the FlatLaf.properties is loaded first
+ * and FlatDarkLaf.properties loaded second.
+ *
+ * @author Karl Tauber
+ */
+class UIDefaultsLoader
+{
+	private static final String TYPE_PREFIX = "{";
+	private static final String TYPE_PREFIX_END = "}";
+	private static final String VARIABLE_PREFIX = "@";
+	private static final String REF_PREFIX = VARIABLE_PREFIX + "@";
+	private static final String OPTIONAL_PREFIX = "?";
+	private static final String GLOBAL_PREFIX = "*.";
+
+	static void loadDefaultsFromProperties( Class<?> lookAndFeelClass, UIDefaults defaults ) {
+		// determine classes in class hierarchy in reverse order
+		ArrayList<Class<?>> lafClasses = new ArrayList<>();
+		for( Class<?> lafClass = lookAndFeelClass;
+			FlatLaf.class.isAssignableFrom( lafClass );
+			lafClass = lafClass.getSuperclass() )
+		{
+			lafClasses.add( 0, lafClass );
+		}
+
+		try {
+			// load properties files
+			Properties properties = new Properties();
+			ServiceLoader<FlatDefaultsAddon> addonLoader = ServiceLoader.load( FlatDefaultsAddon.class );
+			for( Class<?> lafClass : lafClasses ) {
+				// load core properties
+				String propertiesName = "/" + lafClass.getName().replace( '.', '/' ) + ".properties";
+				try( InputStream in = lafClass.getResourceAsStream( propertiesName ) ) {
+					if( in != null )
+						properties.load( in );
+				}
+
+				// load properties from addons
+				for( FlatDefaultsAddon addon : addonLoader ) {
+					try( InputStream in = addon.getDefaults( lafClass ) ) {
+						if( in != null )
+							properties.load( in );
+					}
+				}
+			}
+
+			Function<String, String> resolver = value -> {
+				return resolveValue( properties, value );
+			};
+
+			// get globals, which override all other defaults that end with same suffix
+			HashMap<String, Object> globals = new HashMap<>();
+			for( Map.Entry<Object, Object> e : properties.entrySet() ) {
+				String key = (String) e.getKey();
+				if( !key.startsWith( GLOBAL_PREFIX ) )
+					continue;
+
+				String value = resolveValue( properties, (String) e.getValue() );
+				try {
+					globals.put( key.substring( GLOBAL_PREFIX.length() ), parseValue( key, value, resolver ) );
+				} catch( RuntimeException ex ) {
+					logParseError( key, value, ex );
+				}
+			}
+
+			// override UI defaults with globals
+			for( Object key : defaults.keySet() ) {
+				if( key instanceof String && ((String)key).contains( "." ) ) {
+					String skey = (String) key;
+					String globalKey = skey.substring( skey.lastIndexOf( '.' ) + 1 );
+					Object globalValue = globals.get( globalKey );
+					if( globalValue != null )
+						defaults.put( key, globalValue );
+				}
+			}
+
+			// add non-global properties to UI defaults
+			for( Map.Entry<Object, Object> e : properties.entrySet() ) {
+				String key = (String) e.getKey();
+				if( key.startsWith( VARIABLE_PREFIX ) || key.startsWith( GLOBAL_PREFIX ) )
+					continue;
+
+				String value = resolveValue( properties, (String) e.getValue() );
+				try {
+					defaults.put( key, parseValue( key, value, resolver ) );
+				} catch( RuntimeException ex ) {
+					logParseError( key, value, ex );
+				}
+			}
+		} catch( IOException ex ) {
+			ex.printStackTrace();
+		}
+	}
+
+	private static void logParseError( String key, String value, RuntimeException ex ) {
+		System.err.println( "Failed to parse: '" + key + '=' + value + '\'' );
+		System.err.println( "    " + ex.getMessage() );
+	}
+
+	private static String resolveValue( Properties properties, String value ) {
+		if( !value.startsWith( VARIABLE_PREFIX ) )
+			return value;
+
+		if( value.startsWith( REF_PREFIX ) )
+			value = value.substring( REF_PREFIX.length() );
+
+		boolean optional = false;
+		if( value.startsWith( OPTIONAL_PREFIX ) ) {
+			value = value.substring( OPTIONAL_PREFIX.length() );
+			optional = true;
+		}
+
+		String newValue = properties.getProperty( value );
+		if( newValue == null ) {
+			if( optional )
+				return "null";
+
+			throw new IllegalArgumentException( "variable or reference '" + value + "' not found" );
+		}
+
+		return resolveValue( properties, newValue );
+	}
+
+	private enum ValueType { UNKNOWN, STRING, INTEGER, BORDER, ICON, INSETS, SIZE, COLOR, SCALEDNUMBER }
+
+	private static Object parseValue( String key, String value, Function<String, String> resolver ) {
+		value = value.trim();
+
+		// null, false, true
+		switch( value ) {
+			case "null":	return null;
+			case "false":	return false;
+			case "true":	return true;
+		}
+
+		ValueType valueType = ValueType.UNKNOWN;
+
+		// check whether value type is specified in the value
+		if( value.startsWith( TYPE_PREFIX ) ) {
+			int end = value.indexOf( TYPE_PREFIX_END );
+			if( end != -1 ) {
+				try {
+					String typeStr = value.substring( TYPE_PREFIX.length(), end );
+					valueType = ValueType.valueOf( typeStr.toUpperCase( Locale.ENGLISH ) );
+
+					// remove type from value
+					value = value.substring( end + TYPE_PREFIX_END.length() );
+				} catch( IllegalArgumentException ex ) {
+					// ignore
+				}
+			}
+		}
+
+		// determine value type from key
+		if( valueType == ValueType.UNKNOWN ) {
+			if( key.endsWith( ".border" ) || key.endsWith( "Border" ) )
+				valueType = ValueType.BORDER;
+			else if( key.endsWith( ".icon" ) || key.endsWith( "Icon" ) )
+				valueType = ValueType.ICON;
+			else if( key.endsWith( ".margin" ) || key.endsWith( ".padding" ) ||
+					 key.endsWith( "Margins" ) || key.endsWith( "Insets" ) )
+				valueType = ValueType.INSETS;
+			else if( key.endsWith( "Size" ) )
+				valueType = ValueType.SIZE;
+			else if( key.endsWith( "Width" ) || key.endsWith( "Height" ) )
+				valueType = ValueType.INTEGER;
+		}
+
+		// parse value
+		switch( valueType ) {
+			case STRING:		return value;
+			case INTEGER:		return parseInteger( value, true );
+			case BORDER:		return parseBorder( value, resolver );
+			case ICON:			return parseInstance( value );
+			case INSETS:		return parseInsets( value );
+			case SIZE:			return parseSize( value );
+			case COLOR:			return parseColor( value, true );
+			case SCALEDNUMBER:	return parseScaledNumber( value );
+			case UNKNOWN:
+			default:
+				// colors
+				ColorUIResource color = parseColor( value, false );
+				if( color != null )
+					return color;
+
+				// integer
+				Integer integer = parseInteger( value, false );
+				if( integer != null )
+					return integer;
+
+				// string
+				return value;
+		}
+	}
+
+	private static Object parseBorder( String value, Function<String, String> resolver ) {
+		if( value.indexOf( ',' ) >= 0 ) {
+			// top,left,bottom,right[,lineColor]
+			List<String> parts = split( value, ',' );
+			Insets insets = parseInsets( value );
+			ColorUIResource lineColor = (parts.size() == 5)
+				? parseColor( resolver.apply( parts.get( 4 ) ), true )
+				: null;
+
+			return (LazyValue) t -> {
+				return (lineColor != null)
+					? new FlatLineBorder( insets, lineColor )
+					: new FlatEmptyBorder( insets );
+			};
+		} else
+			return parseInstance( value );
+	}
+
+	private static Object parseInstance( String value ) {
+		return (LazyValue) t -> {
+			try {
+				return Class.forName( value ).newInstance();
+			} catch( InstantiationException | IllegalAccessException | ClassNotFoundException ex ) {
+				ex.printStackTrace();
+				return null;
+			}
+		};
+	}
+
+	private static Insets parseInsets( String value ) {
+		List<String> numbers = split( value, ',' );
+		try {
+			return new InsetsUIResource(
+				Integer.parseInt( numbers.get( 0 ) ),
+				Integer.parseInt( numbers.get( 1 ) ),
+				Integer.parseInt( numbers.get( 2 ) ),
+				Integer.parseInt( numbers.get( 3 ) ) );
+		} catch( NumberFormatException ex ) {
+			throw new IllegalArgumentException( "invalid insets '" + value + "'" );
+		}
+	}
+
+	private static Dimension parseSize( String value ) {
+		List<String> numbers = split( value, ',' );
+		try {
+			return new DimensionUIResource(
+				Integer.parseInt( numbers.get( 0 ) ),
+				Integer.parseInt( numbers.get( 1 ) ) );
+		} catch( NumberFormatException ex ) {
+			throw new IllegalArgumentException( "invalid size '" + value + "'" );
+		}
+	}
+
+	private static ColorUIResource parseColor( String value, boolean reportError ) {
+		if( value.endsWith( ")" ) )
+			return parseColorFunctions( value, reportError );
+
+		try {
+			int rgb = Integer.parseInt( value, 16 );
+			if( value.length() == 6 )
+				return new ColorUIResource( rgb );
+			if( value.length() == 8 )
+				return new ColorUIResource( new Color( rgb, true ) );
+
+			if( reportError )
+				throw new NumberFormatException( value );
+		} catch( NumberFormatException ex ) {
+			if( reportError )
+				throw new IllegalArgumentException( "invalid color '" + value + "'" );
+
+			// not a color --> ignore
+		}
+		return null;
+	}
+
+	private static ColorUIResource parseColorFunctions( String value, boolean reportError ) {
+		int paramsStart = value.indexOf( '(' );
+		if( paramsStart < 0 ) {
+			if( reportError )
+				throw new IllegalArgumentException( "missing opening parenthesis in function '" + value + "'" );
+			return null;
+		}
+
+		String function = value.substring( 0, paramsStart ).trim();
+		List<String> params = split( value.substring( paramsStart + 1, value.length() - 1 ), ',' );
+		if( params.isEmpty() )
+			throw new IllegalArgumentException( "missing parameters in function '" + value + "'" );
+
+		switch( function ) {
+			case "lighten":		return parseColorLightenOrDarken( true, params, reportError );
+			case "darken":		return parseColorLightenOrDarken( false, params, reportError );
+		}
+
+		throw new IllegalArgumentException( "unknown color function '" + value + "'" );
+	}
+
+	/**
+	 * Syntax: lighten(amount[,options]) or darken(amount[,options])
+	 *   - amount: percentage 0-100%
+	 *   - options: [relative] [autoInverse]
+	 */
+	private static ColorUIResource parseColorLightenOrDarken( boolean lighten, List<String> params, boolean reportError ) {
+		int amount = parsePercentage( params.get( 0 ) );
+		boolean relative = false;
+		boolean autoInverse = false;
+
+		if( params.size() >= 2 ) {
+			String options = params.get( 1 );
+			relative = options.contains( "relative" );
+			autoInverse = options.contains( "autoInverse" );
+		}
+
+		return new DerivedColor( lighten
+			? new ColorFunctions.Lighten( amount, relative, autoInverse )
+			: new ColorFunctions.Darken( amount, relative, autoInverse ) );
+	}
+
+	private static int parsePercentage( String value ) {
+		if( !value.endsWith( "%" ) )
+			throw new NumberFormatException( "invalid percentage '" + value + "'" );
+
+		int val;
+		try {
+			val = Integer.parseInt( value.substring( 0, value.length() - 1 ) );
+		} catch( NumberFormatException ex ) {
+			throw new NumberFormatException( "invalid percentage '" + value + "'" );
+		}
+
+		if( val < 0 || val > 100 )
+			throw new IllegalArgumentException( "percentage out of range (0-100%) '" + value + "'" );
+		return val;
+	}
+
+	private static Integer parseInteger( String value, boolean reportError ) {
+		try {
+			return Integer.parseInt( value );
+		} catch( NumberFormatException ex ) {
+			if( reportError )
+				throw new NumberFormatException( "invalid integer '" + value + "'" );
+		}
+		return null;
+	}
+
+	private static ScaledNumber parseScaledNumber( String value ) {
+		try {
+			return new ScaledNumber( Integer.parseInt( value ) );
+		} catch( NumberFormatException ex ) {
+			throw new NumberFormatException( "invalid integer '" + value + "'" );
+		}
+	}
+
+	static List<String> split( String str, char delim ) {
+		ArrayList<String> strs = new ArrayList<>();
+		int delimIndex = str.indexOf( delim );
+		int index = 0;
+		while( delimIndex >= 0 ) {
+			strs.add( str.substring( index, delimIndex ) );
+			index = delimIndex + 1;
+			delimIndex = str.indexOf( delim, index );
+		}
+		strs.add( str.substring( index ) );
+
+		return strs;
+	}
+}

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

@@ -16,14 +16,18 @@
 
 package com.formdev.flatlaf.icons;
 
+import static com.formdev.flatlaf.FlatClientProperties.*;
 import java.awt.BasicStroke;
 import java.awt.Color;
 import java.awt.Component;
 import java.awt.Graphics2D;
 import java.awt.geom.Path2D;
+import java.awt.geom.RoundRectangle2D;
 import javax.swing.AbstractButton;
+import javax.swing.JComponent;
 import javax.swing.UIManager;
 import com.formdev.flatlaf.ui.FlatButtonUI;
+import com.formdev.flatlaf.ui.FlatUIUtils;
 
 /**
  * Icon for {@link javax.swing.JCheckBox}.
@@ -50,6 +54,7 @@ import com.formdev.flatlaf.ui.FlatButtonUI;
  * @uiDefault CheckBox.icon.selectedPressedBackground	Color	optional
  * @uiDefault CheckBox.icon.checkmarkColor				Color
  * @uiDefault CheckBox.icon.disabledCheckmarkColor		Color
+ * @uiDefault CheckBox.arc								int
  *
  * @author Karl Tauber
  */
@@ -58,6 +63,7 @@ public class FlatCheckBoxIcon
 {
 	protected final int focusWidth = UIManager.getInt( "Component.focusWidth" );
 	protected final Color focusColor = UIManager.getColor( "Component.focusColor" );
+	protected final int arc = FlatUIUtils.getUIInt( "CheckBox.arc", 2 );
 
 	protected final Color borderColor = UIManager.getColor( "CheckBox.icon.borderColor" );
 	protected final Color disabledBorderColor = UIManager.getColor( "CheckBox.icon.disabledBorderColor" );
@@ -84,7 +90,8 @@ public class FlatCheckBoxIcon
 
 	@Override
 	protected void paintIcon( Component c, Graphics2D g2 ) {
-		boolean selected = (c instanceof AbstractButton) ? ((AbstractButton)c).isSelected() : false;
+		boolean indeterminate = c instanceof JComponent && clientPropertyEquals( (JComponent) c, SELECTED_STATE, SELECTED_STATE_INDETERMINATE );
+		boolean selected = indeterminate || (c instanceof AbstractButton && ((AbstractButton)c).isSelected());
 
 		// paint focused border
 		if( c.hasFocus() && focusWidth > 0 ) {
@@ -102,17 +109,21 @@ public class FlatCheckBoxIcon
 		paintBorder( g2 );
 
 		// paint background
-		g2.setColor( FlatButtonUI.buttonStateColor( c,
+		FlatUIUtils.setColor( g2, FlatButtonUI.buttonStateColor( c,
 			selected ? selectedBackground : background,
 			disabledBackground,
 			focusedBackground,
 			selected && selectedHoverBackground != null ? selectedHoverBackground : hoverBackground,
-			selected && selectedPressedBackground != null ? selectedPressedBackground : pressedBackground ) );
+			selected && selectedPressedBackground != null ? selectedPressedBackground : pressedBackground ),
+			background );
 		paintBackground( g2 );
 
 		// paint checkmark
-		if( selected ) {
+		if( selected || indeterminate ) {
 			g2.setColor( c.isEnabled() ? checkmarkColor : disabledCheckmarkColor );
+			if( indeterminate )
+				paintIndeterminate( g2 );
+			else
 				paintCheckmark( g2 );
 		}
 	}
@@ -120,15 +131,18 @@ public class FlatCheckBoxIcon
 	protected void paintFocusBorder( Graphics2D g2 ) {
 		// the outline focus border is painted outside of the icon
 		int wh = ICON_SIZE - 1 + (focusWidth * 2);
-		g2.fillRoundRect( -focusWidth + 1, -focusWidth, wh, wh, 8, 8 );
+		int arcwh = (arc + focusWidth) * 2;
+		g2.fillRoundRect( -focusWidth + 1, -focusWidth, wh, wh, arcwh, arcwh );
 	}
 
 	protected void paintBorder( Graphics2D g2 ) {
-		g2.fillRoundRect( 1, 0, 14, 14, 4, 4 );
+		int arcwh = arc * 2;
+		g2.fillRoundRect( 1, 0, 14, 14, arcwh, arcwh );
 	}
 
 	protected void paintBackground( Graphics2D g2 ) {
-		g2.fillRoundRect( 2, 1, 12, 12, 3, 3 );
+		int arcwh = (arc * 2) - 1;
+		g2.fillRoundRect( 2, 1, 12, 12, arcwh, arcwh );
 	}
 
 	protected void paintCheckmark( Graphics2D g2 ) {
@@ -140,4 +154,8 @@ public class FlatCheckBoxIcon
 		g2.setStroke( new BasicStroke( 1.9f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND ) );
 		g2.draw( path );
 	}
+
+	protected void paintIndeterminate( Graphics2D g2 ) {
+		g2.fill( new RoundRectangle2D.Float( 3.75f, 5.75f, 8.5f, 2.5f, 2f, 2f ) );
+	}
 }

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

@@ -24,6 +24,7 @@ import java.awt.geom.Ellipse2D;
 import java.awt.geom.Path2D;
 import javax.swing.UIManager;
 import com.formdev.flatlaf.ui.FlatButtonUI;
+import com.formdev.flatlaf.ui.FlatUIUtils;
 
 /**
  * Help button icon for {@link javax.swing.JButton}.
@@ -99,12 +100,12 @@ public class FlatHelpButtonIcon
 		g2.fill( new Ellipse2D.Float( focusWidth + 0.5f, focusWidth + 0.5f, 21, 21 ) );
 
 		// paint background
-		g2.setColor( FlatButtonUI.buttonStateColor( c,
+		FlatUIUtils.setColor( g2, FlatButtonUI.buttonStateColor( c,
 			background,
 			disabledBackground,
 			focusedBackground,
 			hoverBackground,
-			pressedBackground ) );
+			pressedBackground ), background );
 		g2.fill( new Ellipse2D.Float( focusWidth + 1.5f, focusWidth + 1.5f, 19, 19 ) );
 
 		// paint question mark

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

@@ -23,7 +23,6 @@ import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
 import java.awt.KeyboardFocusManager;
-import java.awt.Paint;
 import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
@@ -83,7 +82,7 @@ public class FlatBorder
 					getLineWidth() + scale( (float) innerFocusWidth ), arc );
 			}
 
-			g2.setPaint( getBorderColor( c ) );
+			g2.setColor( getBorderColor( c ) );
 			FlatUIUtils.drawRoundRectangle( g2, x, y, width, height, focusWidth, borderWidth, arc );
 		} finally {
 			g2.dispose();
@@ -94,7 +93,7 @@ public class FlatBorder
 		return focusColor;
 	}
 
-	protected Paint getBorderColor( Component c ) {
+	protected Color getBorderColor( Component c ) {
 		boolean enabled = c.isEnabled() && (!(c instanceof JTextComponent) || ((JTextComponent)c).isEditable());
 		return enabled
 			? (isFocused( c ) ? focusedBorderColor : borderColor)

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

@@ -21,7 +21,6 @@ import java.awt.Color;
 import java.awt.Component;
 import java.awt.Graphics;
 import java.awt.Insets;
-import java.awt.Paint;
 import javax.swing.JButton;
 import javax.swing.UIManager;
 import javax.swing.plaf.UIResource;
@@ -68,7 +67,7 @@ public class FlatButtonBorder
 	}
 
 	@Override
-	protected Paint getBorderColor( Component c ) {
+	protected Color getBorderColor( Component c ) {
 		boolean def = FlatButtonUI.isDefaultButton( c );
 		return FlatButtonUI.buttonStateColor( c,
 			def ? defaultBorderColor : borderColor,

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

@@ -190,7 +190,7 @@ public class FlatButtonUI
 					float focusWidth = (border instanceof FlatBorder) ? scale( (float) this.focusWidth ) : 0;
 					float arc = (border instanceof FlatButtonBorder || isToolBarButton( c )) ? scale( (float) this.arc ) : 0;
 
-					g2.setColor( background );
+					FlatUIUtils.setColor( g2, background, isDefaultButton(c) ? defaultBackground : c.getBackground() );
 					FlatUIUtils.fillRoundRectangle( g2, 0, 0, c.getWidth(), c.getHeight(), focusWidth, arc );
 				} finally {
 					g2.dispose();

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

@@ -41,6 +41,7 @@ import javax.swing.JComponent;
 import javax.swing.JList;
 import javax.swing.JPanel;
 import javax.swing.ListCellRenderer;
+import javax.swing.LookAndFeel;
 import javax.swing.SwingConstants;
 import javax.swing.UIManager;
 import javax.swing.border.AbstractBorder;
@@ -123,6 +124,8 @@ public class FlatComboBoxUI
 	protected void installDefaults() {
 		super.installDefaults();
 
+		LookAndFeel.installProperty( comboBox, "opaque", false );
+
 		focusWidth = UIManager.getInt( "Component.focusWidth" );
 		arc = UIManager.getInt( "Component.arc" );
 		arrowType = UIManager.getString( "Component.arrowType" );
@@ -209,7 +212,7 @@ public class FlatComboBoxUI
 				String propertyName = e.getPropertyName();
 
 				if( editor != null &&
-					((source == comboBox && (propertyName == "background" || propertyName == "foreground")) ||
+					((source == comboBox && propertyName == "foreground") ||
 					 (source == editor && propertyName == "enabled")) )
 				{
 					// fix editor component colors
@@ -239,6 +242,10 @@ public class FlatComboBoxUI
 		if( editor instanceof JTextComponent )
 			((JTextComponent)editor).setBorder( BorderFactory.createEmptyBorder() );
 
+		// explicitly make non-opaque
+		if( editor instanceof JComponent )
+			((JComponent)editor).setOpaque( false );
+
 		editor.applyComponentOrientation( comboBox.getComponentOrientation() );
 
 		updateEditorColors();
@@ -249,7 +256,6 @@ public class FlatComboBoxUI
 		// is used, then the editor is updated after the combobox and the
 		// colors are again replaced with default colors
 		boolean enabled = editor.isEnabled();
-		editor.setBackground( FlatUIUtils.nonUIResource( enabled ? comboBox.getBackground() : disabledBackground ) );
 		editor.setForeground( FlatUIUtils.nonUIResource( (enabled || editor instanceof JTextComponent)
 			? comboBox.getForeground()
 			: disabledForeground ) );
@@ -271,7 +277,8 @@ public class FlatComboBoxUI
 
 	@Override
 	public void update( Graphics g, JComponent c ) {
-		if( c.isOpaque() ) {
+		// fill background if opaque to avoid garbage if user sets opaque to true
+		if( c.isOpaque() && (focusWidth > 0 || arc != 0) )
 			FlatUIUtils.paintParentBackground( g, c );
 
 		Graphics2D g2 = (Graphics2D) g;
@@ -302,14 +309,13 @@ public class FlatComboBoxUI
 			g2.setClip( oldClip );
 		}
 
-			if( comboBox.isEditable() ) {
 		// paint vertical line between value and arrow button
+		if( comboBox.isEditable() ) {
 			g2.setColor( enabled ? borderColor : disabledBorderColor );
 			float lw = scale( 1f );
 			float lx = isLeftToRight ? arrowX : arrowX + arrowWidth - lw;
 			g2.fill( new Rectangle2D.Float( lx, focusWidth, lw, height - (focusWidth * 2) ) );
 		}
-		}
 
 		paint( g, c );
 	}

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

@@ -19,15 +19,12 @@ package com.formdev.flatlaf.ui;
 import static com.formdev.flatlaf.util.UIScale.scale;
 import java.awt.Dimension;
 import java.awt.Graphics;
-import java.awt.Graphics2D;
-import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import javax.swing.JComponent;
 import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicPasswordFieldUI;
-import javax.swing.text.JTextComponent;
 import com.formdev.flatlaf.util.SystemInfo;
 
 /**
@@ -46,7 +43,7 @@ public class FlatPasswordFieldUI
 	protected int focusWidth;
 	protected int minimumWidth;
 
-	private Handler handler;
+	private FocusListener focusListener;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatPasswordFieldUI();
@@ -63,6 +60,8 @@ public class FlatPasswordFieldUI
 		focusWidth = UIManager.getInt( "Component.focusWidth" );
 		minimumWidth = UIManager.getInt( "Component.minimumWidth" );
 
+		LookAndFeel.installProperty( getComponent(), "opaque", focusWidth == 0 );
+
 		MigLayoutVisualPadding.install( getComponent(), focusWidth );
 	}
 
@@ -77,41 +76,27 @@ public class FlatPasswordFieldUI
 	protected void installListeners() {
 		super.installListeners();
 
-		getComponent().addFocusListener( getHandler() );
+		focusListener = new FlatUIUtils.RepaintFocusListener( getComponent() );
+		getComponent().addFocusListener( focusListener );
 	}
 
 	@Override
 	protected void uninstallListeners() {
 		super.uninstallListeners();
 
-		getComponent().removeFocusListener( getHandler() );
+		getComponent().removeFocusListener( focusListener );
-
+		focusListener = null;
-		handler = null;
 	}
 
-	public Handler getHandler() {
+	@Override
-		if( handler == null )
+	protected void paintSafely( Graphics g ) {
-			handler = new Handler();
+		FlatTextFieldUI.paintBackground( g, getComponent(), focusWidth );
-		return handler;
+		super.paintSafely( g );
 	}
 
 	@Override
 	protected void paintBackground( Graphics g ) {
-		JTextComponent c = getComponent();
+		// background is painted elsewhere
-
-		FlatUIUtils.paintParentBackground( g, c );
-
-		Graphics2D g2 = (Graphics2D) g.create();
-		try {
-			FlatUIUtils.setRenderingHints( g2 );
-
-			float focusWidth = (c.getBorder() instanceof FlatBorder) ? scale( (float) this.focusWidth ) : 0;
-
-			g2.setColor( c.getBackground() );
-			FlatUIUtils.fillRoundRectangle( g2, 0, 0, c.getWidth(), c.getHeight(), focusWidth, 0 );
-		} finally {
-			g2.dispose();
-		}
 	}
 
 	@Override
@@ -129,20 +114,4 @@ public class FlatPasswordFieldUI
 		size.width = Math.max( size.width, scale( minimumWidth + (focusWidth * 2) ) );
 		return size;
 	}
-
-	//---- class Handler ------------------------------------------------------
-
-	private class Handler
-		implements FocusListener
-	{
-		@Override
-		public void focusGained( FocusEvent e ) {
-			getComponent().repaint();
-		}
-
-		@Override
-		public void focusLost( FocusEvent e ) {
-			getComponent().repaint();
-		}
-	}
 }

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

@@ -23,6 +23,7 @@ import java.awt.Insets;
 import java.awt.geom.RoundRectangle2D;
 import javax.swing.JComponent;
 import javax.swing.JProgressBar;
+import javax.swing.LookAndFeel;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicProgressBarUI;
 import com.formdev.flatlaf.util.UIScale;
@@ -39,6 +40,13 @@ public class FlatProgressBarUI
 		return new FlatProgressBarUI();
 	}
 
+	@Override
+	protected void installDefaults() {
+		super.installDefaults();
+
+		LookAndFeel.installProperty( progressBar, "opaque", false );
+	}
+
 	@Override
 	protected Dimension getPreferredInnerHorizontal() {
 		return UIScale.scale( super.getPreferredInnerHorizontal() );

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

@@ -17,10 +17,8 @@
 package com.formdev.flatlaf.ui;
 
 import java.awt.Component;
-import java.awt.Container;
 import java.awt.Graphics;
 import java.awt.Insets;
-import java.awt.Rectangle;
 import java.awt.event.ContainerEvent;
 import java.awt.event.ContainerListener;
 import java.awt.event.FocusEvent;
@@ -29,10 +27,9 @@ import java.beans.PropertyChangeEvent;
 import javax.swing.JComponent;
 import javax.swing.JScrollPane;
 import javax.swing.JViewport;
-import javax.swing.ScrollPaneLayout;
+import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
-import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicScrollPaneUI;
 
 /**
@@ -53,17 +50,14 @@ public class FlatScrollPaneUI
 	public void installUI( JComponent c ) {
 		super.installUI( c );
 
-		if( scrollpane.getLayout() instanceof UIResource )
+		int focusWidth = UIManager.getInt( "Component.focusWidth" );
-			scrollpane.setLayout( new FlatScrollPaneLayout() );
+		LookAndFeel.installProperty( c, "opaque", focusWidth == 0 );
 
-		MigLayoutVisualPadding.install( scrollpane, UIManager.getInt( "Component.focusWidth" ) );
+		MigLayoutVisualPadding.install( scrollpane, focusWidth );
 	}
 
 	@Override
 	public void uninstallUI( JComponent c ) {
-		if( scrollpane.getLayout() instanceof FlatScrollPaneLayout )
-			scrollpane.setLayout( new ScrollPaneLayout.UIResource() );
-
 		MigLayoutVisualPadding.uninstall( scrollpane );
 
 		super.uninstallUI( c );
@@ -169,27 +163,4 @@ public class FlatScrollPaneUI
 			scrollpane.repaint();
 		}
 	}
-
-	//---- class FlatScrollPaneLayout -----------------------------------------
-
-	private static class FlatScrollPaneLayout
-		extends ScrollPaneLayout
-	{
-		@Override
-		public void layoutContainer( Container parent ) {
-			super.layoutContainer( parent );
-
-			// increase height of vertical scroll bar so that it also fills the upper right corner
-			if( colHead != null && vsb != null && colHead.isVisible() && vsb.isVisible() ) {
-				Rectangle colHeadBounds = colHead.getBounds();
-				Rectangle vsbBounds = vsb.getBounds();
-
-				if( vsbBounds.y > colHeadBounds.y ) {
-					vsbBounds.height += (vsbBounds.y - colHeadBounds.y);
-					vsbBounds.y = colHeadBounds.y;
-					vsb.setBounds( vsbBounds );
-				}
-			}
-		}
-	}
 }

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

@@ -35,6 +35,7 @@ import java.beans.PropertyChangeListener;
 import javax.swing.JComponent;
 import javax.swing.JSpinner;
 import javax.swing.JTextField;
+import javax.swing.LookAndFeel;
 import javax.swing.SwingConstants;
 import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
@@ -88,6 +89,8 @@ public class FlatSpinnerUI
 	protected void installDefaults() {
 		super.installDefaults();
 
+		LookAndFeel.installProperty( spinner, "opaque", false );
+
 		focusWidth = UIManager.getInt( "Component.focusWidth" );
 		arc = UIManager.getInt( "Component.arc" );
 		minimumWidth = UIManager.getInt( "Component.minimumWidth" );
@@ -152,6 +155,13 @@ public class FlatSpinnerUI
 	@Override
 	protected JComponent createEditor() {
 		JComponent editor = super.createEditor();
+
+		// explicitly make non-opaque
+		editor.setOpaque( false );
+		JTextField textField = getEditorTextField( editor );
+		if( textField != null )
+			textField.setOpaque( false );
+
 		updateEditorColors();
 		return editor;
 	}
@@ -183,8 +193,6 @@ public class FlatSpinnerUI
 			// use non-UIResource colors because when SwingUtilities.updateComponentTreeUI()
 			// is used, then the text field is updated after the spinner and the
 			// colors are again replaced with default colors
-			textField.setBackground( FlatUIUtils.nonUIResource( spinner.isEnabled()
-				? spinner.getBackground() : disabledBackground ) );
 			textField.setForeground( FlatUIUtils.nonUIResource( spinner.getForeground() ) );
 			textField.setDisabledTextColor( FlatUIUtils.nonUIResource( disabledForeground ) );
 		}
@@ -225,7 +233,8 @@ public class FlatSpinnerUI
 
 	@Override
 	public void update( Graphics g, JComponent c ) {
-		if( c.isOpaque() ) {
+		// fill background if opaque to avoid garbage if user sets opaque to true
+		if( c.isOpaque() && (focusWidth > 0 || arc != 0) )
 			FlatUIUtils.paintParentBackground( g, c );
 
 		Graphics2D g2 = (Graphics2D) g;
@@ -262,7 +271,6 @@ public class FlatSpinnerUI
 		float lw = scale( 1f );
 		float lx = isLeftToRight ? arrowX : arrowX + arrowWidth - lw;
 		g2.fill( new Rectangle2D.Float( lx, focusWidth, lw, height - (focusWidth * 2) ) );
-		}
 
 		paint( g, c );
 	}
@@ -370,7 +378,6 @@ public class FlatSpinnerUI
 		@Override
 		public void propertyChange( PropertyChangeEvent e ) {
 			switch( e.getPropertyName() ) {
-				case "background":
 				case "foreground":
 				case "enabled":
 					updateEditorColors();

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

@@ -21,11 +21,11 @@ import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
-import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JSpinner;
+import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicTextFieldUI;
@@ -47,7 +47,7 @@ public class FlatTextFieldUI
 	protected int focusWidth;
 	protected int minimumWidth;
 
-	private Handler handler;
+	private FocusListener focusListener;
 
 	public static ComponentUI createUI( JComponent c ) {
 		return new FlatTextFieldUI();
@@ -60,6 +60,8 @@ public class FlatTextFieldUI
 		focusWidth = UIManager.getInt( "Component.focusWidth" );
 		minimumWidth = UIManager.getInt( "Component.minimumWidth" );
 
+		LookAndFeel.installProperty( getComponent(), "opaque", focusWidth == 0 );
+
 		MigLayoutVisualPadding.install( getComponent(), focusWidth );
 	}
 
@@ -74,38 +76,51 @@ public class FlatTextFieldUI
 	protected void installListeners() {
 		super.installListeners();
 
-		getComponent().addFocusListener( getHandler() );
+		focusListener = new FlatUIUtils.RepaintFocusListener( getComponent() );
+		getComponent().addFocusListener( focusListener );
 	}
 
 	@Override
 	protected void uninstallListeners() {
 		super.uninstallListeners();
 
-		getComponent().removeFocusListener( getHandler() );
+		getComponent().removeFocusListener( focusListener );
-
+		focusListener = null;
-		handler = null;
 	}
 
-	public Handler getHandler() {
+	@Override
-		if( handler == null )
+	protected void paintSafely( Graphics g ) {
-			handler = new Handler();
+		paintBackground( g, getComponent(), focusWidth );
-		return handler;
+		super.paintSafely( g );
 	}
 
 	@Override
 	protected void paintBackground( Graphics g ) {
-		JTextComponent c = getComponent();
+		// background is painted elsewhere
+	}
 
+	static void paintBackground( Graphics g, JTextComponent c, int focusWidth ) {
+		// do not paint background if:
+		//   - not opaque and
+		//   - border is not a flat border and
+		//   - opaque was explicitly set (to false)
+		// (same behaviour as in AquaTextFieldUI)
+		if( !c.isOpaque() && !(c.getBorder() instanceof FlatBorder) && FlatUIUtils.hasOpaqueBeenExplicitlySet( c ) )
+			return;
+
+		// fill background if opaque to avoid garbage if user sets opaque to true
+		if( c.isOpaque() && focusWidth > 0 )
 			FlatUIUtils.paintParentBackground( g, c );
 
+		// paint background
 		Graphics2D g2 = (Graphics2D) g.create();
 		try {
 			FlatUIUtils.setRenderingHints( g2 );
 
-			float focusWidth = (c.getBorder() instanceof FlatBorder) ? scale( (float) this.focusWidth ) : 0;
+			float fFocusWidth = (c.getBorder() instanceof FlatBorder) ? scale( (float) focusWidth ) : 0;
 
 			g2.setColor( c.getBackground() );
-			FlatUIUtils.fillRoundRectangle( g2, 0, 0, c.getWidth(), c.getHeight(), focusWidth, 0 );
+			FlatUIUtils.fillRoundRectangle( g2, 0, 0, c.getWidth(), c.getHeight(), fFocusWidth, 0 );
 		} finally {
 			g2.dispose();
 		}
@@ -132,20 +147,4 @@ public class FlatTextFieldUI
 		size.width = Math.max( size.width, scale( minimumWidth + (focusWidth * 2) ) );
 		return size;
 	}
-
-	//---- class Handler ------------------------------------------------------
-
-	private class Handler
-		implements FocusListener
-	{
-		@Override
-		public void focusGained( FocusEvent e ) {
-			getComponent().repaint();
-		}
-
-		@Override
-		public void focusLost( FocusEvent e ) {
-			getComponent().repaint();
-		}
-	}
 }

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

@@ -26,6 +26,8 @@ import java.awt.Insets;
 import java.awt.Rectangle;
 import java.awt.RenderingHints;
 import java.awt.Shape;
+import java.awt.event.FocusEvent;
+import java.awt.event.FocusListener;
 import java.awt.event.MouseAdapter;
 import java.awt.event.MouseEvent;
 import java.awt.geom.Path2D;
@@ -33,8 +35,10 @@ import java.awt.geom.Rectangle2D;
 import java.awt.geom.RoundRectangle2D;
 import java.util.function.Consumer;
 import javax.swing.JComponent;
+import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
 import javax.swing.plaf.ColorUIResource;
+import com.formdev.flatlaf.util.DerivedColor;
 import com.formdev.flatlaf.util.JavaCompatibility;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -101,6 +105,12 @@ public class FlatUIUtils
 			MAC_USE_QUARTZ ? RenderingHints.VALUE_STROKE_PURE : RenderingHints.VALUE_STROKE_NORMALIZE );
 	}
 
+	public static void setColor( Graphics g, Color color, Color baseColor ) {
+		if( color instanceof DerivedColor )
+			color = ((DerivedColor)color).derive( baseColor );
+		g.setColor( color );
+	}
+
 	/**
 	 * Draws a round rectangle.
 	 */
@@ -246,15 +256,23 @@ public class FlatUIUtils
 		JavaCompatibility.drawStringUnderlineCharAt( c, g, text, underlinedIndex, x, y );
 	}
 
+	public static boolean hasOpaqueBeenExplicitlySet( JComponent c ) {
+		boolean oldOpaque = c.isOpaque();
+		LookAndFeel.installProperty( c, "opaque", !oldOpaque );
+		boolean explicitlySet = c.isOpaque() == oldOpaque;
+		LookAndFeel.installProperty( c, "opaque", oldOpaque );
+		return explicitlySet;
+	}
+
 	//---- class HoverListener ------------------------------------------------
 
 	public static class HoverListener
 		extends MouseAdapter
 	{
-		private final JComponent repaintComponent;
+		private final Component repaintComponent;
 		private final Consumer<Boolean> hoverChanged;
 
-		public HoverListener( JComponent repaintComponent, Consumer<Boolean> hoverChanged ) {
+		public HoverListener( Component repaintComponent, Consumer<Boolean> hoverChanged ) {
 			this.repaintComponent = repaintComponent;
 			this.hoverChanged = hoverChanged;
 		}
@@ -276,4 +294,26 @@ public class FlatUIUtils
 				repaintComponent.repaint();
 		}
 	}
+
+	//---- class RepaintFocusListener -----------------------------------------
+
+	public static class RepaintFocusListener
+		implements FocusListener
+	{
+		private final Component repaintComponent;
+
+		public RepaintFocusListener( Component repaintComponent ) {
+			this.repaintComponent = repaintComponent;
+		}
+
+		@Override
+		public void focusGained( FocusEvent e ) {
+			repaintComponent.repaint();
+		}
+
+		@Override
+		public void focusLost( FocusEvent e ) {
+			repaintComponent.repaint();
+		}
+	}
 }

flatlaf-core/src/main/java/com/formdev/flatlaf/util/ColorFunctions.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.util;
+
+import java.awt.Color;
+
+/**
+ * Functions that modify colors.
+ *
+ * @author Karl Tauber
+ */
+public class ColorFunctions
+{
+	public static Color applyFunctions( Color color, ColorFunction[] functions ) {
+		float[] hsl = HSLColor.fromRGB( color );
+		float alpha = color.getAlpha() / 255f;
+
+		for( ColorFunction function : functions )
+			function.apply( hsl );
+
+		return HSLColor.toRGB( hsl, alpha );
+	}
+
+	private static float clamp( float value ) {
+		return (value < 0)
+			? 0
+			: ((value > 100)
+				? 100
+				: value);
+	}
+
+	//---- interface ColorFunction --------------------------------------------
+
+	public interface ColorFunction {
+		void apply( float[] hsl );
+	}
+
+	//---- class Lighten ------------------------------------------------------
+
+	/**
+	 * Increase the lightness of a color in the HSL color space by an absolute
+	 * or relative amount.
+	 */
+	public static class Lighten
+		implements ColorFunction
+	{
+		private final float amount;
+		private final boolean relative;
+		private final boolean autoInverse;
+
+		public Lighten( float amount, boolean relative, boolean autoInverse ) {
+			this.amount = amount;
+			this.relative = relative;
+			this.autoInverse = autoInverse;
+		}
+
+		@Override
+		public void apply( float[] hsl ) {
+			float amount2 = autoInverse && shouldInverse( hsl ) ? -amount : amount;
+			hsl[2] = clamp( relative
+				? (hsl[2] * ((100 + amount2) / 100))
+				: (hsl[2] + amount2) );
+		}
+
+		protected boolean shouldInverse( float[] hsl ) {
+			return hsl[2] >= 50;
+		}
+	}
+
+	//---- class Darken -------------------------------------------------------
+
+	/**
+	 * Decrease the lightness of a color in the HSL color space by an absolute
+	 * or relative amount.
+	 */
+	public static class Darken
+		extends Lighten
+	{
+		public Darken( float amount, boolean relative, boolean autoInverse ) {
+			super( -amount, relative, autoInverse );
+		}
+
+		@Override
+		protected boolean shouldInverse( float[] hsl ) {
+			return hsl[2] < 50;
+		}
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/util/DerivedColor.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.util;
+
+import java.awt.Color;
+import javax.swing.plaf.ColorUIResource;
+import com.formdev.flatlaf.util.ColorFunctions.ColorFunction;
+
+/**
+ * A (red) color that acts as a placeholder in UI defaults.
+ * The actual color is derived from another color,
+ * which is modified by the given color functions.
+ *
+ * @author Karl Tauber
+ */
+public class DerivedColor
+	extends ColorUIResource
+{
+	private final ColorFunction[] functions;
+
+	public DerivedColor( ColorFunction... functions ) {
+		super( Color.red );
+		this.functions = functions;
+	}
+
+	public Color derive( Color baseColor ) {
+		return ColorFunctions.applyFunctions( baseColor, functions );
+	}
+}

flatlaf-core/src/main/java/com/formdev/flatlaf/util/HSLColor.java

@@ -0,0 +1,432 @@
+/*
+ * From http://tips4java.wordpress.com/2009/07/05/hsl-color/
+ *
+ * License note on http://tips4java.wordpress.com/about/
+ *   "You are free to use and/or modify any or all code posted on the
+ *    Java Tips Weblog without restriction. A credit in the code comments
+ *    would be nice, but not in any way mandatory."
+ */
+
+package com.formdev.flatlaf.util;
+
+import java.awt.Color;
+
+/**
+ *  The HSLColor class provides methods to manipulate HSL (Hue, Saturation
+ *  Luminance) values to create a corresponding Color object using the RGB
+ *  ColorSpace.
+ *
+ *  The HUE is the color, the Saturation is the purity of the color (with
+ *  respect to grey) and Luminance is the brightness of the color (with respect
+ *  to black and white)
+ *
+ *  The Hue is specified as an angel between 0 - 360 degrees where red is 0,
+ *  green is 120 and blue is 240. In between you have the colors of the rainbow.
+ *  Saturation is specified as a percentage between 0 - 100 where 100 is fully
+ *  saturated and 0 approaches gray. Luminance is specified as a percentage
+ *  between 0 - 100 where 0 is black and 100 is white.
+ *
+ *  In particular the HSL color space makes it easier change the Tone or Shade
+ *  of a color by adjusting the luminance value.
+ */
+public class HSLColor
+{
+	private final Color rgb;
+	private final float[] hsl;
+	private final float alpha;
+
+	/**
+	 *  Create a HSLColor object using an RGB Color object.
+	 *
+	 *  @param rgb the RGB Color object
+	 */
+	public HSLColor(Color rgb)
+	{
+		this.rgb = rgb;
+		hsl = fromRGB( rgb );
+		alpha = rgb.getAlpha() / 255.0f;
+	}
+
+	/**
+	 *  Create a HSLColor object using individual HSL values and a default
+	 * alpha value of 1.0.
+	 *
+	 *  @param h is the Hue value in degrees between 0 - 360
+	 *  @param s is the Saturation percentage between 0 - 100
+	 *  @param l is the Lumanance percentage between 0 - 100
+	 */
+	public HSLColor(float h, float s, float l)
+	{
+		this(h, s, l, 1.0f);
+	}
+
+	/**
+	 *  Create a HSLColor object using individual HSL values.
+	 *
+	 *  @param h     the Hue value in degrees between 0 - 360
+	 *  @param s     the Saturation percentage between 0 - 100
+	 *  @param l     the Lumanance percentage between 0 - 100
+	 *  @param alpha the alpha value between 0 - 1
+	 */
+	public HSLColor(float h, float s, float l, float alpha)
+	{
+		hsl = new float[] {h, s, l};
+		this.alpha = alpha;
+		rgb = toRGB(hsl, alpha);
+	}
+
+	/**
+	 *  Create a HSLColor object using an an array containing the
+	 *  individual HSL values and with a default alpha value of 1.
+	 *
+	 *  @param hsl  array containing HSL values
+	 */
+	public HSLColor(float[] hsl)
+	{
+		this(hsl, 1.0f);
+	}
+
+	/**
+	 *  Create a HSLColor object using an an array containing the
+	 *  individual HSL values.
+	 *
+	 *  @param hsl  array containing HSL values
+	 *  @param alpha the alpha value between 0 - 1
+	 */
+	public HSLColor(float[] hsl, float alpha)
+	{
+		this.hsl = hsl;
+		this.alpha = alpha;
+		rgb = toRGB(hsl, alpha);
+	}
+
+	/**
+	 *  Create a RGB Color object based on this HSLColor with a different
+	 *  Hue value. The degrees specified is an absolute value.
+	 *
+	 *  @param degrees - the Hue value between 0 - 360
+	 *  @return the RGB Color object
+	 */
+	public Color adjustHue(float degrees)
+	{
+		return toRGB(degrees, hsl[1], hsl[2], alpha);
+	}
+
+	/**
+	 *  Create a RGB Color object based on this HSLColor with a different
+	 *  Luminance value. The percent specified is an absolute value.
+	 *
+	 *  @param percent - the Luminance value between 0 - 100
+	 *  @return the RGB Color object
+	 */
+	public Color adjustLuminance(float percent)
+	{
+		return toRGB(hsl[0], hsl[1], percent, alpha);
+	}
+
+	/**
+	 *  Create a RGB Color object based on this HSLColor with a different
+	 *  Saturation value. The percent specified is an absolute value.
+	 *
+	 *  @param percent - the Saturation value between 0 - 100
+	 *  @return the RGB Color object
+	 */
+	public Color adjustSaturation(float percent)
+	{
+		return toRGB(hsl[0], percent, hsl[2], alpha);
+	}
+
+	/**
+	 *  Create a RGB Color object based on this HSLColor with a different
+	 *  Shade. Changing the shade will return a darker color. The percent
+	 *  specified is a relative value.
+	 *
+	 *  @param percent - the value between 0 - 100
+	 *  @return the RGB Color object
+	 */
+	public Color adjustShade(float percent)
+	{
+		float multiplier = (100.0f - percent) / 100.0f;
+		float l = Math.max(0.0f, hsl[2] * multiplier);
+
+		return toRGB(hsl[0], hsl[1], l, alpha);
+	}
+
+	/**
+	 *  Create a RGB Color object based on this HSLColor with a different
+	 *  Tone. Changing the tone will return a lighter color. The percent
+	 *  specified is a relative value.
+	 *
+	 *  @param percent - the value between 0 - 100
+	 *  @return the RGB Color object
+	 */
+	public Color adjustTone(float percent)
+	{
+		float multiplier = (100.0f + percent) / 100.0f;
+		float l = Math.min(100.0f, hsl[2] * multiplier);
+
+		return toRGB(hsl[0], hsl[1], l, alpha);
+	}
+
+	/**
+	 *  Get the Alpha value.
+	 *
+	 *  @return the Alpha value.
+	 */
+	public float getAlpha()
+	{
+		return alpha;
+	}
+
+	/**
+	 *  Create a RGB Color object that is the complementary color of this
+	 *  HSLColor. This is a convenience method. The complementary color is
+	 *  determined by adding 180 degrees to the Hue value.
+	 *  @return the RGB Color object
+	 */
+	public Color getComplementary()
+	{
+		float hue = (hsl[0] + 180.0f) % 360.0f;
+		return toRGB(hue, hsl[1], hsl[2]);
+	}
+
+	/**
+	 *  Get the Hue value.
+	 *
+	 *  @return the Hue value.
+	 */
+	public float getHue()
+	{
+		return hsl[0];
+	}
+
+	/**
+	 *  Get the HSL values.
+	 *
+	 *  @return the HSL values.
+	 */
+	public float[] getHSL()
+	{
+		return hsl;
+	}
+
+	/**
+	 *  Get the Luminance value.
+	 *
+	 *  @return the Luminance value.
+	 */
+	public float getLuminance()
+	{
+		return hsl[2];
+	}
+
+	/**
+	 *  Get the RGB Color object represented by this HDLColor.
+	 *
+	 *  @return the RGB Color object.
+	 */
+	public Color getRGB()
+	{
+		return rgb;
+	}
+
+	/**
+	 *  Get the Saturation value.
+	 *
+	 *  @return the Saturation value.
+	 */
+	public float getSaturation()
+	{
+		return hsl[1];
+	}
+
+	@Override
+	public String toString()
+	{
+		String toString =
+			"HSLColor[h=" + hsl[0] +
+			",s=" + hsl[1] +
+			",l=" + hsl[2] +
+			",alpha=" + alpha + "]";
+
+		return toString;
+	}
+
+	/**
+	 *  Convert a RGB Color to it corresponding HSL values.
+	 *
+	 *  @return an array containing the 3 HSL values.
+	 */
+	public static float[] fromRGB(Color color)
+	{
+		//  Get RGB values in the range 0 - 1
+
+		float[] rgb = color.getRGBColorComponents( null );
+		float r = rgb[0];
+		float g = rgb[1];
+		float b = rgb[2];
+
+		//	Minimum and Maximum RGB values are used in the HSL calculations
+
+		float min = Math.min(r, Math.min(g, b));
+		float max = Math.max(r, Math.max(g, b));
+
+		//  Calculate the Hue
+
+		float h = 0;
+
+		if (max == min)
+			h = 0;
+		else if (max == r)
+			h = ((60 * (g - b) / (max - min)) + 360) % 360;
+		else if (max == g)
+			h = (60 * (b - r) / (max - min)) + 120;
+		else if (max == b)
+			h = (60 * (r - g) / (max - min)) + 240;
+
+		//  Calculate the Luminance
+
+		float l = (max + min) / 2;
+//		System.out.println(max + " : " + min + " : " + l);
+
+		//  Calculate the Saturation
+
+		float s = 0;
+
+		if (max == min)
+			s = 0;
+		else if (l <= .5f)
+			s = (max - min) / (max + min);
+		else
+			s = (max - min) / (2 - max - min);
+
+//		System.out.println(new HSLColor( new float[] {h, s * 100, l * 100} ));
+		return new float[] {h, s * 100, l * 100};
+	}
+
+	/**
+	 *  Convert HSL values to a RGB Color with a default alpha value of 1.
+	 *  H (Hue) is specified as degrees in the range 0 - 360.
+	 *  S (Saturation) is specified as a percentage in the range 1 - 100.
+	 *  L (Lumanance) is specified as a percentage in the range 1 - 100.
+	 *
+	 *  @param hsl an array containing the 3 HSL values
+	 *
+	 *  @returns the RGB Color object
+	 */
+	public static Color toRGB(float[] hsl)
+	{
+		return toRGB(hsl, 1.0f);
+	}
+
+	/**
+	 *  Convert HSL values to a RGB Color.
+	 *  H (Hue) is specified as degrees in the range 0 - 360.
+	 *  S (Saturation) is specified as a percentage in the range 1 - 100.
+	 *  L (Lumanance) is specified as a percentage in the range 1 - 100.
+	 *
+	 *  @param hsl    an array containing the 3 HSL values
+	 *  @param alpha  the alpha value between 0 - 1
+	 *
+	 *  @returns the RGB Color object
+	 */
+	public static Color toRGB(float[] hsl, float alpha)
+	{
+		return toRGB(hsl[0], hsl[1], hsl[2], alpha);
+	}
+
+	/**
+	 *  Convert HSL values to a RGB Color with a default alpha value of 1.
+	 *
+	 *  @param h Hue is specified as degrees in the range 0 - 360.
+	 *  @param s Saturation is specified as a percentage in the range 1 - 100.
+	 *  @param l Lumanance is specified as a percentage in the range 1 - 100.
+	 *
+	 *  @returns the RGB Color object
+	 */
+	public static Color toRGB(float h, float s, float l)
+	{
+		return toRGB(h, s, l, 1.0f);
+	}
+
+	/**
+	 *  Convert HSL values to a RGB Color.
+	 *
+	 *  @param h Hue is specified as degrees in the range 0 - 360.
+	 *  @param s Saturation is specified as a percentage in the range 1 - 100.
+	 *  @param l Lumanance is specified as a percentage in the range 1 - 100.
+	 *  @param alpha  the alpha value between 0 - 1
+	 *
+	 *  @returns the RGB Color object
+	 */
+	public static Color toRGB(float h, float s, float l, float alpha)
+	{
+		if (s <0.0f || s > 100.0f)
+		{
+			String message = "Color parameter outside of expected range - Saturation";
+			throw new IllegalArgumentException( message );
+		}
+
+		if (l <0.0f || l > 100.0f)
+		{
+			String message = "Color parameter outside of expected range - Luminance";
+			throw new IllegalArgumentException( message );
+		}
+
+		if (alpha <0.0f || alpha > 1.0f)
+		{
+			String message = "Color parameter outside of expected range - Alpha";
+			throw new IllegalArgumentException( message );
+		}
+
+		//  Formula needs all values between 0 - 1.
+
+		h = h % 360.0f;
+		h /= 360f;
+		s /= 100f;
+		l /= 100f;
+
+		float q = 0;
+
+		if (l < 0.5)
+			q = l * (1 + s);
+		else
+			q = (l + s) - (s * l);
+
+		float p = 2 * l - q;
+
+		float r = Math.max(0, HueToRGB(p, q, h + (1.0f / 3.0f)));
+		float g = Math.max(0, HueToRGB(p, q, h));
+		float b = Math.max(0, HueToRGB(p, q, h - (1.0f / 3.0f)));
+
+		r = Math.min(r, 1.0f);
+		g = Math.min(g, 1.0f);
+		b = Math.min(b, 1.0f);
+
+		return new Color(r, g, b, alpha);
+	}
+
+	private static float HueToRGB(float p, float q, float h)
+	{
+		if (h < 0) h += 1;
+
+		if (h > 1 ) h -= 1;
+
+		if (6 * h < 1)
+		{
+			return p + ((q - p) * 6 * h);
+		}
+
+		if (2 * h < 1 )
+		{
+			return  q;
+		}
+
+		if (3 * h < 2)
+		{
+			return p + ( (q - p) * 6 * ((2.0f / 3.0f) - h) );
+		}
+
+   		return p;
+	}
+}

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

@@ -31,6 +31,10 @@
 @cellFocusColor=000000
 @icon=adadad
 
+# Button
+@buttonHoverBackground=lighten(3%,autoInverse)
+@buttonPressedBackground=lighten(6%,autoInverse)
+
 
 #---- globals ----
 
@@ -63,8 +67,8 @@ window=@background
 #---- Button ----
 
 Button.background=4c5052
-Button.hoverBackground=525658
+Button.hoverBackground=@buttonHoverBackground
-Button.pressedBackground=5c6164
+Button.pressedBackground=@buttonPressedBackground
 
 Button.borderColor=5e6060
 Button.disabledBorderColor=5e6060
@@ -73,8 +77,8 @@ Button.hoverBorderColor=@@Button.focusedBorderColor
 
 Button.default.background=365880
 Button.default.foreground=bbbbbb
-Button.default.hoverBackground=3d6185
+Button.default.hoverBackground=@buttonHoverBackground
-Button.default.pressedBackground=43688c
+Button.default.pressedBackground=@buttonPressedBackground
 Button.default.borderColor=4c708c
 Button.default.hoverBorderColor=537699
 Button.default.focusedBorderColor=537699
@@ -95,8 +99,8 @@ CheckBox.icon.hoverBorderColor=@@CheckBox.icon.focusedBorderColor
 CheckBox.icon.selectedFocusedBorderColor=466D94
 CheckBox.icon.background=43494A
 CheckBox.icon.disabledBackground=@background
-CheckBox.icon.hoverBackground=4c5052
+CheckBox.icon.hoverBackground=@buttonHoverBackground
-CheckBox.icon.pressedBackground=@@Button.pressedBackground
+CheckBox.icon.pressedBackground=@buttonPressedBackground
 CheckBox.icon.selectedBackground=43494A
 CheckBox.icon.checkmarkColor=A7A7A7
 CheckBox.icon.disabledCheckmarkColor=606060

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

@@ -77,6 +77,7 @@ Button.default.borderWidth=1
 
 CheckBox.border=com.formdev.flatlaf.ui.FlatMarginBorder
 CheckBox.icon=com.formdev.flatlaf.icons.FlatCheckBoxIcon
+CheckBox.arc=2
 CheckBox.margin=2,2,2,2
 CheckBox.iconTextGap=4
 CheckBox.rollover=true
@@ -277,6 +278,7 @@ ScrollBar.width=10
 
 ScrollPane.border=com.formdev.flatlaf.ui.FlatBorder
 ScrollPane.background=@@ScrollBar.track
+ScrollPane.fillUpperCorner=true
 
 
 #---- Separator ----

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

@@ -31,6 +31,10 @@
 @cellFocusColor=000000
 @icon=afafaf
 
+# Button
+@buttonHoverBackground=darken(3%,autoInverse)
+@buttonPressedBackground=darken(10%,autoInverse)
+
 
 #---- globals ----
 
@@ -64,8 +68,8 @@ window=@background
 
 Button.background=ffffff
 Button.focusedBackground=e3f1fa
-Button.hoverBackground=f8f8f8
+Button.hoverBackground=@buttonHoverBackground
-Button.pressedBackground=dfdfdf
+Button.pressedBackground=@buttonPressedBackground
 
 Button.borderColor=bfbfbf
 Button.disabledBorderColor=cfcfcf
@@ -75,8 +79,8 @@ Button.hoverBorderColor=@@Button.focusedBorderColor
 Button.default.background=@@Button.background
 Button.default.foreground=@foreground
 Button.default.focusedBackground=@@Button.focusedBackground
-Button.default.hoverBackground=@@Button.hoverBackground
+Button.default.hoverBackground=@buttonHoverBackground
-Button.default.pressedBackground=@@Button.pressedBackground
+Button.default.pressedBackground=@buttonPressedBackground
 Button.default.borderColor=4D89C9
 Button.default.hoverBorderColor=@@Button.hoverBorderColor
 Button.default.focusedBorderColor=@@Button.focusedBorderColor
@@ -97,8 +101,8 @@ CheckBox.icon.hoverBorderColor=@@CheckBox.icon.focusedBorderColor
 CheckBox.icon.background=FFFFFF
 CheckBox.icon.disabledBackground=@background
 CheckBox.icon.focusedBackground=@@Button.focusedBackground
-CheckBox.icon.hoverBackground=@@Button.hoverBackground
+CheckBox.icon.hoverBackground=@buttonHoverBackground
-CheckBox.icon.pressedBackground=@@Button.pressedBackground
+CheckBox.icon.pressedBackground=@buttonPressedBackground
 CheckBox.icon.selectedBackground=FFFFFF
 CheckBox.icon.checkmarkColor=4D89C9
 CheckBox.icon.disabledCheckmarkColor=ABABAB

flatlaf-extras/README.md

@@ -0,0 +1,13 @@
+FlatLaf Extras
+==============
+
+This sub-project provides some additional components and classes:
+
+- [TriStateCheckBox](src/main/java/com/formdev/flatlaf/extras/TriStateCheckBox.java):
+  A tri-state check box.
+
+
+Download
+--------
+
+Not yet available.

flatlaf-extras/build.gradle.kts

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+version = rootProject.version
+
+plugins {
+	`java-library`
+}
+
+dependencies {
+	implementation( project( ":flatlaf-core" ) )
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}

flatlaf-extras/src/main/java/com/formdev/flatlaf/extras/TriStateCheckBox.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.extras;
+
+import java.awt.event.ItemEvent;
+import javax.swing.JCheckBox;
+
+/**
+ * A tri-state check box.
+ *
+ * To display the third state, this component requires an LaF that supports painting
+ * the indeterminate state if client property {@code "JButton.selectedState"} has the
+ * value {@code "indeterminate"}.
+ *
+ * FlatLaf and Mac Aqua LaF support the third state.
+ *
+ * @author Karl Tauber
+ */
+public class TriStateCheckBox
+	extends JCheckBox
+{
+	public enum State { INDETERMINATE, SELECTED, UNSELECTED }
+
+	private State state;
+	private boolean thirdStateEnabled = true;
+
+	public TriStateCheckBox() {
+		this( null );
+	}
+
+	public TriStateCheckBox( String text ) {
+		this( text, State.INDETERMINATE );
+	}
+
+	public TriStateCheckBox( String text, State initialState ) {
+		super( text );
+
+		setModel( new ToggleButtonModel() {
+			@Override
+			public boolean isSelected() {
+				return state != State.UNSELECTED;
+			}
+
+			@Override
+			public void setSelected( boolean b ) {
+				switch( state ) {
+					case INDETERMINATE:			setState( State.SELECTED ); break;
+					case SELECTED:		setState( State.UNSELECTED ); break;
+					case UNSELECTED:	setState( thirdStateEnabled ? State.INDETERMINATE : State.SELECTED ); break;
+				}
+
+				fireStateChanged();
+				fireItemStateChanged( new ItemEvent( this, ItemEvent.ITEM_STATE_CHANGED, this,
+					isSelected() ? ItemEvent.SELECTED : ItemEvent.DESELECTED ) );
+			}
+		} );
+
+		setState( initialState );
+	}
+
+	public State getState() {
+		return state;
+	}
+
+	public void setState( State state ) {
+		if( this.state == state )
+			return;
+
+		State oldState = this.state;
+		this.state = state;
+
+		putClientProperty( "JButton.selectedState", state == State.INDETERMINATE ? "indeterminate" : null );
+
+		firePropertyChange( "state", oldState, state );
+		repaint();
+	}
+
+	public boolean isThirdStateEnabled() {
+		return thirdStateEnabled;
+	}
+
+	public void setThirdStateEnabled( boolean thirdStateEnabled ) {
+		this.thirdStateEnabled = thirdStateEnabled;
+
+		if( state == State.INDETERMINATE )
+			setState( State.UNSELECTED );
+	}
+
+	@Override
+	public void setSelected( boolean b ) {
+		setState( b ? State.SELECTED : State.UNSELECTED );
+	}
+}

flatlaf-swingx/README.md

@@ -32,7 +32,7 @@ build script:
 
     groupId:     com.formdev
     artifactId:  flatlaf-swingx
-    version:     0.16
+    version:     0.17
 
 Otherwise download `flatlaf-swingx-<version>.jar` here:
 

flatlaf-swingx/build.gradle.kts

@@ -25,10 +25,6 @@ plugins {
 dependencies {
 	implementation( project( ":flatlaf-core" ) )
 	implementation( "org.swinglabs.swingx:swingx-all:1.6.5-1" )
-
-	testImplementation( project( ":flatlaf-core", "testArtifacts" ) )
-	testImplementation( "org.swinglabs.swingx:swingx-beaninfo:1.6.5-1" )
-	testImplementation( "com.miglayout:miglayout-swing:5.2" )
 }
 
 java {
@@ -37,6 +33,12 @@ java {
 }
 
 tasks {
+	assemble {
+		dependsOn(
+			"sourcesJar",
+			"javadocJar"
+		)
+	}
 
 	javadoc {
 		options {

flatlaf-swingx/src/main/java/com/formdev/flatlaf/swingx/ui/FlatDatePickerUI.java

@@ -28,8 +28,6 @@ import java.awt.Insets;
 import java.awt.LayoutManager;
 import java.awt.Rectangle;
 import java.awt.Shape;
-import java.awt.event.FocusEvent;
-import java.awt.event.FocusListener;
 import java.awt.geom.Rectangle2D;
 import java.text.ParseException;
 import java.util.Calendar;
@@ -105,6 +103,8 @@ public class FlatDatePickerUI
 
 		super.installUI( c );
 
+		LookAndFeel.installProperty( datePicker, "opaque", false );
+
 		// hack JXDatePicker.TodayPanel colors
 		// (there is no need to uninstall these changes because only UIResources are used,
 		// which are automatically replaced when switching LaF)
@@ -159,18 +159,7 @@ public class FlatDatePickerUI
 		editor.setName( "dateField" );
 		editor.setBorder( BorderFactory.createEmptyBorder() );
 		editor.setOpaque( false );
-		editor.addFocusListener( new FocusListener() {
+		editor.addFocusListener( new FlatUIUtils.RepaintFocusListener( datePicker ) );
-			@Override
-			public void focusLost( FocusEvent e ) {
-				if( datePicker != null )
-					datePicker.repaint();
-			}
-			@Override
-			public void focusGained( FocusEvent e ) {
-				if( datePicker != null )
-					datePicker.repaint();
-			}
-		} );
 		return editor;
 	}
 
@@ -230,7 +219,8 @@ public class FlatDatePickerUI
 
 	@Override
 	public void update( Graphics g, JComponent c ) {
-		if( c.isOpaque() ) {
+		// fill background if opaque to avoid garbage if user sets opaque to true
+		if( c.isOpaque() )
 			FlatUIUtils.paintParentBackground( g, c );
 
 		Graphics2D g2 = (Graphics2D) g;
@@ -266,7 +256,6 @@ public class FlatDatePickerUI
 		float lw = scale( 1f );
 		float lx = isLeftToRight ? arrowX : arrowX + arrowWidth - lw;
 		g2.fill( new Rectangle2D.Float( lx, focusWidth, lw, height - (focusWidth * 2) ) );
-		}
 
 		paint( g, c );
 	}

flatlaf-testing/build.gradle.kts

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+version = rootProject.version
+
+plugins {
+	`java-library`
+}
+
+dependencies {
+	implementation( project( ":flatlaf-core" ) )
+	implementation( project( ":flatlaf-extras" ) )
+	implementation( project( ":flatlaf-swingx" ) )
+
+	implementation( "com.miglayout:miglayout-swing:5.2" )
+	implementation( "com.jgoodies:jgoodies-forms:1.9.0" )
+	implementation( "org.swinglabs.swingx:swingx-all:1.6.5-1" )
+	implementation( "org.swinglabs.swingx:swingx-beaninfo:1.6.5-1" )
+}
+
+java {
+	sourceCompatibility = JavaVersion.VERSION_1_8
+	targetCompatibility = JavaVersion.VERSION_1_8
+}

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import javax.swing.*;
 import net.miginfocom.swing.*;
@@ -23,12 +23,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatChooserTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatChooserTest" );
-			frame.showFrame( new FlatChooserTest() );
+			frame.showFrame( FlatChooserTest::new );
 		} );
 	}
 
@@ -56,7 +56,7 @@ public class FlatChooserTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"insets 0,hidemode 3,gap 5 5,ltr",
+			"ltr,insets dialog,hidemode 3",
 			// columns
 			"[]" +
 			"[]",

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

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[][]"
 			"$rowConstraints": "[top][top][]"
 		} ) {

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponents2Test.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import javax.swing.*;
 import javax.swing.table.*;
@@ -24,12 +24,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatComponents2Test
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatComponents2Test" );
-			frame.showFrame( new FlatComponents2Test() );
+			frame.showFrame( FlatComponents2Test::new );
 		} );
 	}
 
@@ -62,7 +62,7 @@ public class FlatComponents2Test
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"insets 0,hidemode 3,gap 5 5,ltr",
+			"ltr,insets dialog,hidemode 3",
 			// columns
 			"[]" +
 			"[200]" +

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponents2Test.jfd

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[][200][200]"
 			"$rowConstraints": "[][][][::200][::150]"
 		} ) {

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.*;
 import javax.swing.*;
@@ -25,12 +25,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatComponentsTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatComponentsTest" );
-			frame.showFrame( new FlatComponentsTest() );
+			frame.showFrame( FlatComponentsTest::new );
 		} );
 	}
 
@@ -178,7 +178,7 @@ public class FlatComponentsTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"insets 0,hidemode 3,gap 5 5,ltr",
+			"ltr,insets dialog,hidemode 3",
 			// columns
 			"[]" +
 			"[]" +
@@ -758,8 +758,9 @@ public class FlatComponentsTest
 
 		//======== panel3 ========
 		{
+			panel3.setOpaque(false);
 			panel3.setLayout(new MigLayout(
-				"insets 0,hidemode 3,gap 5 5,ltr",
+				"ltr,insets 0,hidemode 3",
 				// columns
 				"[]",
 				// rows
@@ -801,6 +802,7 @@ public class FlatComponentsTest
 		//======== panel2 ========
 		{
 			panel2.setBorder(new TitledBorder("TitledBorder"));
+			panel2.setOpaque(false);
 			panel2.setLayout(new FlowLayout());
 		}
 		add(panel2, "cell 3 16,grow");

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

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[][][][][][]"
 			"$rowConstraints": "[][][][][][][][][][][][][][][][][][][][][][]"
 		} ) {
@@ -56,7 +56,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 2 1"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatComponentsTest$TestDefaultButton" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatComponentsTest$TestDefaultButton" ) {
 				name: "button5"
 				"text": "default"
 				"displayedMnemonicIndex": 0
@@ -713,9 +713,10 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[]"
 				"$rowConstraints": "[][][]"
-				"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+				"$layoutConstraints": "ltr,insets 0,hidemode 3"
 			} ) {
 				name: "panel3"
+				"opaque": false
 				add( new FormComponent( "javax.swing.JLabel" ) {
 					name: "label3"
 					"text": "<html>JLabel HTML<br>Sample <b>content</b><br> <u>text</u></html>"
@@ -759,6 +760,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.FlowLayout ) ) {
 				name: "panel2"
 				"border": new javax.swing.border.TitledBorder( "TitledBorder" )
+				"opaque": false
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 3 16,grow"
 			} )

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

@@ -2,7 +2,7 @@
  * Created by JFormDesigner on Tue Aug 27 21:47:02 CEST 2019
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.*;
 import javax.swing.*;
@@ -14,12 +14,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatContainerTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatContainerTest" );
-			frame.showFrame( new FlatContainerTest() );
+			frame.showFrame( FlatContainerTest::new );
 		} );
 	}
 
@@ -104,7 +104,7 @@ public class FlatContainerTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"insets 0,hidemode 3",
+			"insets dialog,hidemode 3",
 			// columns
 			"[grow,fill]",
 			// rows
@@ -112,6 +112,7 @@ public class FlatContainerTest
 
 		//======== panel9 ========
 		{
+			panel9.setOpaque(false);
 			panel9.setLayout(new FormLayout(
 				"70dlu:grow, $lcgap, 70dlu:grow",
 				"default, $lgap, fill:70dlu, $lgap, pref, 2*($lgap, fill:70dlu:grow), $lgap, pref"));
@@ -283,6 +284,7 @@ public class FlatContainerTest
 
 			//======== panel14 ========
 			{
+				panel14.setOpaque(false);
 				panel14.setLayout(new MigLayout(
 					"insets 0,hidemode 3",
 					// columns

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

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "insets 0,hidemode 3"
+			"$layoutConstraints": "insets dialog,hidemode 3"
 			"$columnConstraints": "[grow,fill]"
 			"$rowConstraints": "[grow,fill]"
 		} ) {
@@ -17,6 +17,7 @@ new FormModel {
 				"$rowSpecs": "default, linegap, fill:70dlu, linegap, pref, linegap, fill:70dlu:grow, linegap, fill:70dlu:grow, linegap, pref"
 			} ) {
 				name: "panel9"
+				"opaque": false
 				add( new FormComponent( "javax.swing.JLabel" ) {
 					name: "splitPaneLabel"
 					"text": "JSplitPane:"
@@ -203,6 +204,7 @@ new FormModel {
 					"$rowConstraints": "[center]"
 				} ) {
 					name: "panel14"
+					"opaque": false
 					add( new FormComponent( "javax.swing.JCheckBox" ) {
 						name: "moreTabsCheckBox"
 						"text": "more tabs"

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.Color;
 import java.awt.Component;
@@ -58,6 +58,7 @@ public class FlatInspector
 	private Component lastComponent;
 	private int lastX;
 	private int lastY;
+	private boolean inspectParent;
 
 	private JComponent highlightFigure;
 	private JToolTip tip;
@@ -70,6 +71,7 @@ public class FlatInspector
 			public void mouseMoved( MouseEvent e ) {
 				lastX = e.getX();
 				lastY = e.getY();
+				inspectParent = e.isShiftDown();
 				inspect( lastX, lastY );
 			}
 		} );
@@ -105,6 +107,8 @@ public class FlatInspector
 	private void inspect( int x, int y ) {
 		Container contentPane = rootPane.getContentPane();
 		Component c = SwingUtilities.getDeepestComponentAt( contentPane, x, y );
+		if( inspectParent && c != null && c != contentPane )
+			c = c.getParent();
 		if( c == contentPane || (c != null && c.getParent() == contentPane) )
 			c = null;
 
@@ -237,7 +241,8 @@ public class FlatInspector
 		}
 
 		text += "Enabled: " + c.isEnabled() + '\n';
-		text += "Opaque: " + c.isOpaque() + '\n';
+		text += "Opaque: " + c.isOpaque() + (c instanceof JComponent &&
+			FlatUIUtils.hasOpaqueBeenExplicitlySet( (JComponent) c ) ? " EXPLICIT" : "") + '\n';
 		text += "Focusable: " + c.isFocusable() + '\n';
 		text += "Left-to-right: " + c.getComponentOrientation().isLeftToRight() + '\n';
 		text += "Parent: " + c.getParent().getClass().getName();

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.Component;
 import java.awt.Container;
@@ -26,12 +26,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatMenusTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatMenusTest" );
-			frame.showFrame( new FlatMenusTest() );
+			frame.showFrame( FlatMenusTest::new );
 		} );
 	}
 
@@ -103,7 +103,7 @@ public class FlatMenusTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"insets 0,hidemode 3,gap 5 5,ltr",
+			"ltr,insets dialog,hidemode 3",
 			// columns
 			"[125]" +
 			"[]" +
@@ -155,8 +155,9 @@ public class FlatMenusTest
 
 		//======== panel1 ========
 		{
+			panel1.setOpaque(false);
 			panel1.setLayout(new MigLayout(
-				"insets 0,hidemode 3,gap 5 5,ltr",
+				"ltr,insets 0,hidemode 3",
 				// columns
 				"[125,left]" +
 				"[fill]",
@@ -213,8 +214,9 @@ public class FlatMenusTest
 
 		//======== panel2 ========
 		{
+			panel2.setOpaque(false);
 			panel2.setLayout(new MigLayout(
-				"insets 0,gap 5 5",
+				"insets 0",
 				// columns
 				"[fill]",
 				// rows
@@ -253,8 +255,9 @@ public class FlatMenusTest
 
 		//======== panel3 ========
 		{
+			panel3.setOpaque(false);
 			panel3.setLayout(new MigLayout(
-				"insets 0,gap 5 5",
+				"insets 0",
 				// columns
 				"[fill]",
 				// rows
@@ -292,8 +295,9 @@ public class FlatMenusTest
 
 		//======== panel4 ========
 		{
+			panel4.setOpaque(false);
 			panel4.setLayout(new MigLayout(
-				"insets 0,gap 5 5",
+				"insets 0",
 				// columns
 				"[fill]",
 				// rows

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

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[125][][][][]"
 			"$rowConstraints": "[][top][][]"
 		} ) {
@@ -50,9 +50,10 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[125,left][fill]"
 				"$rowConstraints": "[][][][][]"
-				"$layoutConstraints": "insets 0,hidemode 3,gap 5 5,ltr"
+				"$layoutConstraints": "ltr,insets 0,hidemode 3"
 			} ) {
 				name: "panel1"
+				"opaque": false
 				add( new FormComponent( "javax.swing.JLabel" ) {
 					name: "menuLabel"
 					"text": "JMenu:"
@@ -121,9 +122,10 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[fill]"
 				"$rowConstraints": "[][][][][]"
-				"$layoutConstraints": "insets 0,gap 5 5"
+				"$layoutConstraints": "insets 0"
 			} ) {
 				name: "panel2"
+				"opaque": false
 				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
 					name: "menu2"
 					"text": "disabled"
@@ -161,9 +163,10 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[fill]"
 				"$rowConstraints": "[][][][]"
-				"$layoutConstraints": "insets 0,gap 5 5"
+				"$layoutConstraints": "insets 0"
 			} ) {
 				name: "panel3"
+				"opaque": false
 				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
 					name: "menu3"
 					"text": "text"
@@ -201,9 +204,10 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[fill]"
 				"$rowConstraints": "[][][][]"
-				"$layoutConstraints": "insets 0,gap 5 5"
+				"$layoutConstraints": "insets 0"
 			} ) {
 				name: "panel4"
+				"opaque": false
 				add( new FormContainer( "javax.swing.JMenu", new FormLayoutManager( class javax.swing.JMenu ) ) {
 					name: "menu4"
 					"text": "text"

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.*;
 import java.awt.event.MouseAdapter;
@@ -27,12 +27,12 @@ import net.miginfocom.swing.*;
  * @author Karl Tauber
  */
 public class FlatOptionPaneTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatOptionPaneTest" );
-			frame.showFrame( new FlatOptionPaneTest() );
+			frame.showFrame( FlatOptionPaneTest::new );
 		} );
 	}
 
@@ -90,7 +90,7 @@ public class FlatOptionPaneTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"flowy,ltr,insets 0,hidemode 3,gap 5 5",
+			"flowy,ltr,insets dialog,hidemode 3",
 			// columns
 			"[]" +
 			"[]" +

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

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "flowy,ltr,insets 0,hidemode 3,gap 5 5"
+			"$layoutConstraints": "flowy,ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[][][fill]"
 			"$rowConstraints": "[top][top][top][top][top][top][top][top]"
 		} ) {
@@ -30,7 +30,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 0"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "plainShowDialogLabel"
 				"optionPane": new FormReference( "plainOptionPane" )
 				"titleLabel": new FormReference( "plainLabel" )
@@ -60,7 +60,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 1"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "errorShowDialogLabel"
 				"titleLabel": new FormReference( "errorLabel" )
 				"optionPane": new FormReference( "errorOptionPane" )
@@ -90,7 +90,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 2"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "informationShowDialogLabel"
 				"optionPane": new FormReference( "informationOptionPane" )
 				"titleLabel": new FormReference( "informationLabel" )
@@ -120,7 +120,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 3"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "questionShowDialogLabel"
 				"optionPane": new FormReference( "questionOptionPane" )
 				"titleLabel": new FormReference( "questionLabel" )
@@ -147,7 +147,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 4"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "warningShowDialogLabel"
 				"optionPane": new FormReference( "warningOptionPane" )
 				"titleLabel": new FormReference( "warningLabel" )
@@ -174,7 +174,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 5"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "inputShowDialogLabel"
 				"optionPane": new FormReference( "inputOptionPane" )
 				"titleLabel": new FormReference( "inputLabel" )
@@ -202,7 +202,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 6"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "inputIconShowDialogLabel"
 				"titleLabel": new FormReference( "inputIconLabel" )
 				"optionPane": new FormReference( "inputIconOptionPane" )
@@ -230,7 +230,7 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 7"
 			} )
-			add( new FormComponent( "com.formdev.flatlaf.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
+			add( new FormComponent( "com.formdev.flatlaf.testing.FlatOptionPaneTest$ShowDialogLinkLabel" ) {
 				name: "customShowDialogLabel"
 				"optionPane": new FormReference( "customOptionPane" )
 				"titleLabel": new FormReference( "customLabel" )
@@ -239,7 +239,7 @@ new FormModel {
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
-			"size": new java.awt.Dimension( 790, 840 )
+			"size": new java.awt.Dimension( 790, 920 )
 		} )
 	}
 }

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
 
 import java.awt.*;
 import java.awt.event.ComponentAdapter;
@@ -23,11 +23,19 @@ import java.awt.event.KeyEvent;
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
 import java.util.function.BiConsumer;
+import java.util.function.Supplier;
 import java.util.prefs.Preferences;
 import javax.swing.*;
 import javax.swing.plaf.ColorUIResource;
 import javax.swing.plaf.metal.MetalLookAndFeel;
 import javax.swing.plaf.nimbus.NimbusLookAndFeel;
+import com.formdev.flatlaf.FlatDarculaLaf;
+import com.formdev.flatlaf.FlatDarkLaf;
+import com.formdev.flatlaf.FlatIntelliJLaf;
+import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.FlatLightLaf;
+import com.formdev.flatlaf.extras.*;
+import com.formdev.flatlaf.extras.TriStateCheckBox.State;
 import com.formdev.flatlaf.ui.FlatUIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
@@ -44,6 +52,7 @@ public class FlatTestFrame
 	private static final String KEY_SCALE_FACTOR = "scaleFactor";
 
 	private final String title;
+	private Supplier<JComponent> contentFactory;
 	private JComponent content;
 	private FlatInspector inspector;
 
@@ -206,8 +215,9 @@ public class FlatTestFrame
 			JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT );
 	}
 
-	public void showFrame( JComponent content ) {
+	public void showFrame( Supplier<JComponent> contentFactory ) {
-		this.content = content;
+		this.contentFactory = contentFactory;
+		this.content = contentFactory.get();
 
 		contentPanel.getContentPane().add( content );
 		pack();
@@ -297,7 +307,7 @@ public class FlatTestFrame
 					c.setBackground( explicit ? Color.orange : restoreColor );
 				} else {
 					c.setForeground( explicit ? Color.blue : restoreColor );
-					c.setBackground( explicit ? Color.red : restoreColor );
+					c.setBackground( explicit ? Color.green : restoreColor );
 				}
 			} );
 
@@ -308,6 +318,14 @@ public class FlatTestFrame
 		} );
 	}
 
+	private void backgroundChanged() {
+		contentPanel.repaint();
+	}
+
+	boolean isPaintBackgroundPattern() {
+		return backgroundCheckBox.isSelected();
+	}
+
 	private void rightToLeftChanged() {
 		ComponentOrientation orientation = rightToLeftCheckBox.isSelected()
 			? ComponentOrientation.RIGHT_TO_LEFT
@@ -390,17 +408,48 @@ public class FlatTestFrame
 		}
 	}
 
+	private void opaqueChanged() {
+		State opaque = opaqueTriStateCheckBox.getState();
+		if( opaque == State.INDETERMINATE )
+			recreateContent();
+		else {
+			updateComponentsRecur( content, (c, type) -> {
+				if( c instanceof JComponent )
+					((JComponent)c).setOpaque( opaque == State.SELECTED );
+			} );
+			contentPanel.repaint();
+		}
+	}
+
+	private void recreateContent() {
+		contentPanel.getContentPane().remove( content );
+		content = contentFactory.get();
+		contentPanel.getContentPane().add( content );
+
+		if( rightToLeftCheckBox.isSelected() )
+			rightToLeftChanged();
+		if( !enabledCheckBox.isSelected() )
+			enabledChanged();
+		if( explicitColorsCheckBox.isSelected() )
+			explicitColorsChanged();
+
+		contentPanel.revalidate();
+		contentPanel.repaint();
+	}
+
 	private void initComponents() {
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
 		dialogPane = new JPanel();
 		contentPanel = new JRootPane();
 		buttonBar = new JPanel();
 		lookAndFeelComboBox = new JComboBox<>();
-		explicitColorsCheckBox = new JCheckBox();
+		scaleFactorComboBox = new JComboBox<>();
 		rightToLeftCheckBox = new JCheckBox();
 		enabledCheckBox = new JCheckBox();
 		inspectCheckBox = new JCheckBox();
-		scaleFactorComboBox = new JComboBox<>();
+		explicitColorsCheckBox = new JCheckBox();
+		backgroundCheckBox = new JCheckBox();
+		opaqueTriStateCheckBox = new TriStateCheckBox();
 		closeButton = new JButton();
 
 		//======== this ========
@@ -416,7 +465,7 @@ public class FlatTestFrame
 			{
 				Container contentPanelContentPane = contentPanel.getContentPane();
 				contentPanelContentPane.setLayout(new MigLayout(
-					"insets dialog,hidemode 3",
+					"insets 0,hidemode 3",
 					// columns
 					"[grow,fill]",
 					// rows
@@ -435,6 +484,8 @@ public class FlatTestFrame
 					"[fill]" +
 					"[fill]" +
 					"[fill]" +
+					"[fill]" +
+					"[fill]" +
 					"[grow,fill]" +
 					"[button,fill]",
 					// rows
@@ -444,11 +495,23 @@ public class FlatTestFrame
 				lookAndFeelComboBox.addActionListener(e -> lookAndFeelChanged());
 				buttonBar.add(lookAndFeelComboBox, "cell 0 0");
 
-				//---- explicitColorsCheckBox ----
+				//---- scaleFactorComboBox ----
-				explicitColorsCheckBox.setText("explicit colors");
+				scaleFactorComboBox.setModel(new DefaultComboBoxModel<>(new String[] {
-				explicitColorsCheckBox.setMnemonic('X');
+					"default",
-				explicitColorsCheckBox.addActionListener(e -> explicitColorsChanged());
+					"1",
-				buttonBar.add(explicitColorsCheckBox, "cell 1 0");
+					"1.25",
+					"1.5",
+					"1.75",
+					"2.0",
+					"2.25",
+					"2.5",
+					"3",
+					"3.5",
+					"4"
+				}));
+				scaleFactorComboBox.setMaximumRowCount(20);
+				scaleFactorComboBox.addActionListener(e -> scaleFactorChanged());
+				buttonBar.add(scaleFactorComboBox, "cell 1 0");
 
 				//---- rightToLeftCheckBox ----
 				rightToLeftCheckBox.setText("right-to-left");
@@ -469,27 +532,27 @@ public class FlatTestFrame
 				inspectCheckBox.addActionListener(e -> inspectChanged());
 				buttonBar.add(inspectCheckBox, "cell 4 0");
 
-				//---- scaleFactorComboBox ----
+				//---- explicitColorsCheckBox ----
-				scaleFactorComboBox.setModel(new DefaultComboBoxModel<>(new String[] {
+				explicitColorsCheckBox.setText("explicit colors");
-					"default",
+				explicitColorsCheckBox.setMnemonic('X');
-					"1",
+				explicitColorsCheckBox.addActionListener(e -> explicitColorsChanged());
-					"1.25",
+				buttonBar.add(explicitColorsCheckBox, "cell 5 0");
-					"1.5",
+
-					"1.75",
+				//---- backgroundCheckBox ----
-					"2.0",
+				backgroundCheckBox.setText("background");
-					"2.25",
+				backgroundCheckBox.setMnemonic('B');
-					"2.5",
+				backgroundCheckBox.addActionListener(e -> backgroundChanged());
-					"3",
+				buttonBar.add(backgroundCheckBox, "cell 6 0");
-					"3.5",
+
-					"4"
+				//---- opaqueTriStateCheckBox ----
-				}));
+				opaqueTriStateCheckBox.setText("opaque");
-				scaleFactorComboBox.setMaximumRowCount(20);
+				opaqueTriStateCheckBox.setMnemonic('O');
-				scaleFactorComboBox.addActionListener(e -> scaleFactorChanged());
+				opaqueTriStateCheckBox.addActionListener(e -> opaqueChanged());
-				buttonBar.add(scaleFactorComboBox, "cell 5 0");
+				buttonBar.add(opaqueTriStateCheckBox, "cell 7 0");
 
 				//---- closeButton ----
 				closeButton.setText("Close");
-				buttonBar.add(closeButton, "cell 7 0");
+				buttonBar.add(closeButton, "cell 9 0");
 			}
 			dialogPane.add(buttonBar, BorderLayout.SOUTH);
 		}
@@ -502,11 +565,13 @@ public class FlatTestFrame
 	private JRootPane contentPanel;
 	private JPanel buttonBar;
 	private JComboBox<LafInfo> lookAndFeelComboBox;
-	private JCheckBox explicitColorsCheckBox;
+	private JComboBox<String> scaleFactorComboBox;
 	private JCheckBox rightToLeftCheckBox;
 	private JCheckBox enabledCheckBox;
 	private JCheckBox inspectCheckBox;
-	private JComboBox<String> scaleFactorComboBox;
+	private JCheckBox explicitColorsCheckBox;
+	private JCheckBox backgroundCheckBox;
+	private TriStateCheckBox opaqueTriStateCheckBox;
 	private JButton closeButton;
 	// JFormDesigner - End of variables declaration  //GEN-END:variables
 

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

@@ -11,7 +11,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class java.awt.BorderLayout ) ) {
 				name: "dialogPane"
 				add( new FormContainer( "javax.swing.JRootPane", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-					"$layoutConstraints": "insets dialog,hidemode 3"
+					"$layoutConstraints": "insets 0,hidemode 3"
 					"$columnConstraints": "[grow,fill]"
 					"$rowConstraints": "[grow,fill]"
 				} ) {
@@ -21,7 +21,7 @@ new FormModel {
 				} )
 				add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 					"$layoutConstraints": "insets dialog"
-					"$columnConstraints": "[fill][fill][fill][fill][fill][fill][grow,fill][button,fill]"
+					"$columnConstraints": "[fill][fill][fill][fill][fill][fill][fill][fill][grow,fill][button,fill]"
 					"$rowSpecs": "[fill]"
 				} ) {
 					name: "buttonBar"
@@ -34,11 +34,27 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 0 0"
 					} )
-					add( new FormComponent( "javax.swing.JCheckBox" ) {
+					add( new FormComponent( "javax.swing.JComboBox" ) {
-						name: "explicitColorsCheckBox"
+						name: "scaleFactorComboBox"
-						"text": "explicit colors"
+						"model": new javax.swing.DefaultComboBoxModel {
-						"mnemonic": 88
+							selectedItem: "default"
-						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "explicitColorsChanged", false ) )
+							addElement( "default" )
+							addElement( "1" )
+							addElement( "1.25" )
+							addElement( "1.5" )
+							addElement( "1.75" )
+							addElement( "2.0" )
+							addElement( "2.25" )
+							addElement( "2.5" )
+							addElement( "3" )
+							addElement( "3.5" )
+							addElement( "4" )
+						}
+						"maximumRowCount": 20
+						auxiliary() {
+							"JavaCodeGenerator.typeParameters": "String"
+						}
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "scaleFactorChanged", false ) )
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 1 0"
 					} )
@@ -67,35 +83,35 @@ new FormModel {
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 4 0"
 					} )
-					add( new FormComponent( "javax.swing.JComboBox" ) {
+					add( new FormComponent( "javax.swing.JCheckBox" ) {
-						name: "scaleFactorComboBox"
+						name: "explicitColorsCheckBox"
-						"model": new javax.swing.DefaultComboBoxModel {
+						"text": "explicit colors"
-							selectedItem: "default"
+						"mnemonic": 88
-							addElement( "default" )
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "explicitColorsChanged", false ) )
-							addElement( "1" )
-							addElement( "1.25" )
-							addElement( "1.5" )
-							addElement( "1.75" )
-							addElement( "2.0" )
-							addElement( "2.25" )
-							addElement( "2.5" )
-							addElement( "3" )
-							addElement( "3.5" )
-							addElement( "4" )
-						}
-						"maximumRowCount": 20
-						auxiliary() {
-							"JavaCodeGenerator.typeParameters": "String"
-						}
-						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "scaleFactorChanged", false ) )
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 						"value": "cell 5 0"
 					} )
+					add( new FormComponent( "javax.swing.JCheckBox" ) {
+						name: "backgroundCheckBox"
+						"text": "background"
+						"mnemonic": 66
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "backgroundChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 6 0"
+					} )
+					add( new FormComponent( "com.formdev.flatlaf.extras.TriStateCheckBox" ) {
+						name: "opaqueTriStateCheckBox"
+						"text": "opaque"
+						"mnemonic": 79
+						addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "opaqueChanged", false ) )
+					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+						"value": "cell 7 0"
+					} )
 					add( new FormComponent( "javax.swing.JButton" ) {
 						name: "closeButton"
 						"text": "Close"
 					}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
-						"value": "cell 7 0"
+						"value": "cell 9 0"
 					} )
 				}, new FormLayoutConstraints( class java.lang.String ) {
 					"value": "South"

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

@@ -14,7 +14,9 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf;
+package com.formdev.flatlaf.testing;
+
+import com.formdev.flatlaf.FlatLaf;
 
 /**
  * A Flat LaF that has a test color scheme.

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.testing;
+
+import java.awt.Color;
+import java.awt.Graphics;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+
+/**
+ * @author Karl Tauber
+ */
+public class FlatTestPanel
+	extends JPanel
+{
+	@Override
+	protected void paintComponent( Graphics g ) {
+		int width = getWidth();
+		int height = getHeight();
+
+		g.setColor( super.getBackground() );
+		g.fillRect( 0, 0, width, height );
+
+		if( isPaintBackgroundPattern() ) {
+			g.setColor( Color.magenta );
+			for( int y = 0; y < height; y += 2 )
+				g.drawLine( 0, y, width - 1, y );
+		}
+	}
+
+	/**
+	 * Overridden to see which components paint background with color from parent.
+	 */
+	@Override
+	public Color getBackground() {
+		return isPaintBackgroundPattern() ? Color.red : super.getBackground();
+	}
+
+	private boolean isPaintBackgroundPattern() {
+		FlatTestFrame frame = (FlatTestFrame) SwingUtilities.getAncestorOfClass( FlatTestFrame.class, this );
+		return frame != null && frame.isPaintBackgroundPattern();
+	}
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/extras/FlatExtrasTest.java

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.testing.extras;
+
+import javax.swing.*;
+import com.formdev.flatlaf.extras.*;
+import com.formdev.flatlaf.testing.*;
+import net.miginfocom.swing.*;
+
+/**
+ * @author Karl Tauber
+ */
+public class FlatExtrasTest
+	extends FlatTestPanel
+{
+	public static void main( String[] args ) {
+		SwingUtilities.invokeLater( () -> {
+			FlatTestFrame frame = FlatTestFrame.create( args, "FlatExtrasTest" );
+			frame.showFrame( FlatExtrasTest::new );
+		} );
+	}
+
+	public FlatExtrasTest() {
+		initComponents();
+
+		triStateLabel1.setText( triStateCheckBox1.getState().toString() );
+		triStateLabel2.setText( triStateCheckBox2.getState().toString() );
+	}
+
+	private void triStateCheckBox1Changed() {
+		triStateLabel1.setText( triStateCheckBox1.getState().toString() );
+	}
+
+	private void triStateCheckBox2Changed() {
+		triStateLabel2.setText( triStateCheckBox2.getState().toString() );
+	}
+
+	private void initComponents() {
+		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
+		label1 = new JLabel();
+		triStateCheckBox1 = new TriStateCheckBox();
+		triStateLabel1 = new JLabel();
+		triStateCheckBox2 = new TriStateCheckBox();
+		triStateLabel2 = new JLabel();
+
+		//======== this ========
+		setLayout(new MigLayout(
+			"ltr,insets dialog,hidemode 3",
+			// columns
+			"[]" +
+			"[]" +
+			"[left]",
+			// rows
+			"[]" +
+			"[]"));
+
+		//---- label1 ----
+		label1.setText("TriStateCheckBox:");
+		add(label1, "cell 0 0");
+
+		//---- triStateCheckBox1 ----
+		triStateCheckBox1.setText("three states");
+		triStateCheckBox1.addActionListener(e -> triStateCheckBox1Changed());
+		add(triStateCheckBox1, "cell 1 0");
+
+		//---- triStateLabel1 ----
+		triStateLabel1.setText("text");
+		add(triStateLabel1, "cell 2 0");
+
+		//---- triStateCheckBox2 ----
+		triStateCheckBox2.setText("third state disabled");
+		triStateCheckBox2.setThirdStateEnabled(false);
+		triStateCheckBox2.addActionListener(e -> triStateCheckBox2Changed());
+		add(triStateCheckBox2, "cell 1 1");
+
+		//---- triStateLabel2 ----
+		triStateLabel2.setText("text");
+		add(triStateLabel2, "cell 2 1");
+		// JFormDesigner - End of component initialization  //GEN-END:initComponents
+	}
+
+	// JFormDesigner - Variables declaration - DO NOT MODIFY  //GEN-BEGIN:variables
+	private JLabel label1;
+	private TriStateCheckBox triStateCheckBox1;
+	private JLabel triStateLabel1;
+	private TriStateCheckBox triStateCheckBox2;
+	private JLabel triStateLabel2;
+	// JFormDesigner - End of variables declaration  //GEN-END:variables
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/extras/FlatExtrasTest.jfd

@@ -0,0 +1,50 @@
+JFDML JFormDesigner: "7.0.0.0.194" Java: "11.0.2" encoding: "UTF-8"
+
+new FormModel {
+	contentType: "form/swing"
+	root: new FormRoot {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
+			"$columnConstraints": "[][][left]"
+			"$rowConstraints": "[][]"
+		} ) {
+			name: "this"
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "label1"
+				"text": "TriStateCheckBox:"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 0 0"
+			} )
+			add( new FormComponent( "com.formdev.flatlaf.extras.TriStateCheckBox" ) {
+				name: "triStateCheckBox1"
+				"text": "three states"
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "triStateCheckBox1Changed", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 0"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "triStateLabel1"
+				"text": "text"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 2 0"
+			} )
+			add( new FormComponent( "com.formdev.flatlaf.extras.TriStateCheckBox" ) {
+				name: "triStateCheckBox2"
+				"text": "third state disabled"
+				"thirdStateEnabled": false
+				addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "triStateCheckBox2Changed", false ) )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 1 1"
+			} )
+			add( new FormComponent( "javax.swing.JLabel" ) {
+				name: "triStateLabel2"
+				"text": "text"
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 2 1"
+			} )
+		}, new FormLayoutConstraints( null ) {
+			"location": new java.awt.Point( 0, 0 )
+			"size": new java.awt.Dimension( 400, 300 )
+		} )
+	}
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/swingx/FlatSwingXDefaultsTestAddon.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2019 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.testing.swingx;
+
+import java.io.InputStream;
+import com.formdev.flatlaf.FlatDefaultsAddon;
+
+/**
+ * SwingX addon for FlatLaf for testing.
+ *
+ * @author Karl Tauber
+ */
+public class FlatSwingXDefaultsTestAddon
+	extends FlatDefaultsAddon
+{
+	/**
+	 * Finds SwingX addon .properties file for the given LaF class
+	 * in the same package as this class.
+	 */
+	@Override
+	public InputStream getDefaults( Class<?> lafClass ) {
+		Class<?> addonClass = this.getClass();
+		String propertiesName = "/" + addonClass.getPackage().getName().replace( '.', '/' )
+			+ '/' + lafClass.getSimpleName() + ".properties";
+		return addonClass.getResourceAsStream( propertiesName );
+	}
+}

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/swingx/FlatSwingXTest.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package com.formdev.flatlaf.swingx;
+package com.formdev.flatlaf.testing.swingx;
 
 import java.awt.*;
 import java.util.Calendar;
@@ -22,19 +22,20 @@ import java.util.Date;
 import javax.swing.*;
 import net.miginfocom.swing.*;
 import org.jdesktop.swingx.*;
-import com.formdev.flatlaf.FlatTestFrame;
+import com.formdev.flatlaf.testing.FlatTestFrame;
+import com.formdev.flatlaf.testing.FlatTestPanel;
 
 /**
  * @author Karl Tauber
  */
 public class FlatSwingXTest
-	extends JPanel
+	extends FlatTestPanel
 {
 	public static void main( String[] args ) {
 		SwingUtilities.invokeLater( () -> {
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatSwingXTest" );
 			frame.useApplyComponentOrientation = true;
-			frame.showFrame( new FlatSwingXTest() );
+			frame.showFrame( FlatSwingXTest::new );
 		} );
 	}
 
@@ -102,7 +103,7 @@ public class FlatSwingXTest
 
 		//======== this ========
 		setLayout(new MigLayout(
-			"hidemode 3,ltr",
+			"ltr,insets dialog,hidemode 3",
 			// columns
 			"[left]" +
 			"[]" +
@@ -199,7 +200,7 @@ public class FlatSwingXTest
 
 		//---- busyCheckBox ----
 		busyCheckBox.setText("busy");
-		busyCheckBox.setMnemonic('B');
+		busyCheckBox.setMnemonic('Y');
 		busyCheckBox.addActionListener(e -> busyChanged());
 		add(busyCheckBox, "cell 2 6");
 

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/swingx/FlatSwingXTest.jfd

@@ -6,8 +6,8 @@ new FormModel {
 		auxiliary() {
 			"JavaCodeGenerator.defaultVariableLocal": true
 		}
-		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+		add( new FormContainer( "com.formdev.flatlaf.testing.FlatTestPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
-			"$layoutConstraints": "hidemode 3,ltr"
+			"$layoutConstraints": "ltr,insets dialog,hidemode 3"
 			"$columnConstraints": "[left][][][fill]"
 			"$rowConstraints": "[]0[][]0[][][][][]"
 		} ) {
@@ -144,7 +144,7 @@ new FormModel {
 			add( new FormComponent( "javax.swing.JCheckBox" ) {
 				name: "busyCheckBox"
 				"text": "busy"
-				"mnemonic": 66
+				"mnemonic": 89
 				auxiliary() {
 					"JavaCodeGenerator.variableLocal": false
 				}

flatlaf-testing/src/main/resources/META-INF/services/com.formdev.flatlaf.FlatDefaultsAddon

@@ -0,0 +1 @@
+com.formdev.flatlaf.testing.swingx.FlatSwingXDefaultsTestAddon

settings.gradle.kts

@@ -17,5 +17,7 @@
 rootProject.name = "FlatLaf"
 
 include( "flatlaf-core" )
+include( "flatlaf-extras" )
 include( "flatlaf-swingx" )
 include( "flatlaf-demo" )
+include( "flatlaf-testing" )