support multi-resolution images in disabled icons on Java 9+ (e.g. @2x icons on macOS) (issue #70)

flatlaf-core/build.gradle.kts

@@ -23,6 +23,11 @@ plugins {
 
 if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
 	sourceSets {
+		create( "java9" ) {
+			java {
+				setSrcDirs( listOf( "src/main/java9" ) )
+			}
+		}
 		create( "module-info" ) {
 			java {
 				// include "src/main/java" here to get compile errors if classes are
@@ -52,6 +57,12 @@ tasks {
 		archiveBaseName.set( "flatlaf" )
 
 		if( JavaVersion.current() >= JavaVersion.VERSION_1_9 ) {
+			manifest.attributes( "Multi-Release" to "true" )
+
+			into( "META-INF/versions/9" ) {
+				from( sourceSets["java9"].output )
+			}
+
 			from( sourceSets["module-info"].output ) {
 				include( "module-info.class" )
 			}

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

@@ -41,6 +41,7 @@ import java.util.Map;
 import java.util.Properties;
 import java.util.ServiceLoader;
 import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.swing.AbstractButton;
@@ -64,6 +65,7 @@ import javax.swing.plaf.basic.BasicLookAndFeel;
 import javax.swing.text.StyleContext;
 import javax.swing.text.html.HTMLEditorKit;
 import com.formdev.flatlaf.util.GrayFilter;
+import com.formdev.flatlaf.util.MultiResolutionImageSupport;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -136,9 +138,14 @@ public abstract class FlatLaf
 					: new GrayFilter(  25, -25, 100 );
 			}
 
+			ImageFilter filter = (ImageFilter) grayFilter;
+			Function<Image, Image> mapper = img -> {
+				ImageProducer producer = new FilteredImageSource( img.getSource(), filter );
+				return Toolkit.getDefaultToolkit().createImage( producer );
+			};
+
 			Image image = ((ImageIcon)icon).getImage();
-			ImageProducer producer = new FilteredImageSource( image.getSource(), (ImageFilter) grayFilter );
-			return new ImageIconUIResource( Toolkit.getDefaultToolkit().createImage( producer ) );
+			return new ImageIconUIResource( MultiResolutionImageSupport.map( image, mapper ) );
 		}
 
 		return null;

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

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2020 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
+ *
+ *     https://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.Image;
+import java.util.function.Function;
+
+/**
+ * Support for multi-resolution images available since Java 9.
+ *
+ * @author Karl Tauber
+ */
+public class MultiResolutionImageSupport
+{
+	public static boolean isAvailable() {
+		return false;
+	}
+
+	public static boolean isMultiResolutionImage( Image image ) {
+		return false;
+	}
+
+	public static Image create( int baseImageIndex, Image... resolutionVariants ) {
+		return resolutionVariants[baseImageIndex];
+	}
+
+	public static Image map( Image image, Function<Image, Image> mapper ) {
+		return mapper.apply( image );
+	}
+}

flatlaf-core/src/main/java9/com/formdev/flatlaf/util/MultiResolutionImageSupport.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2020 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
+ *
+ *     https://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.Image;
+import java.awt.image.AbstractMultiResolutionImage;
+import java.awt.image.BaseMultiResolutionImage;
+import java.awt.image.MultiResolutionImage;
+import java.util.ArrayList;
+import java.util.IdentityHashMap;
+import java.util.List;
+import java.util.function.Function;
+import javax.swing.ImageIcon;
+
+/**
+ * Support for multi-resolution images available since Java 9.
+ *
+ * @author Karl Tauber
+ */
+public class MultiResolutionImageSupport
+{
+	public static boolean isAvailable() {
+		return true;
+	}
+
+	public static boolean isMultiResolutionImage( Image image ) {
+		return image instanceof MultiResolutionImage;
+	}
+
+	public static Image create( int baseImageIndex, Image... resolutionVariants ) {
+		return new BaseMultiResolutionImage( baseImageIndex, resolutionVariants );
+	}
+
+	public static Image map( Image image, Function<Image, Image> mapper ) {
+		return image instanceof MultiResolutionImage
+			? new MappedMultiResolutionImage( image, mapper )
+			: mapper.apply( image );
+	}
+
+	//---- class MappedMultiResolutionImage -----------------------------------
+
+	private static class MappedMultiResolutionImage
+		extends AbstractMultiResolutionImage
+	{
+		private final Image mrImage;
+		private final Function<Image, Image> mapper;
+		private final IdentityHashMap<Image, Image> cache = new IdentityHashMap<>();
+
+		MappedMultiResolutionImage( Image mrImage, Function<Image, Image> mapper ) {
+			assert mrImage instanceof MultiResolutionImage;
+
+			this.mrImage = mrImage;
+			this.mapper = mapper;
+		}
+
+		@Override
+		public Image getResolutionVariant( double destImageWidth, double destImageHeight ) {
+			Image variant = ((MultiResolutionImage)mrImage).getResolutionVariant( destImageWidth, destImageHeight );
+			return mapAndCacheImage( variant );
+		}
+
+		@Override
+		public List<Image> getResolutionVariants() {
+			List<Image> variants = ((MultiResolutionImage)mrImage).getResolutionVariants();
+			List<Image> mappedVariants = new ArrayList<>();
+			for( Image image : variants )
+				mappedVariants.add( mapAndCacheImage( image ) );
+			return mappedVariants;
+		}
+
+		@Override
+		protected Image getBaseImage() {
+			return mapAndCacheImage( mrImage );
+		}
+
+		private Image mapAndCacheImage( Image image ) {
+			return cache.computeIfAbsent( image, img -> {
+				return new ImageIcon( mapper.apply( img ) ).getImage();
+			} );
+		}
+	}
+}

flatlaf-demo/build.gradle.kts

@@ -43,6 +43,9 @@ tasks {
 
 		manifest {
 			attributes( "Main-Class" to "com.formdev.flatlaf.demo.FlatLafDemo" )
+
+			if( JavaVersion.current() >= JavaVersion.VERSION_1_9 )
+				attributes( "Multi-Release" to "true" )
 		}
 
 		exclude( "module-info.class" )

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/MoreComponentsPanel.java

@@ -101,6 +101,7 @@ class MoreComponentsPanel
 		JButton button7 = new JButton();
 		JButton button8 = new JButton();
 		JToggleButton toggleButton6 = new JToggleButton();
+		JButton button1 = new JButton();
 
 		//======== this ========
 		setLayout(new MigLayout(
@@ -380,6 +381,11 @@ class MoreComponentsPanel
 			toggleButton6.setIcon(UIManager.getIcon("Tree.leafIcon"));
 			toggleButton6.setSelected(true);
 			toolBar1.add(toggleButton6);
+
+			//---- button1 ----
+			button1.setIcon(new ImageIcon(getClass().getResource("/com/formdev/flatlaf/demo/icons/intellij-showWriteAccess.png")));
+			button1.setEnabled(false);
+			toolBar1.add(button1);
 		}
 		add(toolBar1, "cell 1 10 3 1,growx");
 		// JFormDesigner - End of component initialization  //GEN-END:initComponents

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/MoreComponentsPanel.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.0.0.194" Java: "11.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.1.0.272" Java: "13.0.2" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -355,6 +355,11 @@ new FormModel {
 					"icon": new com.jformdesigner.model.SwingIcon( 2, "Tree.leafIcon" )
 					"selected": true
 				} )
+				add( new FormComponent( "javax.swing.JButton" ) {
+					name: "button1"
+					"icon": new com.jformdesigner.model.SwingIcon( 0, "/com/formdev/flatlaf/demo/icons/intellij-showWriteAccess.png" )
+					"enabled": false
+				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 1 10 3 1,growx"
 			} )

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

@@ -27,8 +27,11 @@ import java.awt.image.FilteredImageSource;
 import java.awt.image.ImageProducer;
 import java.awt.image.RGBImageFilter;
 import java.beans.*;
+import java.net.URL;
 import javax.swing.*;
 import com.formdev.flatlaf.FlatLaf;
+import com.formdev.flatlaf.util.MultiResolutionImageSupport;
+import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 import net.miginfocom.swing.*;
 
@@ -575,8 +578,23 @@ public class FlatDisabledIconsTest
 		private final ImageIcon darkIcon;
 
 		LightOrDarkIcon( String lightIconName, String darkIconName ) {
-			this.lightIcon = new ImageIcon( getClass().getResource( lightIconName ) );
-			this.darkIcon = new ImageIcon( getClass().getResource( darkIconName ) );
+			this.lightIcon = loadIcon( lightIconName );
+			this.darkIcon = loadIcon( darkIconName );
+		}
+
+		private static ImageIcon loadIcon( String iconName ) {
+			ImageIcon icon = new ImageIcon( LightOrDarkIcon.class.getResource( iconName ) );
+
+			if( SystemInfo.IS_MAC || !MultiResolutionImageSupport.isAvailable() || !iconName.endsWith( ".png" ) )
+				return icon;
+
+			String iconName2x = iconName.replace( ".png", "@2x.png" );
+			URL url2x = LightOrDarkIcon.class.getResource( iconName2x );
+			if( url2x == null )
+				return icon;
+
+			ImageIcon icon2x = new ImageIcon( url2x );
+			return new ImageIcon( MultiResolutionImageSupport.create( 0, icon.getImage(), icon2x.getImage() ) );
 		}
 
 		private ImageIcon getCurrentIcon() {