Pull Request #72: Improve disabled button rendering #70

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

@@ -40,6 +40,8 @@ import java.util.function.Consumer;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import javax.swing.AbstractButton;
+import javax.swing.Icon;
+import javax.swing.JComponent;
 import javax.swing.JLabel;
 import javax.swing.JRootPane;
 import javax.swing.JTabbedPane;
@@ -52,10 +54,11 @@ import javax.swing.UnsupportedLookAndFeelException;
 import javax.swing.UIDefaults.ActiveValue;
 import javax.swing.plaf.ColorUIResource;
 import javax.swing.plaf.FontUIResource;
-import javax.swing.plaf.UIResource;
+import javax.swing.plaf.IconUIResource;
 import javax.swing.plaf.basic.BasicLookAndFeel;
 import javax.swing.text.StyleContext;
 import javax.swing.text.html.HTMLEditorKit;
+import com.formdev.flatlaf.ui.FlatUIUtils;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -117,6 +120,11 @@ public abstract class FlatLaf
 		return true;
 	}
 
+	@Override
+	public Icon getDisabledIcon(JComponent component, Icon icon) {
+		return ( icon == null ) ? null : new IconUIResource( FlatUIUtils.getDisabledIcon( icon ) );
+	}
+
 	@Override
 	public void initialize() {
 		if( SystemInfo.IS_MAC )

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

@@ -86,6 +86,8 @@ import com.formdev.flatlaf.util.UIScale;
  * @uiDefault Button.toolbar.spacingInsets		Insets
  * @uiDefault Button.toolbar.hoverBackground	Color
  * @uiDefault Button.toolbar.pressedBackground	Color
+ * @uiDefault Button.disabledGrayMinValue		int	optional
+ * @uiDefault Button.disabledGrayMinValue		int	optional
  *
  * @author Karl Tauber
  */

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

@@ -0,0 +1,28 @@
+package com.formdev.flatlaf.ui;
+
+import java.awt.image.RGBImageFilter;
+
+/**
+ * Used to create a disabled Icon with the ocean look.
+ * <p>
+ * Imported from MetalUtils.getOceanDisabledButtonIcon
+ */
+class FlatDisabledButtonImageFilter extends RGBImageFilter {
+	private float min;
+	private float factor;
+
+	FlatDisabledButtonImageFilter( int min, int max ) {
+		canFilterIndexColorModel = true;
+		this.min = ( float ) min;
+		this.factor = ( max - min ) / 255f;
+	}
+
+	public int filterRGB( int x, int y, int rgb ) {
+		// Coefficients are from the sRGB color space:
+		int gray = Math.min( 255, ( int ) ( ( ( 0.2125f * ( ( rgb >> 16 ) & 0xFF ) ) +
+			( 0.7154f * ( ( rgb >> 8 ) & 0xFF ) ) +
+			( 0.0721f * ( rgb & 0xFF )) + .5f ) * factor + min) );
+
+		return ( rgb & 0xff000000 ) | ( gray << 16 ) | ( gray << 8 ) | ( gray );
+	}
+}

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

@@ -23,10 +23,15 @@ import java.awt.Dimension;
 import java.awt.Font;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
+import java.awt.GraphicsConfiguration;
+import java.awt.GraphicsDevice;
+import java.awt.GraphicsEnvironment;
+import java.awt.Image;
 import java.awt.Insets;
 import java.awt.Rectangle;
 import java.awt.RenderingHints;
 import java.awt.Shape;
+import java.awt.Toolkit;
 import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
 import java.awt.event.MouseAdapter;
@@ -34,7 +39,12 @@ import java.awt.event.MouseEvent;
 import java.awt.geom.Path2D;
 import java.awt.geom.Rectangle2D;
 import java.awt.geom.RoundRectangle2D;
+import java.awt.image.BufferedImage;
+import java.awt.image.FilteredImageSource;
+import java.awt.image.ImageProducer;
 import java.util.function.Consumer;
+import javax.swing.Icon;
+import javax.swing.ImageIcon;
 import javax.swing.JComponent;
 import javax.swing.LookAndFeel;
 import javax.swing.UIManager;
@@ -433,6 +443,32 @@ public class FlatUIUtils
 		return explicitlySet;
 	}
 
+	public static Icon getDisabledIcon( Icon icon ) {
+		Image image = safeGetImage(icon);
+		int grayMinValue = FlatUIUtils.getUIInt( "Button.disabledGrayMinValue", 180 );
+		int grayMaxValue = FlatUIUtils.getUIInt( "Button.disabledGrayMaxValue", 215 );
+		FlatDisabledButtonImageFilter imageFilter = new FlatDisabledButtonImageFilter(grayMinValue, grayMaxValue);
+		ImageProducer producer = new FilteredImageSource(image.getSource(), imageFilter);
+		return new ImageIcon(Toolkit.getDefaultToolkit().createImage(producer));
+	}
+
+	private static Image safeGetImage(Icon icon) {
+		if ( icon instanceof ImageIcon ) {
+			return  ( ( ImageIcon ) icon ).getImage();
+		} else {
+			int width = icon.getIconWidth();
+			int height = icon.getIconHeight();
+			GraphicsEnvironment environment = GraphicsEnvironment.getLocalGraphicsEnvironment();
+			GraphicsDevice device = environment.getDefaultScreenDevice();
+			GraphicsConfiguration configuration = device.getDefaultConfiguration();
+			BufferedImage image = configuration.createCompatibleImage( width, height );
+			Graphics2D g = image.createGraphics();
+			icon.paintIcon( null, g, 0, 0 );
+			g.dispose();
+			return image;
+		}
+	}
+
 	//---- class HoverListener ------------------------------------------------
 
 	public static class HoverListener