Improve BrightnessDialog.ColorIcon and move to separate class

src/main/java/bdv/tools/brightness/BrightnessDialog.java

@@ -31,13 +31,9 @@ package bdv.tools.brightness;
 
 import java.awt.BorderLayout;
 import java.awt.Color;
-import java.awt.Component;
 import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Frame;
-import java.awt.Graphics;
-import java.awt.Graphics2D;
-import java.awt.RenderingHints;
 import java.awt.Window;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
@@ -52,7 +48,6 @@ import javax.swing.Action;
 import javax.swing.ActionMap;
 import javax.swing.BorderFactory;
 import javax.swing.BoxLayout;
-import javax.swing.Icon;
 import javax.swing.InputMap;
 import javax.swing.JButton;
 import javax.swing.JCheckBox;
@@ -131,42 +126,6 @@ public class BrightnessDialog extends JDialog
 		setDefaultCloseOperation( WindowConstants.HIDE_ON_CLOSE );
 	}
 
-	/**
-	 * Adapted from http://stackoverflow.com/a/3072979/230513
-	 */
-	private static class ColorIcon implements Icon
-	{
-		private final int size = 16;
-
-		private final Color color;
-
-		public ColorIcon( final Color color )
-		{
-			this.color = color;
-		}
-
-		@Override
-		public void paintIcon( final Component c, final Graphics g, final int x, final int y )
-		{
-			final Graphics2D g2d = ( Graphics2D ) g;
-			g2d.setRenderingHint( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON );
-			g2d.setColor( color );
-			g2d.fillOval( x, y, size, size );
-		}
-
-		@Override
-		public int getIconWidth()
-		{
-			return size;
-		}
-
-		@Override
-		public int getIconHeight()
-		{
-			return size;
-		}
-	}
-
 	public static class ColorsPanel extends JPanel
 	{
 		private final SetupAssignments setupAssignments;
@@ -196,11 +155,7 @@ public class BrightnessDialog extends JDialog
 			for ( final ConverterSetup setup : setupAssignments.getConverterSetups() )
 			{
 				final JButton button = new JButton( new ColorIcon( getColor( setup ) ) );
-				button.addActionListener( new ActionListener()
-				{
-					@Override
-					public void actionPerformed( final ActionEvent e )
-					{
+				button.addActionListener( e -> {
 					colorChooser.setColor( getColor( setup ) );
 					final JDialog d = JColorChooser.createDialog( button, "Choose a color", true, colorChooser, new ActionListener()
 					{
@@ -216,7 +171,6 @@ public class BrightnessDialog extends JDialog
 						}
 					}, null );
 					d.setVisible( true );
-					}
 				} );
 				button.setEnabled( setup.supportsColor() );
 				buttons.add( button );
@@ -237,7 +191,7 @@ public class BrightnessDialog extends JDialog
 				return new Color( value );
 			}
 			else
-				return new Color ( 0xFFBBBBBB );
+				return null;
 		}
 
 		private static void setColor( final ConverterSetup setup, final Color color )

src/main/java/bdv/tools/brightness/ColorIcon.java

+package bdv.tools.brightness;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.RenderingHints;
+import javax.swing.Icon;
+
+/**
+ * Adapted from http://stackoverflow.com/a/3072979/230513
+ */
+public class ColorIcon implements Icon
+{
+	private final int width;
+
+	private final int height;
+
+	private final boolean drawAsCircle;
+
+	private final int arcWidth;
+
+	private final int arcHeight;
+
+	private final Color color;
+
+	private final int size; // == min(width, height)
+
+	private int ox;
+
+	private int oy;
+
+	public ColorIcon( final Color color )
+	{
+		this( color, 16, 16, true );
+	}
+
+	public ColorIcon( final Color color, final int width, final int height, final boolean drawAsCircle )
+	{
+		this( color, width, height, drawAsCircle, 3, 3 );
+	}
+
+	public ColorIcon( final Color color, final int width, final int height, final int arcWidth, final int arcHeight )
+	{
+		this( color, width, height, false, arcWidth, arcHeight );
+	}
+
+	private ColorIcon( final Color color, final int width, final int height, final boolean drawAsCircle, final int arcWidth, final int arcHeight )
+	{
+		this.color = color;
+		this.width = width;
+		this.height = height;
+		this.drawAsCircle = drawAsCircle;
+		this.arcWidth = arcWidth;
+		this.arcHeight = arcHeight;
+
+		size = Math.min( width, height );
+		ox = ( width - size ) / 2;
+		oy = ( height - size ) / 2;
+	}
+
+	@Override
+	public void paintIcon( final Component c, final Graphics g, final int x, final int y )
+	{
+		final Graphics2D g2d = ( Graphics2D ) g;
+		g2d.setRenderingHint( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON );
+		final int x0 = x + ox;
+		final int y0 = y + oy;
+		if ( color == null )
+		{
+			g2d.setColor( new Color( 0xffbcbc ) );
+			g2d.fillArc( x0, y0, size, size, 0, 120 );
+			g2d.setColor( new Color( 0xbcffbc ) );
+			g2d.fillArc( x0, y0, size, size, 120, 120 );
+			g2d.setColor( new Color( 0xbcbcff ) );
+			g2d.fillArc( x0, y0, size, size, 240, 120 );
+		}
+		else
+		{
+			g2d.setColor( color );
+			if ( drawAsCircle )
+				g2d.fillOval( x0, y0, size, size );
+			else
+				g2d.fillRoundRect( x, y, width, height, arcWidth, arcHeight );
+		}
+	}
+
+	@Override
+	public int getIconWidth()
+	{
+		return width;
+	}
+
+	@Override
+	public int getIconHeight()
+	{
+		return height;
+	}
+}