Content of file ExtendedColorRegistry.java

/**
 * Copyright (c) 2008-2010 IBM Corporation and others.
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 * IBM - Initial API and implementation
 */
// REUSED CLASS
package org.eclipse.emf.edit.ui.provider;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.edit.provider.IItemColorProvider;
import org.eclipse.jface.resource.ColorDescriptor;
import org.eclipse.jface.resource.DeviceResourceException;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Display;

/**
 * A color registry for converting a color description into an actual color.
 *
 * @see IItemColorProvider
 */
public class ExtendedColorRegistry {
	public static final ExtendedColorRegistry INSTANCE = new ExtendedColorRegistry() {
		@Override
		public Color getColor(Color foregroundColor, Color backgroundColor, Object object) {
			return ExtendedImageRegistry.getInstance(ExtendedColorRegistry.class).getColor(foregroundColor,
				backgroundColor, object);
		}
	};

	protected Display display;
	protected HashMap<Collection<?>, Color> table = new HashMap<Collection<?>, Color>(10);

	public ExtendedColorRegistry() {
		display = Display.getCurrent();
		hookDisplayDispose(display);
	}

	public ExtendedColorRegistry(Display display) {
		this.display = display;
		hookDisplayDispose(display);
	}

	public Color getColor(Color foregroundColor, Color backgroundColor, Object object) {
		if (object instanceof Color) {
			return (Color) object;
		} else {
			final Collection<Object> key = new ArrayList<Object>(2);
			key.add(foregroundColor);
			key.add(backgroundColor);
			key.add(object);

			Color result = table.get(key);
			if (result == null) {
				if (object instanceof ColorDescriptor) {
					final ColorDescriptor colorDescriptor = (ColorDescriptor) object;
					try {
						result = colorDescriptor.createColor(display);
					} catch (final DeviceResourceException exception) {
						Activator.log(exception);
					}
				} else if (object instanceof URI) {
					final URI colorURI = (URI) object;
					if (!"color".equals(colorURI.scheme())) {
						throw new IllegalArgumentException("Only 'color' scheme is recognized" + colorURI);
					}

					RGB colorData;
					if ("rgb".equals(colorURI.authority())) {
						final int red = Integer.parseInt(colorURI.segment(0));
						final int green = Integer.parseInt(colorURI.segment(1));
						final int blue = Integer.parseInt(colorURI.segment(2));
						colorData = new RGB(red, green, blue);
					} else if ("hsb".equals(colorURI.authority())) {
						final float[] hsb = new float[3];
						for (int i = 0; i < 3; ++i) {
							final String segment = colorURI.segment(i);
							hsb[i] = "".equals(segment) || "foreground".equals(segment)
								? foregroundColor.getRGB().getHSB()[i]
								: "background".equals(segment) ? backgroundColor.getRGB().getHSB()[i]
									: Float.parseFloat(segment);
						}
						colorData = new RGB(hsb[0], hsb[1], hsb[2]);
					} else {
						throw new IllegalArgumentException("Only 'rgb' and 'hsb' authority are recognized" + colorURI);
					}

					try {
						result = ColorDescriptor.createFrom(colorData).createColor(display);
					} catch (final DeviceResourceException exception) {
						Activator.log(exception);
					}
				}

				if (result != null) {
					table.put(key, result);
				}
			}
			return result;
		}
	}

	protected void handleDisplayDispose() {
		for (final Color color : table.values()) {
			color.dispose();
		}
		table = null;
	}

	protected void hookDisplayDispose(Display display) {
		display.disposeExec(new Runnable() {
			@Override
			public void run() {
				handleDisplayDispose();
			}
		});
	}
}