| /******************************************************************************* |
| * Copyright (c) 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jface.resource; |
| |
| import org.eclipse.swt.graphics.Color; |
| import org.eclipse.swt.graphics.Device; |
| import org.eclipse.swt.graphics.RGB; |
| |
| /** |
| * Lightweight descriptor for an SWT color. Each ColorDescriptor will create a particular SWT |
| * Color on demand. This object will be compared so hashCode(...) and equals(...) must |
| * return meaningful values. |
| * |
| * @since 3.1 |
| */ |
| public abstract class ColorDescriptor extends DeviceResourceDescriptor { |
| |
| /** |
| * Creates a ColorDescriptor from an existing Color, given the Device associated |
| * with the original Color. This is the usual way to convert a Color into |
| * a ColorDescriptor. Note that the returned ColorDescriptor depends on the |
| * original Color, and disposing the Color will invalidate the ColorDescriptor. |
| * |
| * @since 3.1 |
| * |
| * @param toCreate Color to convert into a ColorDescriptor. |
| * @param originalDevice this must be the same Device that was passed into the |
| * original Color's constructor. |
| * @return a newly created ColorDescriptor that describes the given Color. |
| */ |
| public static ColorDescriptor createFrom(Color toCreate, Device originalDevice) { |
| return new RGBColorDescriptor(toCreate, originalDevice); |
| } |
| |
| /** |
| * Creates a ColorDescriptor from an existing color. |
| * <p> |
| * This is less efficient than <code>createFrom(Color, Device)</code>, so this |
| * version should only be used in situations where the device associated |
| * with the color is unknown. |
| * </p> |
| * The returned ColorDescriptor depends on the original Color. Disposing |
| * the original colour while the color descriptor is still in use may cause |
| * SWT to throw a graphic disposed exception. |
| * |
| * @since 3.1 |
| * |
| * @param toCreate Color to generate a ColorDescriptor from |
| * @return a newly created ColorDescriptor |
| */ |
| public static ColorDescriptor createFrom(Color toCreate) { |
| return new RGBColorDescriptor(toCreate); |
| } |
| |
| /** |
| * Returns a color descriptor for the given RGB values |
| * @since 3.1 |
| * |
| * @param toCreate RGB values to create |
| * @return a new ColorDescriptor |
| */ |
| public static ColorDescriptor createFrom(RGB toCreate) { |
| return new RGBColorDescriptor(toCreate); |
| } |
| |
| /** |
| * Returns the Color described by this descriptor. |
| * |
| * @param device SWT device on which to allocate the Color |
| * @return a newly allocated SWT Color object (never null) |
| * @throws DeviceResourceException if unable to allocate the Color |
| */ |
| public abstract Color createColor(Device device) throws DeviceResourceException; |
| |
| /** |
| * Undoes whatever was done by createColor. |
| * |
| * @since 3.1 |
| * |
| * @param toDestroy a Color that was previously allocated by an equal ColorDescriptor |
| */ |
| public abstract void destroyColor(Color toDestroy); |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jface.resource.SwtResourceDescriptor#create(org.eclipse.swt.graphics.Device) |
| */ |
| public final Object createResource(Device device) throws DeviceResourceException { |
| return createColor(device); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jface.resource.SwtResourceDescriptor#destroy(java.lang.Object) |
| */ |
| public final void destroyResource(Object previouslyCreatedObject) { |
| destroyColor((Color)previouslyCreatedObject); |
| } |
| } |