Java tutorial
/******************************************************************************* * Copyright (c) 2006, 2015 IBM Corporation and others. * * 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 Corporation - initial API and implementation *******************************************************************************/ package org.eclipse.jface.viewers; import java.util.Arrays; import java.util.function.Supplier; import org.eclipse.jface.resource.CompositeImageDescriptor; import org.eclipse.jface.resource.ImageDescriptor; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.ImageDataProvider; import org.eclipse.swt.graphics.Point; /** * A <code>DecorationOverlayIcon</code> is an image descriptor that can be used * to overlay decoration images on to the 4 corner quadrants of a base image. * The four quadrants are {@link IDecoration#TOP_LEFT}, {@link IDecoration#TOP_RIGHT}, * {@link IDecoration#BOTTOM_LEFT} and {@link IDecoration#BOTTOM_RIGHT}. Additionally, * the overlay can be used to provide an underlay corresponding to {@link IDecoration#UNDERLAY}, * and to replace the base image with {@link IDecoration#REPLACE} (if supported by the context). * * @since 3.3 * @see IDecoration */ public class DecorationOverlayIcon extends CompositeImageDescriptor { private Object referenceImageOrDescriptor; // the overlay images private ImageDescriptor[] overlays; private ImageDataProvider baseImageDataProvider; /** * The size of the base image (that's also the size of this composite image) */ private Supplier<Point> size; /** * Create the decoration overlay for the base image using the array of * provided overlays. The indices of the array correspond to the values * of the 6 overlay constants defined on {@link IDecoration} * ({@link IDecoration#TOP_LEFT}, {@link IDecoration#TOP_RIGHT}, * {@link IDecoration#BOTTOM_LEFT}, {@link IDecoration#BOTTOM_RIGHT}, * {@link IDecoration#UNDERLAY}, and {@link IDecoration#REPLACE}). * * @param baseImage the base image * @param overlaysArray the overlay images, may contain null values * @param sizeValue the size of the resulting image */ public DecorationOverlayIcon(Image baseImage, ImageDescriptor[] overlaysArray, Point sizeValue) { this.referenceImageOrDescriptor = baseImage; this.overlays = overlaysArray; this.baseImageDataProvider = createCachedImageDataProvider(baseImage); this.size = () -> sizeValue; } /** * Create the decoration overlay for the base image using the array of * provided overlays. The indices of the array correspond to the values * of the 6 overlay constants defined on {@link IDecoration} * ({@link IDecoration#TOP_LEFT}, {@link IDecoration#TOP_RIGHT}, * {@link IDecoration#BOTTOM_LEFT}, {@link IDecoration#BOTTOM_RIGHT}, * {@link IDecoration#UNDERLAY}, and {@link IDecoration#REPLACE}). * * @param baseImage the base image * @param overlaysArray the overlay images, may contain null values */ public DecorationOverlayIcon(Image baseImage, ImageDescriptor[] overlaysArray) { this(baseImage, overlaysArray, new Point(baseImage.getBounds().width, baseImage.getBounds().height)); } /** * Create a decoration overlay icon that will place the given overlay icon in * the given quadrant of the base image. * @param baseImage the base image * @param overlayImage the overlay image * @param quadrant the quadrant (one of {@link IDecoration} * ({@link IDecoration#TOP_LEFT}, {@link IDecoration#TOP_RIGHT}, * {@link IDecoration#BOTTOM_LEFT}, {@link IDecoration#BOTTOM_RIGHT} * or {@link IDecoration#UNDERLAY}) */ public DecorationOverlayIcon(Image baseImage, ImageDescriptor overlayImage, int quadrant) { this(baseImage, createArrayFrom(overlayImage, quadrant)); } /** * Create a decoration overlay icon that will place the given overlay icon * in the given quadrant of the base image descriptor. * * @param baseImageDescriptor * the base image descriptor * @param overlayImageDescriptor * the overlay image descriptor * @param quadrant * the quadrant (one of {@link IDecoration} * ({@link IDecoration#TOP_LEFT}, {@link IDecoration#TOP_RIGHT}, * {@link IDecoration#BOTTOM_LEFT}, * {@link IDecoration#BOTTOM_RIGHT} or * {@link IDecoration#UNDERLAY}) * @since 3.13 */ public DecorationOverlayIcon(ImageDescriptor baseImageDescriptor, ImageDescriptor overlayImageDescriptor, int quadrant) { this.referenceImageOrDescriptor = baseImageDescriptor; this.overlays = createArrayFrom(overlayImageDescriptor, quadrant); this.baseImageDataProvider = createCachedImageDataProvider(baseImageDescriptor); this.size = () -> { int zoomLevel = getZoomLevel(); if (zoomLevel != 0) { ImageData data = baseImageDataProvider.getImageData(zoomLevel); if (data != null) { return new Point(autoScaleDown(data.width), autoScaleDown(data.height)); } } ImageData data = baseImageDataProvider.getImageData(100); return new Point(data.width, data.height); }; } /** * Convert the given image and quadrant into the proper input array. * @param overlayImage the overlay image * @param quadrant the quadrant * @return an array with the given image in the proper quadrant */ private static ImageDescriptor[] createArrayFrom(ImageDescriptor overlayImage, int quadrant) { ImageDescriptor[] descs = new ImageDescriptor[] { null, null, null, null, null }; descs[quadrant] = overlayImage; return descs; } /** * Draw the overlays for the receiver. * @param overlaysArray */ private void drawOverlays(ImageDescriptor[] overlaysArray) { for (int i = 0; i < overlays.length; i++) { ImageDescriptor overlay = overlaysArray[i]; if (overlay == null) { continue; } CachedImageDataProvider overlayImageProvider = createCachedImageDataProvider(overlay); switch (i) { case IDecoration.TOP_LEFT: drawImage(overlayImageProvider, 0, 0); break; case IDecoration.TOP_RIGHT: int overlayWidth = overlayImageProvider.getWidth(); drawImage(overlayImageProvider, getSize().x - overlayWidth, 0); break; case IDecoration.BOTTOM_LEFT: int overlayHeight = overlayImageProvider.getHeight(); drawImage(overlayImageProvider, 0, getSize().y - overlayHeight); break; case IDecoration.BOTTOM_RIGHT: overlayWidth = overlayImageProvider.getWidth(); overlayHeight = overlayImageProvider.getHeight(); drawImage(overlayImageProvider, getSize().x - overlayWidth, getSize().y - overlayHeight); break; } } } @Override public boolean equals(Object o) { if (!(o instanceof DecorationOverlayIcon)) { return false; } DecorationOverlayIcon other = (DecorationOverlayIcon) o; return referenceImageOrDescriptor.equals(other.referenceImageOrDescriptor) && Arrays.equals(overlays, other.overlays); } @Override public int hashCode() { int code = System.identityHashCode(referenceImageOrDescriptor); for (ImageDescriptor overlay : overlays) { if (overlay != null) { code ^= overlay.hashCode(); } } return code; } @Override protected void drawCompositeImage(int width, int height) { if (overlays.length > IDecoration.UNDERLAY) { ImageDescriptor underlay = overlays[IDecoration.UNDERLAY]; if (underlay != null) { drawImage(createCachedImageDataProvider(underlay), 0, 0); } } if (overlays.length > IDecoration.REPLACE && overlays[IDecoration.REPLACE] != null) { drawImage(createCachedImageDataProvider(overlays[IDecoration.REPLACE]), 0, 0); } else { drawImage(baseImageDataProvider, 0, 0); } drawOverlays(overlays); } @Override protected Point getSize() { return size.get(); } @Override protected int getTransparentPixel() { return baseImageDataProvider.getImageData(100).transparentPixel; } }