/*******************************************************************************
 * Copyright (c) 2000, 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.ui.internal.ide.misc;

import org.eclipse.jface.resource.CompositeImageDescriptor;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.Point;

/**
 * An OverlayIcon consists of a main icon and several adornments.
 */
public class OverlayIcon extends CompositeImageDescriptor {

    static final int DEFAULT_WIDTH = 22;

    static final int DEFAULT_HEIGHT = 16;

    private Point fSize = null;

    private ImageDescriptor fBase;

    private ImageDescriptor fOverlays[][];

    public OverlayIcon(ImageDescriptor base, ImageDescriptor[][] overlays,
            Point size) {
        fBase = base;
        fOverlays = overlays;
        fSize = size;
    }

    protected void drawBottomLeft(ImageDescriptor[] overlays) {
        if (overlays == null)
            return;
        int length = overlays.length;
        int x = 0;
        for (int i = 0; i < 3; i++) {
            if (i < length && overlays[i] != null) {
                ImageData id = overlays[i].getImageData();
                drawImage(id, x, getSize().y - id.height);
                x += id.width;
            }
        }
    }

    protected void drawBottomRight(ImageDescriptor[] overlays) {
        if (overlays == null)
            return;
        int length = overlays.length;
        int x = getSize().x;
        for (int i = 2; i >= 0; i--) {
            if (i < length && overlays[i] != null) {
                ImageData id = overlays[i].getImageData();
                x -= id.width;
                drawImage(id, x, getSize().y - id.height);
            }
        }
    }

    /**
     * @see CompositeImageDescriptor#drawCompositeImage(int, int)
     */
    protected void drawCompositeImage(int width, int height) {
        ImageData bg;
        if (fBase == null || (bg = fBase.getImageData()) == null)
            bg = DEFAULT_IMAGE_DATA;
        drawImage(bg, 0, 0);

        if (fOverlays != null) {
            if (fOverlays.length > 0)
                drawTopRight(fOverlays[0]);

            if (fOverlays.length > 1)
                drawBottomRight(fOverlays[1]);

            if (fOverlays.length > 2)
                drawBottomLeft(fOverlays[2]);

            if (fOverlays.length > 3)
                drawTopLeft(fOverlays[3]);
        }
    }

    protected void drawTopLeft(ImageDescriptor[] overlays) {
        if (overlays == null)
            return;
        int length = overlays.length;
        int x = 0;
        for (int i = 0; i < 3; i++) {
            if (i < length && overlays[i] != null) {
                ImageData id = overlays[i].getImageData();
                drawImage(id, x, 0);
                x += id.width;
            }
        }
    }

    protected void drawTopRight(ImageDescriptor[] overlays) {
        if (overlays == null)
            return;
        int length = overlays.length;
        int x = getSize().x;
        for (int i = 2; i >= 0; i--) {
            if (i < length && overlays[i] != null) {
                ImageData id = overlays[i].getImageData();
                x -= id.width;
                drawImage(id, x, 0);
            }
        }
    }

    /**
     * @see CompositeImageDescriptor#getSize()
     */
    protected Point getSize() {
        return fSize;
    }
}