org.eclipse.paho.mqtt.ui.util.Images.java Source code

Introduction

Here is the source code for org.eclipse.paho.mqtt.ui.util.Images.java

Source

/*******************************************************************************
 * Copyright (c) 2013 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * and Eclipse Distribution License v1.0 which accompany this distribution. 
 *
 * The Eclipse Public License is available at 
 *    http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at 
 *   http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *    Bin Zhang - initial API and implementation and/or initial documentation
 *******************************************************************************/
package org.eclipse.paho.mqtt.ui.util;

import java.io.File;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.runtime.FileLocator;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.jface.resource.ImageRegistry;
import org.eclipse.paho.mqtt.ui.Activator;
import org.eclipse.swt.graphics.Image;
import org.osgi.framework.Bundle;

/**
 * SWT Image helper
 * 
 * @author Bin Zhang
 */
public final class Images {
    private static Set<String> keys;
    private static ImageRegistry register;
    private static final String ICONS_ENTRY = "icons"; //$NON-NLS-1$
    private static final String[] ICONS_EXTS = new String[] { ".gif", ".png", ".bmp", ".jpg" }; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$

    /**
     * @param key
     */
    public static ImageDescriptor getDescriptor(String key) {
        ImageDescriptor image = register.getDescriptor(key);
        if (image == null) {
            image = getMissingImageDescriptor();
        }
        return image;
    }

    /**
     * @param key
     */
    public static Image get(String key) {
        Image image = register.get(key);
        if (image == null) {
            image = getMissingImageDescriptor().createImage();
        }
        return image;
    }

    /**
     * Returns a set view of image keys
     */
    public static Set<String> getImageKeys() {
        return Collections.unmodifiableSet(keys);
    }

    /**
     * Returns absolute path in the FS
     * 
     * @param path
     */
    public static Image getImageFromURL(String path) {
        try {
            return ImageDescriptor.createFromURL(new File(path).toURI().toURL()).createImage();
        } catch (MalformedURLException e) {
            e.printStackTrace();
            // ignore
        }
        return getMissingImageDescriptor().createImage();
    }

    /**
     * Returns relative path in the Project
     * @param url
     */
    public static Image getImageFromURL(URL url) {
        if (url != null) {
            return ImageDescriptor.createFromURL(url).createImage();
        }

        return getMissingImageDescriptor().createImage();
    }

    /**
     * Returns missing image descriptor
     */
    public static ImageDescriptor getMissingImageDescriptor() {
        return ImageDescriptor.getMissingImageDescriptor();
    }

    /**
     * Disposes all images and clear all image keys.
     */
    public static void dispose() {
        register.dispose();
        keys.clear();
    }

    /**
     * init image keys
     */
    private static void initialize() {
        register = new ImageRegistry();
        keys = new HashSet<String>();

        //
        Bundle bundle = Platform.getBundle(Activator.PLUGIN_ID);
        URL url = bundle.getEntry(ICONS_ENTRY);
        try {
            url = FileLocator.toFileURL(url);
        } catch (Exception e) {
            e.printStackTrace();
            // ignore
        }

        // register all image files
        File file = new File(url.getPath());
        for (File f : file.listFiles()) {
            if (!f.isFile()) {
                continue;
            }
            String name = f.getName().trim().toLowerCase();
            for (String extesion : ICONS_EXTS) {
                if (name.endsWith(extesion)) {
                    break;
                }
            }

            String key = name.substring(0, name.indexOf('.'));
            URL fullPathString = bundle.getEntry(ICONS_ENTRY + "/" + name); //$NON-NLS-1$
            ImageDescriptor des = ImageDescriptor.createFromURL(fullPathString);
            register.put(key, des);
            keys.add(key);
        }
    }

    // init
    static {
        initialize();
    }

}