com.google.gdt.eclipse.designer.util.ui.ImageSelectionDialog.java Source code

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Here is the source code for com.google.gdt.eclipse.designer.util.ui.ImageSelectionDialog.java

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/*******************************************************************************
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * 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
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *******************************************************************************/
package com.google.gdt.eclipse.designer.util.ui;

import com.google.common.collect.Maps;
import com.google.gdt.eclipse.designer.util.ModuleDescription;
import com.google.gdt.eclipse.designer.util.resources.IResourcesProvider;

import org.eclipse.wb.internal.core.utils.ui.DrawUtils;
import org.eclipse.wb.internal.core.utils.ui.GridDataFactory;
import org.eclipse.wb.internal.core.utils.ui.GridLayoutFactory;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

import org.apache.commons.io.IOUtils;

import java.io.InputStream;
import java.util.Map;

/**
 * Dialog for selecting image from public folders of modules.
 * 
 * @author scheglov_ke
 * @coverage gwt.util.ui
 */
public final class ImageSelectionDialog extends ResourceSelectionDialog {
    private static final int ICON_SIZE = 16;

    ////////////////////////////////////////////////////////////////////////////
    //
    // Constructor
    //
    ////////////////////////////////////////////////////////////////////////////
    public ImageSelectionDialog(Shell parentShell, IResourcesProvider provider, ModuleDescription moduleDescription,
            String title) throws Exception {
        super(parentShell, provider, moduleDescription, title);
        addFilter("GIF Files", "*.gif");
        addFilter("JPG Files", "*.jpg");
        addFilter("PNG Files", "*.png");
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Icons support
    //
    ////////////////////////////////////////////////////////////////////////////
    @Override
    protected Image getIcon(ResourceFile file) {
        return getFileIcon(file);
    }

    @Override
    public boolean close() {
        disposeImages();
        return super.close();
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Preview
    //
    ////////////////////////////////////////////////////////////////////////////
    @Override
    protected void previewFile(Composite parent, ResourceFile file) {
        Image image = getFileImage(file);
        if (image != null) {
            GridLayoutFactory.create(parent);
            Canvas canvas = new ImageCanvas(parent, SWT.NONE, image);
            GridDataFactory.create(canvas).grab().fill();
            parent.layout();
        }
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Images access
    //
    ////////////////////////////////////////////////////////////////////////////
    private final Map<ResourceFile, Image> m_fileToImage = Maps.newHashMap();
    private final Map<ResourceFile, Image> m_fileToIcon = Maps.newHashMap();

    /**
     * @return the icon size {@link Image} (16x16) corresponding to the given {@link ResourceFile}.
     */
    private Image getFileIcon(ResourceFile file) {
        Image icon = m_fileToIcon.get(file);
        if (icon == null) {
            // prepare image
            Image image = getFileImage(file);
            if (image == null) {
                return super.getIcon(file);
            }
            // prepare icon
            icon = new Image(Display.getCurrent(), ICON_SIZE, ICON_SIZE);
            m_fileToIcon.put(file, icon);
            // draw image on icon
            GC gc = new GC(icon);
            DrawUtils.drawScaledImage(gc, image, new Rectangle(0, 0, ICON_SIZE, ICON_SIZE));
            gc.dispose();
        }
        return icon;
    }

    /**
     * @return the full size {@link Image} loaded from given {@link ResourceFile}.
     */
    private Image getFileImage(ResourceFile file) {
        Image image = m_fileToImage.get(file);
        if (image == null) {
            InputStream is = null;
            try {
                is = getResourceAsStream(file);
                image = new Image(Display.getCurrent(), is);
                m_fileToImage.put(file, image);
            } catch (Throwable e) {
                return null;
            } finally {
                IOUtils.closeQuietly(is);
            }
        }
        return image;
    }

    /**
     * Disposes creates {@link Image}'s.
     */
    private void disposeImages() {
        disposeImagesMap(m_fileToImage);
        disposeImagesMap(m_fileToIcon);
    }

    /**
     * Disposes given {@link Image}'s map.
     */
    private static void disposeImagesMap(Map<?, Image> fileToImage) {
        for (Image image : fileToImage.values()) {
            image.dispose();
        }
    }
}