FileImageDescriptor.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 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 java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

import org.eclipse.rwt.graphics.Graphics;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;

/**
 * An image descriptor that loads its image information from a file.
 */
class FileImageDescriptor extends ImageDescriptor {

    /**
	 * The class whose resource directory contain the file, or <code>null</code>
	 * if none.
     */
    private Class location;

    /**
     * The name of the file.
     */
    private String name;

    /**
	 * Creates a new file image descriptor. The file has the given file name and
	 * is located in the given class's resource directory. If the given class is
	 * <code>null</code>, the file name must be absolute.
     * <p>
	 * Note that the file is not accessed until its <code>getImageDate</code>
	 * method is called.
     * </p>
     *
	 * @param clazz
	 *            class for resource directory, or <code>null</code>
	 * @param filename
	 *            the name of the file
     */
    FileImageDescriptor(Class clazz, String filename) {
        this.location = clazz;
        this.name = filename;
    }

	/*
	 * (non-Javadoc) Method declared on Object.
     */
    public boolean equals(Object o) {
        if (!(o instanceof FileImageDescriptor)) {
            return false;
        }
        FileImageDescriptor other = (FileImageDescriptor) o;
        if (location != null) {
            if (!location.equals(other.location)) {
                return false;
            }
        } else {
            if (other.location != null) {
                return false;
            }
        }
        return name.equals(other.name);
    }

	/**
	 * @see org.eclipse.jface.resource.ImageDescriptor#getImageData() The
	 *      FileImageDescriptor implementation of this method is not used by
	 *      {@link ImageDescriptor#createImage(boolean, Device)} as of version
	 *      3.4 so that the SWT OS optimised loading can be used.
     */
    public ImageData getImageData() {
        InputStream in = getStream();
        ImageData result = null;
        if (in != null) {
            try {
                result = new ImageData(in);
            } catch (SWTException e) {
                if (e.code != SWT.ERROR_INVALID_IMAGE) {
					throw e;
                // fall through otherwise
				}
            } finally {
                try {
                    in.close();
                } catch (IOException e) {
					// System.err.println(getClass().getName()+".getImageData():
					// "+
                    //  "Exception while closing InputStream : "+e);
                }
            }
        }
        return result;
    }

    // RAP [bm] alternative to ImageData for performance reasons
    public Image createImage(boolean returnMissingImageOnError, Device device) {
      Image result = null;
      if( location != null ) {
        String path = location.getPackage().getName().replace( '.', '/' );
        InputStream is = getStream();
        if( is != null ) {
          result = Graphics.getImage( path + "/" + name, is ); //$NON-NLS-1$
        } else if( returnMissingImageOnError ) {
          path = "org/eclipse/jface/resource/images/missing_image.png"; //$NON-NLS-1$
          ClassLoader loader = getClass().getClassLoader();
          result = Graphics.getImage( path, loader.getResourceAsStream( path ) );
        }
      }
      return result;
    }

    /**
	 * Returns a stream on the image contents. Returns null if a stream could
	 * not be opened.
     *
	 * @return the buffered stream on the file or <code>null</code> if the
	 *         file cannot be found
     */
    private InputStream getStream() {
        InputStream is = null;

        if (location != null) {
            is = location.getResourceAsStream(name);

        } else {
            try {
                is = new FileInputStream(name);
            } catch (FileNotFoundException e) {
                return null;
            }
        }
        if (is == null) {
			return null;
		}
			return new BufferedInputStream(is);

    }

	/*
	 * (non-Javadoc) Method declared on Object.
     */
    public int hashCode() {
        int code = name.hashCode();
        if (location != null) {
            code += location.hashCode();
        }
        return code;
    }

	/*
	 * (non-Javadoc) Method declared on Object.
     */
    /**
	 * The <code>FileImageDescriptor</code> implementation of this
	 * <code>Object</code> method returns a string representation of this
	 * object which is suitable only for debugging.
     */
    public String toString() {
        return "FileImageDescriptor(location=" + location + ", name=" + name + ")";//$NON-NLS-3$//$NON-NLS-2$//$NON-NLS-1$
    }
}