org.eclipse.swt.dnd.ImageTransfer Maven / Gradle / Ivy

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/*******************************************************************************
 * Copyright (c) 2007, 2008 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.swt.dnd;

import org.eclipse.rap.rwt.SingletonUtil;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.ImageData;

/**
 * The class ImageTransfer provides a platform specific mechanism
 * for converting an Image represented as a java ImageData to a
 * platform specific representation of the data and vice versa.
 * 
 * An example of a java ImageData is shown below:
 * 
 *  *     Image image = new Image(display, "C:\temp\img1.gif");
 * 	   ImageData imgData = image.getImageData();
 * 
*
* @see Transfer
* @since 1.3
*/
public class ImageTransfer extends ByteArrayTransfer {
private static final String TYPE_NAME = "image";
private static final int TYPE_ID = registerType( TYPE_NAME );
private ImageTransfer() {
}
/**
* Returns the singleton instance of the ImageTransfer class.
*
* @return the singleton instance of the ImageTransfer class
*/
public static ImageTransfer getInstance() {
return SingletonUtil.getSessionInstance( ImageTransfer.class );
}
/**
* This implementation of javaToNative converts an ImageData
* object represented by java ImageData to a platform specific
* representation.
*
* @param object a java ImageData containing the ImageData to be
* converted
* @param transferData an empty TransferData object that will be
* filled in on return with the platform specific format of the data
* @see Transfer#nativeToJava
*/
public void javaToNative( Object object, TransferData transferData ) {
if( !checkImage( object ) || !isSupportedType( transferData ) ) {
DND.error( DND.ERROR_INVALID_DATA );
}
ImageData imageData = ( ImageData )object;
if( imageData == null )
SWT.error( SWT.ERROR_NULL_ARGUMENT );
transferData.data = imageData;
transferData.result = 1;
}
/**
* This implementation of nativeToJava converts a platform
* specific representation of an image to java ImageData.
*
* @param transferData the platform specific representation of the data to be
* converted
* @return a java ImageData of the image if the conversion was
* successful; otherwise null
* @see Transfer#javaToNative
*/
public Object nativeToJava( TransferData transferData ) {
if( !isSupportedType( transferData ) || transferData.data == null )
return null;
ImageData imageData = ( ImageData )transferData.data;
Object result = imageData.clone();
return result;
}
protected int[] getTypeIds() {
return new int[]{ TYPE_ID };
}
protected String[] getTypeNames() {
return new String[]{ TYPE_NAME };
}
boolean checkImage( Object object ) {
if( object == null || !( object instanceof ImageData ) )
return false;
return true;
}
protected boolean validate( Object object ) {
return checkImage( object );
}
}