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

/*******************************************************************************
 * 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
 *     Outhink - support for typeFileURL
 *******************************************************************************/
package org.eclipse.swt.dnd;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.cocoa.*;
import org.eclipse.swt.widgets.*;

/**
 * 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 3.4
*/
public class ImageTransfer extends ByteArrayTransfer {
static ImageTransfer _instance = new ImageTransfer();
static final String TIFF = OS.NSTIFFPboardType.getString();
static final int TIFFID = registerType(TIFF);
ImageTransfer() {
}
/**
* Returns the singleton instance of the ImageTransfer class.
*
* @return the singleton instance of the ImageTransfer class
*/
public static ImageTransfer getInstance() {
return _instance;
}
/**
* 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
*/
@Override
public void javaToNative(Object object, TransferData transferData) {
if (!checkImage(object) || !isSupportedType(transferData)) {
DND.error(DND.ERROR_INVALID_DATA);
}
ImageData imgData = (ImageData) object;
Image image = new Image(Display.getCurrent(), imgData);
NSImage handle = image.handle;
transferData.data = handle.TIFFRepresentation();
image.dispose();
}
/**
* 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
*/
@Override
public Object nativeToJava(TransferData transferData) {
if (!isSupportedType(transferData) || transferData.data == null) return null;
NSData data = (NSData) transferData.data;
if (data.length() == 0) return null;
NSImage nsImage = (NSImage) new NSImage().alloc();
nsImage.initWithData(data);
NSSize size = nsImage.size();
NSImageRep rep = nsImage.bestRepresentationForDevice(null);
if (size.width != rep.pixelsWide() || size.height != rep.pixelsHigh()) {
size.width /= (rep.pixelsWide() / size.width);
size.height /= (rep.pixelsHigh() / size.height);
NSImage newImage = ((NSImage)new NSImage().alloc()).initWithSize(size);
newImage.lockFocus();
NSRect rect = new NSRect();
rect.width = size.width;
rect.height = size.height;
nsImage.drawInRect(rect, new NSRect(), OS.NSCompositeCopy, 1);
newImage.unlockFocus();
nsImage.release();
nsImage = newImage;
}
//TODO: Image representation wrong???
Image image = Image.cocoa_new(Display.getCurrent(), SWT.BITMAP, nsImage);
ImageData imageData = image.getImageData();
image.dispose();
return imageData;
}
@Override
protected int[] getTypeIds() {
return new int[] { TIFFID };
}
@Override
protected String[] getTypeNames() {
return new String[] { TIFF };
}
boolean checkImage(Object object) {
if (object == null || !(object instanceof ImageData)) return false;
return true;
}
@Override
protected boolean validate(Object object) {
return checkImage(object);
}
}