/*******************************************************************************
* Copyright (c) 2000, 2007 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.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.widgets.*;
public class TreeDragSourceEffect extends DragSourceEffect {
Image dragSourceImage = null;
/**
* Creates a new TreeDragSourceEffect
to handle drag effect
* from the specified Tree
.
*
* @param table the Tree
that the user clicks on to initiate the drag
**/
public TreeDragSourceEffect(Tree tree) {
super(tree);
}
/**
* This implementation of dragFinished
disposes the image
* that was created in TableDragSourceAdapter.dragStart
.
*
* Subclasses that override this method should call super.dragFinsihed(event)
* to dispose the image in the default implementation.
*
* @param event the information associated with the drag finished event
*/
public void dragFinished(DragSourceEvent event) {
if (dragSourceImage != null) dragSourceImage.dispose();
dragSourceImage = null;
}
/**
* This implementation of dragStart
will create a default
* image that will be used during the drag. The image should be disposed
* when the drag is completed in the TableDragSourceAdapter.dragFinished
* method.
*
* Subclasses that override this method should call super.dragStart(event)
* to use the image from the default implementation.
*
* @param event the information associated with the drag start event
*/
public void dragStart(DragSourceEvent event) {
event.image = getDragSourceImage(event);
}
Image getDragSourceImage(DragSourceEvent event) {
if (dragSourceImage != null) dragSourceImage.dispose();
dragSourceImage = null;
Tree tree = (Tree) control;
if (OS.GTK_VERSION < OS.VERSION (2, 2, 0)) return null;
/*
* Bug in GTK. gtk_tree_selection_get_selected_rows() segmentation faults
* in versions smaller than 2.2.4 if the model is NULL. The fix is
* to give a valid pointer instead.
*/
int /*long*/ handle = tree.handle;
int /*long*/ selection = OS.gtk_tree_view_get_selection (handle);
int /*long*/ [] model = OS.GTK_VERSION < OS.VERSION (2, 2, 4) ? new int /*long*/ [1] : null;
int /*long*/ list = OS.gtk_tree_selection_get_selected_rows (selection, model);
if (list == 0) return null;
int count = Math.min(10, OS.g_list_length (list));
Display display = tree.getDisplay();
if (count == 1) {
int /*long*/ path = OS.g_list_nth_data (list, 0);
int /*long*/ pixmap = OS.gtk_tree_view_create_row_drag_icon(handle, path);
dragSourceImage = Image.gtk_new(display, SWT.ICON, pixmap, 0);
} else {
int width = 0, height = 0;
int[] w = new int[1], h = new int[1];
int[] yy = new int[count], hh = new int[count];
int /*long*/ [] pixmaps = new int /*long*/ [count];
GdkRectangle rect = new GdkRectangle ();
for (int i=0; i