/*******************************************************************************
* Copyright (c) 2000, 2012 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.graphics.*;
import org.eclipse.swt.internal.gtk.*;
import org.eclipse.swt.widgets.*;
/**
* This class provides a default drag under effect (eg. select, insert, scroll and expand)
* when a drag occurs over a <code>Tree</code>.
*
* <p>Classes that wish to provide their own drag under effect for a <code>Tree</code>
* can extend the <code>TreeDropTargetEffect</code> class and override any applicable methods
* in <code>TreeDropTargetEffect</code> to display their own drag under effect.</p>
*
* Subclasses that override any methods of this class must call the corresponding
* <code>super</code> method to get the default drag under effect implementation.
*
* <p>The feedback value is either one of the FEEDBACK constants defined in
* class <code>DND</code> which is applicable to instances of this class,
* or it must be built by <em>bitwise OR</em>'ing together
* (that is, using the <code>int</code> "|" operator) two or more
* of those <code>DND</code> effect constants.
* </p>
* <p>
* <dl>
* <dt><b>Feedback:</b></dt>
* <dd>FEEDBACK_SELECT, FEEDBACK_INSERT_BEFORE, FEEDBACK_INSERT_AFTER, FEEDBACK_EXPAND, FEEDBACK_SCROLL</dd>
* </dl>
* </p><p>
* Note: Only one of the styles FEEDBACK_SELECT, FEEDBACK_INSERT_BEFORE or
* FEEDBACK_INSERT_AFTER may be specified.
* </p>
*
* @see DropTargetAdapter
* @see DropTargetEvent
* @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
*
* @since 3.3
*/
public class TreeDropTargetEffect extends DropTargetEffect {
static final int SCROLL_HYSTERESIS = 150; // milli seconds
static final int EXPAND_HYSTERESIS = 1000; // milli seconds
int scrollIndex = -1;
long scrollBeginTime;
int expandIndex = -1;
long expandBeginTime;
/**
* Creates a new <code>TreeDropTargetEffect</code> to handle the drag under effect on the specified
* <code>Tree</code>.
*
* @param tree the <code>Tree</code> over which the user positions the cursor to drop the data
*/
public TreeDropTargetEffect(Tree tree) {
super(tree);
}
int checkEffect(int effect) {
// Some effects are mutually exclusive. Make sure that only one of the mutually exclusive effects has been specified.
if ((effect & DND.FEEDBACK_SELECT) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER & ~DND.FEEDBACK_INSERT_BEFORE;
if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) effect = effect & ~DND.FEEDBACK_INSERT_AFTER;
return effect;
}
/**
* This implementation of <code>dragEnter</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragEnter</code>.
*
* Subclasses that override this method should call <code>super.dragEnter(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag enter event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
@Override
public void dragEnter(DropTargetEvent event) {
expandBeginTime = 0;
expandIndex = -1;
scrollBeginTime = 0;
scrollIndex = -1;
}
/**
* This implementation of <code>dragLeave</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragLeave</code>.
*
* Subclasses that override this method should call <code>super.dragLeave(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag leave event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
@Override
public void dragLeave(DropTargetEvent event) {
Tree tree = (Tree) control;
long /*int*/ handle = tree.handle;
OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);
scrollBeginTime = 0;
scrollIndex = -1;
expandBeginTime = 0;
expandIndex = -1;
}
/**
* This implementation of <code>dragOver</code> provides a default drag under effect
* for the feedback specified in <code>event.feedback</code>.
*
* For additional information see <code>DropTargetAdapter.dragOver</code>.
*
* Subclasses that override this method should call <code>super.dragOver(event)</code>
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag over event
*
* @see DropTargetAdapter
* @see DropTargetEvent
* @see DND#FEEDBACK_SELECT
* @see DND#FEEDBACK_INSERT_BEFORE
* @see DND#FEEDBACK_INSERT_AFTER
* @see DND#FEEDBACK_SCROLL
*/
@Override
public void dragOver(DropTargetEvent event) {
Tree tree = (Tree) control;
int effect = checkEffect(event.feedback);
long /*int*/ handle = tree.handle;
Point coordinates = new Point(event.x, event.y);
coordinates = tree.toControl(coordinates);
long /*int*/ [] path = new long /*int*/ [1];
OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y, path, null, null, null);
int index = -1;
if (path[0] != 0) {
long /*int*/ indices = OS.gtk_tree_path_get_indices(path[0]);
if (indices != 0) {
int depth = OS.gtk_tree_path_get_depth(path[0]);
int[] temp = new int[depth];
OS.memmove (temp, indices, temp.length * 4);
index = temp[temp.length - 1];
}
}
if ((effect & DND.FEEDBACK_SCROLL) == 0) {
scrollBeginTime = 0;
scrollIndex = -1;
} else {
if (index != -1 && scrollIndex == index && scrollBeginTime != 0) {
if (System.currentTimeMillis() >= scrollBeginTime) {
GdkRectangle cellRect = new GdkRectangle ();
OS.gtk_tree_view_get_cell_area (handle, path[0], 0, cellRect);
if (cellRect.y < cellRect.height) {
int[] tx = new int[1], ty = new int[1];
if (OS.GTK_VERSION >= OS.VERSION(2, 12, 0)) {
OS.gtk_tree_view_convert_bin_window_to_tree_coords(handle, cellRect.x, cellRect.y - cellRect.height, tx, ty);
} else {
OS.gtk_tree_view_widget_to_tree_coords(handle, cellRect.x, cellRect.y - cellRect.height, tx, ty);
}
OS.gtk_tree_view_scroll_to_point (handle, -1, ty[0]);
} else {
//scroll down
OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y + cellRect.height, path, null, null, null);
if (path[0] != 0) {
OS.gtk_tree_view_scroll_to_cell(handle, path[0], 0, false, 0, 0);
OS.gtk_tree_path_free(path[0]);
path[0] = 0;
}
OS.gtk_tree_view_get_path_at_pos (handle, coordinates.x, coordinates.y, path, null, null, null);
}
scrollBeginTime = 0;
scrollIndex = -1;
}
} else {
scrollBeginTime = System.currentTimeMillis() + SCROLL_HYSTERESIS;
scrollIndex = index;
}
}
if ((effect & DND.FEEDBACK_EXPAND) == 0) {
expandBeginTime = 0;
expandIndex = -1;
} else {
if (index != -1 && expandIndex == index && expandBeginTime != 0) {
if (System.currentTimeMillis() >= expandBeginTime) {
OS.gtk_tree_view_expand_row (handle, path[0], false);
expandBeginTime = 0;
expandIndex = -1;
}
} else {
expandBeginTime = System.currentTimeMillis() + EXPAND_HYSTERESIS;
expandIndex = index;
}
}
if (path[0] != 0) {
int position = -1;
if ((effect & DND.FEEDBACK_SELECT) != 0) position = OS.GTK_TREE_VIEW_DROP_INTO_OR_BEFORE;
if ((effect & DND.FEEDBACK_INSERT_BEFORE) != 0) position = OS.GTK_TREE_VIEW_DROP_BEFORE;
if ((effect & DND.FEEDBACK_INSERT_AFTER) != 0) position = OS.GTK_TREE_VIEW_DROP_AFTER;
if (position != -1) {
OS.gtk_tree_view_set_drag_dest_row(handle, path[0], position);
} else {
OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);
}
} else {
OS.gtk_tree_view_set_drag_dest_row(handle, 0, OS.GTK_TREE_VIEW_DROP_BEFORE);
}
if (path[0] != 0) OS.gtk_tree_path_free (path [0]);
}
}