/*******************************************************************************
* Copyright (c) 2000, 2011 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.internal.cocoa.*;
import org.eclipse.swt.widgets.*;
/**
* This class provides a default drag under effect (eg. select, insert and scroll)
* when a drag occurs over a Table
.
*
*
Classes that wish to provide their own drag under effect for a Table
* can extend the TableDropTargetEffect
and override any applicable methods
* in TableDropTargetEffect
to display their own drag under effect.
super
method to get the default drag under effect implementation.
*
* The feedback value is either one of the FEEDBACK constants defined in
* class DND
which is applicable to instances of this class,
* or it must be built by bitwise OR'ing together
* (that is, using the int
"|" operator) two or more
* of those DND
effect constants.
*
*
TableDropTargetEffect
to handle the drag under effect on the specified
* Table
.
*
* @param table the Table
over which the user positions the cursor to drop the data
*/
public TableDropTargetEffect(Table table) {
super(table);
}
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 dragEnter
provides a default drag under effect
* for the feedback specified in event.feedback
.
*
* For additional information see DropTargetAdapter.dragEnter
.
*
* Subclasses that override this method should call super.dragEnter(event)
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag enter event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
public void dragEnter(DropTargetEvent event) {
}
/**
* This implementation of dragLeave
provides a default drag under effect
* for the feedback specified in event.feedback
.
*
* For additional information see DropTargetAdapter.dragLeave
.
*
* Subclasses that override this method should call super.dragLeave(event)
* to get the default drag under effect implementation.
*
* @param event the information associated with the drag leave event
*
* @see DropTargetAdapter
* @see DropTargetEvent
*/
public void dragLeave(DropTargetEvent event) {
if (shouldEnableScrolling) {
shouldEnableScrolling = false;
OS.objc_msgSend(control.view.id, OS.sel_setShouldScrollClipView_, 1);
control.redraw();
}
}
/**
* This implementation of dragOver
provides a default drag under effect
* for the feedback specified in event.feedback
. The class description
* lists the FEEDBACK constants that are applicable to the class.
*
* For additional information see DropTargetAdapter.dragOver
.
*
* Subclasses that override this method should call super.dragOver(event)
* 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_SCROLL
*/
public void dragOver(DropTargetEvent event) {
int effect = checkEffect(event.feedback);
((DropTarget)event.widget).feedback = effect;
if ((effect & DND.FEEDBACK_SCROLL) == 0) {
shouldEnableScrolling = true;
OS.objc_msgSend(control.view.id, OS.sel_setShouldScrollClipView_, 0);
} else {
OS.objc_msgSend(control.view.id, OS.sel_setShouldScrollClipView_, 1);
}
}
}