/*
* Copyright 2007 Fred Sauer
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.allen_sauer.gwt.dnd.client.drop;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.Widget;
import com.allen_sauer.gwt.dnd.client.DragContext;
import com.allen_sauer.gwt.dnd.client.VetoDragException;
/**
* A {@link DropController} for the {@link com.google.gwt.user.client.ui.Panel}
* which contains a given draggable widget.
*/
public class BoundaryDropController extends AbsolutePositionDropController {
private boolean allowDroppingOnBoundaryPanel = true;
public BoundaryDropController(AbsolutePanel dropTarget, boolean allowDroppingOnBoundaryPanel) {
super(dropTarget);
dropTarget.addStyleName("dragdrop-boundary");
this.allowDroppingOnBoundaryPanel = allowDroppingOnBoundaryPanel;
}
/**
* Whether or not dropping on the boundary panel is permitted.
*
* @return <code>true</code> if dropping on the boundary panel is allowed
*/
public boolean getBehaviorBoundaryPanelDrop() {
return allowDroppingOnBoundaryPanel;
}
public void onPreviewDrop(DragContext context) throws VetoDragException {
if (!allowDroppingOnBoundaryPanel) {
throw new VetoDragException();
}
super.onPreviewDrop(context);
}
/**
* Set whether or not widgets may be dropped anywhere on the boundary panel.
* Set to <code>false</code> when you only want explicitly registered drop
* controllers to accept drops. Defaults to <code>true</code>.
*
* @param allowDroppingOnBoundaryPanel <code>true</code> to allow dropping
*/
public void setBehaviorBoundaryPanelDrop(boolean allowDroppingOnBoundaryPanel) {
this.allowDroppingOnBoundaryPanel = allowDroppingOnBoundaryPanel;
}
Widget makePositioner(Widget reference) {
if (allowDroppingOnBoundaryPanel) {
return super.makePositioner(reference);
} else {
return new SimplePanel();
}
}
}