/**
* Copyright (c) 2016 committers of YAKINDU 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:
* committers of YAKINDU - initial API and implementation
*
*/
package org.yakindu.sct.examples.wizard.drop;
import org.eclipse.swt.dnd.DND;
import org.eclipse.swt.dnd.DropTarget;
import org.eclipse.swt.dnd.DropTargetAdapter;
import org.eclipse.swt.dnd.DropTargetListener;
import org.eclipse.swt.dnd.Transfer;
import org.eclipse.swt.dnd.URLTransfer;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Shell;
/**
* Copied from
* {@link org.eclipse.epp.internal.mpc.ui.wizards.MarketplaceDropAdapter}.
*
*/
public class ExampleDropTargetInstaller implements IDropTargetInstaller {
private final DropTargetAdapter dropListener = getDropTargetListener();
private Transfer[] transferAgents;
public void installDropTarget(final Shell shell) {
hookUrlTransfer(shell, dropListener);
}
protected DropTargetAdapter getDropTargetListener() {
return new ExampleDropTargetListener();
}
protected DropTarget hookUrlTransfer(final Shell shell, DropTargetAdapter dropListener) {
DropTarget target = findDropTarget(shell);
if (target != null) {
// target exists, get it and check proper registration
registerWithExistingTarget(target);
} else {
target = new DropTarget(shell, DROP_OPERATIONS);
if (transferAgents == null) {
transferAgents = new Transfer[]{URLTransfer.getInstance()};
}
target.setTransfer(transferAgents);
}
registerDropListener(target, dropListener);
Control[] children = shell.getChildren();
for (Control child : children) {
hookRecursive(child, dropListener);
}
return target;
}
protected void registerDropListener(DropTarget target, DropTargetListener dropListener) {
target.removeDropListener(dropListener);
target.addDropListener(dropListener);
}
protected void hookRecursive(Control child, DropTargetListener dropListener) {
DropTarget childTarget = findDropTarget(child);
if (childTarget != null) {
registerWithExistingTarget(childTarget);
registerDropListener(childTarget, dropListener);
}
if (child instanceof Composite) {
Composite composite = (Composite) child;
Control[] children = composite.getChildren();
for (Control control : children) {
hookRecursive(control, dropListener);
}
}
}
protected void registerWithExistingTarget(DropTarget target) {
Transfer[] transfers = target.getTransfer();
boolean exists = false;
if (transfers != null) {
for (Transfer transfer : transfers) {
if (transfer instanceof URLTransfer) {
exists = true;
break;
}
}
if (!exists) {
Transfer[] newTransfers = new Transfer[transfers.length + 1];
System.arraycopy(transfers, 0, newTransfers, 0, transfers.length);
newTransfers[transfers.length] = URLTransfer.getInstance();
target.setTransfer(newTransfers);
}
}
}
protected DropTarget findDropTarget(Control control) {
Object object = control.getData(DND.DROP_TARGET_KEY);
if (object instanceof DropTarget) {
return (DropTarget) object;
}
return null;
}
}