/*
* Copyright (c) 2016 Fraunhofer IGD
*
* All rights reserved. This program and the accompanying materials are made
* available under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the License,
* or (at your option) any later version.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution. If not, see <http://www.gnu.org/licenses/>.
*
* Contributors:
* Fraunhofer IGD <http://www.igd.fraunhofer.de/>
*/
package de.fhg.igd.mapviewer.view;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.swt.widgets.Display;
import org.eclipse.ui.PlatformUI;
/**
* Based on AbstractSelectionMediator
*
* @author Michel Kraemer
* @author Simon Templer
*/
public class SelectionProviderFacade implements ISelectionProvider {
/**
* The object whose events shall be filtered
*/
private ISelectionProvider _decoratee;
/**
* A list of selection listeners
*/
private final ListenerList _selectionListeners = new ListenerList();
private final ISelectionChangedListener selectionListener = new ISelectionChangedListener() {
@Override
public void selectionChanged(SelectionChangedEvent event) {
doSelectionChanged();
}
};
/**
* Set the current selection provider
*
* @param prov the selection provider
*/
public void setSelectionProvider(ISelectionProvider prov) {
if (_decoratee != null) {
_decoratee.removeSelectionChangedListener(selectionListener);
}
_decoratee = prov;
if (_decoratee != null) {
_decoratee.addSelectionChangedListener(selectionListener);
}
}
/**
* @return the object whose events shall be filtered
*/
public ISelectionProvider getDecoratee() {
return _decoratee;
}
/**
* @see ISelectionProvider#addSelectionChangedListener(ISelectionChangedListener)
*/
@Override
public void addSelectionChangedListener(ISelectionChangedListener listener) {
_selectionListeners.add(listener);
}
/**
* @see ISelectionProvider#removeSelectionChangedListener(ISelectionChangedListener)
*/
@Override
public void removeSelectionChangedListener(ISelectionChangedListener listener) {
_selectionListeners.remove(listener);
}
/**
* @see ISelectionProvider#setSelection(ISelection)
*/
@Override
public void setSelection(ISelection selection) {
if (_decoratee != null) {
_decoratee.setSelection(selection);
}
fireSelectionChanged();
}
/**
* This method will be called when the selection of the decoratee changed
*/
private void doSelectionChanged() {
fireSelectionChanged();
}
/**
* Notifies the selection listeners about a new selection
*/
private void fireSelectionChanged() {
if (Display.getCurrent() != null) {
fireSelectionChangedInternal();
}
else {
final Display display = PlatformUI.getWorkbench().getDisplay();
display.syncExec(new Runnable() {
@Override
public void run() {
fireSelectionChangedInternal();
}
});
}
}
/**
* Notifies the selection listeners about a new selection, should be called
* only by {@link #fireSelectionChanged()}
*/
private void fireSelectionChangedInternal() {
SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection());
Object[] listeners = _selectionListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
ISelectionChangedListener listener = (ISelectionChangedListener) listeners[i];
listener.selectionChanged(event);
}
}
/**
* @see ISelectionProvider#getSelection()
*/
@Override
public ISelection getSelection() {
if (_decoratee != null) {
return _decoratee.getSelection();
}
else {
return null;
}
}
}