/*
* Copyright (C) 2006-2016 DLR, Germany
*
* All rights reserved
*
* http://www.rcenvironment.de/
*/
package de.rcenvironment.components.excel.gui.view;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.viewers.IPostSelectionProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.ISelectionProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
/**
* SelectionProvider which works with multiple view elements.
*
* @author Markus Kunde
*/
public class SelectionProviderIntermediate implements IPostSelectionProvider {
/**
* Selection provider, makes it possible to change selection providers during lifecycle.
*/
private ISelectionProvider delegate = null;
/**
* All selection listeners.
*/
private final ListenerList selectionListeners = new ListenerList();
/**
* All post selection listeners.
*/
private final ListenerList postSelectionListeners = new ListenerList();
/**
* Selection listener with selection changed event listener.
*/
private ISelectionChangedListener selectionListener = new ISelectionChangedListener() {
@Override
public void selectionChanged(SelectionChangedEvent event) {
if (event.getSelectionProvider() == delegate) {
fireSelectionChanged(event.getSelection());
}
}
};
/**
* Post selection listener with selection changed event listener.
*/
private ISelectionChangedListener postSelectionListener = new ISelectionChangedListener() {
@Override
public void selectionChanged(SelectionChangedEvent event) {
if (event.getSelectionProvider() == delegate) {
firePostSelectionChanged(event.getSelection());
}
}
};
/**
* Sets a new selection provider to delegate to. Selection listeners
* registered with the previous delegate are removed before.
*
* @param newDelegate new selection provider
*/
public void setSelectionProviderDelegate(ISelectionProvider newDelegate) {
if (delegate == newDelegate) {
return;
}
if (delegate != null) {
delegate.removeSelectionChangedListener(selectionListener);
if (delegate instanceof IPostSelectionProvider) {
((IPostSelectionProvider) delegate).removePostSelectionChangedListener(postSelectionListener);
}
}
delegate = newDelegate;
if (newDelegate != null) {
newDelegate.addSelectionChangedListener(selectionListener);
if (newDelegate instanceof IPostSelectionProvider) {
((IPostSelectionProvider) newDelegate).addPostSelectionChangedListener(postSelectionListener);
}
fireSelectionChanged(newDelegate.getSelection());
firePostSelectionChanged(newDelegate.getSelection());
}
}
/**
* Facade between multiple selection listeners and single interface.
*
* @param selection current selection
*/
protected void fireSelectionChanged(ISelection selection) {
fireSelectionChanged(selectionListeners, selection);
}
/**
* Facade between multiple post selection listeners and single interface.
*
* @param selection current post selection
*/
protected void firePostSelectionChanged(ISelection selection) {
fireSelectionChanged(postSelectionListeners, selection);
}
/**
* Fire selection changed event to all selection listeners.
*
* @param list list of all listeners
* @param selection current selection
*/
private void fireSelectionChanged(ListenerList list, ISelection selection) {
SelectionChangedEvent event = new SelectionChangedEvent(delegate, selection);
Object[] listeners = list.getListeners();
for (Object listener2 : listeners) {
ISelectionChangedListener listener = (ISelectionChangedListener) listener2;
listener.selectionChanged(event);
}
}
@Override
public void addSelectionChangedListener(ISelectionChangedListener listener) {
selectionListeners.add(listener);
}
@Override
public ISelection getSelection() {
if (delegate == null) {
return null;
}
return delegate.getSelection();
}
@Override
public void removeSelectionChangedListener(ISelectionChangedListener listener) {
selectionListeners.remove(listener);
}
@Override
public void setSelection(ISelection selection) {
if (delegate != null) {
delegate.setSelection(selection);
}
}
@Override
public void addPostSelectionChangedListener(ISelectionChangedListener listener) {
postSelectionListeners.add(listener);
}
@Override
public void removePostSelectionChangedListener(ISelectionChangedListener listener) {
postSelectionListeners.remove(listener);
}
}