/*******************************************************************************
* Copyright Technophobia Ltd 2012
*
* This file is part of the Substeps Eclipse Plugin.
*
* The Substeps Eclipse Plugin is free software: you can redistribute it and/or modify
* it under the terms of the Eclipse Public License v1.0.
*
* The Substeps Eclipse Plugin is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Eclipse Public License for more details.
*
* You should have received a copy of the Eclipse Public License
* along with the Substeps Eclipse Plugin. If not, see <http://www.eclipse.org/legal/epl-v10.html>.
******************************************************************************/
package com.technophobia.substeps.junit.ui.component;
import org.eclipse.core.runtime.Assert;
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;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Widget;
/**
* A selection provider for view parts with more that one viewer. Tracks the
* focus of the viewers to provide the correct selection.
*/
public class SelectionProviderMediator implements IPostSelectionProvider {
private class InternalListener implements ISelectionChangedListener, FocusListener {
/*
* @see ISelectionChangedListener#selectionChanged
*/
@Override
public void selectionChanged(final SelectionChangedEvent event) {
doSelectionChanged(event);
}
/*
* @see FocusListener#focusGained
*/
@Override
public void focusGained(final FocusEvent e) {
doFocusChanged(e.widget);
}
/*
* @see FocusListener#focusLost
*/
@Override
public void focusLost(final FocusEvent e) {
// do not reset due to focus behavior on GTK
// fViewerInFocus= null;
}
}
private class InternalPostSelectionListener implements ISelectionChangedListener {
@Override
public void selectionChanged(final SelectionChangedEvent event) {
doPostSelectionChanged(event);
}
}
private final StructuredViewer[] viewers;
private StructuredViewer viewerInFocus;
private final ListenerList selectionChangedListeners;
private final ListenerList postSelectionChangedListeners;
/**
* @param viewers
* All viewers that can provide a selection
* @param viewerInFocus
* the viewer currently in focus or <code>null</code>
*/
public SelectionProviderMediator(final StructuredViewer[] viewers, final StructuredViewer viewerInFocus) {
Assert.isNotNull(viewers);
this.viewers = viewers;
final InternalListener listener = new InternalListener();
this.selectionChangedListeners = new ListenerList();
this.postSelectionChangedListeners = new ListenerList();
this.viewerInFocus = viewerInFocus;
for (int i = 0; i < viewers.length; i++) {
final StructuredViewer viewer = viewers[i];
viewer.addSelectionChangedListener(listener);
viewer.addPostSelectionChangedListener(new InternalPostSelectionListener());
final Control control = viewer.getControl();
control.addFocusListener(listener);
}
}
private void doFocusChanged(final Widget control) {
for (int i = 0; i < viewers.length; i++) {
if (viewers[i].getControl() == control) {
propagateFocusChanged(viewers[i]);
return;
}
}
}
final void doPostSelectionChanged(final SelectionChangedEvent event) {
final ISelectionProvider provider = event.getSelectionProvider();
if (provider == viewerInFocus) {
firePostSelectionChanged();
}
}
final void doSelectionChanged(final SelectionChangedEvent event) {
final ISelectionProvider provider = event.getSelectionProvider();
if (provider == viewerInFocus) {
fireSelectionChanged();
}
}
final void propagateFocusChanged(final StructuredViewer viewer) {
if (viewer != viewerInFocus) { // OK to compare by identity
viewerInFocus = viewer;
fireSelectionChanged();
firePostSelectionChanged();
}
}
private void fireSelectionChanged() {
if (selectionChangedListeners != null) {
final SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection());
final Object[] listeners = selectionChangedListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
final ISelectionChangedListener listener = (ISelectionChangedListener) listeners[i];
listener.selectionChanged(event);
}
}
}
private void firePostSelectionChanged() {
if (postSelectionChangedListeners != null) {
final SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection());
final Object[] listeners = postSelectionChangedListeners.getListeners();
for (int i = 0; i < listeners.length; i++) {
final ISelectionChangedListener listener = (ISelectionChangedListener) listeners[i];
listener.selectionChanged(event);
}
}
}
/*
* @see ISelectionProvider#addSelectionChangedListener
*/
@Override
public void addSelectionChangedListener(final ISelectionChangedListener listener) {
selectionChangedListeners.add(listener);
}
/*
* @see ISelectionProvider#removeSelectionChangedListener
*/
@Override
public void removeSelectionChangedListener(final ISelectionChangedListener listener) {
selectionChangedListeners.remove(listener);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.viewers.IPostSelectionProvider#
* addPostSelectionChangedListener
* (org.eclipse.jface.viewers.ISelectionChangedListener)
*/
@Override
public void addPostSelectionChangedListener(final ISelectionChangedListener listener) {
postSelectionChangedListeners.add(listener);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.jface.viewers.IPostSelectionProvider#
* removePostSelectionChangedListener
* (org.eclipse.jface.viewers.ISelectionChangedListener)
*/
@Override
public void removePostSelectionChangedListener(final ISelectionChangedListener listener) {
postSelectionChangedListeners.remove(listener);
}
/*
* @see ISelectionProvider#getSelection
*/
@Override
public ISelection getSelection() {
if (viewerInFocus != null) {
return viewerInFocus.getSelection();
}
return StructuredSelection.EMPTY;
}
/*
* @see ISelectionProvider#setSelection
*/
@Override
public void setSelection(final ISelection selection) {
if (viewerInFocus != null) {
viewerInFocus.setSelection(selection);
}
}
public void setSelection(final ISelection selection, final boolean reveal) {
if (viewerInFocus != null) {
viewerInFocus.setSelection(selection, reveal);
}
}
/**
* Returns the viewer in focus or null if no viewer has the focus
*
* @return returns the current viewer in focus
*/
public StructuredViewer getViewerInFocus() {
return viewerInFocus;
}
}