Java tutorial
/******************************************************************************* * Copyright (c) 2006-2013 The RCP Company 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: * The RCP Company - initial API and implementation *******************************************************************************/ package com.rcpcompany.utils.selection; import java.util.HashMap; import java.util.Map; 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.SWT; import org.eclipse.swt.events.FocusEvent; import org.eclipse.swt.events.FocusListener; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Event; import org.eclipse.swt.widgets.Listener; import org.eclipse.ui.forms.widgets.Section; /** * A selection provider for view parts with more that one viewer. Tracks the * focus of the viewers to provide the correct selection. */ public class ControlSelectionProvider implements IPostSelectionProvider { /** * Whether debug is enabled for this provider. */ public static boolean DEBUG = false; /** * All round listener. */ private class MyListener implements ISelectionChangedListener, FocusListener, Listener { private final Control myControl; public MyListener(Control control) { myControl = control; } /* * @see ISelectionChangedListener#selectionChanged */ @Override public void selectionChanged(SelectionChangedEvent event) { if (myControl == controlInFocus) { fireSelectionChanged(); } } @Override public void focusGained(FocusEvent e) { setFocusControl(myControl); } @Override public void focusLost(FocusEvent e) { // do not reset due to focus behavior on GTK // fViewerInFocus= null; } @Override public void handleEvent(Event event) { if (event.type == SWT.Activate) { setFocusControl(myControl); } } } private class PostSelectionListener implements ISelectionChangedListener { private final Control myControl; public PostSelectionListener(Control control) { myControl = control; } @Override public void selectionChanged(SelectionChangedEvent event) { if (myControl == controlInFocus) { firePostSelectionChanged(); } } } private final Map<Control, ISelectionProvider> selectionProviders = new HashMap<Control, ISelectionProvider>(); private Control controlInFocus; private final ListenerList selectionChangedListeners = new ListenerList();; private final ListenerList postSelectionChangedListeners = new ListenerList();; public ControlSelectionProvider() { debug("created"); //$NON-NLS-1$ } protected void debug(String message) { if (DEBUG) { System.out.println(this + ": " + message); //$NON-NLS-1$ } } @Override public String toString() { return getClass().getSimpleName() + ":" + hashCode(); //$NON-NLS-1$ } /** * @param viewers * All viewers that can provide a selection * @param viewerInFocus * the viewer currently in focus or <code>null</code> */ public ControlSelectionProvider(StructuredViewer[] viewers, StructuredViewer viewerInFocus) { for (final StructuredViewer viewer : viewers) { addViewer(viewer); } if (viewerInFocus != null) { setFocusControl(viewerInFocus.getControl()); } } /** * @param controls * @param providers */ public ControlSelectionProvider(Control[] controls, ISelectionProvider[] providers) { this(); Assert.isNotNull(controls); Assert.isNotNull(providers); Assert.isTrue(controls.length == providers.length); for (int i = 0; i < controls.length; i++) { addControl(controls[i], providers[i]); } } /** * Returns the control that currently has focus. * * @return the control or <code>null</code> */ public Control getFocusControl() { return controlInFocus; } /** * Returns the selection provider of the current control. * * @return the provider or <code>null</code> */ public ISelectionProvider getCurrentSelectionProvider() { if (controlInFocus == null) return null; return selectionProviders.get(controlInFocus); } /** * Adds a new control with a specific provider. * * @param control * the control * @param provider * the provider */ public void addControl(Control control, ISelectionProvider provider) { debug("added(" + control + ", " + provider + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ final MyListener listener = new MyListener(control); provider.addSelectionChangedListener(listener); selectionProviders.put(control, provider); control.addFocusListener(listener); control.addListener(SWT.Activate, listener); if (control instanceof Section) { final Section s = (Section) control; for (final Control c : s.getChildren()) { c.addListener(SWT.Activate, listener); } } if (provider instanceof IPostSelectionProvider) { final IPostSelectionProvider post = (IPostSelectionProvider) provider; post.addPostSelectionChangedListener(new PostSelectionListener(control)); } } public void addViewer(StructuredViewer viewer) { addControl(viewer.getControl(), viewer); } /** * @param control */ public void setFocusControl(Control control) { Assert.isNotNull(control); if (control == controlInFocus) return; debug("focus: " + control); //$NON-NLS-1$ controlInFocus = control; if (!control.isFocusControl()) { control.setFocus(); } final ISelectionProvider provider = selectionProviders.get(control); if (provider == null) return; fireSelectionChanged(); firePostSelectionChanged(); } private void fireSelectionChanged() { debug("selectionChanged(" + getCurrentSelectionProvider() + ": " + getSelection() + ")"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ if (selectionChangedListeners != null) { final SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection()); final Object[] listeners = selectionChangedListeners.getListeners(); for (final Object listener2 : listeners) { final ISelectionChangedListener listener = (ISelectionChangedListener) listener2; listener.selectionChanged(event); } } } private void firePostSelectionChanged() { if (postSelectionChangedListeners != null) { final SelectionChangedEvent event = new SelectionChangedEvent(this, getSelection()); final Object[] listeners = postSelectionChangedListeners.getListeners(); for (final Object listener2 : listeners) { final ISelectionChangedListener listener = (ISelectionChangedListener) listener2; listener.selectionChanged(event); } } } @Override public void addSelectionChangedListener(ISelectionChangedListener listener) { selectionChangedListeners.add(listener); } @Override public void removeSelectionChangedListener(ISelectionChangedListener listener) { selectionChangedListeners.remove(listener); } @Override public void addPostSelectionChangedListener(ISelectionChangedListener listener) { postSelectionChangedListeners.add(listener); } @Override public void removePostSelectionChangedListener(ISelectionChangedListener listener) { postSelectionChangedListeners.remove(listener); } @Override public ISelection getSelection() { final ISelectionProvider provider = getCurrentSelectionProvider(); if (provider == null) return StructuredSelection.EMPTY; final ISelection selection = provider.getSelection(); debug("getSelection()=" + selection); //$NON-NLS-1$ return selection; } /* * @see ISelectionProvider#setSelection */ @Override public void setSelection(ISelection selection) { final ISelectionProvider provider = getCurrentSelectionProvider(); if (provider == null) return; provider.setSelection(selection); } }