| /******************************************************************************* |
| * Copyright (c) 2000, 2017 IBM Corporation 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: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.ui.actions; |
| |
| import org.eclipse.jface.action.Action; |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.jface.viewers.ISelectionChangedListener; |
| import org.eclipse.jface.viewers.ISelectionProvider; |
| import org.eclipse.jface.viewers.IStructuredSelection; |
| import org.eclipse.jface.viewers.SelectionChangedEvent; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| |
| /** |
| * The abstract superclass for actions that listen to selection changes |
| * from a particular selection provider. This implementation splits the current |
| * selection along structured/unstructured lines, providing a convenient place |
| * to monitor selection changes that require adjusting action state. |
| * <p> |
| * Subclasses must implement the following <code>IAction</code> method: |
| * <ul> |
| * <li><code>run</code> - to do the action's work</li> |
| * </ul> |
| * </p> |
| * <p> |
| * Subclasses may reimplement either of the following methods: |
| * <ul> |
| * <li><code>selectionChanged(IStructuredSelection)</code></li> |
| * <li><code>selectionChanged(ISelection)</code></li> |
| * </ul> |
| * </p> |
| */ |
| public abstract class SelectionProviderAction extends Action implements |
| ISelectionChangedListener { |
| |
| /** |
| * The selection provider that is the target of this action. |
| */ |
| private ISelectionProvider provider; |
| |
| /** |
| * Creates a new action with the given text that monitors selection changes |
| * within the given selection provider. |
| * The resulting action is added as a listener on the selection provider. |
| * |
| * @param provider the selection provider that will provide selection notification |
| * @param text the string used as the text for the action, |
| * or <code>null</code> if there is no text |
| */ |
| protected SelectionProviderAction(ISelectionProvider provider, String text) { |
| super(text); |
| this.provider = provider; |
| provider.addSelectionChangedListener(this); |
| } |
| |
| /** |
| * Disposes this action by removing it as a listener from the selection provider. |
| * This must be called by the creator of the action when the action is no longer needed. |
| */ |
| public void dispose() { |
| provider.removeSelectionChangedListener(this); |
| } |
| |
| /** |
| * Returns the current selection in the selection provider. |
| * |
| * @return the current selection in the selection provider |
| */ |
| public ISelection getSelection() { |
| return provider.getSelection(); |
| } |
| |
| /** |
| * Returns the selection provider that is the target of this action. |
| * |
| * @return the target selection provider of this action |
| */ |
| public ISelectionProvider getSelectionProvider() { |
| return provider; |
| } |
| |
| /** |
| * Returns the current structured selection in the selection provider, or an |
| * empty selection if nothing is selected or if selection does not include |
| * objects (for example, raw text). |
| * |
| * @return the current structured selection in the selection provider |
| */ |
| public IStructuredSelection getStructuredSelection() { |
| ISelection selection = provider.getSelection(); |
| if (selection instanceof IStructuredSelection) { |
| return (IStructuredSelection) selection; |
| } |
| return new StructuredSelection(); |
| } |
| |
| /** |
| * Notifies this action that the given (non-structured) selection has changed |
| * in the selection provider. |
| * <p> |
| * The <code>SelectionProviderAction</code> implementation of this method |
| * does nothing. Subclasses may reimplement to react to this selection change. |
| * </p> |
| * |
| * @param selection the new selection |
| */ |
| public void selectionChanged(ISelection selection) { |
| } |
| |
| /** |
| * Notifies this action that the given structured selection has changed |
| * in the selection provider. |
| * <p> |
| * The <code>SelectionProviderAction</code> implementation of this method |
| * does nothing. Subclasses may reimplement to react to this selection change. |
| * </p> |
| * |
| * @param selection the new selection |
| */ |
| public void selectionChanged(IStructuredSelection selection) { |
| // Hook in subclass. |
| } |
| |
| /** |
| * The <code>SelectionProviderAction</code> implementation of this |
| * <code>ISelectionChangedListener</code> method calls |
| * <code>selectionChanged(IStructuredSelection)</code> if the selection is |
| * a structured selection but <code>selectionChanged(ISelection)</code> if it is |
| * not. Subclasses should override either of those methods method to react to |
| * selection changes. |
| */ |
| @Override |
| public final void selectionChanged(SelectionChangedEvent event) { |
| ISelection selection = event.getSelection(); |
| if (selection instanceof IStructuredSelection) { |
| selectionChanged((IStructuredSelection) selection); |
| } else { |
| selectionChanged(selection); |
| } |
| } |
| } |