001: /*******************************************************************************
002: * Copyright (c) 2000, 2006 IBM Corporation and others.
003: * All rights reserved. This program and the accompanying materials
004: * are made available under the terms of the Eclipse Public License v1.0
005: * which accompanies this distribution, and is available at
006: * http://www.eclipse.org/legal/epl-v10.html
007: *
008: * Contributors:
009: * IBM Corporation - initial API and implementation
010: *******************************************************************************/package org.eclipse.ui.actions;
011:
012: import org.eclipse.jface.action.Action;
013: import org.eclipse.ui.IPartListener;
014: import org.eclipse.ui.IWorkbenchPart;
015:
016: /**
017: * The abstract superclass for actions that listen to part activation and
018: * open/close events. This implementation tracks the active part (see
019: * <code>getActivePart</code>) and provides a convenient place to monitor
020: * part lifecycle events that could affect the availability of the action.
021: * <p>
022: * Subclasses must implement the following <code>IAction</code> method:
023: * <ul>
024: * <li><code>run</code> - to do the action's work</li>
025: * </ul>
026: * </p>
027: * <p>
028: * Subclasses may extend any of the <code>IPartListener</code> methods if the
029: * action availablity needs to be recalculated:
030: * <ul>
031: * <li><code>partActivated</code></li>
032: * <li><code>partDeactivated</code></li>
033: * <li><code>partOpened</code></li>
034: * <li><code>partClosed</code></li>
035: * <li><code>partBroughtToTop</code></li>
036: * </ul>
037: * </p>
038: * <p>
039: * Although this method implements the <code>IPartListener</code> interface,
040: * it does NOT register itself.
041: * </p>
042: */
043: public abstract class PartEventAction extends Action implements
044: IPartListener {
045:
046: /**
047: * The active part, or <code>null</code> if none.
048: */
049: private IWorkbenchPart activePart;
050:
051: /**
052: * Creates a new action with the given text.
053: *
054: * @param text the action's text, or <code>null</code> if there is no text
055: */
056: protected PartEventAction(String text) {
057: super (text);
058: }
059:
060: /**
061: * Creates a new action with the given text and style.
062: *
063: * @param text the action's text, or <code>null</code> if there is no text
064: * @param style one of <code>AS_PUSH_BUTTON</code>, <code>AS_CHECK_BOX</code>,
065: * <code>AS_DROP_DOWN_MENU</code>, <code>AS_RADIO_BUTTON</code>, and
066: * <code>AS_UNSPECIFIED</code>
067: * @since 3.0
068: */
069: protected PartEventAction(String text, int style) {
070: super (text, style);
071: }
072:
073: /**
074: * Returns the currently active part in the workbench.
075: *
076: * @return currently active part in the workbench, or <code>null</code> if none
077: */
078: public IWorkbenchPart getActivePart() {
079: return activePart;
080: }
081:
082: /**
083: * The <code>PartEventAction</code> implementation of this
084: * <code>IPartListener</code> method records that the given part is active.
085: * Subclasses may extend this method if action availability has to be
086: * recalculated.
087: */
088: public void partActivated(IWorkbenchPart part) {
089: activePart = part;
090: }
091:
092: /**
093: * The <code>PartEventAction</code> implementation of this
094: * <code>IPartListener</code> method does nothing. Subclasses should extend
095: * this method if action availability has to be recalculated.
096: */
097: public void partBroughtToTop(IWorkbenchPart part) {
098: // do nothing
099: }
100:
101: /**
102: * The <code>PartEventAction</code> implementation of this
103: * <code>IPartListener</code> method clears the active part if it just closed.
104: * Subclasses may extend this method if action availability has to be
105: * recalculated.
106: */
107: public void partClosed(IWorkbenchPart part) {
108: if (part == activePart) {
109: activePart = null;
110: }
111: }
112:
113: /**
114: * The <code>PartEventAction</code> implementation of this
115: * <code>IPartListener</code> method records that there is no active part.
116: * Subclasses may extend this method if action availability has to be
117: * recalculated.
118: */
119: public void partDeactivated(IWorkbenchPart part) {
120: activePart = null;
121: }
122:
123: /**
124: * The <code>PartEventAction</code> implementation of this
125: * <code>IPartListener</code> method does nothing. Subclasses should extend
126: * this method if action availability has to be recalculated.
127: */
128: public void partOpened(IWorkbenchPart part) {
129: // do nothing
130: }
131: }
|