Source code: org/eclipse/ui/internal/PluginAction.java
1 /*******************************************************************************
2 * Copyright (c) 2000, 2004 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Common Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/cpl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 *******************************************************************************/
11 package org.eclipse.ui.internal;
12
13 import java.util.ArrayList;
14 import java.util.List;
15
16 import org.eclipse.core.runtime.CoreException;
17 import org.eclipse.core.runtime.IAdaptable;
18 import org.eclipse.core.runtime.IConfigurationElement;
19 import org.eclipse.core.runtime.IStatus;
20 import org.eclipse.jface.action.Action;
21 import org.eclipse.jface.dialogs.MessageDialog;
22 import org.eclipse.jface.viewers.ISelection;
23 import org.eclipse.jface.viewers.ISelectionChangedListener;
24 import org.eclipse.jface.viewers.IStructuredSelection;
25 import org.eclipse.jface.viewers.SelectionChangedEvent;
26 import org.eclipse.jface.viewers.StructuredSelection;
27 import org.eclipse.swt.widgets.Display;
28 import org.eclipse.swt.widgets.Event;
29 import org.eclipse.ui.IActionDelegate;
30 import org.eclipse.ui.IActionDelegate2;
31 import org.eclipse.ui.IActionDelegateWithEvent;
32 import org.eclipse.ui.INullSelectionListener;
33 import org.eclipse.ui.IPluginContribution;
34 import org.eclipse.ui.ISelectionListener;
35 import org.eclipse.ui.IWorkbenchPart;
36 import org.eclipse.ui.SelectionEnabler;
37 import org.eclipse.ui.WorkbenchException;
38 import org.eclipse.ui.internal.misc.StatusUtil;
39 import org.eclipse.ui.internal.util.BundleUtility;
40
41 /**
42 * A PluginAction is a proxy for an action extension.
43 *
44 * At startup we read the registry and create a PluginAction for each action extension.
45 * This plugin action looks like the real action ( label, icon, etc ) and acts as
46 * a proxy for the action until invoked. At that point the proxy will instantiate
47 * the real action and delegate the run method to the real action.
48 * This makes it possible to load the action extension lazily.
49 *
50 * Occasionally the class will ask if it is OK to
51 * load the delegate (on selection changes). If the plugin containing
52 * the action extension has been loaded then the action extension itself
53 * will be instantiated.
54 */
55
56 public abstract class PluginAction extends Action
57 implements ISelectionListener, ISelectionChangedListener, INullSelectionListener, IPluginContribution
58 {
59 private IActionDelegate delegate;
60 private SelectionEnabler enabler;
61 private ISelection selection;
62 private IConfigurationElement configElement;
63 private String pluginId;
64 private String runAttribute = ActionDescriptor.ATT_CLASS;
65 private static int actionCount = 0;
66
67 //a boolean that returns whether or not this action
68 //is Adaptable - i.e. is defined on a resource type
69 boolean isAdaptableAction = false;
70 boolean adaptableNotChecked = true;
71
72 /**
73 * PluginAction constructor.
74 */
75 public PluginAction(IConfigurationElement actionElement, String id, int style) {
76 super(null, style);
77
78 this.configElement = actionElement;
79
80 if (id != null) {
81 setId(id);
82 }
83 else {
84 // Create unique action id.
85 setId("PluginAction." + Integer.toString(actionCount)); //$NON-NLS-1$
86 ++actionCount;
87 }
88
89 String defId = actionElement.getAttribute(ActionDescriptor.ATT_DEFINITION_ID);
90 setActionDefinitionId(defId);
91
92 pluginId = configElement.getDeclaringExtension().getNamespace();
93
94 // Read enablement declaration.
95 if (configElement.getAttribute(PluginActionBuilder.ATT_ENABLES_FOR) != null) {
96 enabler = new SelectionEnabler(configElement);
97 } else {
98 IConfigurationElement[] kids = configElement.getChildren(PluginActionBuilder.TAG_ENABLEMENT);
99 if (kids.length > 0)
100 enabler = new SelectionEnabler(configElement);
101 }
102
103 // Give enabler or delegate a chance to adjust enable state
104 selectionChanged(new StructuredSelection());
105 }
106
107 /**
108 * Creates the delegate and refreshes its enablement.
109 */
110 protected final void createDelegate() {
111 // The runAttribute is null if delegate creation failed previously...
112 if (delegate == null && runAttribute != null) {
113 try {
114 Object obj = WorkbenchPlugin.createExtension(configElement, runAttribute);
115 delegate = validateDelegate(obj);
116 initDelegate();
117 refreshEnablement();
118 } catch (Throwable e) {
119 runAttribute = null;
120 IStatus status = null;
121 if (e instanceof CoreException) {
122 status = ((CoreException)e).getStatus();
123 } else {
124 status = StatusUtil.newStatus(IStatus.ERROR, "Internal plug-in action delegate error on creation.", e); //$NON-NLS-1$
125 }
126 String id = configElement.getAttribute(ActionDescriptor.ATT_ID);
127 WorkbenchPlugin.log("Could not create action delegate for id: " + id, status); //$NON-NLS-1$
128 return;
129 }
130 }
131 }
132
133 /**
134 * Validates the object is a delegate of the expected type. Subclasses can
135 * override to check for specific delegate types.
136 * <p>
137 * <b>Note:</b> Calls to the object are not allowed during this method.
138 * </p>
139 *
140 * @param obj a possible action delegate implementation
141 * @return the <code>IActionDelegate</code> implementation for the object
142 * @throws a <code>WorkbenchException</code> if not expect delegate type
143 */
144 protected IActionDelegate validateDelegate(Object obj) throws WorkbenchException {
145 if (obj instanceof IActionDelegate)
146 return (IActionDelegate)obj;
147 else
148 throw new WorkbenchException("Action must implement IActionDelegate"); //$NON-NLS-1$
149 }
150
151 /**
152 * Initialize the action delegate by calling its lifecycle method.
153 * Subclasses may override but must call this implementation first.
154 */
155 protected void initDelegate() {
156 if (delegate instanceof IActionDelegate2)
157 ((IActionDelegate2)delegate).init(this);
158 }
159
160 /**
161 * Returns the action delegate if created. Can be <code>null</code>
162 * if the delegate is not created yet or if previous delegate
163 * creation failed.
164 */
165 protected IActionDelegate getDelegate() {
166 return delegate;
167 }
168
169 /**
170 * Returns true if the declaring plugin has been loaded
171 * and there is no need to delay creating the delegate
172 * any more.
173 */
174 protected boolean isOkToCreateDelegate() {
175 // test if the plugin has loaded
176 String bundleId = configElement.getDeclaringExtension().getNamespace();
177 return BundleUtility.isActive(bundleId);
178 }
179
180 /**
181 * Return whether or not this action could have been registered
182 * due to an adaptable - i.e. it is a resource type.
183 */
184 private boolean hasAdaptableType() {
185 if (adaptableNotChecked) {
186 Object parentConfig = configElement.getParent();
187 String typeName = null;
188 if(parentConfig != null && parentConfig instanceof IConfigurationElement)
189 typeName = ((IConfigurationElement) parentConfig).getAttribute("objectClass"); //$NON-NLS-1$
190
191 //See if this is typed at all first
192 if(typeName == null){
193 adaptableNotChecked = false;
194 return false;
195 }
196 Class resourceClass = LegacyResourceSupport.getResourceClass();
197 if (resourceClass == null) {
198 // resources plug-in not even present
199 isAdaptableAction = false;
200 adaptableNotChecked = false;
201 return false;
202 }
203
204 if (typeName.equals(resourceClass.getName())) {
205 isAdaptableAction = true;
206 adaptableNotChecked = false;
207 return isAdaptableAction;
208 }
209 Class[] children = resourceClass.getDeclaredClasses();
210 for (int i = 0; i < children.length; i++) {
211 if (children[i].getName().equals(typeName)) {
212 isAdaptableAction = true;
213 adaptableNotChecked = false;
214 return isAdaptableAction;
215 }
216 }
217 adaptableNotChecked = false;
218 }
219 return isAdaptableAction;
220 }
221
222 /**
223 * Refresh the action enablement.
224 */
225 protected void refreshEnablement() {
226 if (enabler != null) {
227 setEnabled(enabler.isEnabledForSelection(selection));
228 }
229 if (delegate != null) {
230 delegate.selectionChanged(this, selection);
231 }
232 }
233
234 /* (non-Javadoc)
235 * Method declared on IAction.
236 */
237 public void run() {
238 runWithEvent(null);
239 }
240
241 /* (non-Javadoc)
242 * Method declared on IAction.
243 */
244 public void runWithEvent(Event event) {
245 // this message dialog is problematic.
246 if (delegate == null) {
247 createDelegate();
248 if (delegate == null) {
249 MessageDialog.openInformation(
250 Display.getDefault().getActiveShell(),
251 WorkbenchMessages.getString("Information"), //$NON-NLS-1$
252 WorkbenchMessages.getString("PluginAction.operationNotAvailableMessage")); //$NON-NLS-1$
253 return;
254 }
255 if (!isEnabled()) {
256 MessageDialog.openInformation(
257 Display.getDefault().getActiveShell(),
258 WorkbenchMessages.getString("Information"), //$NON-NLS-1$
259 WorkbenchMessages.getString("PluginAction.disabledMessage")); //$NON-NLS-1$
260 return;
261 }
262 }
263
264 if (event != null) {
265 if (delegate instanceof IActionDelegate2) {
266 ((IActionDelegate2)delegate).runWithEvent(this, event);
267 return;
268 }
269 // Keep for backward compatibility with R2.0
270 if (delegate instanceof IActionDelegateWithEvent) {
271 ((IActionDelegateWithEvent) delegate).runWithEvent(this, event);
272 return;
273 }
274 }
275
276 delegate.run(this);
277 }
278
279 /**
280 * Handles selection change. If rule-based enabled is
281 * defined, it will be first to call it. If the delegate
282 * is loaded, it will also be given a chance.
283 */
284 public void selectionChanged(ISelection newSelection) {
285 // Update selection.
286 selection = newSelection;
287 if (selection == null)
288 selection = StructuredSelection.EMPTY;
289 if (hasAdaptableType())
290 selection = getResourceAdapters(selection);
291
292 // If the delegate can be loaded, do so.
293 // Otherwise, just update the enablement.
294 if (delegate == null && isOkToCreateDelegate())
295 createDelegate();
296 else
297 refreshEnablement();
298 }
299
300 /**
301 * The <code>SelectionChangedEventAction</code> implementation of this
302 * <code>ISelectionChangedListener</code> method calls
303 * <code>selectionChanged(IStructuredSelection)</code> when the selection is
304 * a structured one.
305 */
306 public void selectionChanged(SelectionChangedEvent event) {
307 ISelection sel = event.getSelection();
308 selectionChanged(sel);
309 }
310
311 /**
312 * The <code>SelectionChangedEventAction</code> implementation of this
313 * <code>ISelectionListener</code> method calls
314 * <code>selectionChanged(IStructuredSelection)</code> when the selection is
315 * a structured one. Subclasses may extend this method to react to the change.
316 */
317 public void selectionChanged(IWorkbenchPart part, ISelection sel) {
318 selectionChanged(sel);
319 }
320
321 /**
322 * Get a new selection with the resource adaptable version
323 * of this selection
324 */
325 private ISelection getResourceAdapters(ISelection sel) {
326 if (sel instanceof IStructuredSelection) {
327 List adaptables = new ArrayList();
328 Object[] elements = ((IStructuredSelection)sel).toArray();
329 for (int i = 0; i < elements.length; i++) {
330 Object originalValue = elements[i];
331 if (originalValue instanceof IAdaptable) {
332 Class resourceClass = LegacyResourceSupport.getResourceClass();
333 if (resourceClass != null) {
334 Object adaptedValue = ((IAdaptable)originalValue).getAdapter(resourceClass);
335 if (adaptedValue != null) {
336 adaptables.add(adaptedValue);
337 }
338 }
339 }
340 }
341 return new StructuredSelection(adaptables);
342 } else {
343 return sel;
344 }
345 }
346
347 /**
348 * Returns the action identifier this action overrides.
349 * Default implementation returns <code>null</code>.
350 *
351 * @return the action identifier to override or <code>null</code>
352 */
353 public String getOverrideActionId() {
354 return null;
355 }
356
357 /**
358 * @return the IConfigurationElement used to create this PluginAction.
359 *
360 * @since 3.0
361 */
362 protected IConfigurationElement getConfigElement() {
363 return configElement;
364 }
365
366 /* (non-Javadoc)
367 * @see org.eclipse.ui.IPluginContribution#getLocalId()
368 */
369 public String getLocalId() {
370 return getId();
371 }
372
373 /* (non-Javadoc)
374 * @see org.eclipse.ui.IPluginContribution#getPluginId()
375 */
376 public String getPluginId() {
377 return pluginId;
378 }
379 }