| /******************************************************************************* |
| * Copyright (c) 2000, 2007 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.internal; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.jface.action.Action; |
| import org.eclipse.jface.action.IMenuCreator; |
| import org.eclipse.jface.dialogs.MessageDialog; |
| import org.eclipse.jface.viewers.ISelection; |
| import org.eclipse.jface.viewers.ISelectionChangedListener; |
| import org.eclipse.jface.viewers.SelectionChangedEvent; |
| import org.eclipse.jface.viewers.StructuredSelection; |
| import org.eclipse.swt.widgets.Event; |
| import org.eclipse.ui.IActionDelegate; |
| import org.eclipse.ui.IActionDelegate2; |
| import org.eclipse.ui.IActionDelegateWithEvent; |
| import org.eclipse.ui.INullSelectionListener; |
| import org.eclipse.ui.IPluginContribution; |
| import org.eclipse.ui.ISelectionListener; |
| import org.eclipse.ui.IWorkbenchPart; |
| import org.eclipse.ui.IWorkbenchWindowActionDelegate; |
| import org.eclipse.ui.SelectionEnabler; |
| import org.eclipse.ui.WorkbenchException; |
| import org.eclipse.ui.internal.misc.StatusUtil; |
| import org.eclipse.ui.internal.registry.IWorkbenchRegistryConstants; |
| import org.eclipse.ui.internal.util.BundleUtility; |
| import org.eclipse.ui.internal.util.Util; |
| |
| /** |
| * A PluginAction is a proxy for an action extension. |
| * |
| * At startup we read the registry and create a PluginAction for each action extension. |
| * This plugin action looks like the real action ( label, icon, etc ) and acts as |
| * a proxy for the action until invoked. At that point the proxy will instantiate |
| * the real action and delegate the run method to the real action. |
| * This makes it possible to load the action extension lazily. |
| * |
| * Occasionally the class will ask if it is OK to |
| * load the delegate (on selection changes). If the plugin containing |
| * the action extension has been loaded then the action extension itself |
| * will be instantiated. |
| */ |
| |
| public abstract class PluginAction extends Action implements |
| ISelectionListener, ISelectionChangedListener, INullSelectionListener, |
| IPluginContribution { |
| private IActionDelegate delegate; |
| |
| private SelectionEnabler enabler; |
| |
| private ISelection selection; |
| |
| private IConfigurationElement configElement; |
| |
| private String pluginId; |
| |
| private String runAttribute = IWorkbenchRegistryConstants.ATT_CLASS; |
| |
| private static int actionCount = 0; |
| |
| /** |
| * PluginAction constructor. |
| * |
| * @param actionElement the element |
| * @param id the identifier |
| * @param style the style bits |
| */ |
| public PluginAction(IConfigurationElement actionElement, String id, |
| int style) { |
| super(null, style); |
| |
| this.configElement = actionElement; |
| |
| if (id != null) { |
| setId(id); |
| } else { |
| // Create unique action id. |
| setId("PluginAction." + Integer.toString(actionCount)); //$NON-NLS-1$ |
| ++actionCount; |
| } |
| |
| String defId = actionElement |
| .getAttribute(IWorkbenchRegistryConstants.ATT_DEFINITION_ID); |
| setActionDefinitionId(defId); |
| |
| pluginId = configElement.getNamespace(); |
| |
| // Read enablement declaration. |
| if (configElement.getAttribute(IWorkbenchRegistryConstants.ATT_ENABLES_FOR) != null) { |
| enabler = new SelectionEnabler(configElement); |
| } else { |
| IConfigurationElement[] kids = configElement |
| .getChildren(IWorkbenchRegistryConstants.TAG_ENABLEMENT); |
| IConfigurationElement[] kids2 = configElement |
| .getChildren(IWorkbenchRegistryConstants.TAG_SELECTION); |
| if (kids.length > 0 || kids2.length>0) { |
| enabler = new SelectionEnabler(configElement); |
| } |
| } |
| |
| // Give enabler or delegate a chance to adjust enable state |
| selectionChanged(StructuredSelection.EMPTY); |
| } |
| |
| /** |
| * Creates the delegate and refreshes its enablement. |
| */ |
| protected final void createDelegate() { |
| // The runAttribute is null if delegate creation failed previously... |
| if (delegate == null && runAttribute != null) { |
| try { |
| Object obj = WorkbenchPlugin.createExtension(configElement, |
| runAttribute); |
| delegate = validateDelegate(obj); |
| initDelegate(); |
| refreshEnablement(); |
| } catch (Throwable e) { |
| runAttribute = null; |
| IStatus status = null; |
| if (e instanceof CoreException) { |
| status = ((CoreException) e).getStatus(); |
| } else { |
| status = StatusUtil |
| .newStatus( |
| IStatus.ERROR, |
| "Internal plug-in action delegate error on creation.", e); //$NON-NLS-1$ |
| } |
| String id = configElement.getAttribute(IWorkbenchRegistryConstants.ATT_ID); |
| WorkbenchPlugin |
| .log( |
| "Could not create action delegate for id: " + id, status); //$NON-NLS-1$ |
| return; |
| } |
| } |
| } |
| |
| /** |
| * Validates the object is a delegate of the expected type. Subclasses can |
| * override to check for specific delegate types. |
| * <p> |
| * <b>Note:</b> Calls to the object are not allowed during this method. |
| * </p> |
| * |
| * @param obj a possible action delegate implementation |
| * @return the <code>IActionDelegate</code> implementation for the object |
| * @throws WorkbenchException if not of the expected delegate type |
| */ |
| protected IActionDelegate validateDelegate(Object obj) |
| throws WorkbenchException { |
| if (obj instanceof IActionDelegate) { |
| return (IActionDelegate) obj; |
| } |
| |
| throw new WorkbenchException( |
| "Action must implement IActionDelegate"); //$NON-NLS-1$ |
| } |
| |
| /** |
| * Initialize the action delegate by calling its lifecycle method. |
| * Subclasses may override but must call this implementation first. |
| */ |
| protected void initDelegate() { |
| if (delegate instanceof IActionDelegate2) { |
| ((IActionDelegate2) delegate).init(this); |
| } |
| } |
| |
| /** |
| * Returns the action delegate if created. Can be <code>null</code> |
| * if the delegate is not created yet or if previous delegate |
| * creation failed. |
| */ |
| protected IActionDelegate getDelegate() { |
| return delegate; |
| } |
| |
| /** |
| * Returns true if the declaring plugin has been loaded |
| * and there is no need to delay creating the delegate |
| * any more. |
| */ |
| protected boolean isOkToCreateDelegate() { |
| // test if the plugin has loaded |
| String bundleId = configElement.getContributor().getName(); |
| return BundleUtility.isActive(bundleId); |
| } |
| |
| /** |
| * Refresh the action enablement. |
| */ |
| protected void refreshEnablement() { |
| if (enabler != null) { |
| setEnabled(enabler.isEnabledForSelection(selection)); |
| } |
| if (delegate != null) { |
| delegate.selectionChanged(this, selection); |
| } |
| } |
| |
| /* (non-Javadoc) |
| * Method declared on IAction. |
| */ |
| public void run() { |
| runWithEvent(null); |
| } |
| |
| /* (non-Javadoc) |
| * Method declared on IAction. |
| */ |
| public void runWithEvent(Event event) { |
| // this message dialog is problematic. |
| if (delegate == null) { |
| createDelegate(); |
| if (delegate == null) { |
| MessageDialog |
| .openInformation( |
| Util.getShellToParentOn(), |
| WorkbenchMessages.Information, |
| WorkbenchMessages.PluginAction_operationNotAvailableMessage); |
| return; |
| } |
| if (!isEnabled()) { |
| MessageDialog.openInformation(Util.getShellToParentOn(), WorkbenchMessages.Information, |
| WorkbenchMessages.PluginAction_disabledMessage); |
| return; |
| } |
| } |
| |
| if (event != null) { |
| if (delegate instanceof IActionDelegate2) { |
| ((IActionDelegate2) delegate).runWithEvent(this, event); |
| return; |
| } |
| // Keep for backward compatibility with R2.0 |
| if (delegate instanceof IActionDelegateWithEvent) { |
| ((IActionDelegateWithEvent) delegate).runWithEvent(this, event); |
| return; |
| } |
| } |
| |
| delegate.run(this); |
| } |
| |
| /** |
| * Handles selection change. If rule-based enabled is |
| * defined, it will be first to call it. If the delegate |
| * is loaded, it will also be given a chance. |
| * |
| * @param newSelection the new selection |
| */ |
| public void selectionChanged(ISelection newSelection) { |
| // Update selection. |
| selection = newSelection; |
| if (selection == null) { |
| selection = StructuredSelection.EMPTY; |
| } |
| |
| // The selection is passed to the delegate as-is without |
| // modification. If the selection needs to be modified |
| // the action contributors should do so. |
| |
| // If the delegate can be loaded, do so. |
| // Otherwise, just update the enablement. |
| if (delegate == null && isOkToCreateDelegate()) { |
| createDelegate(); |
| } else { |
| refreshEnablement(); |
| } |
| } |
| |
| /** |
| * The <code>SelectionChangedEventAction</code> implementation of this |
| * <code>ISelectionChangedListener</code> method calls |
| * <code>selectionChanged(IStructuredSelection)</code> when the selection is |
| * a structured one. |
| */ |
| public void selectionChanged(SelectionChangedEvent event) { |
| ISelection sel = event.getSelection(); |
| selectionChanged(sel); |
| } |
| |
| /** |
| * The <code>SelectionChangedEventAction</code> implementation of this |
| * <code>ISelectionListener</code> method calls |
| * <code>selectionChanged(IStructuredSelection)</code> when the selection is |
| * a structured one. Subclasses may extend this method to react to the change. |
| */ |
| public void selectionChanged(IWorkbenchPart part, ISelection sel) { |
| selectionChanged(sel); |
| } |
| |
| /** |
| * For testing purposes only. |
| * |
| * @return the selection |
| * @since 3.1 |
| */ |
| public ISelection getSelection() { |
| return selection; |
| } |
| |
| /** |
| * Returns the action identifier this action overrides. |
| * Default implementation returns <code>null</code>. |
| * |
| * @return the action identifier to override or <code>null</code> |
| */ |
| public String getOverrideActionId() { |
| return null; |
| } |
| |
| /** |
| * @return the IConfigurationElement used to create this PluginAction. |
| * |
| * @since 3.0 |
| */ |
| protected IConfigurationElement getConfigElement() { |
| return configElement; |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.ui.IPluginContribution#getLocalId() |
| */ |
| public String getLocalId() { |
| return getId(); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.ui.IPluginContribution#getPluginId() |
| */ |
| public String getPluginId() { |
| return pluginId; |
| } |
| |
| /** |
| * Disposes the delegate, if created. |
| * |
| * @since 3.1 |
| */ |
| public void disposeDelegate() { |
| // avoid calling dispose() twice if the delegate implements |
| // both IActionDelegate2 and IWorkbenchWindowActionDelegate |
| if (getDelegate() instanceof IActionDelegate2) { |
| ((IActionDelegate2) getDelegate()).dispose(); |
| } |
| else if (getDelegate() instanceof IWorkbenchWindowActionDelegate) { |
| ((IWorkbenchWindowActionDelegate) getDelegate()).dispose(); |
| } |
| delegate = null; |
| } |
| |
| /** |
| * Disposes this plugin action. |
| * |
| * @since 3.1 |
| */ |
| public void dispose() { |
| disposeDelegate(); |
| selection = null; |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jface.action.Action#getMenuCreator() |
| */ |
| public IMenuCreator getMenuCreator() { |
| // now that action contribution item defers asking for the menu |
| // creator until its ready o show the menu, asking for the menu |
| // creator is time to instantiate the delegate |
| if (getDelegate()==null) { |
| createDelegate(); |
| } |
| return super.getMenuCreator(); |
| } |
| } |
