bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/PluginAction.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2003 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.ui.internal;


 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.core.internal.plugins.ConfigurationElement;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IPluginDescriptor;
 import org.eclipse.jface.action.Action;
 import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.viewers.ISelection;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.viewers.SelectionChangedEvent;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.swt.widgets.Display;
 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.ISelectionListener;
 import org.eclipse.ui.IWorkbenchPart;
 import org.eclipse.ui.WorkbenchException;

 /**
  * 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
 {
 	private IActionDelegate delegate;
 	private SelectionEnabler enabler;
 	private ISelection selection;
 	private IConfigurationElement configElement;
 	private String runAttribute;
 	private static int actionCount = 0;

 	//a boolean that returns whether or not this action
 	//is Adaptable - i.e. is defined on a resource type
 	boolean isAdaptableAction = false;
 	boolean adaptableNotChecked = true;

 	/**
 	 * PluginAction constructor.
 	 */
 	public PluginAction(IConfigurationElement actionElement, String runAttribute, String definitionId, int style) {
 		super(null, style);

 		// Create unique action id.
 		setId("PluginAction." + Integer.toString(actionCount)); //$NON-NLS-1$
 		++actionCount;
 		setActionDefinitionId(definitionId);

 		this.configElement = actionElement;
 		this.runAttribute = runAttribute;

 		// Read enablement declaration.
 		if (configElement.getAttribute(PluginActionBuilder.ATT_ENABLES_FOR) != null) {
 			enabler = new SelectionEnabler(configElement);
 		} else {
 			IConfigurationElement[] kids = configElement.getChildren(PluginActionBuilder.TAG_ENABLEMENT);
 			if (kids.length > 0)
 				enabler = new SelectionEnabler(configElement);
 		}

 		// Give enabler or delegate a chance to adjust enable state
 		selectionChanged(new StructuredSelection());
 	}

 	/**
 	 * Creates the delegate and refreshes its enablement.
 	 */
 	protected final void createDelegate() {
 		if (delegate == null) {
 			try {
 				Object obj = WorkbenchPlugin.createExtension(configElement, runAttribute);
 				delegate = validateDelegate(obj);
 				initDelegate();
 				refreshEnablement();
 			} catch (CoreException e) {
 				String id = configElement.getAttribute(ActionDescriptor.ATT_ID);
 				WorkbenchPlugin.log("Could not create action delegate for id: " + id, e.getStatus()); //$NON-NLS-1$
 				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 a <code>WorkbenchException</code> if not expect delegate type
 	 */
 	protected IActionDelegate validateDelegate(Object obj) throws WorkbenchException {
 		if (obj instanceof IActionDelegate)
 			return (IActionDelegate)obj;
 		else
 			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);
 	}

 	/**
 	 * Return the delegate action or null if not created yet
 	 */
 	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
 		IPluginDescriptor plugin =
 			configElement.getDeclaringExtension().getDeclaringPluginDescriptor();
 		return plugin.isPluginActivated();
 	}

 	/**
 	 * Return whether or not this action could have been registered
 	 * due to an adaptable - i.e. it is a resource type.
 	 */
 	private boolean hasAdaptableType() {
 		if (adaptableNotChecked) {
 			Object parentConfig = ((ConfigurationElement) configElement).getParent();
 			String typeName = null;
 			if(parentConfig != null && parentConfig instanceof IConfigurationElement)
 				typeName = ((IConfigurationElement) parentConfig).getAttribute("objectClass"); //$NON-NLS-1$

 			//See if this is typed at all first
 			if(typeName == null){
 				adaptableNotChecked = false;
 				return false;
 			}
 			Class resourceClass = IResource.class;

 			if (typeName.equals(resourceClass.getName())) {
 				isAdaptableAction = true;
 				adaptableNotChecked = false;
 				return isAdaptableAction;
 			}
 			Class[] children = resourceClass.getDeclaredClasses();
 			for (int i = 0; i < children.length; i++) {
 				if (children[i].getName().equals(typeName)) {
 					isAdaptableAction = true;
 					adaptableNotChecked = false;
 					return isAdaptableAction;
 				}
 			}
 			adaptableNotChecked = false;
 		}
 		return isAdaptableAction;
 	}

 	/**
 	 * 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(
 					Display.getDefault().getActiveShell(),
 					WorkbenchMessages.getString("Information"), //$NON-NLS-1$
 					WorkbenchMessages.getString("PluginAction.operationNotAvailableMessage")); //$NON-NLS-1$
 				return;
 			}
 			if (!isEnabled()) {
 				MessageDialog.openInformation(
 					Display.getDefault().getActiveShell(),
 					WorkbenchMessages.getString("Information"), //$NON-NLS-1$
 					WorkbenchMessages.getString("PluginAction.disabledMessage")); //$NON-NLS-1$
 				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.
 	 */
 	public void selectionChanged(ISelection newSelection) {
 		// Update selection.
 		selection = newSelection;
 		if (selection == null)
 			selection = StructuredSelection.EMPTY;
 		if (hasAdaptableType())
 			selection = getResourceAdapters(selection);

 		// 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);
 	}

 	/**
 	 * Get a new selection with the resource adaptable version
 	 * of this selection
 	 */
 	private ISelection getResourceAdapters(ISelection sel) {
 		if (sel instanceof IStructuredSelection) {
 			List adaptables = new ArrayList();
 			Object[] elements = ((IStructuredSelection)sel).toArray();
 			for (int i = 0; i < elements.length; i++) {
 				Object originalValue = elements[i];
 				if (originalValue instanceof IAdaptable) {
 					Object adaptedValue = ((IAdaptable)originalValue).getAdapter(IResource.class);
 					if (adaptedValue != null)
 						adaptables.add(adaptedValue);
 				}
 			}
 			return new StructuredSelection(adaptables);
 		} else {
 			return sel;
 		}
 	}

 	/**
 	 * 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;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2003 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.ui.internal;


	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.core.internal.plugins.ConfigurationElement;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IAdaptable;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IPluginDescriptor;
	import org.eclipse.jface.action.Action;
	import org.eclipse.jface.dialogs.MessageDialog;
	import org.eclipse.jface.viewers.ISelection;
	import org.eclipse.jface.viewers.ISelectionChangedListener;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.jface.viewers.SelectionChangedEvent;
	import org.eclipse.jface.viewers.StructuredSelection;
	import org.eclipse.swt.widgets.Display;
	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.ISelectionListener;
	import org.eclipse.ui.IWorkbenchPart;
	import org.eclipse.ui.WorkbenchException;

	/**
	* 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
	{
	private IActionDelegate delegate;
	private SelectionEnabler enabler;
	private ISelection selection;
	private IConfigurationElement configElement;
	private String runAttribute;
	private static int actionCount = 0;

	//a boolean that returns whether or not this action
	//is Adaptable - i.e. is defined on a resource type
	boolean isAdaptableAction = false;
	boolean adaptableNotChecked = true;

	/**
	* PluginAction constructor.
	*/
	public PluginAction(IConfigurationElement actionElement, String runAttribute, String definitionId, int style) {
	super(null, style);

	// Create unique action id.
	setId("PluginAction." + Integer.toString(actionCount)); //$NON-NLS-1$
	++actionCount;
	setActionDefinitionId(definitionId);

	this.configElement = actionElement;
	this.runAttribute = runAttribute;

	// Read enablement declaration.
	if (configElement.getAttribute(PluginActionBuilder.ATT_ENABLES_FOR) != null) {
	enabler = new SelectionEnabler(configElement);
	} else {
	IConfigurationElement[] kids = configElement.getChildren(PluginActionBuilder.TAG_ENABLEMENT);
	if (kids.length > 0)
	enabler = new SelectionEnabler(configElement);
	}

	// Give enabler or delegate a chance to adjust enable state
	selectionChanged(new StructuredSelection());
	}

	/**
	* Creates the delegate and refreshes its enablement.
	*/
	protected final void createDelegate() {
	if (delegate == null) {
	try {
	Object obj = WorkbenchPlugin.createExtension(configElement, runAttribute);
	delegate = validateDelegate(obj);
	initDelegate();
	refreshEnablement();
	} catch (CoreException e) {
	String id = configElement.getAttribute(ActionDescriptor.ATT_ID);
	WorkbenchPlugin.log("Could not create action delegate for id: " + id, e.getStatus()); //$NON-NLS-1$
	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 a <code>WorkbenchException</code> if not expect delegate type
	*/
	protected IActionDelegate validateDelegate(Object obj) throws WorkbenchException {
	if (obj instanceof IActionDelegate)
	return (IActionDelegate)obj;
	else
	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);
	}

	/**
	* Return the delegate action or null if not created yet
	*/
	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
	IPluginDescriptor plugin =
	configElement.getDeclaringExtension().getDeclaringPluginDescriptor();
	return plugin.isPluginActivated();
	}

	/**
	* Return whether or not this action could have been registered
	* due to an adaptable - i.e. it is a resource type.
	*/
	private boolean hasAdaptableType() {
	if (adaptableNotChecked) {
	Object parentConfig = ((ConfigurationElement) configElement).getParent();
	String typeName = null;
	if(parentConfig != null && parentConfig instanceof IConfigurationElement)
	typeName = ((IConfigurationElement) parentConfig).getAttribute("objectClass"); //$NON-NLS-1$

	//See if this is typed at all first
	if(typeName == null){
	adaptableNotChecked = false;
	return false;
	}
	Class resourceClass = IResource.class;

	if (typeName.equals(resourceClass.getName())) {
	isAdaptableAction = true;
	adaptableNotChecked = false;
	return isAdaptableAction;
	}
	Class[] children = resourceClass.getDeclaredClasses();
	for (int i = 0; i < children.length; i++) {
	if (children[i].getName().equals(typeName)) {
	isAdaptableAction = true;
	adaptableNotChecked = false;
	return isAdaptableAction;
	}
	}
	adaptableNotChecked = false;
	}
	return isAdaptableAction;
	}

	/**
	* 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(
	Display.getDefault().getActiveShell(),
	WorkbenchMessages.getString("Information"), //$NON-NLS-1$
	WorkbenchMessages.getString("PluginAction.operationNotAvailableMessage")); //$NON-NLS-1$
	return;
	}
	if (!isEnabled()) {
	MessageDialog.openInformation(
	Display.getDefault().getActiveShell(),
	WorkbenchMessages.getString("Information"), //$NON-NLS-1$
	WorkbenchMessages.getString("PluginAction.disabledMessage")); //$NON-NLS-1$
	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.
	*/
	public void selectionChanged(ISelection newSelection) {
	// Update selection.
	selection = newSelection;
	if (selection == null)
	selection = StructuredSelection.EMPTY;
	if (hasAdaptableType())
	selection = getResourceAdapters(selection);

	// 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);
	}

	/**
	* Get a new selection with the resource adaptable version
	* of this selection
	*/
	private ISelection getResourceAdapters(ISelection sel) {
	if (sel instanceof IStructuredSelection) {
	List adaptables = new ArrayList();
	Object[] elements = ((IStructuredSelection)sel).toArray();
	for (int i = 0; i < elements.length; i++) {
	Object originalValue = elements[i];
	if (originalValue instanceof IAdaptable) {
	Object adaptedValue = ((IAdaptable)originalValue).getAdapter(IResource.class);
	if (adaptedValue != null)
	adaptables.add(adaptedValue);
	}
	}
	return new StructuredSelection(adaptables);
	} else {
	return sel;
	}
	}

	/**
	* 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;
	}
	}