bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/internal/actions/CommonActionProviderDescriptor.java - platform/eclipse.platform.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2003, 2005 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.navigator.internal.actions;

 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.Set;

 import org.eclipse.core.expressions.ElementHandler;
 import org.eclipse.core.expressions.EvaluationContext;
 import org.eclipse.core.expressions.EvaluationResult;
 import org.eclipse.core.expressions.Expression;
 import org.eclipse.core.expressions.ExpressionConverter;
 import org.eclipse.core.expressions.IEvaluationContext;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.ui.navigator.CommonActionProvider;
 import org.eclipse.ui.navigator.internal.NavigatorPlugin;
 import org.eclipse.ui.navigator.internal.extensions.INavigatorContentExtPtConstants;
 import org.eclipse.ui.navigator.internal.extensions.SkeletonActionProvider;

 /**
  *
  * <p>
  * <strong>EXPERIMENTAL</strong>. This class or interface has been added as
  * part of a work in progress. There is a guarantee neither that this API will
  * work nor that it will remain the same. Please do not use this API without
  * consulting with the Platform/UI team.
  * </p>
  *
  * @since 3.2
  */
 public class CommonActionProviderDescriptor implements INavigatorContentExtPtConstants {

 	private static final String DEFAULT_ID = "org.eclipse.ui.navigator.actionProvider"; //$NON-NLS-1$

 	private final IConfigurationElement configurationElement;

 	private final boolean isNested;

 	private Set dependentDescriptors;

 	private IConfigurationElement enablementElement;

 	private Expression enablement;

 	private boolean hasLoadingFailed;

 	private String id;


 	private String dependsOnId;

 	private String toString;

 	/**
 	 * @param aConfigElement
 	 *            A configuration element with the name 'actionProvider' and a
 	 *            'class' attribute conforming to the
 	 *            {@link ICommonActionProvider} interface.
 	 */
 	public CommonActionProviderDescriptor(IConfigurationElement aConfigElement) {
 		super();
 		Assert.isTrue(TAG_ACTION_PROVIDER.equals(aConfigElement.getName()));
 		configurationElement = aConfigElement;
 		isNested = false;
 		init();
 	}

 	/**
 	 * @param aConfigElement
 	 *            A configuration element with the name 'actionProvider' and a
 	 *            'class' attribute conforming to the
 	 *            {@link ICommonActionProvider} interface.
 	 * @param anEnablementExpression
 	 *            A configuration element with the name 'enablement' or
 	 *            'triggerPoints' and containing an Eclipse Core Expression
 	 * @param anOverrideId
 	 *            A unique identifier for this descriptor. Ids can be used as a
 	 *            filtering device for activities or viewer***Bindings.
 	 * @param nestedUnderNavigatorContent
 	 *            A value of <b>true</b> indicates that this CommonActionProvider
 	 *            was declared as a nested &lt;actionProvider /&gt; element under
 	 *            a &lt;navigatorContent /&gt; element.
 	 */
 	public CommonActionProviderDescriptor(IConfigurationElement aConfigElement,
 			IConfigurationElement anEnablementExpression, String anOverrideId,
 			boolean nestedUnderNavigatorContent) {
 		super();
 		Assert.isTrue(TAG_ACTION_PROVIDER.equals(aConfigElement.getName()));
 		Assert.isTrue(TAG_TRIGGER_POINTS.equals(anEnablementExpression
 				.getName())
 				|| TAG_ENABLEMENT.equals(anEnablementExpression.getName()));
 		configurationElement = aConfigElement;
 		enablementElement = anEnablementExpression;
 		id = anOverrideId;
 		isNested = nestedUnderNavigatorContent;
 		init();
 	}

 	private void init() {

 		try {

 			// we try the id attribute if no override id was supplied.
 			if (id == null)
 				id = configurationElement.getAttribute(ATT_ID);
 			// if there was no id attribute, use the default id.
 			if (id == null)
 				id = DEFAULT_ID;

 			dependsOnId = configurationElement.getAttribute(ATT_DEPENDS_ON);

 			IConfigurationElement[] children = configurationElement
 					.getChildren(TAG_ENABLEMENT);
 			// if no child enablement is specified, and we have an override, use
 			// it
 			if (children.length == 0 && enablementElement != null) {
 				enablement = ElementHandler.getDefault().create(
 						ExpressionConverter.getDefault(), enablementElement);
 				// otherwise the child enablement takes priority
 			} else if (children.length == 1) {
 				enablement = ElementHandler.getDefault().create(
 						ExpressionConverter.getDefault(), children[0]);

 			} else {
 				System.err.println("Incorrect number of expressions: " + //$NON-NLS-1$
 						TAG_ENABLEMENT
 						+ " in navigator extension: " + //$NON-NLS-1$
 						configurationElement.getDeclaringExtension()
 								.getUniqueIdentifier());
 			}
 		} catch (CoreException e) {
 			NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
 		}
 	}

 	/**
 	 *
 	 * @return The instantiated CommonActionProvider for this descriptor as
 	 *         declared in the ATT_CLASS attribute or
 	 *         {@link SkeletonActionProvider} if a problem occurs while loading
 	 *         the instance.
 	 */
 	public CommonActionProvider createActionProvider() {
 		if (hasLoadingFailed)
 			return SkeletonActionProvider.INSTANCE;
 		CommonActionProvider provider = null;
 		try {
 			provider = (CommonActionProvider) configurationElement
 					.createExecutableExtension(ATT_CLASS);
 		} catch (CoreException exception) {
 			NavigatorPlugin.log("Unable to create navigator extension: " + //$NON-NLS-1$
 					getClassName(), exception.getStatus());
 			hasLoadingFailed = true;
 			provider = SkeletonActionProvider.INSTANCE;
 		} catch (Exception e) {
 			NavigatorPlugin.log("Unable to create navigator extension: " + //$NON-NLS-1$
 					getClassName(), new Status(IStatus.ERROR,
 					NavigatorPlugin.PLUGIN_ID, 0, e.getMessage(), e));
 			hasLoadingFailed = true;
 			provider = SkeletonActionProvider.INSTANCE;
 		}

 		return provider;
 	}

 	private String getClassName() {
 		return configurationElement.getAttribute(ATT_CLASS);
 	}

 	/**
 	 * Determine if this content extension is enabled for the given selection.
 	 * The content extension is enabled for the selection if and only if it is
 	 * enabled for each element in the selection.
 	 *
 	 * @param aStructuredSelection
 	 *            The selection from the viewer
 	 * @return True if and only if the extension is enabled for each element in
 	 *         the selection.
 	 */
 	public boolean isEnabledFor(IStructuredSelection aStructuredSelection) {
 		if (enablement == null)
 			return false;

 		IEvaluationContext context = null;

 		Iterator elements = aStructuredSelection.iterator();
 		while (elements.hasNext()) {
 			context = new EvaluationContext(null, elements.next());
 			try {
 				if (enablement.evaluate(context) == EvaluationResult.FALSE
 						|| enablement.evaluate(context) == EvaluationResult.NOT_LOADED)
 					return false;
 			} catch (CoreException e) {
 				NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
 				return false;
 			}
 		}
 		return true;
 	}

 	/**
 	 * Determine if this content extension is enabled for the given element.
 	 *
 	 * @param anElement
 	 *            The element that should be used for the evaluation.
 	 * @return True if and only if the extension is enabled for the element.
 	 */
 	public boolean isEnabledFor(Object anElement) {
 		if (enablement == null || anElement == null)
 			return false;

 		try {
 			return (enablement.evaluate(new EvaluationContext(null, anElement)) == EvaluationResult.TRUE);
 		} catch (CoreException e) {
 			NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
 		}
 		return false;
 	}

 	/**
 	 *
 	 * @return An identifier for this ICommonActionProvider. Defaults to
 	 *         'org.eclipse.ui.navigator.actionProvider'. May not be unique.
 	 */
 	public String getId() {
 		return id;
 	}

 	/**
 	 *
 	 * @return True if this is a nested &lt;actionProvider /&gt; element.
 	 */
 	public boolean isNested() {
 		return isNested;
 	}

 	/**
 	 *
 	 * @return The value specified by the 'dependsOn' attribute of the &lt;actionProvider /&gt; element.
 	 */
 	public String getDependsOnId() {
 		return dependsOnId;
 	}

 	public boolean equals(Object obj) {

 		if(obj != null && obj instanceof CommonActionProviderDescriptor) {
 			CommonActionProviderDescriptor other = (CommonActionProviderDescriptor) obj;
 			return getId().equals(other.getId());
 		}
 		return false;
 	}

 	public int hashCode() {
 		return getId().hashCode();
 	}

 	protected void addDependentDescriptor(CommonActionProviderDescriptor dependentDescriptor) {
 		Assert.isTrue(this != dependentDescriptor);
 		if(dependentDescriptors == null)
 			dependentDescriptors = new HashSet();
 		dependentDescriptors.add(dependentDescriptor);
 	}

 	protected boolean hasDependentDescriptors() {
 		return dependentDescriptors != null && !dependentDescriptors.isEmpty();
 	}

 	protected Iterator dependentDescriptors() {
 		return dependentDescriptors.iterator();
 	}

 	public String toString() {
 		if(toString == null)
 			toString = "CommonActionProviderDescriptor["+getId()+", dependsOn="+getDependsOnId()+"]";   //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
 		return toString;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2003, 2005 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.navigator.internal.actions;

	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.Set;

	import org.eclipse.core.expressions.ElementHandler;
	import org.eclipse.core.expressions.EvaluationContext;
	import org.eclipse.core.expressions.EvaluationResult;
	import org.eclipse.core.expressions.Expression;
	import org.eclipse.core.expressions.ExpressionConverter;
	import org.eclipse.core.expressions.IEvaluationContext;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.jface.viewers.IStructuredSelection;
	import org.eclipse.ui.navigator.CommonActionProvider;
	import org.eclipse.ui.navigator.internal.NavigatorPlugin;
	import org.eclipse.ui.navigator.internal.extensions.INavigatorContentExtPtConstants;
	import org.eclipse.ui.navigator.internal.extensions.SkeletonActionProvider;

	/**
	*
	* <p>
	* <strong>EXPERIMENTAL</strong>. This class or interface has been added as
	* part of a work in progress. There is a guarantee neither that this API will
	* work nor that it will remain the same. Please do not use this API without
	* consulting with the Platform/UI team.
	* </p>
	*
	* @since 3.2
	*/
	public class CommonActionProviderDescriptor implements INavigatorContentExtPtConstants {

	private static final String DEFAULT_ID = "org.eclipse.ui.navigator.actionProvider"; //$NON-NLS-1$

	private final IConfigurationElement configurationElement;

	private final boolean isNested;

	private Set dependentDescriptors;

	private IConfigurationElement enablementElement;

	private Expression enablement;

	private boolean hasLoadingFailed;

	private String id;


	private String dependsOnId;

	private String toString;

	/**
	* @param aConfigElement
	* A configuration element with the name 'actionProvider' and a
	* 'class' attribute conforming to the
	* {@link ICommonActionProvider} interface.
	*/
	public CommonActionProviderDescriptor(IConfigurationElement aConfigElement) {
	super();
	Assert.isTrue(TAG_ACTION_PROVIDER.equals(aConfigElement.getName()));
	configurationElement = aConfigElement;
	isNested = false;
	init();
	}

	/**
	* @param aConfigElement
	* A configuration element with the name 'actionProvider' and a
	* 'class' attribute conforming to the
	* {@link ICommonActionProvider} interface.
	* @param anEnablementExpression
	* A configuration element with the name 'enablement' or
	* 'triggerPoints' and containing an Eclipse Core Expression
	* @param anOverrideId
	* A unique identifier for this descriptor. Ids can be used as a
	* filtering device for activities or viewer***Bindings.
	* @param nestedUnderNavigatorContent
	* A value of <b>true</b> indicates that this CommonActionProvider
	* was declared as a nested <actionProvider /> element under
	* a <navigatorContent /> element.
	*/
	public CommonActionProviderDescriptor(IConfigurationElement aConfigElement,
	IConfigurationElement anEnablementExpression, String anOverrideId,
	boolean nestedUnderNavigatorContent) {
	super();
	Assert.isTrue(TAG_ACTION_PROVIDER.equals(aConfigElement.getName()));
	Assert.isTrue(TAG_TRIGGER_POINTS.equals(anEnablementExpression
	.getName())
	\|\| TAG_ENABLEMENT.equals(anEnablementExpression.getName()));
	configurationElement = aConfigElement;
	enablementElement = anEnablementExpression;
	id = anOverrideId;
	isNested = nestedUnderNavigatorContent;
	init();
	}

	private void init() {

	try {

	// we try the id attribute if no override id was supplied.
	if (id == null)
	id = configurationElement.getAttribute(ATT_ID);
	// if there was no id attribute, use the default id.
	if (id == null)
	id = DEFAULT_ID;

	dependsOnId = configurationElement.getAttribute(ATT_DEPENDS_ON);

	IConfigurationElement[] children = configurationElement
	.getChildren(TAG_ENABLEMENT);
	// if no child enablement is specified, and we have an override, use
	// it
	if (children.length == 0 && enablementElement != null) {
	enablement = ElementHandler.getDefault().create(
	ExpressionConverter.getDefault(), enablementElement);
	// otherwise the child enablement takes priority
	} else if (children.length == 1) {
	enablement = ElementHandler.getDefault().create(
	ExpressionConverter.getDefault(), children[0]);

	} else {
	System.err.println("Incorrect number of expressions: " + //$NON-NLS-1$
	TAG_ENABLEMENT
	+ " in navigator extension: " + //$NON-NLS-1$
	configurationElement.getDeclaringExtension()
	.getUniqueIdentifier());
	}
	} catch (CoreException e) {
	NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
	}
	}

	/**
	*
	* @return The instantiated CommonActionProvider for this descriptor as
	* declared in the ATT_CLASS attribute or
	* {@link SkeletonActionProvider} if a problem occurs while loading
	* the instance.
	*/
	public CommonActionProvider createActionProvider() {
	if (hasLoadingFailed)
	return SkeletonActionProvider.INSTANCE;
	CommonActionProvider provider = null;
	try {
	provider = (CommonActionProvider) configurationElement
	.createExecutableExtension(ATT_CLASS);
	} catch (CoreException exception) {
	NavigatorPlugin.log("Unable to create navigator extension: " + //$NON-NLS-1$
	getClassName(), exception.getStatus());
	hasLoadingFailed = true;
	provider = SkeletonActionProvider.INSTANCE;
	} catch (Exception e) {
	NavigatorPlugin.log("Unable to create navigator extension: " + //$NON-NLS-1$
	getClassName(), new Status(IStatus.ERROR,
	NavigatorPlugin.PLUGIN_ID, 0, e.getMessage(), e));
	hasLoadingFailed = true;
	provider = SkeletonActionProvider.INSTANCE;
	}

	return provider;
	}

	private String getClassName() {
	return configurationElement.getAttribute(ATT_CLASS);
	}

	/**
	* Determine if this content extension is enabled for the given selection.
	* The content extension is enabled for the selection if and only if it is
	* enabled for each element in the selection.
	*
	* @param aStructuredSelection
	* The selection from the viewer
	* @return True if and only if the extension is enabled for each element in
	* the selection.
	*/
	public boolean isEnabledFor(IStructuredSelection aStructuredSelection) {
	if (enablement == null)
	return false;

	IEvaluationContext context = null;

	Iterator elements = aStructuredSelection.iterator();
	while (elements.hasNext()) {
	context = new EvaluationContext(null, elements.next());
	try {
	if (enablement.evaluate(context) == EvaluationResult.FALSE
	\|\| enablement.evaluate(context) == EvaluationResult.NOT_LOADED)
	return false;
	} catch (CoreException e) {
	NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
	return false;
	}
	}
	return true;
	}

	/**
	* Determine if this content extension is enabled for the given element.
	*
	* @param anElement
	* The element that should be used for the evaluation.
	* @return True if and only if the extension is enabled for the element.
	*/
	public boolean isEnabledFor(Object anElement) {
	if (enablement == null \|\| anElement == null)
	return false;

	try {
	return (enablement.evaluate(new EvaluationContext(null, anElement)) == EvaluationResult.TRUE);
	} catch (CoreException e) {
	NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
	}
	return false;
	}

	/**
	*
	* @return An identifier for this ICommonActionProvider. Defaults to
	* 'org.eclipse.ui.navigator.actionProvider'. May not be unique.
	*/
	public String getId() {
	return id;
	}

	/**
	*
	* @return True if this is a nested <actionProvider /> element.
	*/
	public boolean isNested() {
	return isNested;
	}

	/**
	*
	* @return The value specified by the 'dependsOn' attribute of the <actionProvider /> element.
	*/
	public String getDependsOnId() {
	return dependsOnId;
	}

	public boolean equals(Object obj) {

	if(obj != null && obj instanceof CommonActionProviderDescriptor) {
	CommonActionProviderDescriptor other = (CommonActionProviderDescriptor) obj;
	return getId().equals(other.getId());
	}
	return false;
	}

	public int hashCode() {
	return getId().hashCode();
	}

	protected void addDependentDescriptor(CommonActionProviderDescriptor dependentDescriptor) {
	Assert.isTrue(this != dependentDescriptor);
	if(dependentDescriptors == null)
	dependentDescriptors = new HashSet();
	dependentDescriptors.add(dependentDescriptor);
	}

	protected boolean hasDependentDescriptors() {
	return dependentDescriptors != null && !dependentDescriptors.isEmpty();
	}

	protected Iterator dependentDescriptors() {
	return dependentDescriptors.iterator();
	}

	public String toString() {
	if(toString == null)
	toString = "CommonActionProviderDescriptor["+getId()+", dependsOn="+getDependsOnId()+"]"; //$NON-NLS-1$//$NON-NLS-2$//$NON-NLS-3$
	return toString;
	}

	}