| /******************************************************************************* |
| * 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.decorators; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| import org.eclipse.jface.viewers.IBaseLabelProvider; |
| import org.eclipse.jface.viewers.ILabelProviderListener; |
| import org.eclipse.ui.internal.ActionExpression; |
| import org.eclipse.ui.internal.WorkbenchPlugin; |
| import org.eclipse.ui.internal.registry.RegistryReader; |
| |
| /** |
| * The DecoratorDefinition is the class that holds onto |
| * the label decorator, the name and the name of the |
| * class a decorator definition applies to, |
| */ |
| |
| public abstract class DecoratorDefinition { |
| |
| private static final String ATT_LABEL = "label"; //$NON-NLS-1$ |
| |
| private static final String ATT_OBJECT_CLASS = "objectClass"; //$NON-NLS-1$ |
| |
| static final String CHILD_ENABLEMENT = "enablement"; //$NON-NLS-1$ |
| |
| private static final String ATT_ADAPTABLE = "adaptable"; //$NON-NLS-1$ |
| |
| private static final String ATT_ENABLED = "state"; //$NON-NLS-1$ |
| |
| private ActionExpression enablement; |
| |
| protected boolean enabled; |
| |
| private boolean defaultEnabled; |
| |
| private String id; |
| |
| protected IConfigurationElement definingElement; |
| |
| //A flag that is set if there is an error creating the decorator |
| protected boolean labelProviderCreationFailed = false; |
| |
| private boolean hasReadEnablement; |
| |
| static final String ATT_CLASS = "class";//$NON-NLS-1$ |
| |
| /** |
| * Create a new instance of the receiver with the |
| * supplied values. |
| */ |
| |
| DecoratorDefinition(String identifier, IConfigurationElement element) { |
| |
| this.id = identifier; |
| this.definingElement = element; |
| |
| this.enabled = this.defaultEnabled = Boolean.valueOf(element.getAttribute(ATT_ENABLED)).booleanValue(); |
| } |
| |
| /** |
| * Gets the name. |
| * @return Returns a String |
| */ |
| public String getName() { |
| return definingElement.getAttribute(ATT_LABEL); |
| } |
| |
| /** |
| * Returns the description. |
| * @return String |
| */ |
| public String getDescription() { |
| return RegistryReader.getDescription(definingElement); |
| } |
| |
| /** |
| * Gets the enabled. |
| * @return Returns a boolean |
| */ |
| public boolean isEnabled() { |
| return enabled; |
| } |
| |
| /** |
| * Sets the enabled flag and adds or removes the decorator |
| * manager as a listener as appropriate. |
| * @param newState The enabled to set |
| */ |
| public void setEnabled(boolean newState) { |
| |
| //Only refresh if there has been a change |
| if (this.enabled != newState) { |
| this.enabled = newState; |
| try { |
| refreshDecorator(); |
| } catch (CoreException exception) { |
| handleCoreException(exception); |
| } |
| |
| } |
| } |
| |
| /** |
| * Refresh the current decorator based on our enable |
| * state. |
| */ |
| protected abstract void refreshDecorator() throws CoreException; |
| |
| /** |
| * Dispose the decorator instance and remove listeners |
| * as appropirate. |
| * @param disposedDecorator |
| */ |
| protected void disposeCachedDecorator(IBaseLabelProvider disposedDecorator) { |
| disposedDecorator.removeListener(WorkbenchPlugin.getDefault() |
| .getDecoratorManager()); |
| disposedDecorator.dispose(); |
| |
| } |
| |
| /** |
| * Return whether or not this decorator should be |
| * applied to adapted types. |
| * |
| * @return whether or not this decorator should be |
| * applied to adapted types |
| */ |
| public boolean isAdaptable() { |
| return Boolean.valueOf(definingElement.getAttribute(ATT_ADAPTABLE)).booleanValue(); |
| } |
| |
| /** |
| * Gets the id. |
| * @return Returns a String |
| */ |
| public String getId() { |
| return id; |
| } |
| |
| /** |
| * Return the default value for this type - this value |
| * is the value read from the element description. |
| * |
| * @return the default value for this type - this value |
| * is the value read from the element description |
| */ |
| public boolean getDefaultValue() { |
| return defaultEnabled; |
| } |
| |
| /** |
| * Returns the enablement. |
| * @return ActionExpression |
| */ |
| protected ActionExpression getEnablement() { |
| if (!hasReadEnablement) { |
| hasReadEnablement = true; |
| initializeEnablement(); |
| } |
| return enablement; |
| } |
| |
| /** |
| * Initialize the enablement expression for this decorator |
| */ |
| protected void initializeEnablement() { |
| IConfigurationElement[] elements = definingElement.getChildren(CHILD_ENABLEMENT); |
| if (elements.length == 0) { |
| String className = definingElement.getAttribute(ATT_OBJECT_CLASS); |
| if (className != null) { |
| enablement = new ActionExpression(ATT_OBJECT_CLASS, |
| className); |
| } |
| } else { |
| enablement = new ActionExpression(elements[0]); |
| } |
| } |
| |
| /** |
| * Add a listener for the decorator.If there is an exception |
| * then inform the user and disable the receiver. |
| * This method should not be called unless a check for |
| * isEnabled() has been done first. |
| */ |
| void addListener(ILabelProviderListener listener) { |
| try { |
| //Internal decorator might be null so be prepared |
| IBaseLabelProvider currentDecorator = internalGetLabelProvider(); |
| if (currentDecorator != null) { |
| currentDecorator.addListener(listener); |
| } |
| } catch (CoreException exception) { |
| handleCoreException(exception); |
| } |
| } |
| |
| /** |
| * Return whether or not the decorator registered for element |
| * has a label property called property name. If there is an |
| * exception disable the receiver and return false. |
| * This method should not be called unless a check for |
| * isEnabled() has been done first. |
| */ |
| boolean isLabelProperty(Object element, String property) { |
| try { //Internal decorator might be null so be prepared |
| IBaseLabelProvider currentDecorator = internalGetLabelProvider(); |
| if (currentDecorator != null) { |
| return currentDecorator.isLabelProperty(element, property); |
| } |
| } catch (CoreException exception) { |
| handleCoreException(exception); |
| return false; |
| } |
| return false; |
| } |
| |
| /** |
| * Gets the label provider and creates it if it does not exist yet. |
| * Throws a CoreException if there is a problem |
| * creating the labelProvider. |
| * This method should not be called unless a check for |
| * enabled to be true is done first. |
| * @return Returns a ILabelDecorator |
| */ |
| protected abstract IBaseLabelProvider internalGetLabelProvider() |
| throws CoreException; |
| |
| /** |
| * A CoreException has occured. Inform the user and disable |
| * the receiver. |
| */ |
| |
| protected void handleCoreException(CoreException exception) { |
| |
| //If there is an error then reset the enabling to false |
| WorkbenchPlugin.log(exception); |
| crashDisable(); |
| } |
| |
| /** |
| * A crash has occured. Disable the receiver without notification. |
| */ |
| public void crashDisable() { |
| this.enabled = false; |
| } |
| |
| /** |
| * Return whether or not this is a full or lightweight definition. |
| * @return <code>true</code> if this is not a lightweight decorator. |
| */ |
| public abstract boolean isFull(); |
| |
| /** |
| * Return the configuration element. |
| * |
| * @return the configuration element |
| * @since 3.1 |
| */ |
| public IConfigurationElement getConfigurationElement() { |
| return definingElement; |
| } |
| |
| /** |
| * Return whether the decorator is applicable to the given element |
| * @param element the element to be decorated |
| * @return whether the decorator w=should be applied to the element |
| */ |
| public boolean isEnabledFor(Object element) { |
| if(isEnabled()){ |
| ActionExpression expression = getEnablement(); |
| if(expression != null) { |
| return expression.isEnabledFor(element); |
| } |
| return true;//Always on if no expression |
| } |
| return false; |
| |
| } |
| } |
