/*******************************************************************************
* Copyright (c) 2000, 2006 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.core.runtime.ISafeRunnable;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.viewers.IBaseLabelProvider;
import org.eclipse.jface.viewers.IDecoration;
import org.eclipse.jface.viewers.ILightweightLabelDecorator;
import org.eclipse.ui.internal.ActionExpression;
import org.eclipse.ui.internal.IObjectContributor;
import org.eclipse.ui.internal.LegacyResourceSupport;
import org.eclipse.ui.internal.WorkbenchPlugin;
/**
* The DeclarativeDecoratorDefinition is a decorator definition that is defined
* entirely from xml and will not require the activation of its defining
* plug-in.
*/
class LightweightDecoratorDefinition extends DecoratorDefinition implements
IObjectContributor {
private static final String ATT_LOCATION = "location"; //$NON-NLS-1$
static final String ATT_ICON = "icon"; //$NON-NLS-1$
// Constants for quadrants
/**
* Position <code>TOP_LEFT</code>. Value <code>0</code>
*/
public static final int TOP_LEFT = 0;
/**
* Position <code>TOP_RIGHT</code>. Value <code>1</code>
*/
public static final int TOP_RIGHT = 1;
/**
* Position <code>BOTTOM_LEFT</code>. Value <code>2</code>
*/
public static final int BOTTOM_LEFT = 2;
/**
* Position <code>BOTTOM_RIGHT</code>. Value <code>3</code>
*/
public static final int BOTTOM_RIGHT = 3;
/**
* Position <code>UNDERLAY</code>. Value <code>4</code>
*/
public static final int UNDERLAY = 4;
private static final String UNDERLAY_STRING = "UNDERLAY"; //$NON-NLS-1$
private static final String ATT_QUADRANT = "quadrant"; //$NON-NLS-1$
// Constants for quadrants
private static final String TOP_LEFT_STRING = "TOP_LEFT"; //$NON-NLS-1$
private static final String TOP_RIGHT_STRING = "TOP_RIGHT"; //$NON-NLS-1$
private static final String BOTTOM_LEFT_STRING = "BOTTOM_LEFT"; //$NON-NLS-1$
/**
* The DeclarativeDecorator is the internal decorator supplied by the
* decorator definition.
*/
private ILightweightLabelDecorator decorator;
private int quadrant;
private boolean hasReadQuadrant;
private String[] objectClasses;
LightweightDecoratorDefinition(String identifier,
IConfigurationElement element) {
super(identifier, element);
}
/**
* Gets the decorator and creates it if it does not exist yet. Throws a
* CoreException if there is a problem creating the decorator. This method
* should not be called unless a check for enabled to be true is done first.
*
* @return Returns a ILabelDecorator
*/
protected ILightweightLabelDecorator internalGetDecorator()
throws CoreException {
if (labelProviderCreationFailed) {
return null;
}
final CoreException[] exceptions = new CoreException[1];
if (decorator == null) {
if (isDeclarative()) {
decorator = new DeclarativeDecorator(definingElement,
getIconLocation());
} else {
Platform.run(new ISafeRunnable() {
public void run() {
try {
decorator = (ILightweightLabelDecorator) WorkbenchPlugin
.createExtension(definingElement,
DecoratorDefinition.ATT_CLASS);
decorator.addListener(WorkbenchPlugin.getDefault()
.getDecoratorManager());
} catch (CoreException exception) {
exceptions[0] = exception;
}
}
/*
* (non-Javadoc) Method declared on ISafeRunnable.
*/
public void handleException(Throwable e) {
// Do nothing as Core will handle the logging
}
});
}
} else {
return decorator;
}
if (decorator == null) {
this.labelProviderCreationFailed = true;
setEnabled(false);
}
if (exceptions[0] != null) {
throw exceptions[0];
}
return decorator;
}
/**
* Return whether or not this represents a declarative decorator.
*
* @return boolean <code>true</code> if this is declarative
*/
private boolean isDeclarative() {
return definingElement.getAttribute(DecoratorDefinition.ATT_CLASS) == null;
}
/**
* Return the icon location.
*
* @return the icon location
*/
private String getIconLocation() {
return definingElement.getAttribute(ATT_ICON);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.decorators.DecoratorDefinition#internalGetLabelProvider()
*/
protected IBaseLabelProvider internalGetLabelProvider()
throws CoreException {
return internalGetDecorator();
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.decorators.DecoratorDefinition#isFull()
*/
public boolean isFull() {
return false;
}
/**
* Returns the quadrant.One of the following constants in
* DecoratorRegistryReader: TOP_LEFT TOP_RIGHT BOTTOM_LEFT BOTTOM_RIGHT
* UNDERLAY
*
* @return int
*/
public int getQuadrant() {
if (!hasReadQuadrant) {
hasReadQuadrant = true;
quadrant = getLocationConstant(definingElement
.getAttribute(ATT_LOCATION), definingElement);
}
return quadrant;
}
/**
* Get the constant value based on the location supplied. Default to bottom
* right.
*
* @since 3.1
*/
private int getLocationConstant(String locationDefinition,
IConfigurationElement element) {
// Backwards compatibility
if (locationDefinition == null) {
locationDefinition = element.getAttribute(ATT_QUADRANT);
}
if (TOP_RIGHT_STRING.equals(locationDefinition)) {
return TOP_RIGHT;
}
if (TOP_LEFT_STRING.equals(locationDefinition)) {
return TOP_LEFT;
}
if (BOTTOM_LEFT_STRING.equals(locationDefinition)) {
return BOTTOM_LEFT;
}
if (UNDERLAY_STRING.equals(locationDefinition)) {
return UNDERLAY;
}
return BOTTOM_RIGHT;
}
/**
* Decorate the element using the decoration to store the result.
* @param element
* @param decoration
*/
public void decorate(Object element, IDecoration decoration) {
try {
// Internal decorator might be null so be prepared
ILightweightLabelDecorator currentDecorator = internalGetDecorator();
if(currentDecorator == null) {
return;
}
if (isAdaptable()) {
String[] classes = getObjectClasses();
for (int i = 0; i < classes.length; i++) {
String className = classes[i];
Object adapted = LegacyResourceSupport.getAdapter(element,
className);
if (adapted != null) {
currentDecorator.decorate(adapted, decoration);
}
}
}
else{
if (currentDecorator != null && element != null) {
currentDecorator.decorate(element, decoration);
}
}
} catch (CoreException exception) {
handleCoreException(exception);
}
}
/**
* Returns the lightweight decorator, or <code>null</code> if not enabled.
*
* @return the lightweight decorator, or <code>null</code> if not enabled
*/
public ILightweightLabelDecorator getDecorator() {
return decorator;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.decorators.DecoratorDefinition#refreshDecorator()
*/
protected void refreshDecorator() {
// Only do something if disabled so as to prevent
// gratutitous activation
if (!this.enabled && decorator != null) {
IBaseLabelProvider cached = decorator;
decorator = null;
disposeCachedDecorator(cached);
}
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.IObjectContributor#isApplicableTo(java.lang.Object)
*/
public boolean isApplicableTo(Object object) {
return isEnabledFor(object);
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.IObjectContributor#canAdapt()
*/
public boolean canAdapt() {
return isAdaptable();
}
/**
* Get the object classes to which this decorator is registered.
*
* @return String [] the object classes to which this decorator is
* registered
*/
public String[] getObjectClasses() {
if (objectClasses == null) {
getEnablement();
}
return objectClasses;
}
/*
* (non-Javadoc)
*
* @see org.eclipse.ui.internal.decorators.DecoratorDefinition#initializeEnablement()
*/
protected void initializeEnablement() {
super.initializeEnablement();
ActionExpression expression = getEnablement();
if (expression != null) {
objectClasses = expression.extractObjectClasses();
}
// If the class is null set it to Object
if (objectClasses == null) {
objectClasses = new String[] {Object.class.getName()};
}
}
}