/*******************************************************************************
* Copyright (c) 2003, 2015 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.navigator.extensions;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Set;
import java.util.TreeSet;
import org.eclipse.osgi.util.NLS;
import org.eclipse.core.expressions.ElementHandler;
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.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.ui.IPluginContribution;
import org.eclipse.ui.WorkbenchException;
import org.eclipse.ui.internal.navigator.CommonNavigatorMessages;
import org.eclipse.ui.internal.navigator.CustomAndExpression;
import org.eclipse.ui.internal.navigator.NavigatorPlugin;
import org.eclipse.ui.internal.navigator.Policy;
import org.eclipse.ui.navigator.ICommonContentProvider;
import org.eclipse.ui.navigator.ICommonLabelProvider;
import org.eclipse.ui.navigator.INavigatorContentDescriptor;
import org.eclipse.ui.navigator.OverridePolicy;
import org.eclipse.ui.navigator.Priority;
/**
* Encapsulates the <code>org.eclipse.ui.navigator.navigatorContent</code>
* extension point.
*
* @since 3.2
*/
public final class NavigatorContentDescriptor implements
INavigatorContentDescriptor, INavigatorContentExtPtConstants {
private static final int HASH_CODE_NOT_COMPUTED = -1;
private String id;
private String name;
private IConfigurationElement configElement;
private int priority = Priority.NORMAL_PRIORITY_VALUE;
/**
* This is calculated based on the priority and appearsBeforeId when all of the descriptors
* are first loaded. This is what's used to sort on after that.
*/
private int sequenceNumber;
private String appearsBeforeId;
private Expression enablement;
private Expression possibleChildren;
private Expression initialActivation;
private String icon;
private boolean activeByDefault;
private IPluginContribution contribution;
private boolean sortOnly;
private Set overridingExtensions;
private List overridingExtensionsList; // FIXME: will replace 'overridingExtensions' in 3.6
private OverridePolicy overridePolicy;
private String suppressedExtensionId;
private INavigatorContentDescriptor overriddenDescriptor;
private int hashCode = HASH_CODE_NOT_COMPUTED;
private boolean providesSaveables;
/**
* Creates a new content descriptor from a configuration element.
*
* @param configElement
* configuration element to create a descriptor from
*
* @throws WorkbenchException
* if the configuration element could not be parsed. Reasons
* include:
* <ul>
* <li>A required attribute is missing.</li>
* <li>More elements are define than is allowed.</li>
* </ul>
*/
/* package */ NavigatorContentDescriptor(IConfigurationElement configElement)
throws WorkbenchException {
super();
this.configElement = configElement;
init();
}
@Override
public String getId() {
return id;
}
@Override
public String getName() {
return name;
}
@Override
public int getPriority() {
return priority;
}
/**
* @return the sequence number
*/
@Override
public int getSequenceNumber() {
return sequenceNumber;
}
void setSequenceNumber(int num) {
sequenceNumber = num;
}
/**
*
* @return The value specified by the <i>appearsBefore</i> attribute of the
* <navigatorContent/> element.
*/
@Override
public String getAppearsBeforeId() {
return appearsBeforeId;
}
@Override
public boolean isSortOnly() {
return sortOnly;
}
/**
* Parses the configuration element.
*
* @throws WorkbenchException
* if the configuration element could not be parsed. Reasons
* include:
* <ul>
* <li>A required attribute is missing.</li>
* <li>More elements are define than is allowed.</li>
* </ul>
*/
private void init() throws WorkbenchException {
id = configElement.getAttribute(ATT_ID);
name = configElement.getAttribute(ATT_NAME);
String priorityString = configElement.getAttribute(ATT_PRIORITY);
icon = configElement.getAttribute(ATT_ICON);
String activeByDefaultString = configElement
.getAttribute(ATT_ACTIVE_BY_DEFAULT);
activeByDefault = (activeByDefaultString != null && activeByDefaultString
.length() > 0) ? Boolean.valueOf(activeByDefaultString)
.booleanValue() : true;
String providesSaveablesString = configElement
.getAttribute(ATT_PROVIDES_SAVEABLES);
providesSaveables = (providesSaveablesString != null && providesSaveablesString
.length() > 0) ? Boolean.valueOf(providesSaveablesString)
.booleanValue() : false;
appearsBeforeId = configElement.getAttribute(ATT_APPEARS_BEFORE);
if (priorityString != null) {
try {
Priority p = Priority.get(priorityString);
priority = p != null ? p.getValue()
: Priority.NORMAL_PRIORITY_VALUE;
} catch (NumberFormatException exception) {
priority = Priority.NORMAL_PRIORITY_VALUE;
}
}
// We start with this because the sort ExtensionPriorityComparator works
// from the sequenceNumber
sequenceNumber = priority;
String sortOnlyString = configElement.getAttribute(ATT_SORT_ONLY);
sortOnly = (sortOnlyString != null && sortOnlyString.length() > 0) ? Boolean.valueOf(
sortOnlyString).booleanValue() : false;
if (id == null) {
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Attribute_Missing_Warning,
new Object[] {
ATT_ID,
id,
configElement.getDeclaringExtension()
.getNamespaceIdentifier() }));
}
contribution = new IPluginContribution() {
@Override
public String getLocalId() {
return getId();
}
@Override
public String getPluginId() {
return configElement.getDeclaringExtension().getNamespaceIdentifier();
}
};
IConfigurationElement[] children;
children = configElement.getChildren(TAG_INITIAL_ACTIVATION);
if (children.length > 0) {
if (children.length == 1) {
initialActivation = new CustomAndExpression(children[0]);
} else {
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Attribute_Missing_Warning, new Object[] {
TAG_INITIAL_ACTIVATION, id,
configElement.getDeclaringExtension().getNamespaceIdentifier() }));
}
}
if (sortOnly)
return;
children = configElement.getChildren(TAG_ENABLEMENT);
if (children.length == 0) {
children = configElement.getChildren(TAG_TRIGGER_POINTS);
if (children.length == 1) {
enablement = new CustomAndExpression(children[0]);
} else {
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Attribute_Missing_Warning,
new Object[] {
TAG_TRIGGER_POINTS,
id,
configElement.getDeclaringExtension()
.getNamespaceIdentifier() }));
}
children = configElement.getChildren(TAG_POSSIBLE_CHILDREN);
if (children.length == 1) {
possibleChildren = new CustomAndExpression(children[0]);
} else if(children.length > 1){
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Attribute_Missing_Warning,
new Object[] {
TAG_POSSIBLE_CHILDREN,
id,
configElement.getDeclaringExtension()
.getNamespaceIdentifier() }));
}
} else if (children.length == 1) {
try {
enablement = ElementHandler.getDefault().create(
ExpressionConverter.getDefault(), children[0]);
} catch (CoreException e) {
NavigatorPlugin.log(IStatus.ERROR, 0, e.getMessage(), e);
}
} else if (children.length > 1) {
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Attribute_Missing_Warning,
new Object[] {
TAG_ENABLEMENT,
id,
configElement.getDeclaringExtension()
.getNamespaceIdentifier() }));
}
children = configElement.getChildren(TAG_OVERRIDE);
if (children.length == 0) {
overridePolicy = OverridePolicy.get(OverridePolicy.InvokeAlwaysRegardlessOfSuppressedExt_LITERAL);
} else if (children.length == 1) {
suppressedExtensionId = children[0]
.getAttribute(ATT_SUPPRESSED_EXT_ID);
overridePolicy = OverridePolicy.get(children[0]
.getAttribute(ATT_POLICY));
} else if (children.length > 1) {
throw new WorkbenchException(NLS.bind(
CommonNavigatorMessages.Too_many_elements_Warning,
new Object[] {
TAG_OVERRIDE,
id,configElement.getDeclaringExtension()
.getNamespaceIdentifier() }));
}
}
/**
* @return Returns the icon.
*/
public String getIcon() {
return icon;
}
/**
* @return Returns the suppressedExtensionId or null if none specified.
*/
@Override
public String getSuppressedExtensionId() {
return suppressedExtensionId;
}
/**
* @return Returns the overridePolicy or null if this extension does not
* override another extension.
*/
@Override
public OverridePolicy getOverridePolicy() {
return overridePolicy;
}
/**
* @return Returns the contribution.
*/
public IPluginContribution getContribution() {
return contribution;
}
/**
* @return the configuration element
*/
public IConfigurationElement getConfigElement() {
return configElement;
}
/**
* The content provider could be an instance of
* {@link ICommonContentProvider}, but only {@link ITreeContentProvider} is
* required.
*
*
* @return An instance of the Content provider defined for this extension.
* @throws CoreException
* if an instance of the executable extension could not be
* created for any reason
*
*/
public ITreeContentProvider createContentProvider() throws CoreException {
if (Policy.DEBUG_EXTENSION_SETUP)
System.out.println("createContentProvider: " + this); //$NON-NLS-1$
return (ITreeContentProvider) configElement
.createExecutableExtension(ATT_CONTENT_PROVIDER);
}
/**
*
* The content provider could be an instance of {@link ICommonLabelProvider},
* but only {@link ILabelProvider} is required.
*
* @return An instance of the Label provider defined for this extension
* @throws CoreException
* if an instance of the executable extension could not be
* created for any reason
*/
public ILabelProvider createLabelProvider() throws CoreException {
if (Policy.DEBUG_EXTENSION_SETUP)
System.out.println("createLabelProvider: " + this); //$NON-NLS-1$
return (ILabelProvider) configElement
.createExecutableExtension(ATT_LABEL_PROVIDER);
}
@Override
public boolean isActiveByDefault() {
if (activeByDefault)
return true;
if (initialActivation == null)
return false;
IEvaluationContext context = NavigatorPlugin.getEvalContext(new Object());
return NavigatorPlugin.safeEvaluate(initialActivation, context) == EvaluationResult.TRUE;
}
/**
* Determine if this content extension would be able to provide children 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.
*/
@Override
public boolean isTriggerPoint(Object anElement) {
if (enablement == null || anElement == null) {
return false;
}
IEvaluationContext context = NavigatorPlugin.getEvalContext(anElement);
return NavigatorPlugin.safeEvaluate(enablement, context) == EvaluationResult.TRUE;
}
/**
* Determine if this content extension could provide the given element as a
* child.
*
* <p>
* This method is used to determine what the parent of an element could be
* for Link with Editor support.
* </p>
*
* @param anElement
* The element that should be used for the evaluation.
* @return True if and only if the extension might provide an object of this
* type as a child.
*/
@Override
public boolean isPossibleChild(Object anElement) {
if ((enablement == null && possibleChildren == null)
|| anElement == null) {
return false;
} else if(anElement instanceof IStructuredSelection) {
return arePossibleChildren((IStructuredSelection) anElement);
}
IEvaluationContext context = NavigatorPlugin.getEvalContext(anElement);
if (possibleChildren != null) {
return NavigatorPlugin.safeEvaluate(possibleChildren, context) == EvaluationResult.TRUE;
} else if (enablement != null) {
return NavigatorPlugin.safeEvaluate(enablement, context) == EvaluationResult.TRUE;
}
return false;
}
/**
* A convenience method to check all elements in a selection.
*
* @param aSelection A non-null selection
* @return True if and only if every element in the selection is a possible child.
*/
@Override
public boolean arePossibleChildren(IStructuredSelection aSelection) {
if(aSelection.isEmpty()) {
return false;
}
for (Iterator iter = aSelection.iterator(); iter.hasNext();) {
Object element = iter.next();
if(!isPossibleChild(element)) {
return false;
}
}
return true;
}
/**
*
* Does not force the creation of the set of overriding extensions.
*
* @return True if this extension has overriding extensions.
*/
@Override
public boolean hasOverridingExtensions() {
return overridingExtensions != null && overridingExtensions.size() > 0;
}
/**
* @return The set of overriding extensions (of type
* {@link INavigatorContentDescriptor}
*/
@Override
public Set getOverriddingExtensions() {
if (overridingExtensions == null) {
overridingExtensions = new TreeSet(ExtensionSequenceNumberComparator.DESCENDING);
}
return overridingExtensions;
}
/**
* Returns a list iterator over the overriding extensions.
*
* @param fromStart
* <code>true</code> if list iterator starts at the beginning and
* <code>false</code> if it starts at the end of the list
* @return a list iterator over the overriding extensions which are ordered
* by ExtensionPriorityComparator.DESCENDING
*/
public ListIterator getOverridingExtensionsListIterator(boolean fromStart) {
if (overridingExtensions == null)
return Collections.EMPTY_LIST.listIterator();
if (overridingExtensionsList == null)
overridingExtensionsList = new ArrayList(overridingExtensions);
return overridingExtensionsList.listIterator(fromStart ? 0 : overridingExtensionsList.size());
}
@Override
public String toString() {
return "Content[" + id + "(" + sequenceNumber + ") " + ", \"" + name + "\"]"; //$NON-NLS-1$ //$NON-NLS-2$//$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
}
@Override
public int hashCode() {
if (hashCode == HASH_CODE_NOT_COMPUTED) {
String hashCodeString = configElement.getNamespaceIdentifier() + getId();
hashCode = hashCodeString.hashCode();
if (hashCode == HASH_CODE_NOT_COMPUTED)
hashCode++;
}
return hashCode;
}
/**
* @return The descriptor of the <code>suppressedExtensionId</code> if
* non-null.
*/
@Override
public INavigatorContentDescriptor getOverriddenDescriptor() {
return overriddenDescriptor;
}
/**
* @param theOverriddenDescriptor
* The overriddenDescriptor to set.
*/
/* package */void setOverriddenDescriptor(
INavigatorContentDescriptor theOverriddenDescriptor) {
overriddenDescriptor = theOverriddenDescriptor;
}
@Override
public boolean hasSaveablesProvider() {
return providesSaveables;
}
}