/*******************************************************************************
* 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
*
*******************************************************************************/
package org.eclipse.dltk.internal.core;
import java.util.HashSet;
import java.util.Iterator;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.IModelElementDelta;
import org.eclipse.dltk.core.IProjectFragment;
import org.eclipse.dltk.core.IScriptProject;
import org.eclipse.dltk.core.ISourceModule;
import org.eclipse.dltk.core.ModelException;
/**
* This class is used by <code>ModelManager</code> to update the Model
* based on some <code>IElementDelta</code>s.
*/
public class ModelUpdater {
HashSet projectsToUpdate = new HashSet();
/**
* Adds the given child handle to its parent's cache of children.
*/
protected void addToParentInfo(Openable child) {
Openable parent = (Openable) child.getParent();
if (parent != null && parent.isOpen()) {
try {
ModelElementInfo info = (ModelElementInfo)parent.getElementInfo();
info.addChild(child);
} catch (ModelException e) {
// do nothing - we already checked if open
}
}
}
/**
* Closes the given element, which removes it from the cache of open elements.
*/
protected static void close(Openable element) {
try {
element.close();
} catch (ModelException e) {
// do nothing
}
}
/**
* Processing for an element that has been added:<ul>
* <li>If the element is a project, do nothing, and do not process
* children, as when a project is created it does not yet have any
* natures - specifically a script nature.
* <li>If the elemet is not a project, process it as added (see
* <code>basicElementAdded</code>.
* </ul>
*/
protected void elementAdded(Openable element) {
int elementType = element.getElementType();
if (elementType == IModelElement.SCRIPT_PROJECT) {
// project add is handled by ScriptProject.configure() because
// when a project is created, it does not yet have a script nature
addToParentInfo(element);
this.projectsToUpdate.add(element);
} else {
addToParentInfo(element);
// Force the element to be closed as it might have been opened
// before the resource modification came in and it might have a new child
// For example, in an IWorkspaceRunnable:
// 1. create a package fragment p using a script model operation
// 2. open package p
// 3. add file X.java in folder p
// When the resource delta comes in, only the addition of p is notified,
// but the package p is already opened, thus its children are not recomputed
// and it appears empty.
close(element);
}
switch (elementType) {
case IModelElement.PROJECT_FRAGMENT :
// when a root is added, and is on the buildpath, the project must be updated
this.projectsToUpdate.add(element.getScriptProject());
break;
case IModelElement.SCRIPT_FOLDER :
// get rid of package fragment cache
ScriptProject project = (ScriptProject) element.getScriptProject();
project.resetCaches();
break;
}
}
/**
* Generic processing for elements with changed contents:<ul>
* <li>The element is closed such that any subsequent accesses will re-open
* the element reflecting its new structure.
* </ul>
*/
protected void elementChanged(Openable element) {
close(element);
}
/**
* Generic processing for a removed element:<ul>
* <li>Close the element, removing its structure from the cache
* <li>Remove the element from its parent's cache of children
* <li>Add a REMOVED entry in the delta
* </ul>
*/
protected void elementRemoved(Openable element) {
if (element.isOpen()) {
close(element);
}
removeFromParentInfo(element);
int elementType = element.getElementType();
switch (elementType) {
case IModelElement.SCRIPT_MODEL :
ModelManager.getModelManager().getIndexManager().reset();
break;
case IModelElement.SCRIPT_PROJECT :
ModelManager manager = ModelManager.getModelManager();
ScriptProject scriptProject = (ScriptProject) element;
manager.removePerProjectInfo(scriptProject);
manager.containerRemove(scriptProject);
break;
case IModelElement.PROJECT_FRAGMENT :
this.projectsToUpdate.add(element.getScriptProject());
break;
case IModelElement.SCRIPT_FOLDER :
// get rid of package fragment cache
ScriptProject project = (ScriptProject) element.getScriptProject();
project.resetCaches();
break;
}
}
/**
* Converts a <code>IResourceDelta</code> rooted in a <code>Workspace</code> into
* the corresponding set of <code>IModelElementDelta</code>, rooted in the
* relevant <code>Model</code>s.
*/
public void processDelta(IModelElementDelta delta) {
// if (DeltaProcessor.VERBOSE){
// System.out.println("UPDATING Model with Delta: ["+Thread.currentThread()+":" + delta + "]:");
// }
try {
this.traverseDelta(delta, null, null); // traverse delta
// update package fragment roots of projects that were affected
Iterator iterator = this.projectsToUpdate.iterator();
while (iterator.hasNext()) {
ScriptProject project = (ScriptProject) iterator.next();
project.updateProjectFragments();
}
} finally {
this.projectsToUpdate = new HashSet();
}
}
/**
* Removes the given element from its parents cache of children. If the
* element does not have a parent, or the parent is not currently open,
* this has no effect.
*/
protected void removeFromParentInfo(Openable child) {
Openable parent = (Openable) child.getParent();
if (parent != null && parent.isOpen()) {
try {
ModelElementInfo info = (ModelElementInfo)parent.getElementInfo();
info.removeChild(child);
} catch (ModelException e) {
// do nothing - we already checked if open
}
}
}
/**
* Converts an <code>IResourceDelta</code> and its children into
* the corresponding <code>IModelElementDelta</code>s.
* Return whether the delta corresponds to a resource on the buildpath.
* If it is not a resource on the buildpath, it will be added as a non-java
* resource by the sender of this method.
*/
protected void traverseDelta(
IModelElementDelta delta,
IProjectFragment root,
IScriptProject project) {
boolean processChildren = true;
Openable element = (Openable) delta.getElement();
switch (element.getElementType()) {
case IModelElement.SCRIPT_PROJECT :
project = (IScriptProject) element;
break;
case IModelElement.PROJECT_FRAGMENT :
root = (IProjectFragment) element;
break;
case IModelElement.SOURCE_MODULE :
// filter out working copies that are not primary (we don't want to add/remove them to/from the package fragment
ISourceModule cu = (ISourceModule)element;
if (cu.isWorkingCopy() && !cu.isPrimary()) {
return;
}
case IModelElement.BINARY_MODULE :
processChildren = false;
break;
}
switch (delta.getKind()) {
case IModelElementDelta.ADDED :
elementAdded(element);
break;
case IModelElementDelta.REMOVED :
elementRemoved(element);
break;
case IModelElementDelta.CHANGED :
if ((delta.getFlags() & IModelElementDelta.F_CONTENT) != 0){
elementChanged(element);
}
break;
}
if (processChildren) {
IModelElementDelta[] children = delta.getAffectedChildren();
for (int i = 0; i < children.length; i++) {
IModelElementDelta childDelta = children[i];
this.traverseDelta(childDelta, root, project);
}
}
}
}