plugins/org.eclipse.sphinx.emf.workspace.ui/src/org/eclipse/sphinx/emf/workspace/ui/viewers/state/providers/TransientElementStateProvider.java - sphinx/org.eclipse.sphinx - Git at Google

 /**
  * <copyright>
  *
  * Copyright (c) 2015-2016 itemis and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
  *
  * Contributors:
  *     itemis - Initial API and implementation
  *     itemis - [480105] Occasional ConcurrentModificationException when re-launching Sphinx on previously used workspace
  *
  * </copyright>
  */
 package org.eclipse.sphinx.emf.workspace.ui.viewers.state.providers;

 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.edit.provider.IWrapperItemProvider;
 import org.eclipse.jface.viewers.IContentProvider;
 import org.eclipse.jface.viewers.ITreeContentProvider;
 import org.eclipse.jface.viewers.TreeViewer;
 import org.eclipse.sphinx.emf.edit.TransientItemProvider;
 import org.eclipse.sphinx.emf.model.IModelDescriptor;
 import org.eclipse.sphinx.emf.model.ModelDescriptorRegistry;
 import org.eclipse.sphinx.emf.util.EcorePlatformUtil;
 import org.eclipse.sphinx.emf.util.EcoreResourceUtil;
 import org.eclipse.sphinx.emf.workspace.loading.ModelLoadManager;
 import org.eclipse.ui.IMemento;

 public class TransientElementStateProvider extends AbstractTreeElementStateProvider {

 	protected static final String TRANSIENT_CHILDREN_SEPARATOR = "/"; //$NON-NLS-1$

 	private URI parentURI = null;
 	private EObject parentEObject = null;
 	private List<Object> transientChildren;
 	private boolean stale = false;

 	public TransientElementStateProvider(TreeViewer viewer, IMemento memento) {
 		super(viewer);
 		Assert.isNotNull(memento);

 		String parentURIAsString = memento.getString(TreeElementStateProviderFactory.MEMENTO_KEY_PARENT_URI);
 		if (parentURIAsString != null) {
 			parentURI = URI.createURI(parentURIAsString, true);
 		}

 		String transientChildrenAsString = memento.getString(TreeElementStateProviderFactory.MEMENTO_KEY_TRANSIENT_CHILDREN);
 		transientChildren = readTransientChildrenFromString(transientChildrenAsString);
 	}

 	public TransientElementStateProvider(TreeViewer viewer, URI parentURI, List<Object> transientChildren) {
 		super(viewer);
 		Assert.isNotNull(transientChildren);

 		this.parentURI = parentURI;
 		this.transientChildren = deresolveTransientChildren(transientChildren);
 	}

 	protected EObject getParentEObject() {
 		if (parentEObject == null) {
 			parentEObject = EcorePlatformUtil.getEObject(parentURI);

 			if (parentEObject == null && isUnderlyingModelLoaded()) {
 				// At this point we know that the transient children's parent EObject can definitely not be found and
 				// that transient element targeted by this tree element state provider does not exist
 				stale = true;
 			}
 		}
 		return parentEObject;
 	}

 	protected List<Object> readTransientChildrenFromString(String transientChildrenAsString) {
 		if (transientChildrenAsString != null) {
 			return new ArrayList<Object>(Arrays.asList(transientChildrenAsString.split(TRANSIENT_CHILDREN_SEPARATOR)));
 		}
 		return Collections.emptyList();
 	}

 	protected String writeTransientChildrenToString(List<Object> transientChildren) {
 		Assert.isNotNull(transientChildren);

 		List<Object> deresolvedTransientChildren = deresolveTransientChildren(transientChildren);
 		StringBuilder transientChildrenAsString = new StringBuilder();
 		Iterator<?> iter = deresolvedTransientChildren.iterator();
 		while (iter.hasNext()) {
 			Object transientChild = iter.next();
 			transientChildrenAsString.append(transientChild);

 			if (iter.hasNext()) {
 				transientChildrenAsString.append(TRANSIENT_CHILDREN_SEPARATOR);
 			}
 		}
 		return transientChildrenAsString.toString();
 	}

 	protected List<Object> resolveTransientChildren(List<Object> transientChildren) {
 		Assert.isNotNull(transientChildren);

 		// Transient children already fully resolved?
 		if (transientChildren.isEmpty() || !(transientChildren.get(transientChildren.size() - 1) instanceof String)) {
 			return transientChildren;
 		}
 		if (stale) {
 			return transientChildren;
 		}

 		// Get the transient children's parent EObject
 		Object parent = getParentEObject();
 		if (parent == null) {
 			return transientChildren;
 		}

 		// Resolve transient children
 		List<Object> resolvedTransientChildren = new ArrayList<Object>();
 		for (Object transientChild : transientChildren) {
 			// Current transient child not yet resolved?
 			if (transientChild instanceof String) {
 				// Resolve ...
 				Object resolvedTransientChild = resolveTransientChild(parent, (String) transientChild);

 				// ... and store current transient child
 				resolvedTransientChildren.add(resolvedTransientChild);
 			} else {
 				// Store current transient child as is
 				resolvedTransientChildren.add(transientChild);
 			}

 			// Let current transient child be next parent
 			parent = transientChild;
 		}
 		return resolvedTransientChildren;
 	}

 	protected Object resolveTransientChild(Object parent, String transientChildAsString) {
 		IContentProvider contentProvider = viewer.getContentProvider();
 		if (contentProvider instanceof ITreeContentProvider) {
 			// Content provider ready to return children of given parent?
 			if (isTreeContentProviderAvailable(parent)) {
 				// Try to find child among the given parent's children that matches specified transient child
 				for (Object child : ((ITreeContentProvider) contentProvider).getChildren(parent)) {
 					if (child instanceof TransientItemProvider) {
 						if (child.getClass().getName().equals(transientChildAsString)) {
 							return child;
 						}
 					}
 					if (child instanceof IWrapperItemProvider) {
 						IWrapperItemProvider wrapperItemProvider = (IWrapperItemProvider) child;
 						Object value = wrapperItemProvider.getValue();
 						if (value instanceof EObject) {
 							EStructuralFeature feature = wrapperItemProvider.getFeature();
 							if (feature != null && feature.getName().equals(transientChildAsString)) {
 								return child;
 							}
 						} else if (value instanceof TransientItemProvider) {
 							if (value.getClass().getName().equals(transientChildAsString)) {
 								return child;
 							}
 						}
 					}
 				}

 				// At this point we know that specified transient child can definitely not be found and that transient
 				// element targeted by this tree element state provider does not exist
 				stale = true;
 			}
 		}
 		return transientChildAsString;
 	}

 	protected List<Object> deresolveTransientChildren(List<Object> transientChildren) {
 		Assert.isNotNull(transientChildren);

 		// Deresolve transient children
 		List<Object> deresolvedTransientChildren = new ArrayList<Object>();
 		for (Object transientChild : transientChildren) {
 			// Current transient child not yet deresolved?
 			if (!(transientChild instanceof String)) {
 				// Deresolve ...
 				Object deresolvedTransientChild = deresolveTransientChild(transientChild);

 				// ... and store current transient child
 				deresolvedTransientChildren.add(deresolvedTransientChild);
 			} else {
 				// Store current transient child as is
 				deresolvedTransientChildren.add(transientChild);
 			}
 		}
 		return deresolvedTransientChildren;
 	}

 	protected Object deresolveTransientChild(Object transientChild) {
 		if (transientChild instanceof TransientItemProvider) {
 			return transientChild.getClass().getName();
 		} else if (transientChild instanceof IWrapperItemProvider) {
 			IWrapperItemProvider wrapperItemProvider = (IWrapperItemProvider) transientChild;
 			Object value = wrapperItemProvider.getValue();
 			if (value instanceof EObject) {
 				EStructuralFeature feature = wrapperItemProvider.getFeature();
 				if (feature != null) {
 					return feature.getName();
 				}
 			} else if (value instanceof TransientItemProvider) {
 				return value.getClass().getName();
 			}
 		}
 		return transientChild;
 	}

 	protected Object getLastTransientChild() {
 		if (!transientChildren.isEmpty()) {
 			Object lastTransientChild = transientChildren.get(transientChildren.size() - 1);
 			if (!(lastTransientChild instanceof String)) {
 				return lastTransientChild;
 			}
 		}
 		return null;
 	}

 	@Override
 	public boolean hasUnderlyingModel() {
 		return true;
 	}

 	@Override
 	public boolean canUnderlyingModelBeLoaded() {
 		return EcoreResourceUtil.exists(parentURI);
 	}

 	@Override
 	public boolean isUnderlyingModelLoaded() {
 		return EcorePlatformUtil.getResource(parentURI) != null;
 	}

 	@Override
 	public void loadUnderlyingModel() {
 		IFile file = EcorePlatformUtil.getFile(parentURI);
 		IModelDescriptor modelDescriptor = ModelDescriptorRegistry.INSTANCE.getModel(file);
 		if (modelDescriptor != null) {
 			// Request asynchronous loading of model behind given workspace file
 			ModelLoadManager.INSTANCE.loadModel(modelDescriptor, true, null);
 		}
 	}

 	@Override
 	public boolean isStale() {
 		return stale;
 	}

 	@Override
 	public Object getTreeElement() {
 		transientChildren = resolveTransientChildren(transientChildren);
 		return getLastTransientChild();
 	}

 	@Override
 	public void appendToMemento(IMemento parentMemento) {
 		if (parentURI != null) {
 			IMemento memento = parentMemento.createChild(TreeElementStateProviderFactory.MEMENTO_TYPE_ELEMENT_TRANSIENT);
 			memento.putString(TreeElementStateProviderFactory.MEMENTO_KEY_PARENT_URI, parentURI.toString());
 			String transientChildrenAsString = writeTransientChildrenToString(transientChildren);
 			memento.putString(TreeElementStateProviderFactory.MEMENTO_KEY_TRANSIENT_CHILDREN, transientChildrenAsString);
 		}
 	}

 	@Override
 	public String toString() {
 		return "TransientElementProvider [parentURI=" + parentURI + ", transientChildren=" + writeTransientChildrenToString(transientChildren) + "]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
 	}
 }
	/**
	* <copyright>
	*
	* Copyright (c) 2015-2016 itemis and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
	*
	* Contributors:
	* itemis - Initial API and implementation
	* itemis - [480105] Occasional ConcurrentModificationException when re-launching Sphinx on previously used workspace
	*
	* </copyright>
	*/
	package org.eclipse.sphinx.emf.workspace.ui.viewers.state.providers;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.runtime.Assert;
	import org.eclipse.emf.common.util.URI;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EStructuralFeature;
	import org.eclipse.emf.edit.provider.IWrapperItemProvider;
	import org.eclipse.jface.viewers.IContentProvider;
	import org.eclipse.jface.viewers.ITreeContentProvider;
	import org.eclipse.jface.viewers.TreeViewer;
	import org.eclipse.sphinx.emf.edit.TransientItemProvider;
	import org.eclipse.sphinx.emf.model.IModelDescriptor;
	import org.eclipse.sphinx.emf.model.ModelDescriptorRegistry;
	import org.eclipse.sphinx.emf.util.EcorePlatformUtil;
	import org.eclipse.sphinx.emf.util.EcoreResourceUtil;
	import org.eclipse.sphinx.emf.workspace.loading.ModelLoadManager;
	import org.eclipse.ui.IMemento;

	public class TransientElementStateProvider extends AbstractTreeElementStateProvider {

	protected static final String TRANSIENT_CHILDREN_SEPARATOR = "/"; //$NON-NLS-1$

	private URI parentURI = null;
	private EObject parentEObject = null;
	private List<Object> transientChildren;
	private boolean stale = false;

	public TransientElementStateProvider(TreeViewer viewer, IMemento memento) {
	super(viewer);
	Assert.isNotNull(memento);

	String parentURIAsString = memento.getString(TreeElementStateProviderFactory.MEMENTO_KEY_PARENT_URI);
	if (parentURIAsString != null) {
	parentURI = URI.createURI(parentURIAsString, true);
	}

	String transientChildrenAsString = memento.getString(TreeElementStateProviderFactory.MEMENTO_KEY_TRANSIENT_CHILDREN);
	transientChildren = readTransientChildrenFromString(transientChildrenAsString);
	}

	public TransientElementStateProvider(TreeViewer viewer, URI parentURI, List<Object> transientChildren) {
	super(viewer);
	Assert.isNotNull(transientChildren);

	this.parentURI = parentURI;
	this.transientChildren = deresolveTransientChildren(transientChildren);
	}

	protected EObject getParentEObject() {
	if (parentEObject == null) {
	parentEObject = EcorePlatformUtil.getEObject(parentURI);

	if (parentEObject == null && isUnderlyingModelLoaded()) {
	// At this point we know that the transient children's parent EObject can definitely not be found and
	// that transient element targeted by this tree element state provider does not exist
	stale = true;
	}
	}
	return parentEObject;
	}

	protected List<Object> readTransientChildrenFromString(String transientChildrenAsString) {
	if (transientChildrenAsString != null) {
	return new ArrayList<Object>(Arrays.asList(transientChildrenAsString.split(TRANSIENT_CHILDREN_SEPARATOR)));
	}
	return Collections.emptyList();
	}

	protected String writeTransientChildrenToString(List<Object> transientChildren) {
	Assert.isNotNull(transientChildren);

	List<Object> deresolvedTransientChildren = deresolveTransientChildren(transientChildren);
	StringBuilder transientChildrenAsString = new StringBuilder();
	Iterator<?> iter = deresolvedTransientChildren.iterator();
	while (iter.hasNext()) {
	Object transientChild = iter.next();
	transientChildrenAsString.append(transientChild);

	if (iter.hasNext()) {
	transientChildrenAsString.append(TRANSIENT_CHILDREN_SEPARATOR);
	}
	}
	return transientChildrenAsString.toString();
	}

	protected List<Object> resolveTransientChildren(List<Object> transientChildren) {
	Assert.isNotNull(transientChildren);

	// Transient children already fully resolved?
	if (transientChildren.isEmpty() \|\| !(transientChildren.get(transientChildren.size() - 1) instanceof String)) {
	return transientChildren;
	}
	if (stale) {
	return transientChildren;
	}

	// Get the transient children's parent EObject
	Object parent = getParentEObject();
	if (parent == null) {
	return transientChildren;
	}

	// Resolve transient children
	List<Object> resolvedTransientChildren = new ArrayList<Object>();
	for (Object transientChild : transientChildren) {
	// Current transient child not yet resolved?
	if (transientChild instanceof String) {
	// Resolve ...
	Object resolvedTransientChild = resolveTransientChild(parent, (String) transientChild);

	// ... and store current transient child
	resolvedTransientChildren.add(resolvedTransientChild);
	} else {
	// Store current transient child as is
	resolvedTransientChildren.add(transientChild);
	}

	// Let current transient child be next parent
	parent = transientChild;
	}
	return resolvedTransientChildren;
	}

	protected Object resolveTransientChild(Object parent, String transientChildAsString) {
	IContentProvider contentProvider = viewer.getContentProvider();
	if (contentProvider instanceof ITreeContentProvider) {
	// Content provider ready to return children of given parent?
	if (isTreeContentProviderAvailable(parent)) {
	// Try to find child among the given parent's children that matches specified transient child
	for (Object child : ((ITreeContentProvider) contentProvider).getChildren(parent)) {
	if (child instanceof TransientItemProvider) {
	if (child.getClass().getName().equals(transientChildAsString)) {
	return child;
	}
	}
	if (child instanceof IWrapperItemProvider) {
	IWrapperItemProvider wrapperItemProvider = (IWrapperItemProvider) child;
	Object value = wrapperItemProvider.getValue();
	if (value instanceof EObject) {
	EStructuralFeature feature = wrapperItemProvider.getFeature();
	if (feature != null && feature.getName().equals(transientChildAsString)) {
	return child;
	}
	} else if (value instanceof TransientItemProvider) {
	if (value.getClass().getName().equals(transientChildAsString)) {
	return child;
	}
	}
	}
	}

	// At this point we know that specified transient child can definitely not be found and that transient
	// element targeted by this tree element state provider does not exist
	stale = true;
	}
	}
	return transientChildAsString;
	}

	protected List<Object> deresolveTransientChildren(List<Object> transientChildren) {
	Assert.isNotNull(transientChildren);

	// Deresolve transient children
	List<Object> deresolvedTransientChildren = new ArrayList<Object>();
	for (Object transientChild : transientChildren) {
	// Current transient child not yet deresolved?
	if (!(transientChild instanceof String)) {
	// Deresolve ...
	Object deresolvedTransientChild = deresolveTransientChild(transientChild);

	// ... and store current transient child
	deresolvedTransientChildren.add(deresolvedTransientChild);
	} else {
	// Store current transient child as is
	deresolvedTransientChildren.add(transientChild);
	}
	}
	return deresolvedTransientChildren;
	}

	protected Object deresolveTransientChild(Object transientChild) {
	if (transientChild instanceof TransientItemProvider) {
	return transientChild.getClass().getName();
	} else if (transientChild instanceof IWrapperItemProvider) {
	IWrapperItemProvider wrapperItemProvider = (IWrapperItemProvider) transientChild;
	Object value = wrapperItemProvider.getValue();
	if (value instanceof EObject) {
	EStructuralFeature feature = wrapperItemProvider.getFeature();
	if (feature != null) {
	return feature.getName();
	}
	} else if (value instanceof TransientItemProvider) {
	return value.getClass().getName();
	}
	}
	return transientChild;
	}

	protected Object getLastTransientChild() {
	if (!transientChildren.isEmpty()) {
	Object lastTransientChild = transientChildren.get(transientChildren.size() - 1);
	if (!(lastTransientChild instanceof String)) {
	return lastTransientChild;
	}
	}
	return null;
	}

	@Override
	public boolean hasUnderlyingModel() {
	return true;
	}

	@Override
	public boolean canUnderlyingModelBeLoaded() {
	return EcoreResourceUtil.exists(parentURI);
	}

	@Override
	public boolean isUnderlyingModelLoaded() {
	return EcorePlatformUtil.getResource(parentURI) != null;
	}

	@Override
	public void loadUnderlyingModel() {
	IFile file = EcorePlatformUtil.getFile(parentURI);
	IModelDescriptor modelDescriptor = ModelDescriptorRegistry.INSTANCE.getModel(file);
	if (modelDescriptor != null) {
	// Request asynchronous loading of model behind given workspace file
	ModelLoadManager.INSTANCE.loadModel(modelDescriptor, true, null);
	}
	}

	@Override
	public boolean isStale() {
	return stale;
	}

	@Override
	public Object getTreeElement() {
	transientChildren = resolveTransientChildren(transientChildren);
	return getLastTransientChild();
	}

	@Override
	public void appendToMemento(IMemento parentMemento) {
	if (parentURI != null) {
	IMemento memento = parentMemento.createChild(TreeElementStateProviderFactory.MEMENTO_TYPE_ELEMENT_TRANSIENT);
	memento.putString(TreeElementStateProviderFactory.MEMENTO_KEY_PARENT_URI, parentURI.toString());
	String transientChildrenAsString = writeTransientChildrenToString(transientChildren);
	memento.putString(TreeElementStateProviderFactory.MEMENTO_KEY_TRANSIENT_CHILDREN, transientChildrenAsString);
	}
	}

	@Override
	public String toString() {
	return "TransientElementProvider [parentURI=" + parentURI + ", transientChildren=" + writeTransientChildrenToString(transientChildren) + "]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
	}
	}