455075: [Properties View] Providers instantiated from DataSource are never updated.

https://bugs.eclipse.org/bugs/show_bug.cgi?id=455075

Implement a delegation strategy for content providers and label providers created by the DataSource.  When its selection is changed, the providers created by a data source ditch and re-create their delegates.

2 files changed, 149 insertions, 4 deletions

diff --git a/plugins/infra/widget/org.eclipse.papyrus.infra.widgets/src/org/eclipse/papyrus/infra/widgets/providers/EncapsulatedContentProvider.java b/plugins/infra/widget/org.eclipse.papyrus.infra.widgets/src/org/eclipse/papyrus/infra/widgets/providers/EncapsulatedContentProvider.java
index 9dcfd50fd82..2358f17c527 100644
--- a/plugins/infra/widget/org.eclipse.papyrus.infra.widgets/src/org/eclipse/papyrus/infra/widgets/providers/EncapsulatedContentProvider.java
+++ b/plugins/infra/widget/org.eclipse.papyrus.infra.widgets/src/org/eclipse/papyrus/infra/widgets/providers/EncapsulatedContentProvider.java
@@ -1,5 +1,5 @@
 /*****************************************************************************

- * Copyright (c) 2010 CEA LIST.

+ * Copyright (c) 2010, 2014 CEA LIST, Christian W. Damus, and others.

  *

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

@@ -8,6 +8,8 @@
  *

  * Contributors:

  *  Camille Letavernier (CEA LIST) camille.letavernier@cea.fr - Initial API and implementation

+ *  Christian W. Damus - bug 455075

+ *  

  *****************************************************************************/

 package org.eclipse.papyrus.infra.widgets.providers;

 

@@ -102,6 +104,23 @@ public class EncapsulatedContentProvider implements IHierarchicContentProvider,
 		// encapsulated = null;

 	}

 

+	/**

+	 * Updates me to encapsulate a new {@code delegate}. If it makes sense for a particular instance, this may

+	 * collapse any chain of providers that are exactly of {@link EncapsulatedContentProvider} type (not some

+	 * subclass that may have different behaviour). If it is necessary to delegate to another encapsulated

+	 * instance as is, then simply assign the protected {@link #encapsulated} field.

+	 * 

+	 * @param delegate

+	 *            my new delegate, or {@code null} to simply forget the previous delegate

+	 */

+	protected void encapsulate(IStructuredContentProvider delegate) {

+		while ((delegate != null) && (delegate.getClass() == EncapsulatedContentProvider.class)) {

+			delegate = ((EncapsulatedContentProvider) delegate).encapsulated;

+		}

+

+		this.encapsulated = delegate;

+	}

+

 	protected void addViewerFilter(StructuredViewer viewer, ViewerFilter filter) {

 		Set<ViewerFilter> currentFilters = new LinkedHashSet<ViewerFilter>(Arrays.asList(viewer.getFilters()));

 		currentFilters.add(filter);

diff --git a/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/modelelement/DataSource.java b/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/modelelement/DataSource.java
index b7aacc6c624..1178da2e99c 100644
--- a/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/modelelement/DataSource.java
+++ b/plugins/views/properties/org.eclipse.papyrus.views.properties/src/org/eclipse/papyrus/views/properties/modelelement/DataSource.java
@@ -1,5 +1,5 @@
 /*****************************************************************************

- * Copyright (c) 2010, 2014 CEA LIST and others.

+ * Copyright (c) 2010, 2014 CEA LIST, Christian W. Damus, and others.

  *

  * All rights reserved. This program and the accompanying materials

  * are made available under the terms of the Eclipse Public License v1.0

@@ -10,12 +10,14 @@
  *  Camille Letavernier (CEA LIST) camille.letavernier@cea.fr - Initial API and implementation

  *  Thibault Le Ouay t.leouay@sherpa-eng.com - Add binding implementation

  *  Christian W. Damus (CEA) - bug 417409

+ *  Christian W. Damus - bug 455075

  *

  *****************************************************************************/

 package org.eclipse.papyrus.views.properties.modelelement;

 

 import java.util.HashMap;

 import java.util.Map;

+import java.util.concurrent.CopyOnWriteArrayList;

 

 import org.eclipse.core.databinding.observable.ChangeEvent;

 import org.eclipse.core.databinding.observable.IChangeListener;

@@ -23,12 +25,17 @@ import org.eclipse.core.databinding.observable.IObservable;
 import org.eclipse.core.databinding.validation.IValidator;

 import org.eclipse.core.runtime.ListenerList;

 import org.eclipse.jface.viewers.ILabelProvider;

+import org.eclipse.jface.viewers.ILabelProviderListener;

 import org.eclipse.jface.viewers.IStructuredSelection;

+import org.eclipse.jface.viewers.LabelProvider;

+import org.eclipse.jface.viewers.LabelProviderChangedEvent;

 import org.eclipse.papyrus.infra.widgets.creation.ReferenceValueFactory;

 import org.eclipse.papyrus.infra.widgets.providers.EmptyContentProvider;

+import org.eclipse.papyrus.infra.widgets.providers.EncapsulatedContentProvider;

 import org.eclipse.papyrus.infra.widgets.providers.IStaticContentProvider;

 import org.eclipse.papyrus.views.properties.Activator;

 import org.eclipse.papyrus.views.properties.contexts.View;

+import org.eclipse.swt.graphics.Image;

 

 /**

  * A DataSource is an object encapsulating one or more {@link ModelElement}s.

@@ -143,7 +150,44 @@ public class DataSource implements IChangeListener {
 	 * @return

 	 *         The IStaticContentProvider corresponding to the given propertyPath

 	 */

-	public IStaticContentProvider getContentProvider(String propertyPath) {

+	public IStaticContentProvider getContentProvider(final String propertyPath) {

+		class Delegator extends EncapsulatedContentProvider implements IDataSourceListener {

+

+			{

+				createDelegate();

+				DataSource.this.addDataSourceListener(this);

+			}

+

+			@Override

+			public void dispose() {

+				disposeDelegate();

+				DataSource.this.removeDataSourceListener(this);

+			}

+

+			private void disposeDelegate() {

+				if (encapsulated != null) {

+					encapsulated.dispose();

+					encapsulated = null;

+				}

+

+				// If I had any temporary elements, then they cannot now be relevant

+				clearTemporaryElements();

+			}

+

+			private void createDelegate() {

+				encapsulate(doGetContentProvider(propertyPath));

+			}

+

+			public void dataSourceChanged(DataSourceChangedEvent event) {

+				disposeDelegate();

+				createDelegate();

+			}

+		}

+

+		return new Delegator();

+	}

+

+	protected IStaticContentProvider doGetContentProvider(String propertyPath) {

 		ModelElement element = getModelElement(propertyPath);

 		if (element == null) {

 			return EmptyContentProvider.instance;

@@ -162,7 +206,89 @@ public class DataSource implements IChangeListener {
 	 * @return

 	 *         The ILabelProvider corresponding to the given propertyPath

 	 */

-	public ILabelProvider getLabelProvider(String propertyPath) {

+	public ILabelProvider getLabelProvider(final String propertyPath) {

+		class Delegator extends LabelProvider implements IDataSourceListener, ILabelProviderListener {

+			private ILabelProvider delegate;

+

+			private final CopyOnWriteArrayList<ILabelProviderListener> listeners = new CopyOnWriteArrayList<ILabelProviderListener>();

+

+			{

+				DataSource.this.addDataSourceListener(this);

+			}

+

+			@Override

+			public void dispose() {

+				disposeDelegate();

+				super.dispose();

+			}

+

+			private void disposeDelegate() {

+				if (delegate != null) {

+					delegate.removeListener(this);

+					delegate.dispose();

+					delegate = null;

+				}

+			}

+

+			public void dataSourceChanged(DataSourceChangedEvent event) {

+				disposeDelegate();

+			}

+

+			@Override

+			public void addListener(ILabelProviderListener listener) {

+				listeners.addIfAbsent(listener);

+			}

+

+			@Override

+			public void removeListener(ILabelProviderListener listener) {

+				listeners.remove(listener);

+			}

+

+			public void labelProviderChanged(LabelProviderChangedEvent event) {

+				if (!listeners.isEmpty()) {

+					LabelProviderChangedEvent forward = new LabelProviderChangedEvent(this, event.getElements());

+					for (ILabelProviderListener next : listeners) {

+						try {

+							next.labelProviderChanged(forward);

+						} catch (Exception e) {

+							Activator.log.error("Uncaught exception in label provider listener.", e); //$NON-NLS-1$

+						}

+					}

+				}

+			}

+

+			ILabelProvider getDelegate() {

+				if (delegate == null) {

+					delegate = doGetLabelProvider(propertyPath);

+					if (delegate == null) {

+						delegate = new LabelProvider();

+					}

+					delegate.addListener(this);

+				}

+

+				return delegate;

+			}

+

+			@Override

+			public Image getImage(Object element) {

+				return getDelegate().getImage(element);

+			}

+

+			@Override

+			public String getText(Object element) {

+				return getDelegate().getText(element);

+			}

+

+			@Override

+			public boolean isLabelProperty(Object element, String property) {

+				return getDelegate().isLabelProperty(element, property);

+			}

+		}

+

+		return new Delegator();

+	}

+

+	protected ILabelProvider doGetLabelProvider(String propertyPath) {

 		ModelElement element = getModelElement(propertyPath);

 		if (element == null) {

 			return null;