Bug 371087 - [EAP] No way to store UI-State like in 3.x with IMementov20120213-1719

* added new annotation
* implemented in rendering lifecycle
* added unit tests

4 files changed, 129 insertions, 2 deletions

diff --git a/bundles/org.eclipse.e4.ui.di/src/org/eclipse/e4/ui/di/PersistState.java b/bundles/org.eclipse.e4.ui.di/src/org/eclipse/e4/ui/di/PersistState.java
new file mode 100644
index 0000000..6f6d3ff
--- a/dev/null
+++ b/bundles/org.eclipse.e4.ui.di/src/org/eclipse/e4/ui/di/PersistState.java
@@ -0,0 +1,33 @@
+/*******************************************************************************
+ * Copyright (c) 2012 BestSolution.at 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:
+ *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.e4.ui.di;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Parts can specify this annotation on one of the methods to tag it as the
+ * method that performs the "visual state persit" operation
+ * <p>
+ * This annotation must not be applied to more than one method on a class. If multiple methods of
+ * the class are tagged with this this annotation, only one of them will be called to persist visual 
+ * state.
+ * </p>
+ */
+@Documented
+@Target({ ElementType.METHOD })
+@Retention(RetentionPolicy.RUNTIME)
+public @interface PersistState {
+	// intentionally left empty
+}
\ No newline at end of file
diff --git a/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java b/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
index 98417fb..1c170d8 100644
--- a/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
+++ b/bundles/org.eclipse.e4.ui.workbench.swt/src/org/eclipse/e4/ui/internal/workbench/swt/PartRenderingEngine.java
@@ -38,6 +38,7 @@ import org.eclipse.e4.ui.css.core.util.impl.resources.OSGiResourceLocator;
 import org.eclipse.e4.ui.css.swt.engine.CSSSWTEngineImpl;
 import org.eclipse.e4.ui.css.swt.theme.IThemeEngine;
 import org.eclipse.e4.ui.css.swt.theme.IThemeManager;
+import org.eclipse.e4.ui.di.PersistState;
 import org.eclipse.e4.ui.internal.workbench.Activator;
 import org.eclipse.e4.ui.internal.workbench.E4Workbench;
 import org.eclipse.e4.ui.internal.workbench.Policy;
@@ -814,6 +815,22 @@ public class PartRenderingEngine implements IPresentationEngine {
 				}
 			}
 
+			if (element instanceof MContribution) {
+				MContribution contribution = (MContribution) element;
+				Object client = contribution.getObject();
+				IEclipseContext parentContext = renderer.getContext(element);
+				if (parentContext != null && client != null) {
+					try {
+						ContextInjectionFactory.invoke(client,
+								PersistState.class, parentContext);
+					} catch (Exception e) {
+						if (logger != null) {
+							logger.error(e);
+						}
+					}
+				}
+			}
+
 			renderer.disposeWidget(element);
 
 			// unset the client object
diff --git a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
index 3a0b33a..7cacc50 100644
--- a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
+++ b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/PartRenderingEngineTests.java
@@ -3235,4 +3235,66 @@ public class PartRenderingEngineTests extends TestCase {
 
 		assertFalse(logged);
 	}
+
+	public void test_persistState_371087() {
+		MApplication application = ApplicationFactoryImpl.eINSTANCE
+				.createApplication();
+		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
+		application.getChildren().add(window);
+		application.setSelectedElement(window);
+
+		MPart part = BasicFactoryImpl.eINSTANCE.createPart();
+		part.setContributionURI("bundleclass://org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
+		window.getChildren().add(part);
+		window.setSelectedElement(part);
+
+		application.setContext(appContext);
+		appContext.set(MApplication.class.getName(), application);
+
+		wb = new E4Workbench(application, appContext);
+		wb.createAndRunUI(window);
+
+		assertNotNull(part.getObject());
+		assertNotNull(part.getContext());
+
+		SampleView view = (SampleView) part.getObject();
+		view.errorOnWidgetDisposal = true;
+
+		part.setToBeRendered(false);
+		assertTrue("The view should have been destroyed",
+				view.isStatePersisted());
+		assertNull(part.getObject());
+		assertNull(part.getContext());
+	}
+
+	public void test_persistState_371087_1() {
+		MApplication application = ApplicationFactoryImpl.eINSTANCE
+				.createApplication();
+		MWindow window = BasicFactoryImpl.eINSTANCE.createWindow();
+		application.getChildren().add(window);
+		application.setSelectedElement(window);
+
+		MPart part = BasicFactoryImpl.eINSTANCE.createPart();
+		part.setContributionURI("bundleclass://org.eclipse.e4.ui.tests/org.eclipse.e4.ui.tests.workbench.SampleView");
+		window.getChildren().add(part);
+		window.setSelectedElement(part);
+
+		application.setContext(appContext);
+		appContext.set(MApplication.class.getName(), application);
+
+		wb = new E4Workbench(application, appContext);
+		wb.createAndRunUI(window);
+
+		assertNotNull(part.getObject());
+		assertNotNull(part.getContext());
+
+		SampleView view = (SampleView) part.getObject();
+		view.errorOnWidgetDisposal = true;
+
+		window.setToBeRendered(false);
+		assertTrue("The view should have been destroyed",
+				view.isStatePersisted());
+		assertNull(part.getObject());
+		assertNull(part.getContext());
+	}
 }
diff --git a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/SampleView.java b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/SampleView.java
index 0e188d5..3b8b498 100644
--- a/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/SampleView.java
+++ b/tests/org.eclipse.e4.ui.tests/src/org/eclipse/e4/ui/tests/workbench/SampleView.java
@@ -17,6 +17,7 @@ import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.e4.core.contexts.IEclipseContext;
+import org.eclipse.e4.ui.di.PersistState;
 import org.eclipse.e4.ui.services.IServiceConstants;
 import org.eclipse.jface.layout.GridLayoutFactory;
 import org.eclipse.jface.viewers.ISelectionChangedListener;
@@ -46,6 +47,10 @@ public class SampleView {
 
 	boolean nullParentContext = false;
 
+	private TreeViewer viewer;
+
+	private boolean statePersisted;
+
 	/**
 	 * Create the sample view.
 	 * 
@@ -65,8 +70,7 @@ public class SampleView {
 			}
 		});
 
-		TreeViewer viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL
-				| SWT.V_SCROLL);
+		viewer = new TreeViewer(parent, SWT.MULTI | SWT.H_SCROLL | SWT.V_SCROLL);
 		viewer.getTree().setData("class", "navigator"); //$NON-NLS-1$ //$NON-NLS-2$
 		viewer.addSelectionChangedListener(new ISelectionChangedListener() {
 			public void selectionChanged(SelectionChangedEvent event) {
@@ -165,6 +169,17 @@ public class SampleView {
 		}
 	}
 
+	@PersistState
+	void persistState() {
+		if (!viewer.getControl().isDisposed()) {
+			statePersisted = true;
+		}
+	}
+
+	public boolean isStatePersisted() {
+		return statePersisted;
+	}
+
 	public boolean isDestroyed() {
 		return destroyed;
 	}