Bug 434658 - execute a feature in an asynchronous job
* Introduced new AbstractAsynchronousCustomFeature
* Added basic example to tutorial
** TutorialLongRunningCustomFeature
Change-Id: Iac463a3a51878c0b20a6145dad6700a2f5c5a2de
diff --git a/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/diagram/TutorialFeatureProvider.java b/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/diagram/TutorialFeatureProvider.java
index ab68e27..5f577a9 100644
--- a/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/diagram/TutorialFeatureProvider.java
+++ b/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/diagram/TutorialFeatureProvider.java
@@ -9,6 +9,7 @@
*
* Contributors:
* SAP AG - initial API, implementation and documentation
+ * mwenz - Bug 434658 - execute a feature in an asynchronous job
*
* </copyright>
*
@@ -29,6 +30,7 @@
import org.eclipse.graphiti.examples.tutorial.features.TutorialDirectEditEClassFeature;
import org.eclipse.graphiti.examples.tutorial.features.TutorialDrillDownEClassFeature;
import org.eclipse.graphiti.examples.tutorial.features.TutorialLayoutEClassFeature;
+import org.eclipse.graphiti.examples.tutorial.features.TutorialLongRunningCustomFeature;
import org.eclipse.graphiti.examples.tutorial.features.TutorialMoveEClassFeature;
import org.eclipse.graphiti.examples.tutorial.features.TutorialPasteEClassFeature;
import org.eclipse.graphiti.examples.tutorial.features.TutorialReconnectionFeature;
@@ -133,7 +135,7 @@
public ICustomFeature[] getCustomFeatures(ICustomContext context) {
return new ICustomFeature[] { new TutorialRenameEClassFeature(this), new TutorialDrillDownEClassFeature(this),
new TutorialAssociateDiagramEClassFeature(this), new TutorialCollapseDummyFeature(this),
- new TutorialChangeColorEClassFeature(this) };
+ new TutorialChangeColorEClassFeature(this), new TutorialLongRunningCustomFeature(this) };
}
@Override
diff --git a/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/features/TutorialLongRunningCustomFeature.java b/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/features/TutorialLongRunningCustomFeature.java
new file mode 100644
index 0000000..bc3f7d4
--- /dev/null
+++ b/examples/org.eclipse.graphiti.examples.tutorial/src/org/eclipse/graphiti/examples/tutorial/features/TutorialLongRunningCustomFeature.java
@@ -0,0 +1,60 @@
+/*******************************************************************************
+ * <copyright>
+ *
+ * Copyright (c) 2014, 2014 SAP AG.
+ * 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:
+ * mwenz - Bug 434658 - execute a feature in an asynchronous job
+ *
+ * </copyright>
+ *
+ *******************************************************************************/
+package org.eclipse.graphiti.examples.tutorial.features;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.graphiti.features.IFeatureProvider;
+import org.eclipse.graphiti.features.context.ICustomContext;
+import org.eclipse.graphiti.features.custom.AbstractAsynchronousCustomFeature;
+
+public class TutorialLongRunningCustomFeature extends AbstractAsynchronousCustomFeature {
+
+ public TutorialLongRunningCustomFeature(IFeatureProvider fp) {
+ super(fp);
+ }
+
+ @Override
+ public String getName() {
+ return "Long running custom feature";
+ }
+
+ @Override
+ public String getDescription() {
+ return "Simple example for a long running feature that is executed in the background showing a progress monitor";
+ }
+
+ @Override
+ public boolean canExecute(ICustomContext context) {
+ return true;
+ }
+
+ @Override
+ protected void execute(ICustomContext context, IProgressMonitor monitor) {
+ monitor.beginTask("Long work", 10);
+ for (int i = 0; i < 10; i++) {
+ try {
+ Thread.sleep(1000);
+ } catch (InterruptedException e) {
+ monitor.setCanceled(true);
+ }
+ monitor.worked(i);
+ if (monitor.isCanceled()) {
+ break;
+ }
+ }
+ monitor.done();
+ }
+}
diff --git a/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/features/custom/AbstractAsynchronousCustomFeature.java b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/features/custom/AbstractAsynchronousCustomFeature.java
new file mode 100644
index 0000000..178046c
--- /dev/null
+++ b/plugins/org.eclipse.graphiti/src/org/eclipse/graphiti/features/custom/AbstractAsynchronousCustomFeature.java
@@ -0,0 +1,192 @@
+/*
+ * <copyright>
+ *
+ * Copyright (c) 2014, IETR/INSA of Rennes
+ * 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:
+ * IETR/INSA of Rennes - initial API, implementation and documentation
+ *
+ * </copyright>
+ *
+ */
+package org.eclipse.graphiti.features.custom;
+
+import java.util.Collection;
+import java.util.Collections;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.OperationCanceledException;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.emf.transaction.RecordingCommand;
+import org.eclipse.emf.transaction.TransactionalEditingDomain;
+import org.eclipse.graphiti.features.IFeatureProvider;
+import org.eclipse.graphiti.features.context.IContext;
+import org.eclipse.graphiti.features.context.ICustomContext;
+
+/**
+ * <p>
+ * This class should be used if for some reason a CustomFeature can be long to
+ * execute. It runs {@link #execute(ICustomContext, IProgressMonitor)} in a
+ * Command on top of current TransactionalEditingDomain. This command itself is
+ * run in a Job, and can use the associated IProgressMonitor
+ * </p>
+ * <p>
+ * This is useful to indicate to users that the job is running, but eclipse has
+ * not crashed.
+ * </p>
+ *
+ * @author Antoine Lorence
+ * @since 0.12
+ */
+public abstract class AbstractAsynchronousCustomFeature extends AbstractCustomFeature {
+
+ public AbstractAsynchronousCustomFeature(IFeatureProvider fp) {
+ super(fp);
+ }
+
+ /**
+ * Concrete code to execute. Sub-classes should use the given monitor
+ * correctly: create tasks (and eventually sub-tasks), notify for worked and
+ * done tasks and check if user cancelled the task.
+ *
+ * @param context
+ * The CustomFeature context
+ * @param monitor
+ * The monitor used to manage progress bar and Job cancellation
+ */
+ protected abstract void execute(ICustomContext context, IProgressMonitor monitor);
+
+ /**
+ * Callback executed just before job scheduling; called in the feature
+ * execution thread. Default implementation is empty.
+ */
+ protected void beforeJobExecution() {
+ }
+
+ /**
+ * Callback executed immediately after job execution in the background job
+ * execution thread. Default implementation is empty.
+ */
+ protected void afterJobExecution() {
+ }
+
+ /**
+ * Initialize the Job.
+ *
+ * @param context
+ * The CustomContext that will be given to
+ * {@link #execute(ICustomContext, IProgressMonitor)}.
+ * @return The Job instance
+ */
+ protected Job initializeJob(final ICustomContext context) {
+ return new Job(getName()) {
+ @Override
+ protected IStatus run(final IProgressMonitor monitor) {
+
+ final TransactionalEditingDomain editingDomain = getDiagramBehavior().getEditingDomain();
+
+ final RecordingCommand command = new RecordingCommand(editingDomain, getName()) {
+
+ private IStatus result = null;
+
+ @Override
+ protected void doExecute() {
+ try {
+ AbstractAsynchronousCustomFeature.this.execute(context, monitor);
+ result = Status.OK_STATUS;
+ } catch (OperationCanceledException e) {
+ result = Status.CANCEL_STATUS;
+ }
+ }
+
+ @Override
+ public Collection<?> getResult() {
+ return result == null ? Collections.EMPTY_LIST : Collections.singletonList(result);
+ }
+ };
+
+ // Execute (synchronously) the defined command in a proper EMF
+ // transaction
+ editingDomain.getCommandStack().execute(command);
+
+ // Update the dirty state of the diagram
+ getDiagramBehavior().getDiagramContainer().updateDirtyState();
+
+ // Callback
+ afterJobExecution();
+
+ return (IStatus) command.getResult().iterator().next();
+ }
+ };
+ }
+
+ /**
+ * Initialize parameters of the given Job
+ *
+ * @param job
+ * The Job instance to configure
+ */
+ protected void configureJob(Job job) {
+ job.setUser(true);
+ job.setPriority(Job.LONG);
+ }
+
+ /**
+ * Must not be overridden in order to guarantee correct delegation to the
+ * background job, see {@link #execute(ICustomContext)}.
+ */
+ @Override
+ final public void execute(IContext context) {
+ super.execute(context);
+ }
+
+ /**
+ * The implementation of this method will during the execution of the
+ * feature trigger the creation of a background job, configure it and
+ * execute it.<br>
+ * Clients should implement their feature functionality in
+ * {@link #execute(ICustomContext, IProgressMonitor)}, potentially also in
+ * the {@link #beforeJobExecution()} and {@link #afterJobExecution()} hooks.
+ * The background job and its behavior can be changed in the methods
+ * {@link #initializeJob(ICustomContext)} and {@link #configureJob(Job)}.
+ *
+ * @param context
+ * The CustomFeature context
+ *
+ */
+ @Override
+ final public void execute(ICustomContext context) {
+
+ final Job job = initializeJob(context);
+ configureJob(job);
+
+ // Callback
+ beforeJobExecution();
+
+ // Job is run
+ job.schedule();
+ }
+
+ /**
+ * The default implementation returns <code>false</code> in any case. This
+ * is usually the desired return value, because this method will be queried
+ * already before the asynchronous feature will be executed (
+ * {@link #execute(ICustomContext, IProgressMonitor)} is called). Returning
+ * <code>true</code> here would mean that users could already undo the
+ * feature while it is still being executed; this would mean also canceling
+ * the a running job. Because of potentially strange effects and complexity
+ * this is not possible.
+ *
+ * @return Always <code>false</code>
+ */
+ @Override
+ final public boolean hasDoneChanges() {
+ return false;
+ }
+}
