Remove UI dependencies to JCR.

[lgpl/argeo-commons.git] / jcr / org.argeo.cms.jcr.ui / src / org / argeo / eclipse / ui / jcr / AsyncUiEventListener.java

diff --git a/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/AsyncUiEventListener.java b/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/AsyncUiEventListener.java
new file mode 100644 (file)
index 0000000..b880a63
--- /dev/null
+++ b/jcr/org.argeo.cms.jcr.ui/src/org/argeo/eclipse/ui/jcr/AsyncUiEventListener.java
@@ -0,0 +1,83 @@
+package org.argeo.eclipse.ui.jcr;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.jcr.RepositoryException;
+import javax.jcr.observation.Event;
+import javax.jcr.observation.EventIterator;
+import javax.jcr.observation.EventListener;
+
+import org.argeo.api.cms.CmsLog;
+import org.argeo.eclipse.ui.EclipseUiException;
+import org.eclipse.swt.widgets.Display;
+
+/**
+ * {@link EventListener} which simplifies running actions within the UI thread.
+ */
+public abstract class AsyncUiEventListener implements EventListener {
+       // private final static Log logSuper = LogFactory
+       // .getLog(AsyncUiEventListener.class);
+       private final CmsLog logThis = CmsLog.getLog(getClass());
+
+       private final Display display;
+
+       public AsyncUiEventListener(Display display) {
+               super();
+               this.display = display;
+       }
+
+       /** Called asynchronously in the UI thread. */
+       protected abstract void onEventInUiThread(List<Event> events) throws RepositoryException;
+
+       /**
+        * Whether these events should be processed in the UI or skipped with no UI
+        * job created.
+        */
+       protected Boolean willProcessInUiThread(List<Event> events) throws RepositoryException {
+               return true;
+       }
+
+       protected CmsLog getLog() {
+               return logThis;
+       }
+
+       public final void onEvent(final EventIterator eventIterator) {
+               final List<Event> events = new ArrayList<Event>();
+               while (eventIterator.hasNext())
+                       events.add(eventIterator.nextEvent());
+
+               if (logThis.isTraceEnabled())
+                       logThis.trace("Received " + events.size() + " events");
+
+               try {
+                       if (!willProcessInUiThread(events))
+                               return;
+               } catch (RepositoryException e) {
+                       throw new EclipseUiException("Cannot test skip events " + events, e);
+               }
+
+               // Job job = new Job("JCR Events") {
+               // protected IStatus run(IProgressMonitor monitor) {
+               // if (display.isDisposed()) {
+               // logSuper.warn("Display is disposed cannot update UI");
+               // return Status.CANCEL_STATUS;
+               // }
+
+               if (!display.isDisposed())
+                       display.asyncExec(new Runnable() {
+                               public void run() {
+                                       try {
+                                               onEventInUiThread(events);
+                                       } catch (RepositoryException e) {
+                                               throw new EclipseUiException("Cannot process events " + events, e);
+                                       }
+                               }
+                       });
+
+               // return Status.OK_STATUS;
+               // }
+               // };
+               // job.schedule();
+       }
+}