Merge pull request #114 from scijava/event-publication-thread

Save reference to the calling thread in each event

Author: ctrueden

src/main/java/org/scijava/event/DefaultEventService.java

@@ -91,12 +91,14 @@ public class DefaultEventService extends AbstractService implements
 	@Override
 	public <E extends SciJavaEvent> void publish(final E e) {
 		e.setContext(getContext());
+		e.setCallingThread(Thread.currentThread());
 		eventBus.publishNow(e);
 	}
 
 	@Override
 	public <E extends SciJavaEvent> void publishLater(final E e) {
 		e.setContext(getContext());
+		e.setCallingThread(Thread.currentThread());
 		eventBus.publishLater(e);
 	}
 

src/main/java/org/scijava/event/SciJavaEvent.java

@@ -40,8 +40,15 @@
  */
 public abstract class SciJavaEvent extends AbstractContextual {
 
+	/** Whether the event has been handled already. */
 	private boolean consumed;
 
+	/** The thread which published this event. */
+	private Thread callingThread;
+
+	/** The stack trace of the calling thread when the event was published. */
+	private StackTraceElement[] stackTrace;
+
 	// -- SciJavaEvent methods --
 
 	public boolean isConsumed() {
@@ -56,6 +63,25 @@ public void consume() {
 		setConsumed(true);
 	}
 
+	/** Gets the thread that published the event. */
+	public Thread getCallingThread() {
+		return callingThread;
+	}
+
+	/** Sets the thread that published the event. */
+	public void setCallingThread(final Thread callingThread) {
+		this.callingThread = callingThread;
+		stackTrace = callingThread.getStackTrace();
+	}
+
+	/**
+	 * Gets the stack trace of the calling thread when the event was published.
+	 * This method is useful for debugging what triggered an event.
+	 */
+	public StackTraceElement[] getStackTrace() {
+		return stackTrace;
+	}
+
 	// Object methods --
 
 	@Override