Cancel modules when preprocessors are canceled

If the preprocessor of a module was canceled, it was not causing the
module itself to be canceled. For example, if the file chooser dialog
was canceled during OpenImage execution, the OpenImage module was not
actually marked as canceled.

Now, if a preprocessor is canceled, we cancel the whole module. This
should allow appropriate response to preprocessor cancelation.

Author: hinerm

src/main/java/org/scijava/module/ModuleRunner.java

@@ -156,20 +156,19 @@ public void run() {
 		final ModulePreprocessor canceler = preProcess();
 		if (canceler != null) {
 			// module execution was canceled by preprocessor
-			cancel(title, canceler.getCancelReason());
+			final String reason = canceler.getCancelReason();
+			cancel(reason);
+			cleanupAndBroadcastCancelation(title, reason);
 			return;
 		}
 
 		// execute module
 		if (es != null) es.publish(new ModuleExecutingEvent(module));
 		module.run();
-		if (module instanceof Cancelable) {
-			final Cancelable cancelable = (Cancelable) module;
-			if (cancelable.isCanceled()) {
-				// module execution was canceled by the module itself
-				cancel(title, cancelable.getCancelReason());
-				return;
-			}
+		if (isCanceled()) {
+			// module execution was canceled by the module itself
+			cleanupAndBroadcastCancelation(title, getCancelReason());
+			return;
 		}
 		if (es != null) es.publish(new ModuleExecutedEvent(module));
 
@@ -183,7 +182,9 @@ public void run() {
 
 	// -- Helper methods --
 
-	private void cancel(final String title, final String reason) {
+	private void cleanupAndBroadcastCancelation(final String title,
+		final String reason)
+	{
 		if (ss != null) ss.showStatus("Canceling command: " + title);
 		module.cancel();
 		if (es != null) es.publish(new ModuleCanceledEvent(module, reason));
@@ -193,4 +194,18 @@ private void cancel(final String title, final String reason) {
 		}
 	}
 
+	private boolean isCanceled() {
+		return module instanceof Cancelable && ((Cancelable) module).isCanceled();
+	}
+
+	private String getCancelReason() {
+		return module instanceof Cancelable ?
+			((Cancelable) module).getCancelReason() : null;
+	}
+
+	private void cancel(final String reason) {
+		if (!(module instanceof Cancelable)) return;
+		((Cancelable) module).cancel(reason);
+	}
+
 }