Support cancelation during module initialization

Thanks to Richard Domander for pointing out this limitation.

See: https://gitter.im/fiji/fiji/archives/2015/12/08

Author: ctrueden

src/main/java/org/scijava/module/process/InitPreprocessor.java

@@ -31,6 +31,7 @@
 
 package org.scijava.module.process;
 
+import org.scijava.Cancelable;
 import org.scijava.Priority;
 import org.scijava.log.LogService;
 import org.scijava.module.MethodCallException;
@@ -58,6 +59,7 @@ public class InitPreprocessor extends AbstractPreprocessorPlugin {
 	public void process(final Module module) {
 		try {
 			module.initialize();
+			if (isCanceled(module)) cancel(getCancelReason(module));
 		}
 		catch (final MethodCallException exc) {
 			if (log != null) log.error(exc);
@@ -66,4 +68,16 @@ public void process(final Module module) {
 		}
 	}
 
+	// -- Helper methods --
+
+	private boolean isCanceled(final Module module) {
+		return module instanceof Cancelable && ((Cancelable) module).isCanceled();
+	}
+
+	private String getCancelReason(final Module module) {
+		if (!(module instanceof Cancelable)) return null;
+		final String cancelReason = ((Cancelable) module).getCancelReason();
+		return cancelReason == null ? "" : cancelReason;
+	}
+
 }