ResultsPostprocessor: handle Object outputs better

If the output type is Object, let's look at the actual object value when
deciding whether to lump it into the table. We use this heuristic here
because an Object output is very often the default "result" output, and
we want that value to show in the table if its type is compatible.

Author: ctrueden

src/main/java/net/imagej/table/process/ResultsPostprocessor.java

@@ -70,7 +70,7 @@ public void process(final Module module) {
 			final String name = output.getName();
 			if (module.isOutputResolved(name)) return;
 			if (module.getOutput(name) == null) return;
-			if (!isSimpleType(output.getType())) return;
+			if (!isSimple(module, output)) return;
 			outputs.add(output);
 		});
 
@@ -104,9 +104,21 @@ public void process(final Module module) {
 
 	// -- Helper methods --
 
+	private boolean isSimple(final Module m, final ModuleItem<?> item) {
+		final Class<?> type = item.getType();
+		return isSimpleType(type) || //
+			// NB: The output is typed on Object -- maybe the default result output.
+			// In this case, let's decide based on the actual value rather than type.
+			type == Object.class && isSimpleValue(item.getValue(m));
+	}
+
 	private boolean isSimpleType(final Class<?> type) {
 		return ClassUtils.isText(type) || //
 			ClassUtils.isNumber(type) || //
 			ClassUtils.isBoolean(type);
 	}
+
+	private boolean isSimpleValue(final Object o) {
+		return o != null && isSimpleType(o.getClass());
+	}
 }