Harvest convertible module inputs

When harvesting inputs via WidgetModel, inputs that are convertible to
the desired type will now be added to the object pool and automatically
converted when set as a module input's value.

Author: hinerm

src/main/java/org/scijava/widget/AbstractInputHarvester.java

@@ -35,6 +35,7 @@
 import java.util.List;
 
 import org.scijava.AbstractContextual;
+import org.scijava.convert.ConvertService;
 import org.scijava.module.Module;
 import org.scijava.module.ModuleCanceledException;
 import org.scijava.module.ModuleException;
@@ -63,6 +64,9 @@ public abstract class AbstractInputHarvester<P, W> extends AbstractContextual
 	@Parameter
 	private ObjectService objectService;
 
+	@Parameter
+	private ConvertService convertService;
+
 	// -- InputHarvester methods --
 
 	@Override
@@ -142,9 +146,13 @@ private <T> WidgetModel addInput(final InputPanel<P, W> inputPanel,
 		return null;
 	}
 
-	/** Asks the object service for valid choices */
-	private <T> List<T> getObjects(final Class<T> type) {
-		return objectService.getObjects(type);
+	/** Asks the object service and convert service for valid choices */
+	@SuppressWarnings("unchecked")
+	private List<?> getObjects(final Class<?> type) {
+		@SuppressWarnings("rawtypes")
+		List compatibleInputs = convertService.getCompatibleInputs(type);
+		compatibleInputs.addAll(objectService.getObjects(type));
+		return compatibleInputs;
 	}
 
 }

src/main/java/org/scijava/widget/WidgetModel.java

@@ -33,10 +33,13 @@
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
+import java.util.WeakHashMap;
 
 import org.scijava.AbstractContextual;
 import org.scijava.Context;
 import org.scijava.ItemVisibility;
+import org.scijava.convert.ConvertService;
 import org.scijava.log.LogService;
 import org.scijava.module.MethodCallException;
 import org.scijava.module.Module;
@@ -59,10 +62,14 @@ public class WidgetModel extends AbstractContextual {
 	private final Module module;
 	private final ModuleItem<?> item;
 	private final List<?> objectPool;
+	private final Map<Object, Object> convertedObjectPool;
 
 	@Parameter
 	private ThreadService threadService;
 
+	@Parameter
+	private ConvertService convertService;
+
 	@Parameter(required = false)
 	private LogService log;
 
@@ -76,6 +83,7 @@ public WidgetModel(final Context context, final InputPanel<?, ?> inputPanel,
 		this.module = module;
 		this.item = item;
 		this.objectPool = objectPool;
+		convertedObjectPool = new WeakHashMap<Object, Object>();
 	}
 
 	/** Gets the input panel intended to house the widget. */
@@ -159,7 +167,25 @@ public Object getValue() {
 	public void setValue(final Object value) {
 		final String name = item.getName();
 		if (MiscUtils.equal(item.getValue(module), value)) return; // no change
-		module.setInput(name, value);
+
+		// Check if a converted value is present
+		Object convertedInput = convertedObjectPool.get(value);
+		if (convertedInput != null &&
+			MiscUtils.equal(item.getValue(module), convertedInput))
+		{
+			return; // no change
+		}
+
+		// Pass the vale through the convertService
+		convertedInput = convertService.convert(value, item.getType());
+
+		// If we get a different (covnerted) value back, cache it weakly.
+		if (convertedInput != value) {
+			convertedObjectPool.put(value, convertedInput);
+		}
+
+		module.setInput(name, convertedInput);
+
 		if (initialized) {
 			threadService.run(new Runnable() {
 
@@ -363,6 +389,11 @@ private Object ensureValidObject(final Object value) {
 	private Object ensureValid(final Object value, final List<?> list) {
 		for (final Object o : list) {
 			if (o.equals(value)) return value; // value is valid
+			// check if value was converted and cached
+			final Object convertedValue = convertedObjectPool.get(o);
+			if (convertedValue != null && value.equals(convertedValue)) {
+				return convertedValue;
+			}
 		}
 
 		// value is not valid; override with the first item on the list instead