Bug 140644 [DataBinding] Binding to ValidationError of DataBindingContext is broken
Hello, I wanted to bind the ValidationError Observable to a Widget, and it doesn't seem to work. I tested with Jface Databinding sample and in TestMasterDetails.java example, instead of binding the simple date error to a label, I bound the ValidationError of DBC to the Label (with a simple converter). dbc.bind(validationError, dbc.getValidationError(), new BindSpec().setUpdateModel(false).setModelToTargetConverter(new IConverter() { public Object convert(Object fromObject) { // TODO Auto-generated method stub if (fromObject == null) return null; return ((ValidationError) fromObject).message; } public Object getFromType() { // TODO Auto-generated method stub return Object.class; } public Object getToType() { // TODO Auto-generated method stub return String.class; } })); After investigating, I saw the ValidationError is a computed value (very interesting concept and useful) on the ValidationErrorList. 1. The ComputedValue mechanism seems to use the StateListener to the Object, but I don't see any management of staleness in ValidationErrorList (or ObservableList). 2. When one of the field gets an error, I debug and saw the ChangedListener on my binding was null (whereas the ValidationErrorList registers listeners on them). At the beginning, it's registered, the removed and not added again when needed. I have not enough time to go deeper in the mechanism, could you help me to understand what I'm doing wrong with this simple binding (With previous releases I was already binding with that mechanism and it worked). Is there an other way to do this? (My workaround is a listener on DBC, but I would prefer to use ValidationError Computed value). Thanks in advance
tests/org.eclipse.jface.tests.databinding/src/org/eclipse/jface/tests/databinding/DatabindingContextTest.java
public IObservable createObservable(Object description) {
			Property property = (Property) description;
			return new MockObservableValue(property.getObject(), property
					.getPropertyID(), property.getPropertyType());
		}
	}
	public class MockObservableValue extends AbstractObservableValue {
		public Object targetObject;
		public Object description;
		private Class type;
		public MockObservableValue(Object targetObject, Object description,
				Class type) {
			super();
			this.targetObject = targetObject;
			this.description = description;
			this.type = type;
		}
		public Object getDescription() {
			return description;
		}
		public Class getType() {
			return type;
		}
		public Object getOuterObservableValue() {
			return targetObject;
		}
		public Object computeValue() {