CheckboxItem and ChangedHandler

[slovekfhu]

Hi.
I'm facing problem with executing onChanged handler while onChange handler cancels event,
is it normal behavior, or maybe it's a bug ??

here's an example:

DynamicForm form = new DynamicForm();
CheckboxItem checkbox = new CheckboxItem("test", "My CheckBox");
checkbox.addChangeHandler(new ChangeHandler() {
	@Override
	public void onChange(ChangeEvent event) {
		event.cancel();
	}
});
checkbox.addChangedHandler(new ChangedHandler() {
	@Override
	public void onChanged(ChangedEvent event) {
		SC.say("Why is this fired ?");
	}
});
form.setFields(checkbox);

tested on:
SmartClient Version: v8.3_2012-11-20/LGPL Development Only (built 2012-11-20)

FF 16.0.1
Chrome 27,0,1453,116 m

[TWiStErRob]

Change(d)Event semantics

I have the same problem, but here's what I found (all empirical observations):

* Checkbox state is unchecked
* User checks it
* onChange called (remember, because we're checking it):
event.getItem().getValue() == event.getOldValue() == false
event.getValue() == true
* onChange cancels
* ChangeEvent.isCancelled is called and then onChanged is called, but
event.getItem().getValue() == event.getValue() == false!!!

Same for the reverse.

So the semantics of Change(d)Event is the following:
ChangeEvent is fired on change, ChangedEvent is fired after ChangeEvent (always)
if ChangeEvent is cancelled, ChangedEvent.getValue() == ChangeEvent.getOldValue()
if ChangeEvent is intact, ChangedEvent.getValue() == ChangeEvent.getValue()

Can't say anything about multiple Change(d)Handlers right now.