Possible additions to JavaFX to facilitate forms and validations

[Knut Arne Vedaa]

On 06.12.2011 17:14, Richard Bair wrote:

 > Oh, I just had a crazy idea. What if we just reused WritableValue? 
Have value holding controls implement WritableValue. Hmmm.

That's not so crazy. Actually, I proposed it in the forum thread. :) 
(Ok, I proposed ObservableValue.)

There's a set of interfaces that may be considered for this.

The simplest would be Observable. That gives you add/remove listener. 
Since these are not parameterized, you could have a List<Control> and 
call them on each item.

Next up is ObservableValue/WritableValue, which gives you 
getValue/+setValue.

Since these are parameterized, you won't be able to iterate through a 
List<Control<T>> and use them on each item without casting; could be 
useful still.

Lastly, Property, which gives you the binding methods as well.

In that case, i.e. class Control<T> implements Property<T>, the control 
would *be* the property for the value it holds, i.e. instead of 
textField.textProperty.bind(someObservable) you could do 
textField.bind(someObservable). The actual methods could just could be 
proxies to the control-specific value property.

(This is what would be compatible with zonski's original proposal.)

I'm not sure how much it gives though, since most controls will hold 
different datatypes so you can't really abstract over them.

Just some quick thoughts.




Knut Arne