Re: add calculating methods to bind

[Tom Eugelink]

If I ever write a real application, I'm most definitely will use EasyBind. But 
this is for sharping up Agenda in JFXtras. I try to minimize the dependencies.

Tom


On 2014-5-21 22:00, Tomas Mikula wrote:

Just a side note, you could use

     EasyBind.map(heightProperty(), value ->
NodeUtil.snapXY(value.doubleValue() * 0.2));

instead of

     snap(heightProperty().multiply(0.2))

and you don't need your custom DoubleBinding implementation. But note
that it returns Binding<Double>, not DoubleBinding.

EasyBind is at http://www.fxmisc.org/easybind/

Tomas

On Wed, May 21, 2014 at 9:47 PM, Tomas Mikula <tomas.mik...@gmail.com> wrote:

Yeah, and you could also eliminate "Observable... dependencies" from
snap's signature, since now you are not using them to invalidate your
binding.

On Wed, May 21, 2014 at 9:36 PM, Tom Eugelink <t...@tbee.org> wrote:

Found it! Slightly different DoubleBinding was required (copied it from
negate).

     private DoubleBinding snap(final ObservableNumberValue value, final
Observable... dependencies) {
         return new DoubleBinding() {
             {
                 super.bind(value);
             }

             @Override
             public void dispose() {
                 super.unbind(value);
             }

             @Override
             protected double computeValue() {
                 return NodeUtil.snapXY(value.doubleValue());

             }

             @Override
             public ObservableList<?> getDependencies() {
                 return FXCollections.singletonObservableList(value);
             }
         };

     }



On 2014-5-21 21:34, Tomas Mikula wrote:

Hi Tom,

it seems to me that in your custom DoubleBinding implementation
`other` is not its dependency, thus it does not react to it's
invalidations.

Tomas

On Wed, May 21, 2014 at 9:25 PM, Tom Eugelink <t...@tbee.org> wrote:

I came up with this:

startXProperty().bind( *snap(*heightProperty().multiply(0.2)) )


And then:

      private DoubleBinding snap(final ObservableNumberValue other, final
Observable... dependencies) {
          return new DoubleBinding() {
              {
                  super.bind(dependencies);
              }

              @Override
              public void dispose() {
                  super.unbind(dependencies);
              }

              @Override
              protected double computeValue() {
                  return NodeUtil.snap(other.doubleValue());
              }

              @Override
              public ObservableList<?> getDependencies() {
                  return new
ImmutableObservableList<Observable>(dependencies);
              }
          };
      }

But that always returns 0... I feel this should have worked.

Tom