[announce] InhiBeans: mitigate redundant recalculations

[Tomas Mikula]

As a matter of fact, I have. Only to the extent of the "Principles of
Reactive Programming" [1] course that is currently in progress on
Coursera. From what I have seen so far, it's all about asynchronous
composition (with emphasis on both "asynchronous" and "composition").
I didn't see it addressing this specific problem of multiple redundant
updates, but I might be wrong. The truth is, this problem doesn't even
exist if you don't have any eager observers (i.e. when you don't ever
attach any ChangeListeners, and InvalidationListeners only propagate
invalidation and never require the value to be recomputed). The
problem is, although you can design your component without any eager
evaluation (JavaFX bindings are already composed this way), you then
bind a Label.textProperty() to the end of a binding chain and it all
becomes eager.

Regards,
Tomas

[1] https://www.coursera.org/course/reactive

On Mon, Dec 16, 2013 at 5:30 PM, Richard Bair <richard.bair at oracle.com> wrote:
> Have you looked at https://github.com/Netflix/RxJava by chance? I've been dying to see somebody do an RxJava in JavaFX ever since devoxx and it looks like you may have inadvertently started down that path :-).
>
> Richard
>
> On Dec 16, 2013, at 8:09 AM, Tomas Mikula <tomas.mikula at gmail.com> wrote:
>
>> On Mon, Dec 16, 2013 at 1:47 AM, Tomas Mikula <tomas.mikula at gmail.com> wrote:
>>> On Mon, Dec 16, 2013 at 1:07 AM, Scott Palmer <swpalmer at gmail.com> wrote:
>>>> Interesting, no worse than John's pattern though.
>>>> I thought of using a try/finally to make sure release was called and that
>>>> naturally lead to thinking of try-with-resources, where the "resource" in
>>>> this case is a binding of some sort (or a wrapper around a binding) that is
>>>> invalidated on close() if needed.
>>>
>>> That is an interesting idea. I didn't intend blockWhile() to be safe
>>> with respect to exceptions, but merely
>>>
>>> void blockWhile(Runnable r) {
>>>    block();
>>>    r.run();
>>>    release();
>>> }
>>>
>>> Enhancement you are suggesting could be fleshed out as block()
>>> returning an AutoCloseable and the usage would be
>>>
>>> try(AutoCloseable a = relaxedArea.block()) {
>>>    obj.setWidth(w);
>>>    obj.setHeight(h);
>>> }
>>
>> OK, done. I implemented both:
>> 1. added the blockWhile() method;
>> 2. made bindings AutoCloseable, and block() returns `this`.
>>
>> Tomas
>