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Re: Design thought for callbacks

Subject Re: Design thought for callbacks
From Cem Karan <cfkaran2@gmail.com>
Date 2015-02-22 07:07 -0500
References (3 earlier) <CAPTjJmrfMowbK7z+eN7xfMv2Ck5peJpBPyBRHvhXM4-ocxRR6w@mail.gmail.com> <BB15CAE6-4C31-4544-A9DE-DC9D6F827B45@gmail.com> <CAPTjJmrA2suEdKDZkn44Xxsq4m_mZ=Jf6C19GvBjoBfCaTEyzg@mail.gmail.com> <C82546F4-1CBB-4D83-834F-CF1BAE52E8E9@gmail.com> <CAPTjJmoZsB8=xpadFp_S5TFqHcSjW9kO-SfmJzM2dLvq+yCPRA@mail.gmail.com>
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On Feb 21, 2015, at 10:55 AM, Chris Angelico <rosuav@gmail.com> wrote:

> On Sun, Feb 22, 2015 at 2:45 AM, Cem Karan <cfkaran2@gmail.com> wrote:
>> OK, so if I'm reading your code correctly, you're breaking the cycle in your object graph by making the GUI the owner of the callback, correct?  No other chunk of code has a reference to the callback, correct?
> 
> Correct. The GUI engine ultimately owns everything. Of course, this is
> a very simple case (imagine a little notification popup; you don't
> care about it, you don't need to know when it's been closed, the only
> event on it is "hit Close to destroy the window"), and most usage
> would have other complications, but it's not uncommon for me to build
> a GUI program that leaves everything owned by the GUI engine.
> Everything is done through callbacks. Destroy a window, clean up its
> callbacks. The main window will have an "on-deletion" callback that
> terminates the program, perhaps. It's pretty straight-forward.

How do you handle returning information?  E.g., the user types in a number and expects that to update the internal state of your code somewhere.

Thanks,
Cem Karan

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Re: Design thought for callbacks Cem Karan <cfkaran2@gmail.com> - 2015-02-22 07:07 -0500

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