[haiku-appserver] Re: drawing thread

  • From: Adi Oanca <adioanca@xxxxxxxxxxxxxx>
  • To: haiku-appserver@xxxxxxxxxxxxx
  • Date: Wed, 27 Oct 2004 12:49:57 +0300

Hi,

Stefano Ceccherini wrote:
>>      Begin/EndViewTransaction() caches the whole >BView::Draw() in a 
>> BPicture just like you said - for 
>>every BView in window. When EndViewTransaction() is called, >app_server will 
>>update each affected 
>>view (the ones for which BPicture is not empty(or NULL)) but <instead of 
>>sending the _UPDATE_ message 
>>if renders the associated BPicture's data.
> 
> 
> Hmmm not exactly.
> Here:
> http://www.beatjapan.org/mirror/www.be.com/aboutbe/benewsletter/volume_II/Issue45.html
> 
> "The view system will behave as before without these calls, but if you 
> bracket resizing and moving of
  views between these two calls, the parent's clipping region is not 
recalculated until the call to
  EndViewTransaction(). These calls also do implicit DisableUpdates() and 
EnableUpdates()."

        :-)) This funny!
        When I wrote this email in the morning, I wanted to say that Stefano 
knows better because he gave 
me once the link from above. It is now that I have remembered that I forgot to 
mention that. :-)) Sorry.

> So it's just the clipping region that is not recalculated.
 > It's not written anywhere that it stores the data in a BPicture.

        That makes _a lot_ of sense. Thanks Stefano!



Bye,
Adi.

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