[racket] how to stop canvas% from refreshing after on-event

I was using os x 10.7.5 (and saw the same flashing).


On Tue, Feb 12, 2013 at 12:59 PM, Philipp Dikmann <philipp at dikmann.de>wrote:

> The OS here is Mac OS 10.6.8, running Racket 5.3.1 -
> so I guess its an issue with the OpenGL implementation.
> Thanks for taking a look, though :)
>
>
>
> On 12.02.13 19:37, Michael Wilber wrote:
>
>> Your OpenGL example still doesn't flash for me when I move the mouse
>> over it, on 64-bit linux.
>>
>> It does, however, flash when I change window focus... for some reason?
>>
>> What OS are you using?
>>
>> Philipp Dikmann <philipp at dikmann.de> writes:
>>
>>> I'm sorry, I should have been more specific – it happens when using a
>>> gl-enabled canvas (example below).
>>> I hope that does not turn it into a dragons' den? ;)
>>>
>>> Philipp
>>>
>>> #lang racket/gui
>>>
>>> (require sgl)
>>>
>>> (define c%
>>>     (class canvas%
>>>       (inherit with-gl-context swap-gl-buffers)
>>>       (define/override (on-paint)
>>>         (with-gl-context
>>>          (lambda ()
>>>            (gl-clear-color (random) (random) (random) 1)
>>>            (gl-clear 'color-buffer-bit)
>>>            (swap-gl-buffers)
>>>            (gl-flush))))
>>>       (super-new (style '(gl no-autoclear)))))
>>>
>>> (define f (new frame% [label ""] [width 100] [height 100]))
>>> (define c (new c% [parent f]))
>>> (send f show #t)
>>>
>>>
>>> On 11.02.13 22:39, Robby Findler wrote:
>>>
>>>> I don't think it does that. The program below, at least for me,
>>>> doesn't do crazy colors when I move the mouse around (it does when
>>>> resizing, tho).
>>>>
>>>> Robby
>>>>
>>>> #lang racket/gui
>>>>
>>>> (define c%
>>>>    (class canvas%
>>>>      (inherit get-client-size get-dc)
>>>>      (define/override (on-paint)
>>>>        (define-values (w h) (get-client-size))
>>>>        (define dc (get-dc))
>>>>        (define c (make-object color% (random 255) (random 255) (random
>>>> 255)))
>>>>        (send dc set-brush c 'solid)
>>>>        (send dc set-pen "black" 1 'transparent)
>>>>        (send dc draw-ellipse 0 0 w h))
>>>>      (super-new)))
>>>>
>>>> (define f (new frame% [label ""] [width 100] [height 100]))
>>>> (define c (new c% [parent f]))
>>>> (send f show #t)
>>>>
>>>>
>>>> On Mon, Feb 11, 2013 at 9:41 AM, Philipp Dikmann <philipp at dikmann.de
>>>> <mailto:philipp at dikmann.de>> wrote:
>>>>
>>>>      It appears that the GUI canvas% refreshes itself whenever it
>>>>      receives a mouse-event%.
>>>>      I intend to refresh the canvas at a steady pace (using a timer%)
>>>>      and independently of any mouse-events instead.
>>>>      Is there a reasonable way to suppress the default behavior?
>>>>
>>>>      Thanks for your time,
>>>>      Philipp
>>>>      ____________________
>>>>       Racket Users list:
>>>>      http://lists.racket-lang.org/**users<http://lists.racket-lang.org/users>
>>>>
>>>>
>>>>  ____________________
>>>    Racket Users list:
>>>    http://lists.racket-lang.org/**users<http://lists.racket-lang.org/users>
>>>
>>
>
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