[plt-scheme] MrEd+Allegro on MacOS

From: alex mitchell (cnmmai at nus.edu.sg)
Date: Sun Mar 2 09:24:04 EST 2008

Hi Jon,

Your theory about the Allegro window stealing input events seems to match my
observations. Let me know if you manage to fix it. :)


On 3/1/08 1:58 PM, "Jon Rafkind" <workmin at ccs.neu.edu> wrote:

> alex mitchell wrote:
>> Hi Jon (and the list),
>> The postings about the Tetris game reminded me of the problems I was having
>> on MacOS with the Allegro Scheme bindings. A while back I was building a
>> simplified version of Logo, using Allegro for the turtle graphics. It was
>> working well under Windows, but on MacOS the MrEd UI elements would stop
>> responding, or only give intermittent, laggy responces, once the Allegro
>> window appeared.
>> Here's a simple example of the problem, which I've tried (unsuccessfully) to
>> solve using a separate thread for the game loop. In this example, there's an
>> Allegro window showing the sample "Hello world" program, and a MrEd window
>> with a single button, which closes the Allegro window. The MrEd button
>> sometimes responds to mouse clicks, but sometimes doesn't, and after closing
>> the program, DrScheme doesn't respond properly, and needs a "force quit" to
>> exit.
> I tried your test program and I was able to click the exit button each
> time, closing the Allegro window. The drscheme window did not respond to
> mouse clicks while the Allegro window was open though, I think thats
> because the Allegro window is stealing input events. I'll see if I can
> fix that.

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