On Wed, Dec 02, 2009 at 03:07:30PM -0600, Luke Paireepinart wrote: > 3) Reading the SDL Mailing list, I learned that event loss when the > event queue is full is already a topic of discussion for SDL1.3 > > I wouldn't think this is the issue you're running into, otherwise you'd > lose other characters too. It sounds like there's some debouncing code in > the SDL keyboard input handler, which probably shouldn't be there...
Yes, that is right. "1234567890" never drops a single event, but "1111111111" almost always drops all but one or two events... although this behavior is strangely inconsistent. In my stripped-down mimimal test app, the events are lost almost 100% of the time. In my actual full aplication, the events are only ever lost on the first scan. Weird. > I'm sure you've already thought of this, but you could always just open > /dev/keyboard or whatever and manually post keyboard events yourself, or > just use the keyboard data directly... I have no idea where to look for the usb keyboard device associated with the barcode scanner... and even if I could find it, I am fairly certain that my app would have to be running as root if I wanted to read directly fom it, so that would be unacceptable :( > And you could even roll this in to > a module so other people could use it too. Might be hard to make it > cross-platform though and it sucks to have to completely throw out SDL's > keyboard event handling. Also I don't know how you'd keep SDL from > posting repeated events, I guess you'd just create your custom events > under a different event ID and just watch for that ID instead. Re-implementing my application in pygtk or wxpython sounds like a hell of a lot less work :) > 4) I also discovered, while searching for a workaround, an SDL mailing > list post from Sam Lantinga last January mentioning a "simple callback > mechanism for SDL events that bypasses the event queue". Does anybody > know if there is a pygame way to make event callbacks? > > I don't know, but I'd guess it would be possible with Pygame-Ctypes. But > I think Alex is no longer maintaining that module in preference to his > Pyglet module. I did a quick test with Pyglet, and it suffers from the same problem. I take that to mean that using sdl event callbacks does not work around this problem. --- James Paige
