On Wed, Sep 22, 2010 at 05:41:24PM -0700, Wolf Tivy wrote: > > In particular, XCheckIfEvent seems well suited to this situation- > > -feed in a predicate which specifically finds the repeated KeyPress > > (matches time, key, etc.). But this can perform unnecessary > > computation since it checks things with higher times as well, of > > course--I'm still amazed there is no nonblocking analog to > > XPeekEvent. > > Yeah, I looked at the various X*check* functions, they all seem to > scan the whole queue, which could cause funkyness in this application, > so they don't seem to be a perfect fit. There _must_ be some way to do > a nonblocking peek, it would be insane if there wasn't, I just can't > find it.
Can you explain what could go wrong? The predicate would be passed in the KeyRelease event (as an XPointer), and return True if it finds a KeyPress with matching time and keycode. I dislike scanning the whole queue for efficiency reasons (ostensibly these are minor, the queue shouldn't become too huge when repeats are involved?), and agree it is a weird omission. But who knows, maybe the queue ordering is too unspecified for such an XPeekEvent to actually be worthwhile (i.e., maybe the X protocol really grants no sequencing, and therefore, providing such a call would wrongly imply some sequence guarantees..).
