It seems to queue up all mouse movement messages and process every message. For me this can result in 10 second delays when I sweep my mouse across an application that draws tool tips and the like. This happens to me on the plasma task manager widget and several apps include VLC. I can slowly watch all the mouse movement messages get processed. This is resulting in a horrendous user experience. This reeks of poor implementation. I'm pretty sure the correct way to handle mouse movement is to set a flag when the mouse is moved and when you are able to then process it and get the current mouse location. That way by the time you are processing the message, if your system has been busy, you are only processing the latest mouse movement message and that is it, the rest should be ignored, except for any message preceding a click.
This would also drastically reduce general cpu processing time for systems that are slow enough to build up mouse move messages, and they are the ones that really need it.
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