Drop Queued keyboard and mouse events

bundickt

Is there a way to turn off queueing of keyboard and mouse events?

What I want:
If a keyboard event comes in before the previous event has been processed it does't get added the the event queue; it will get dropped.

What happens:
In my event queue thread (main application thread) I can make calls that can block for up to 2 seconds. While the thread is blocking, if the user presses some keys they will be queued up and processed after the block is done. The problem I am facing is sometimes the users key events will cause more 2 second blocking calls and cause even more queueing. This will make my GUI pretty much stop and is not my desired affect. I don't mind if the GUI freezes for 2 seconds here or there, but it's when the gui freezes for minutes it's a problem.

frankcyblogic.de

Blocking calls in the GUI threads sounds quite evil. Why not put those into a background thread? Make it signal the foreground thread once something is done. Simply use Qt's thread-aware signal-slot mechanism.

Hope, you don't mind for my short recipe;)

bundickt

Even if i remove the non blocking calls from the main event thread I still need a way to get rid of queue events. It still causes undesired affects. Is this possible? and if it is how?

frankcyblogic.de

I don't think your architecture is all right. Anyways, there was something to eat queued events... QCoreApplication::processEvents(). Maybe, you want to give it a try. Of course you can't do it directly in QML.

goetz

I would just introduce a boolean sentinel:

Set it to true before you do your work.
Check it in the slots connected to your UI elements. If it's true do nothing, if it's false start the workload.
After your work is done reset it to false.