read-only mirror of https://gitlab.freedesktop.org/libinput/libinput

Neil Roberts 96ec0936ca evdev: Only track one pending event ... Instead of having a mask of pending events there is now an enum with a single value to represent the one pending event. The event gets flushed explicitly as part of the handling code for each event type rather than in the outer event reading loop. The pending event is used so that we can combine multiple motion events into one and to make sure that we have recieved the latest position before sending a touch up or down event. This should fix the following problems with the old approach: • If you release a finger and press it down again quickly you could get the up and down events in the same batch. However the pending events were always processed in the order down then up so it would end up notifying two down events and then an up. The pending event is now always flushed when there is a new up or down event so they will always be in the right order. • When it got a slot event it would immediately change the slot number and then set the pending event. Then when it flushed the events it would use the new slot number to flush the old pending event so the events could have the wrong finger. The pending event is now immediately flushed when a slot event is received so it will have the right finger. • If you get more than 32 events in one read then it was resetting the pending events before processing the next batch in evdev_process_events. If four fingers were pressed down at once then it ended up with more than 32 events and the sync message would be in the second batch. The pending flag for the last finger was getting cleared so it never got emitted. In this patch the pending event is no longer reset after reading nor is it explicitly flushed. Instead it is flushed when we receive a EV_SYN event or a different pending event needs to replace it. The touchpad handling code was trying to use the pending event mechanism to notify the relative motion events. I'm not sure why it was doing this because it looks the event would effectively get emitted as soon as the touchpad_process function is finished anyway and it wasn't accumulating the values. Instead I've just changed it to emit the event directly. https://bugs.freedesktop.org/show_bug.cgi?id=67563		2013-11-10 17:51:33 +01:00
src	evdev: Only track one pending event	2013-11-10 17:51:33 +01:00