[PATCH weston 1/2] libinput: Ignore non seat wide pointer button events

[Jonas Ådahl]

On Wed, Jan 28, 2015 at 01:09:09PM -0800, Bill Spitzak wrote:
> I would greatly prefer to get an event when this happens. The user expects
> something to happen when they push a button. You cannot just throw it away.
> 
> I think it is perfectly safe to send multiple press and release events. No
> program is going to fail because of this. And as this demonstrates, trying
> to avoid that means you are going to throw away information, and vastly
> complicate the code.

Just because it might not break existing applications that has dealt
with what should be considered as invalid input doesn't mean we
shouldn't we should continue providing invalid input.

Jonas

> 
> On 01/27/2015 08:18 PM, Jonas Ådahl wrote:
> >Pointer button events will be received from a device where a button has
> >been pressed, even though an equivalent button has been pressed (same
> >button code) on a device connected to the same seat. notify_button()
> >expects to only be called as if there was only one pointer device
> >associated with the given seat, so to achieve this, ignore every event
> >where forwarding it would result in multiple 'pressed' or 'released'
> >notifications.
> >
> >Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
> >---
> >
> >These two should be safe for the upcoming stable release IMO.
> >
> >
> >Jonas
> >
> >  src/libinput-device.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> >diff --git a/src/libinput-device.c b/src/libinput-device.c
> >index 3ce74b8..5c5b9b9 100644
> >--- a/src/libinput-device.c
> >+++ b/src/libinput-device.c
> >@@ -119,6 +119,17 @@ handle_pointer_button(struct libinput_device *libinput_device,
> >  {
> >  	struct evdev_device *device =
> >  		libinput_device_get_user_data(libinput_device);
> >+	int button_state =
> >+		libinput_event_pointer_get_button_state(pointer_event);
> >+	int seat_button_count =
> >+		libinput_event_pointer_get_seat_button_count(pointer_event);
> >+
> >+	/* Ignore button events that are not seat wide state changes. */
> >+	if ((button_state == LIBINPUT_BUTTON_STATE_PRESSED &&
> >+	     seat_button_count != 1) ||
> >+	    (button_state == LIBINPUT_BUTTON_STATE_RELEASED &&
> >+	     seat_button_count != 0))
> >+		return;
> >
> >  	notify_button(device->seat,
> >  		      libinput_event_pointer_get_time(pointer_event),
> >