On Mon, Jul 28, 2014 at 10:03:25AM -0700, Bill Spitzak wrote: > > > On 07/27/2014 11:48 PM, Ran Benita wrote: > >Hi Jonas, > > > >On Sun, Jul 27, 2014 at 11:28:28PM +0200, Jonas Ådahl wrote: > >>The kernel may send a 'release' event without ever having sent a key > >>'pressed' event in case the key was pressed before libinput was > >>initiated. Ignore these events so that we always guarantee a release > >>event always comes after a pressed event for any given key or button. > > > >Would it be possible to describe in the docs the invariants that > >libinput is keeping w.r.t. key press/release ordering and count? > >If the user can rely on such invariants, it can simplify how he > >interfaces with e.g. libxkbcommon, which expects a coherent key event > >stream (things like modifier press with a missed release can cause some > >fun). > > IMHO such invariants are a waste of time, and add complexity to each > software layer for no benefit.
strict, well-defined behaviour that maps the real world and expectations of the users and developers and guarantees no suprises is not a waste of time. Cheers, Peter > The final consumer of the events either can easily handle mismatched pairs, > or is forced to implement the map of currently-pressed events anyway (due to > the client having it's own internal routing of events which also has to > match pairs, such as when objects that receive events are created or > deleted). So there is no reason to waste effort implementing these maps at > every level since in effect the next level is not going to rely on them. > > I would prefer a count of the number of down buttons, which will allow a > layer to re-sync it's map in many cases, even if events were mishandled by > intermediate software layers. > > _______________________________________________ > wayland-devel mailing list > wayland-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/wayland-devel > _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/wayland-devel