From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: How to indicate hover touch when exact distance unknown? Date: Tue, 23 Sep 2014 17:27:12 -0700 Message-ID: <20140924002712.GB16747@core.coreip.homeip.net> References: <20140923145916.GA3110@mail.corp.redhat.com> <20140923162811.GB40700@core.coreip.homeip.net> <5421C15C.6030302@euromail.se> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f43.google.com ([209.85.220.43]:39252 "EHLO mail-pa0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751232AbaIXA1R (ORCPT ); Tue, 23 Sep 2014 20:27:17 -0400 Received: by mail-pa0-f43.google.com with SMTP id kx10so7627636pab.2 for ; Tue, 23 Sep 2014 17:27:17 -0700 (PDT) Content-Disposition: inline In-Reply-To: <5421C15C.6030302@euromail.se> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Henrik Rydberg Cc: Andrew de los Reyes , Benjamin Tissoires , hdegoede@redhat.com, jikos@jikos.cz, David Herrmann , peter.hutterer@who-t.net, Linux Input On Tue, Sep 23, 2014 at 08:52:12PM +0200, Henrik Rydberg wrote: > >>> So I am not very happy with having a new > >>> tool. In the end, it may also disturb older clients which will not know > >>> what to do with HOVER. > >>> And the ABS_MT_DISTANCE approach used to be fully retro-compatible > >>> (assuming that the hovering distance is small enough for the user not to > >>> detect it). > >> > >> Except that if we start getting devices that can actually tell the > >> distance we'd need special casing 0/1 handling, no? > > Logically, a hovering object which does not support real distance reporting > would simply be present in the contact list but have ABS_MT_TOUCH = 0. However, > I do not think all layers of the stack supports this notion. That unfortunately does not give us indication whether device supports hover or not: we'll know only when we see it. -- Dmitry