On Fri, Jan 02, 2015 at 01:49:01PM -0500, Ben Gamari wrote: > > Hello all, > > My Latitude E7440 has a touch screen panel and a few external display > interfaces. I've noticed that when I plug in an external monitor touch > events no longer correspond to the location I have touched on the panel. > > For instance, take the case where I have an external HDMI monitor with > the same native resolution as my panel. If I place the external monitor > to the left of the panel, > > xrandr --output HDMI1 --left-of eDP1 --auto > > I find that touches on the panel map to the corresponding point on the > external monitor. > > If I place the monitor to the right of the panel, touches map to the > panel as expected. This isn't terribly surprising: the input presumably > has no idea that the touch device has any particular relation to the > panel so the input device events are mapped to a location relative to > the origin of the screen, not the panel. How is this situation supposed > to be handled? Is ensuring that input devices and output geometries > remain consistent left up to higher layers of the stack? This would be > straightforward if xinput transformation matrices could encode > translations; unfortunately it appears that they can not.
yes, supposed to be handled by the rest of the stack. the X server doesn't change the matrix, it only reads it. and translations are handled on absolute devices, but they're just ignored for relative devices. > It does appear, however, that some component in the stack is updating > the input transformation matrix of the input device when the output > geometry is invoked. For instance after I light up the external display > on either the right or left side of the panel the transformation matrix > for the touch screen is, > > Coordinate Transformation Matrix (141): 0.500000, 0.000000, 0.000000, > 0.000000, 1.000000, 0.000000, 0.000000, 0.000000, 1.000000 > > Unfortunately, whatever is doing this does not reset the transformation > matrix when the external monitor is disabled, resulting in the input > events to be incorrectly scaled (e.g. a touch event on the right edge of > the panel places the cursor at the middle of the screen). Does anyone > know component of the stack is responsible for this update and why it > fails to handle the `--off` case properly? gnome-settings-daemon most likely, file plugins/common/gsd-device-mapper.c Cheers, Peter _______________________________________________ xorg@lists.x.org: X.Org support Archives: http://lists.freedesktop.org/archives/xorg Info: http://lists.x.org/mailman/listinfo/xorg Your subscription address: %(user_address)s
