Provided by: libinput-tools_1.20.0-1ubuntu0.3_amd64 bug

NAME

       libinput-debug-gui - visual debug helper for libinput

SYNOPSIS

       libinput debug-gui [options]

       libinput debug-gui [options] --udev <seat>

       libinput debug-gui [options] [--device] /dev/input/event0

DESCRIPTION

       The  libinput  debug-gui  tool  creates a libinput context and a full-screen GTK window to
       visualize events processed by libinput. This tool exclusively grabs pointing  devices  and
       stops them from interacting with the rest of the GUI.

       Hit Esc to exit this tool.

       This  is a debugging tool only, its output or behavior may change at any time. Do not rely
       on the output or the behavior.

       This tool usually needs to be run as root to have access to the /dev/input/eventX nodes.

OPTIONS

       --device /dev/input/event0
               Use the given device with the path backend. The --device argument may be omitted.

       --grab  Exclusively grab all opened devices. This will prevent events from being delivered
               to the host system.

       --help  Print help

       --udev <seat>
               Use  the  udev  backend to listen for device notifications on the given seat.  The
               default behavior is equivalent to --udev "seat0".

       --verbose
               Use verbose output

       For libinput configuration options, see libinput-debug-events(1)

FEATURES

       Cursor movement
               The cursor is displayed as black triangle. Various markers are displayed in  light
               grey  to  help  debug cusor positioning. The cursor movement is the one as seen by
               libinput and may not match the cursor movement of the display server.

       The unaccelerated cusor motion is displayed as a grey upside-down triangle.  The  movement
       of  this  cursor  typically  reflects  the  relative motion in device units and can differ
       significantly to the normal cursor movement.

       The unaccelerated cursor motion is also displayed as a yellow snake. This is the connected
       set  of  recent deltas. Unlike the unaccelerated cursor, these coordinates are not clipped
       to the window.

       Button testing
               Four oblongs are displayed at the bottom. The top three are left,  middle,  right,
               the bottom one is for any other button and displays the button name on press.

       Scrolling
               The  green oblongs show the scrolling in continuous space, the smaller red oblongs
               the scroll steps in discrete steps.

       Gestures
               A set of four horizontal black rings show  swipe  gestures,  with  the  number  of
               detected  fingers  filled in. A set of two black rings show pinch gestures, filled
               when events are detected.

       Touch and absolute mouse events
               Touch  and  absolute  mouse  events  are  displayed  as  red  and  blue   circles,
               respectively, at the touch point or absolute position.

       Tablet tools
               Events  from tablet tools show a cyan square at the proximity-in and proximity-out
               positions. The tool position is shown as  circle  and  increases  in  radius  with
               increasing  pressure  or  distance.  Pressure  and  distance are also shown in the
               vertical bar south-east of center. Where tilt is available, the circle changes  to
               an  ellipsis to indicate the tilt angle.  Relative events from the tablet tool are
               displayed as a yellow snake, always starting from the  center  of  the  window  on
               proximity  in.  Button events are displayed in the bottom-most button oblong, with
               the name of the button displayed on press.

       Tablet pads
               Button events are displayed in the bottom-most button oblong, with the name of the
               button  displayed on press. Ring and strip events are displayed in the yellow 'IO'
               symbol, with the position and the number of the ring/strip filled in  when  events
               are available.

       Kernel events
               Left  of  the  center  is  a  blue ring to debug kernel relative events (REL_X and
               REL_Y). Each unit is displayed as one arrow in the respective direction.  Right of
               the  center  is  a  blue  oblong representing the most recently-used touch device.
               Touch events are displayed as they are read from the kernel.

NOTES

       Events shown by this tool may not correspond to the events seen by  a  different  user  of
       libinput. This tool initializes a separate context.

LIBINPUT

       Part of the libinput(1) suite