Option to filter libinput by device

[z0rc]

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Read Documents. https://github.com/iberianpig/fusuma#installation
  • Checked that libinput-debug-events worked correctly.
  • Reproduced the problem in latest version. Update fusuma with gem update fusuma
  • Checked that your issue isn't already filed: https://github.com/iberianpig/fusuma/issues

Description

libinput-debug-events by default catches all events, in addition to touchpad events there are keyboard, mouse and more. libinput-debug-events allows to filter those out by using --device option. This filtering allows to consume less CPU time by fusuma+libinput-debug-events. For example, when I plug mouse to laptop and move it relatively quickly in constant manner fusuma and libinput-debug-events consume about 10-15% of single CPU core. libinput-debug-events --device ... allows to ignore mouse events and effectively consume zero CPU time on mouse movements.

This option is a bit tricky, as user have to know device name before hand. So maybe we can add an advanced option to define libinput-debug-events launch parameters?

Versions

fusuma: b1ab717
OS: Kubuntu 17.10
libinput: 1.8.4

[z0rc]

A bit more clarification.

Seems there is a code that tries to enable filtering at https://github.com/iberianpig/fusuma/blob/master/lib/fusuma.rb#L56-L58. But in my case it doesn't work because usually I'm booting laptop with dock station enabled and mouse attached. At this case Devices class has 3 names (2 for mouse, doh), here is relevant libinput list-devices output:

Device:           DLL075B:01 06CB:76AF Touchpad
Kernel:           /dev/input/event20
Group:            8
Seat:             seat0, default
Size:             101x57mm
Capabilities:     pointer 
Tap-to-click:     disabled
Tap-and-drag:     enabled
Tap drag lock:    disabled
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      n/a
Scroll methods:   *two-finger edge 
Click methods:    *button-areas clickfinger 
Disable-w-typing: enabled
Accel profiles:   none
Rotation:         n/a

Device:           Logitech G700 Laser Mouse
Kernel:           /dev/input/event8
Group:            10
Seat:             seat0, default
Capabilities:     pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      disabled
Nat.scrolling:    disabled
Middle emulation: disabled
Calibration:      n/a
Scroll methods:   button
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   flat *adaptive
Rotation:         n/a

Device:           Logitech G700 Laser Mouse
Kernel:           /dev/input/event9
Group:            10
Seat:             seat0, default
Capabilities:     keyboard pointer 
Tap-to-click:     n/a
Tap-and-drag:     n/a
Tap drag lock:    n/a
Left-handed:      n/a
Nat.scrolling:    disabled
Middle emulation: n/a
Calibration:      n/a
Scroll methods:   none
Click methods:    none
Disable-w-typing: n/a
Accel profiles:   n/a
Rotation:         n/a

Maybe in addition to filtering out devices that don't have Nat.scrolling, we can filter out devices with mouse (case insensitive) in Device name? Or switch to other criteria for detecting touchpad? For example only touchpad has Size field in my case.

[iberianpig]

Thanks for your suggestion!
I will remove the device that doesn't include Size:.

[iberianpig]

@z0rc --device= option is available 🎉