Bug 94755

Summary: Middle button emulation on software buttons is unreliable
Product: Wayland Reporter: Peter Hutterer <peter.hutterer>
Component: libinputAssignee: Wayland bug list <wayland-bugs>
Status: RESOLVED FIXED QA Contact:
Severity: normal    
Priority: medium CC: benjamin.tissoires, jwrdegoede, peter.hutterer
Version: unspecified   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Bug Depends on:    
Bug Blocks: 94474    

Description Peter Hutterer 2016-03-30 06:15:44 UTC 
Out of 10 clicks with both fingers in the software button areas, I get 5-7 as middle-clicks at best, the rest is either left or right buttons. event-debug --verbose shows that the button state machine detects the right button areas but does not send the right button event then.
Comment 1 Peter Hutterer 2016-03-31 22:32:04 UTC 
tested on a T450 and a T440 and it's pretty much the same effect on both. In most cases this isn't a libinput bug (all cases?) but the type of interaction we do with the middle button.

Primarily it's used for paste which is a single click immediately after putting the fingers down. It's very common to trigger the click before the sensor detected the second finger, resulting in a left or right click only. I don't think we can meaningfully put delays in without making actual button clicks sluggish, so I think that changing the software button code to include an actual middle button area is the only/best solution.
Comment 3 Peter Hutterer 2016-04-05 21:54:38 UTC 
commit 886b5a2cd8c785e48ddf5ceb4a902cd1f518d2a9
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Mon Apr 4 10:06:36 2016 +1000

    touchpad: add a middle button software area

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