Bug 95171

Summary: Selecting words with triple-tap + drag no longer works after new default MaxDoubleTapTime=100
Product: xorg Reporter: Dick Streefland <dick>
Component: Input/synapticsAssignee: Peter Hutterer <peter.hutterer>
Status: RESOLVED FIXED QA Contact:
Severity: normal    
Priority: medium CC: gabriele.mzt, peter.hutterer
Version: git   
Hardware: x86-64 (AMD64)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:

Description Dick Streefland 2016-04-27 13:48:38 UTC
After upgrading my Asus zenbook UX305FA from Ubuntu 15.04 to 16.04, one feature of the touchpad no longer worked: triple-tap to select a word, and then drag to extend the selection to multiple words. In 16.04, the initial word is selected, but the selection is not extended by the drag.

I traced back this difference to the following git commit:

commit 90c6d7fc60f3db1bd9db1c7702062fcaef3b3352
Author: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Date:   Thu Jan 15 22:04:17 2015 +0100
    [...]
    In addition, decrease the default value of MaxDoubleTapTime from 180 ms
    to 100 ms in order to make double taps faster.

Indeed, after reseting MaxDoubleTapTime back to 180, everything works as before. It seems that his value needs to be at least 160 to work reliably.
Comment 1 Gabriele Mazzotta 2016-04-28 10:46:36 UTC
I honestly can't remember exactly why I wanted to lower the timeout, I think that that commit increased the time required to complete double taps and I wanted to balance the increase with a lower timeout.

I can still do the triple-tap and drag thing, but I have to say it's harder now. To be honest, 180ms seems fine now and I guess it's better to revert to that value.
Comment 2 Peter Hutterer 2016-04-29 00:53:51 UTC
https://patchwork.freedesktop.org/patch/84419/
Comment 3 Peter Hutterer 2016-05-23 01:32:56 UTC
commit 979fbec84197cd2c8ea3ffdd8e7726e8a617328b
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Fri Apr 29 10:51:17 2016 +1000

    Revert MaxDoubleTapTime back to 180

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