951163 - Touch handling errors on Alcatel OneTouch fire device

Status: RESOLVED INVALID

(Firefox OS Graveyard :: GonkIntegration, defect)

Description

[Adrian Custer]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:28.0) Gecko/20100101 Firefox/28.0 (Beta/Release)
Build ID: 20131213004002

Steps to reproduce:

I wrote an app, attached, that shows the lack of touch handling accuracy on the Alcatel OneTouch Fire device. It would be useful to determine if this was:
  1. limited to that device only
  2. a Gecko issue
  3. a driver issue
  4. a hardware issue.

To see the bug:
1. download the web app, install and run it.
2. put two fingers down on the screen
3. move the fingers around, including changing direction
4. remove the fingers from the screen.
=> There will often be some touchstart and touchend events in the middle of the finger movement. 

Even if the fingers never leave the screen, there can be touchend and touchstart events.

Note, that even if the finger leaves the screen there is no 'touchcancel' or 'touchleave' events but I understand that is a wider, gecko level issue and perhaps hard to detect where the screen == touch surface == browser window.

Comment 1

[Adrian Custer]

Attachment: touch-debug.zip

Web app to test touch events, in a zip bundle.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Attachment: Standalone test case

Standalone test case that can be loaded in the browser, extracted from touch-debug.zip

Comment 3

[Kartikaya Gupta (email:[e-mail])]

I can repro this on the hamachi but not the flame. It's almost certainly a driver or hardware issue.

Comment 4

[Adrian Custer]

Closing the bug as out of scope.

The FirefoxOS team does not have time to deal with more serious bugs and probably cannot address this since it is device specific.

https://bugzilla.mozilla.org/show_bug.cgi?id=1038045 
is a related bug trying to isolate issues in the multi-touch handling on FirefoxOS.

The only work around available is writing a very smart touch handing library that could guess when the driver is reporting incorrect data (by incorporating a delay in the reaction to events and calculations about probable finger movement). That problem is hard.

So multi-touch apps on Hamachi probably need to be coded to be robust to bad input.