Bug 88359 - [chromium] More than 8 fingers get ignored by touch
Summary: [chromium] More than 8 fingers get ignored by touch
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: UI Events (show other bugs)
Version: 528+ (Nightly build)
Hardware: All All
: P3 Normal
Assignee: Eugene Girard
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2012-06-05 13:27 PDT by Eugene Girard
Modified: 2012-06-20 06:12 PDT (History)
7 users (show)

See Also:


Attachments
Patch (1.24 KB, patch)
2012-06-05 13:47 PDT, Robert Kroeger
no flags Details | Formatted Diff | Diff
Patch (1.36 KB, patch)
2012-06-08 10:39 PDT, Robert Kroeger
no flags Details | Formatted Diff | Diff

Note You need to log in before you can comment on or make changes to this bug.
Description Eugene Girard 2012-06-05 13:27:35 PDT
WebTouchEvent::touchesLengthCap is set to 8.

On devices that support more than 8 touches, additional touches get ignored.  Bump this up to 12.
Comment 1 Robert Kroeger 2012-06-05 13:47:10 PDT
Created attachment 145862 [details]
Patch
Comment 2 Robert Kroeger 2012-06-05 13:47:44 PDT
I think this is sufficient. What do you think?
Comment 3 WebKit Review Bot 2012-06-05 13:50:41 PDT
Please wait for approval from abarth@webkit.org, dglazkov@chromium.org, fishd@chromium.org, jamesr@chromium.org or tkent@chromium.org before submitting, as this patch contains changes to the Chromium public API. See also https://trac.webkit.org/wiki/ChromiumWebKitAPI.
Comment 4 Eugene Girard 2012-06-05 13:59:39 PDT
LGTM
Comment 5 James Robinson 2012-06-05 14:29:30 PDT
Both of these numbers seem really arbitrary.  Is the use case here two-handed polydactylic users?
Comment 6 Robert Kroeger 2012-06-05 14:49:07 PDT
fwiw: my justification for 12: it's 1 more than the best commonly available touchscreen hardware and as you observe: more than the normal human finger count.
Comment 7 Eugene Girard 2012-06-05 15:41:56 PDT
Arbitrary, yes.  The justification is that we have ten fingers, so eight is clearly too low.  The Gesture Recognizer (part of Chromium) assumes 12 points.  The iPad supports 11, 3M reportedly makes a 30 touch screen, and my home brew device supports, well, an unlimited number of points.

12 seemed to be a good value since it's in line with the GR.
Comment 8 James Robinson 2012-06-05 15:56:50 PDT
Comment on attachment 145862 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=145862&action=review

> Source/WebKit/chromium/public/WebInputEvent.h:388
> +    enum { touchesLengthCap = 12 };

Please document where this number is coming from (i.e. this is matching chromium's gesture recognition library).
Comment 9 Robert Kroeger 2012-06-08 10:39:29 PDT
Created attachment 146599 [details]
Patch
Comment 10 WebKit Review Bot 2012-06-08 11:15:11 PDT
Comment on attachment 146599 [details]
Patch

Clearing flags on attachment: 146599

Committed r119843: <http://trac.webkit.org/changeset/119843>
Comment 11 WebKit Review Bot 2012-06-08 11:15:16 PDT
All reviewed patches have been landed.  Closing bug.
Comment 12 Eric Seidel (no email) 2012-06-20 06:12:10 PDT
Comment on attachment 146599 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=146599&action=review

> Source/WebKit/chromium/public/WebInputEvent.h:389
> +    // Maximum number of simultaneous touches supported on
> +    // Ash/Aura.

Odd wrapping.  Odd names.