WebTouchEvent::touchesLengthCap is set to 8. On devices that support more than 8 touches, additional touches get ignored. Bump this up to 12.
Created attachment 145862 [details] Patch
I think this is sufficient. What do you think?
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.
LGTM
Both of these numbers seem really arbitrary. Is the use case here two-handed polydactylic users?
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.
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 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).
Created attachment 146599 [details] Patch
Comment on attachment 146599 [details] Patch Clearing flags on attachment: 146599 Committed r119843: <http://trac.webkit.org/changeset/119843>
All reviewed patches have been landed. Closing bug.
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.