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This document defines extensions to the Touch Events specification that have been implemented by one or more browsers.
We recommend that user agents implement the Touch Events Recommendation and/or the newer Pointer Events specification instead.
This document is no longer being developed.
This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.
This is the 31 October 2013 Working Group Note of "Touch Events Extensions". The W3C Membership and other interested parties are invited to review the document. If you wish to make comments regarding this document, please send them to public-webevents@w3.org (subscribe, public archive). All comments are welcome.
This document was developed by the Web Events Working Group. This Working Group will not advance this Working Group Note to Recommendation Status.
Publication as a Working Group Note does not imply endorsement by the W3C Membership. This is a draft document and may be updated, replaced or obsoleted by other documents at any time. It is inappropriate to cite this document as other than work in progress.
This document was produced by a group operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of any patent disclosures made in connection with the deliverables of the group; that page also includes instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.
This section is non-normative.
This document defines extensions to the Touch Events specification that have been implemented by one or more browsers.
Touch Interface
This section defines extensions to the Touch interface
defined in [TOUCH-EVENTS].
partial interface Touch {
readonly attribute float radiusX;
readonly attribute float radiusY;
readonly attribute float rotationAngle;
readonly attribute float force;
};force of type float, readonly 0 to
1, where 0 is no pressure, and
1 is the highest level of pressure the touch device is
capable of sensing; 0 if no value is known. In
environments where force is known, the absolute pressure
represented by the force attribute, and the sensitivity in
levels of pressure, may vary.
Issue: Consider aligning with other "channels" and values from Ink Markup Language (InkML), in addition to force, e.g. adding angle, clientZ, rotation, etc.
radiusX of type float, readonly 0 if no value is
known. The value must not be negative.
radiusY of type float, readonly 0 if no value is
known. The value must not be negative.
rotationAngle of type float, readonly
the angle (in degrees) that the ellipse described by radiusX
and radiusY is rotated clockwise about its center;
0 if no value is known. The value must be greater
than or equal to 0 and less than 90.
If the ellipse described by radiusX and radiusY is
circular, then rotationAngle has no effect. The user agent
may use 0 as the value in this case, or it may use any
other value in the allowed range. (For example, the user agent may
use the rotationAngle value from the previous touch event,
to avoid sudden changes.)
TouchList Interface
This section defines an extension to the TouchList
interface defined in [TOUCH-EVENTS].
partial interface TouchList {
Touch? identifiedTouch (long identifier);
};This section is non-normative.
The working group maintains a list of open issues for its documents.
This section is non-normative.
Many thanks to the WebKit engineers for developing the model used as a basis for this document and to the members of the Web Events Working Group.