Touch Emulator

Forked from hammerjs/touchemulator, add the attribute data-emulate-touch to control certain DOM can trigger the touch emulation.

Install

Download the script from this repo, via NPM:

npm install git+https://github.com/AkatQuas/touchemulator

How to use

Include the javascript file, and call the TouchEmulator() function before any other libraries that do something with the touch input. It will set some fake properties to spoof the touch detection of some libraries, and triggers touchstart, touchmove and touchend events on the mouse target.

<div data-emulate-touch="on">This dom can trigger touch-related event</div>

<div data-emulate-touch="off">This dom can NOT trigger touch-related event</div>

<div>This dom can NOT trigger touch-related event</div>

<script src="touch-emulator.js"></script>
<script>
  // mannually invoke the function
  TouchEmulator();
</script>

function log(ev) {
  console.log(ev);
}

document.body.addEventListener('touchstart', log, false);
document.body.addEventListener('touchmove', log, false);
document.body.addEventListener('touchend', log, false);

Also, the script includes polyfills for document.createTouch and document.createTouchList.

How it works

It listens to the mousedown, mousemove and mouseup events, and translates them to touch events. If the mouseevent has the shiftKey property to true, it enables multi-touch.

The script also prevents the following mouse events on the page: mousedown, mouseenter, mouseleave, mousemove, mouseout, mouseover and mouseup.

Web platform tests

The script has been tested with the w3c web platform tests and passes all tests, except these;

assert_true: event is a TouchEvent event expected true got false
- We trigger an event of the type Event
assert_equals: touch list is of type TouchList expected "[object TouchList]" but got "[object Array]"
assert_equals: touch is of type Touch expected "[object Touch]" but got "[object Object]"

Options

You might change some properties before invoking the function.

TouchEmulator.template = Function(touch)

Change the css properties of the rendered touches.

TouchEmulator.multiTouchOffset = 75

The distance between the two touch points when entering the multi-touch zone.

AkatQuas / touchemulator