imclab / track

Interaction tracker library (mouse, touch, keyboard)

Usage

Track the entire document

var track = new Track();
document.addEventListener(track.up, function () {
  alert('You held down for ' + track.duration + 'ms');
}, false);

API

• new Track(<context>) - defaults to the document returns a new track object which contains live information about the position of cursor

Mouse & Touch based information

Note that all x/y coordinates are relative to the context passed in to the Track object. If you want the x/y relative to the screen, set the context to the document.

• track.touch - boolean to indicate touch event support
• track.x, track.x - last knowning x/y corrdinates - these are updated on any move event on the context, and are available at all times
• track.downX, track.downY - the x/y corrdinates on the down event
• track.upX, track.upY - the x/y corrdinates on the up event
• track.startTime - the time in milliseconds when the last down event occurred
• track.duration - the duration in milliseconds between the down and up event
• track.down - boolean to indicate whether the cursor (or finger) is down

Event names

There are three connivence strings that allow you to easily bind to the right event type depending on whether track.touch is true or not. For example track.events.up is mouseup if track.touch is false, and touchend if track.touch is true.

• track.events.up
• track.events.down
• track.events.move

Momentum

• track.weight - an arbitrary value that affects the momentum of a move event. The lower the number, the heavier the move event and therefore the lower the momentum. Higher numbers like 1500 give a sense of the move event having momentum (as seen in the demo)
• track.momentumX, track.momentumY - values that must be subtracted from the track.x/y to get the final x/y position after momentum.

For example:

var track = new Track();
document.addEventListener(track.events.up, function () {
  animate({
    start: [track.downX, track.downY],
    end: [track.x - track.momentumX, track.y - track.momentumY]
  });
}, false);

Keyboard

Any key pressed will hold a true value whilst down with the keycode (via event.which):

For example:

if (track.key[27]) {
  // user is holding the escape key
}

Serialisation

Nothing special, just outputs to JSON:

• track.toString() or track+'' - to get the JSON respresentation of the object

License

MIT-License: http://rem.mit-license.org