Touch events (Mozilla experimental)

The experimental touch events API described on this page was available from Gecko 2.0 (Firefox 4 / Thunderbird 3.3 / SeaMonkey 2.1) to Gecko/Firefox 17. You should instead use the standard touch events API, supported since Gecko/Firefox 6 with multi-touch support added in Gecko/Firefox 12.

This API allowed you to track the movement of the user's finger on a touch screen, monitoring the raw touch events generated by the system. Although touch events were based on — and work similarly to — mouse events, each event included an identifier that allowed you to track multiple fingers moving on the screen at the same time.

Event fields

Touch events were based upon MouseEvent, and thereby shared all mouse event fields. They included one additional field.

streamId

A unique integer identifying the finger generating the event. When the MozTouchDown event is built, a unique value is assigned to that finger. Corresponding MozTouchMove and MozTouchUp events for that finger will have the same streamId value. This lets you track each finger's movements on the touch screen independently. The stream ID is unique until the MozTouchUp event occurs; after that, the value may be recycled for another series of events.

Types of touch events

MozTouchDown

Sent when the user begins a screen touch action.

MozTouchMove

Sent when the user moves his finger on the touch screen.

MozTouchUp

Sent when the user lifts his finger off the screen.