The TouchEvent
interface represents an event sent when the state of contacts with a touch-sensitive surface changes. This surface can be a touch screen or trackpad, for example. The event can describe one or more points of contact with the screen and includes support for detecting movement, addition and removal of contact points, and so forth.
Touches are represented by the Touch
object; each touch is described by a position, size and shape, amount of pressure, and target element. Lists of touches are represented by TouchList
objects.
Constructor
TouchEvent()
- Creates a Touch
Event
object.
Properties
This interface inherits properties from its parent, UIEvent
and Event
.
TouchEvent.altKey
Read only- A Boolean value indicating whether or not the alt key was down when the touch event was fired.
TouchEvent.changedTouches
Read only- A
TouchList
of all theTouch
objects representing individual points of contact whose states changed between the previous touch event and this one. TouchEvent.ctrlKey
Read only- A Boolean value indicating whether or not the control key was down when the touch event was fired.
TouchEvent.metaKey
Read only- A Boolean value indicating whether or not the meta key was down when the touch event was fired.
TouchEvent.shiftKey
Read only- A Boolean value indicating whether or not the shift key was down when the touch event was fired.
TouchEvent.targetTouches
Read only- A
TouchList
of all theTouch
objects that are both currently in contact with the touch surface and were also started on the same element that is the target of the event. TouchEvent.touches
Read only- A
TouchList
of all theTouch
objects representing all current points of contact with the surface, regardless of target or changed status.
Touch event types
There are several types of event that can be fired to indicate that touch-related changes have occurred. You can determine which of these has happened by looking at the event's TouchEvent.type
property.
event.preventDefault()
to keep the mouse event from being sent as well.touchstart
Sent when the user places a touch point on the touch surface. The event's target will be the element
in which the touch occurred.
touchend
Sent when the user removes a touch point from the surface (that is, when they lift a finger or stylus from the surface). This is also sent if the touch point moves off the edge of the surface; for example, if the user's finger slides off the edge of the screen.
The event's target is the same element
that received the touchstart
event corresponding to the touch point, even if the touch point has moved outside that element.
The touch point (or points) that were removed from the surface can be found in the TouchList
specified by the changedTouches
attribute.
touchmove
Sent when the user moves a touch point along the surface. The event's target is the same element
that received the touchstart
event corresponding to the touch point, even if the touch point has moved outside that element.
This event is also sent if the values of the radius, rotation angle, or force attributes of a touch point change.
touchmove
events is sent is browser-specific, and may also vary depending on the capability of the user's hardware. You must not rely on a specific granularity of these events.touchcancel
Sent when a touch point has been disrupted in some way. There are several possible reasons why this might happen (and the exact reasons will vary from device to device, as well as browser to browser):
- An event of some kind occurred that canceled the touch; this might happen if a modal alert pops up during the interaction.
- The touch point has left the document window and moved into the browser's UI area, a plug-in, or other external content.
- The user has placed more touch points on the screen than can be supported, in which case the earliest
Touch
in theTouchList
gets canceled.
GlobalEventHandlers
This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.
GlobalEventHandlers.ontouchstart
- A
global event handler
for thetouchstart
event. GlobalEventHandlers.ontouchend
- A
global event handler
for thetouchend
event. GlobalEventHandlers.ontouchmove
- A
global event handler
for thetouchmove
event. GlobalEventHandlers.ontouchcancel
- A
global event handler
for thetouchcancel
event.
Example
See the example on the main Touch events article.
Specifications
Specification | Status | Comment |
---|---|---|
Touch Events – Level 2 The definition of 'TouchEvent' in that specification. |
Editor's Draft | Added ontouchstart , ontouchend , ontouchmove , ontouchend global attribute handlers |
Touch Events The definition of 'TouchEvent' in that specification. |
Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 22.0 | 18.0 (18.0) | Not supported | Not supported | Not supported |
Feature | Android | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | 6.0 (6.0) | (Yes) | 11 | (Yes) | (Yes) |
TouchEvent() | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |