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TouchEvent Class Reference

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TouchEvent

The TouchEvent class encapsulates information about a touch event.

The system continually sends TouchEvent objects to an application as fingers touch and move across a surface. A touch event provides a snapshot of all touches during a multi-touch sequence, most importantly the touches that are new or have changed for a particular target. A multi-touch sequence begins when a finger first touches the surface. Other fingers may subsequently touch the surface, and all fingers may move across the surface. The sequence ends when the last of these fingers is lifted from the surface. An application receives touch event objects during each phase of any touch.

The different types of TouchEvent objects that can occur are:

touchstart

Sent when a finger for a given event touches the surface.

touchmove

Sent when a given event moves on the surface.

touchend

Sent when a given event lifts from the surface.

touchcancel

Sent when the system cancels tracking for the touch.

TouchEvent objects are combined together to form high-level GestureEvent objects that are also sent during a multi-touch sequence. See GestureEvent for details on GestureEvent objects and an example of the events sent for a two finger multi-touch gesture.

Inheritance


Not Applicable

Conforms To


Not Applicable

Import Statement


Not Applicable Not Applicable

Availability


Available in iOS 2.0 and later.
  • altKey Property

    A Boolean value indicating whether the alt key is pressed.

    Declaration

    JavaScript

    readonly attribute boolean altKey

    Discussion

    If true, the alt key is pressed; otherwise, it is not. If there is no keyboard, this value is false.

    Availability

    Available in iOS 2.0 and later.

  • ctrlKey Property

    A Boolean value indicating whether the control key is pressed.

    Declaration

    JavaScript

    readonly attribute boolean ctrlKey

    Discussion

    If true, the control key is pressed; otherwise, it is not. If there is no keyboard, this value is false.

    Availability

    Available in iOS 2.0 and later.

  • metaKey Property

    A Boolean value indicating whether the meta key is pressed.

    Declaration

    JavaScript

    readonly attribute boolean metaKey

    Discussion

    If true, the meta key is pressed; otherwise, it is not. If there is no keyboard, this value is false.

    Availability

    Available in iOS 2.0 and later.

  • shiftKey Property

    A Boolean value indicating whether the shift key is pressed.

    Declaration

    JavaScript

    readonly attribute boolean shiftKey

    Discussion

    If true, the shift key is pressed; otherwise, it is not. If there is no keyboard, this value is false.

    Availability

    Available in iOS 2.0 and later.

  • changedTouches Property

    A collection of Touch objects representing all touches that changed in this event.

    Declaration

    JavaScript

    readonly attribute TouchList changedTouches

    Discussion

    You manipulate this collection using TouchList methods.

    Availability

    Available in iOS 2.0 and later.

  • targetTouches Property

    A collection of Touch objects representing all touches associated with this target.

    Declaration

    JavaScript

    readonly attribute TouchList targetTouches

    Availability

    Available in iOS 2.0 and later.

  • touches Property

    A collection of Touch objects representing all touches associated with this event.

    Declaration

    JavaScript

    readonly attribute TouchList touches

    Availability

    Available in iOS 2.0 and later.

  • rotation Property

    The delta rotation since the start of an event in degrees where clockwise is positive and counter-clockwise is negative.

    Declaration

    JavaScript

    readonly attribute float rotation

    Discussion

    The initial value is 0.0.

    Availability

    Available in iOS 2.0 and later.

  • scale Property

    The distance between two fingers since the start of an event as a multiplier of the initial distance.

    Declaration

    JavaScript

    readonly attribute float scale

    Discussion

    The initial value is 1.0. If less than 1.0 the gesture is pinch close to zoom out. If greater than 1.0 the gesture is pinch open to zoom in.

    Availability

    Available in iOS 2.0 and later.

  • Initializes a newly created TouchEvent object.

    Declaration

    JavaScript

    void initTouchEvent (in DOMString type, in boolean canBubble, in boolean cancelable, in DOMWindow view, in long detail, in long screenX, in long screenY, in long clientX, in long clientY, in boolean ctrlKey, in boolean altKey, in boolean shiftKey, in boolean metaKey, in TouchList touches, in TouchList targetTouches, in TouchList changedTouches, in float scale, in float rotation);

    Parameters

    type

    The type of event that occurred.

    canBubble

    Indicates whether an event can bubble. If true, the event can bubble; otherwise, it cannot.

    cancelable

    Indicates whether an event can have its default action prevented. If true, the default action can be prevented; otherwise, it cannot.

    view

    The view (DOM window) in which the event occurred.

    detail

    Specifies some detail information about the event depending on the type of event.

    screenX

    The x-coordinate of the event’s location in screen coordinates.

    screenY

    The y-coordinate of the event’s location in screen coordinates.

    clientX

    The x-coordinate of the event’s location relative to the window’s viewport.

    clientY

    The y-coordinate of the event’s location relative to the window’s viewport.

    ctrlKey

    If true, the control key is pressed; otherwise, it is not.

    altKey

    If true, the alt key is pressed; otherwise, it is not.

    shiftKey

    If true, the shift key is pressed; otherwise, it is not.

    metaKey

    If true, the meta key is pressed; otherwise, it is not.

    touches

    A collection of Touch objects representing all touches associated with this event.

    targetTouches

    A collection of Touch objects representing all touches associated with this target.

    changedTouches

    A collection of Touch objects representing all touches that changed in this event.

    scale

    The distance between two fingers since the start of an event as a multiplier of the initial distance. The initial value is 1.0. If less than 1.0, the gesture is pinch close (to zoom out). If greater than 1.0, the gesture is pinch open (to zoom in).

    rotation

    The delta rotation since the start of an event, in degrees, where clockwise is positive and counter-clockwise is negative. The initial value is 0.0.

    Discussion

    Use this method to programmatically create a TouchEvent object.

    Availability

    Available in iOS 2.0 and later.