ALKMaps.Handler.Pinch

The pinch handler is used to deal with sequences of browser events related to pinch gestures. The handler is used by controls that want to know when a pinch sequence begins, when a pinch is happening, and when it has finished.

Controls that use the pinch handler typically construct it with callbacks for ‘start’, ‘move’, and ‘done’. Callbacks for these keys are called when the pinch begins, with each change, and when the pinch is done.

Create a new pinch handler with the ALKMaps.Handler.Pinch constructor.

Inherits from

ALKMaps.Handler

Summary

ALKMaps.Handler.Pinch	The pinch handler is used to deal with sequences of browser events related to pinch gestures.
Properties
started	{Boolean} When a touchstart event is received, we want to record it, but not set ‘pinching’ until the touchmove get started after starting.
stopDown	{Boolean} Stop propagation of touchstart events from getting to listeners on the same element.
pinching	{Boolean}
last	{Object} Object that store informations related to pinch last touch.
start	{Object} Object that store informations related to pinch touchstart.
singleTouchPanMap	{Boolean} If true, single touch and move will pan the map.
Constructor
ALKMaps.Handler.Pinch	Returns ALKMaps.Handler.Pinch
Functions
touchstart	Handle touchstart events
touchmove	Handle touchmove events
touchend	Handle touchend events
activate	Activate the handler.
deactivate	Deactivate the handler.
getDistance	Get the distance in pixels between two touches.
getPinchData	Get informations about the pinch event.

Properties

started

{Boolean} When a touchstart event is received, we want to record it, but not set ‘pinching’ until the touchmove get started after starting.

stopDown

{Boolean} Stop propagation of touchstart events from getting to listeners on the same element. Default is false.

pinching

{Boolean}

last

{Object} Object that store informations related to pinch last touch.

start

{Object} Object that store informations related to pinch touchstart.

singleTouchPanMap

{Boolean} If true, single touch and move will pan the map. Otherwise will drag the document.

Constructor

ALKMaps.Handler.Pinch

Returns ALKMaps.Handler.Pinch

Parameters

control	{ALKMaps.Control} The control that is making use of this handler. If a handler is being used without a control, the handlers setMap method must be overridden to deal properly with the map.
callbacks	{Object} An object containing functions to be called when the pinch operation start, change, or is finished. The callbacks should expect to receive an object argument, which contains information about scale, distance, and position of touch points.
options	{Object}

Functions

touchstart

touchstart: function( evt )

Handle touchstart events

Parameters

evt

{Event}

Returns

{Boolean} Let the event propagate.

touchmove

touchmove: function( evt )

Handle touchmove events

Parameters

evt

{Event}

Returns

{Boolean} Let the event propagate.

touchend

touchend: function( evt )

Handle touchend events

Parameters

evt

{Event}

Returns

{Boolean} Let the event propagate.

activate

activate: function()

Activate the handler.

Returns

{Boolean} The handler was successfully activated.

deactivate

deactivate: function()

Deactivate the handler.

Returns

{Boolean} The handler was successfully deactivated.

getDistance

getDistance: function( touches )

Get the distance in pixels between two touches.

Parameters

touches

{Array(Object)}

Returns

{Number} The distance in pixels.

getPinchData

getPinchData: function( evt )

Get informations about the pinch event.

Parameters

evt

{Event}

Returns

{Object} Object that contains data about the current pinch.