SystemEvent Class

Extends EventTarget

Module: cc

The System event, it currently supports keyboard events and accelerometer events.
You can get the SystemEvent instance with cc.systemEvent.
example:

cc.systemEvent.on(cc.SystemEvent.EventType.DEVICEMOTION, this.onDeviceMotionEvent, this);
cc.systemEvent.off(cc.SystemEvent.EventType.DEVICEMOTION, this.onDeviceMotionEvent, this);

Index

Methods

• setAccelerometerEnabled whether enable accelerometer event
• setAccelerometerInterval set accelerometer interval value
• hasEventListener Checks whether the EventTarget object has any callback registered for a specific type of event.
• on Register an callback of a specific event type on the EventTarget.
• off Removes the listeners previously registered with the same type, callback, target and or useCapture,...
• targetOff Removes all callbacks previously registered with the same target (passed as parameter).
• once Register an callback of a specific event type on the EventTarget,...
• emit Trigger an event directly with the event name and necessary arguments.
• dispatchEvent Send an event with the event object.

Details

Methods

setAccelerometerEnabled

whether enable accelerometer event

Parameters

• isEnable Boolean

setAccelerometerInterval

set accelerometer interval value

Parameters

• interval Number

hasEventListener

Checks whether the EventTarget object has any callback registered for a specific type of event.

Parameters

• type String The type of event.

on

Register an callback of a specific event type on the EventTarget. This type of event should be triggered via emit.

Parameters

• type String A string representing the event type to listen for.
• callback Function The callback that will be invoked when the event is dispatched.

                         The callback is ignored if it is a duplicate (the callbacks are unique).
  

  • arg1 Any arg1
  • arg2 Any arg2
  • arg3 Any arg3
  • arg4 Any arg4
  • arg5 Any arg5
• target Object The target (this object) to invoke the callback, can be null

Examples

eventTarget.on('fire', function () {
    cc.log("fire in the hole");
}, node);

off

Removes the listeners previously registered with the same type, callback, target and or useCapture, if only type is passed as parameter, all listeners registered with that type will be removed.

Parameters

• type String A string representing the event type being removed.
• callback Function The callback to remove.
• target Object The target (this object) to invoke the callback, if it's not given, only callback without target will be removed

Examples

// register fire eventListener
var callback = eventTarget.on('fire', function () {
    cc.log("fire in the hole");
}, target);
// remove fire event listener
eventTarget.off('fire', callback, target);
// remove all fire event listeners
eventTarget.off('fire');

targetOff

Removes all callbacks previously registered with the same target (passed as parameter). This is not for removing all listeners in the current event target, and this is not for removing all listeners the target parameter have registered. It's only for removing all listeners (callback and target couple) registered on the current event target by the target parameter.

Parameters

• target Object The target to be searched for all related listeners

once

Register an callback of a specific event type on the EventTarget, the callback will remove itself after the first time it is triggered.

Parameters

• type String A string representing the event type to listen for.
• callback Function The callback that will be invoked when the event is dispatched.

                         The callback is ignored if it is a duplicate (the callbacks are unique).
  

  • arg1 Any arg1
  • arg2 Any arg2
  • arg3 Any arg3
  • arg4 Any arg4
  • arg5 Any arg5
• target Object The target (this object) to invoke the callback, can be null

Examples

eventTarget.once('fire', function () {
    cc.log("this is the callback and will be invoked only once");
}, node);

emit

Trigger an event directly with the event name and necessary arguments.

Parameters

• type String event type
• arg1 Any First argument
• arg2 Any Second argument
• arg3 Any Third argument
• arg4 Any Fourth argument
• arg5 Any Fifth argument

Examples

eventTarget.emit('fire', event);
eventTarget.emit('fire', message, emitter);

dispatchEvent

Send an event with the event object.

Parameters

• event Event