EventDispatcher

From GiderosMobile
Revision as of 09:27, 24 August 2018 by Hgy29 (talk | contribs)

Supported platforms: File:Platform androidFile:Platform iosFile:Platform macFile:Platform pc
Available since: Gideros 2011.6
Inherits from: Object

Description


All classes that dispatch events inherit from `EventDispatcher`. The target of an event is a listener function and an optional data value.
When an event is dispatched, the registered function is called.
If the optional data value is given, it is used as a first parameter while calling the listener function.
Event dispatching and event targets are the core part of the Gideros event model. Different event types (such as `Event.ENTER_FRAME`, `Event.TOUCHES_BEGIN` or `Event.MOUSE_DOWN`) flow through the scene tree hierarchy differently. When a touch or mouse event occurs, Gideros dispatches an event object into the event flow from the root of the scene tree.
On the other hand, `Event.ENTER_FRAME` event is dispatched to all `Sprite` objects.

If you want to define a class that dispatches events, you can inherit your class from `EventDispatcher`.

Examples

Example

-- example 1
ClassA = Core.class(EventDispatcher)
ClassB = Core.class(EventDispatcher)

function ClassA:funcA(event)
	print("funcA", self, event:getType(), event:getTarget())
end

local a = ClassA.new()
local b = ClassB.new()

b:addEventListener("myevent", a.funcA, a)	-- when b dispatches an "myevent" event,
										-- a.funcA will be called with 'a'
										-- as first parameter

b:dispatchEvent(Event.new("myevent"))		-- will print "funcA"


-- example 2
Ball = Core.class(Sprite)

function Ball:onEnterFrame()
	self:setX(self:getX()   1)
end

ball = Ball.new()
ball:addEventListener(Event.ENTER_FRAME, ball.onEnterFrame, ball)

Methods

EventDispatcher.new creates a new EventDispatcher object
EventDispatcher:addEventListener registers a listener function
EventDispatcher:dispatchEvent dispatches an event
EventDispatcher:hasEventListener checks if the EventDispatcher object has a event listener
EventDispatcher:removeAllListeners remove all listeners
EventDispatcher:removeEventListener removes a listener function

Events

Event.APPLICATION_BACKGROUND
Event.APPLICATION_EXIT
Event.APPLICATION_FOREGROUND
Event.APPLICATION_RESIZE
Event.APPLICATION_RESUME
Event.APPLICATION_START
Event.APPLICATION_SUSPEND
Event.MEMORY_WARNING
Event.OPEN_URL

Constants