EventDispatcher

Supported platforms:
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 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 a "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

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• EventDispatcher
• EventDispatcher.new
• EventDispatcher:addEventListener
• EventDispatcher:dispatchEvent
• EventDispatcher:hasEventListener
• EventDispatcher:removeAllListeners
• EventDispatcher:removeEventListener