EventDispatcher

From GiderosMobile
(Redirected from Category:EventDispatcher)

Supported platforms: Platform android.pngPlatform ios.pngPlatform mac.pngPlatform pc.pngPlatform html5.pngPlatform winrt.pngPlatform win32.png
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

User created event

local event = Event.new("myevent")
event.data1 = "12345"
event.data2 = "abcde"
mydispatcher:dispatchEvent(event)

Game loop

Ball = Core.class(Sprite)

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

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

EventDispatcher inheritance

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"

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