EventDispatcher
Supported platforms: android, ios, mac, pc
Available since: Gideros 2011.6
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)