timer.performWithDelay()

Type Function
Library timer.*
Return value Object
Revision Current Public Release (2014.2393)
Keywords timer, delay, performWithDelay
See also timer
timer.cancel()

Overview

Call a specified function after a delay. This function returns an object that can be used with other timer.* functions. For example, the returned handle could be passed to timer.cancel() to cancel the invocation of the specified listener.

Syntax

timer.performWithDelay( delay, listener [, iterations] )
delay (required)

Number. The delay in milliseconds, for example, 1000 = 1 second

listener (required)

Listener. The listener to invoke after the delay. This may be either a function listener or a table listener. If a table listener, it must have a timer method because timer events are sent to the listener.

iterations (optional)

Number. Optionally specifies the number of times listener is to be invoked. By default, it is 1; pass 0 or -1 if you want the timer to loop forever.

Examples

Function Listener
local function listener( event )
    print( "listener called" )
end

timer.performWithDelay( 1000, listener )
Table Listener
local listener = {}
function listener:timer( event )
    print( "listener called" )
end

timer.performWithDelay( 1000, listener )
Passing Parameters (1)
-- Lua closure method

local function spawnBall( randomPosition )
    ballPosition = display.newCircle( 100, 100, 20 )
    ballPosition.x = randomPosition
end

-- Obtain a random number for the spawned object's x position
local randomPosition = 100 + math.random(200)

-- Wrap "spawnBall" and "randomPosition" inside a closure
local myClosure = function() return spawnBall( randomPosition ) end
timer.performWithDelay( 2000, myClosure, 1 )
Passing Parameters (2)
-- Variable handle method

local function onTimer( event )
    -- Access "params" table by pointing to "event.source" (the timer handle)
    local params = event.source.params
    print( params.myParam1 )
    print( params.myParam2 )
end

-- Assign the timer to a variable "tm"
local tm = timer.performWithDelay( 1000, onTimer )
-- Assign a table of parameters to the "tm" handle
tm.params = { myParam1 = "Parameter1", myParam2 = "Parameter2" }