Are there other ways to stop/cancel a timer delay?

Getting Started Newbie Questions
1

So I understand how to create and use timer.performWithDelay(options) but is there a way to cancel this outside of the function that is being called?

I am looking at this tutorial: https://docs.coronalabs.com/api/library/timer/cancel.html and it appears that the only option to cancel a timer is from within the Table Listener Function.

I have an exit button that when pressed, I need to stop the timer. So the only way I can see this working is if I have a boolean variable for the timer function to check every call and to set it to true if the exit button is pressed. Is there a simpler method to do this?

Cheers.

2

Any timer can be canceled from anywhere as long as you have the timer ID.

(I wouldn’t call that a tutorial.  Its just a piece of sample code in the API docs.)

math.randomseed( os.time() ) local myTimers = {} local function createSomeTimers( delay ) local count = #myTimers + 1 local function tmp() print( "Timer call #", count ) myTimers[count] = nil -- clear so we know it is done/cancelled end myTimers[#myTimers + 1] = timer.performWithDelay( delay, tmp ) end local function cancelRandomTimer() local num = math.random(1,#myTimers) if( myTimers[num] ~= nil ) then timer.cancel( myTimers[num] ) myTimers[num] = nil -- clear so we know it is done/cancelled end end for i = 1, 10 do createSomeTimers( math.random( 1000, 2000 ) ) end cancelRandomTimer() cancelRandomTimer()

Assuming I didn’t typo something, you can run the code above and get a random result each time. 

15:58:07.005 Timer call # 7 15:58:07.125 Timer call # 6 15:58:07.155 Timer call # 1 15:58:07.475 Timer call # 9 15:58:07.777 Timer call # 4 15:58:07.877 Timer call # 8 15:58:07.927 Timer call # 2 15:58:07.927 Timer call # 5

Pay close attention to how I tracked the timer handles and cancelled them elsewhere.

3

Now that I’ve shown that you can cancel a timer anywhere as long as you have its ID, let me introduce you to a far superior timer:

http://www.jasonschroeder.com/2015/02/25/timer-2-0-library-for-corona-sdk/

Jason’s timer 2 code is super nice, because it allows you to:

  • Give timers string tags (multiple timers can have the same tag) that can later be used to cancel them w/o knowing the ID
  • Cancel all timers in one fell swoop
  • … more.

Jason Rocks and this module rocks.

4

When you call timer.performWithDelay() it will return a timer ID value that you can store for future use.

local spawnTimer = timer.performWithDelay(1000, spawnBadGuy, 0)

later you could:

timer.cancel( spawnTimer )

Rob

5

Thanks for the super fast response.

It looks like you can cancel the timer based on the entire timer object. The API docs made it look like I needed to get into the timer object and pull out the timer ID from it.

6

Any timer can be canceled from anywhere as long as you have the timer ID.

(I wouldn’t call that a tutorial.  Its just a piece of sample code in the API docs.)

math.randomseed( os.time() ) local myTimers = {} local function createSomeTimers( delay ) local count = #myTimers + 1 local function tmp() print( "Timer call #", count ) myTimers[count] = nil -- clear so we know it is done/cancelled end myTimers[#myTimers + 1] = timer.performWithDelay( delay, tmp ) end local function cancelRandomTimer() local num = math.random(1,#myTimers) if( myTimers[num] ~= nil ) then timer.cancel( myTimers[num] ) myTimers[num] = nil -- clear so we know it is done/cancelled end end for i = 1, 10 do createSomeTimers( math.random( 1000, 2000 ) ) end cancelRandomTimer() cancelRandomTimer()

Assuming I didn’t typo something, you can run the code above and get a random result each time. 

15:58:07.005 Timer call # 7 15:58:07.125 Timer call # 6 15:58:07.155 Timer call # 1 15:58:07.475 Timer call # 9 15:58:07.777 Timer call # 4 15:58:07.877 Timer call # 8 15:58:07.927 Timer call # 2 15:58:07.927 Timer call # 5

Pay close attention to how I tracked the timer handles and cancelled them elsewhere.

7

Now that I’ve shown that you can cancel a timer anywhere as long as you have its ID, let me introduce you to a far superior timer:

http://www.jasonschroeder.com/2015/02/25/timer-2-0-library-for-corona-sdk/

Jason’s timer 2 code is super nice, because it allows you to:

  • Give timers string tags (multiple timers can have the same tag) that can later be used to cancel them w/o knowing the ID
  • Cancel all timers in one fell swoop
  • … more.

Jason Rocks and this module rocks.

8

When you call timer.performWithDelay() it will return a timer ID value that you can store for future use.

local spawnTimer = timer.performWithDelay(1000, spawnBadGuy, 0)

later you could:

timer.cancel( spawnTimer )

Rob

9

Thanks for the super fast response.

It looks like you can cancel the timer based on the entire timer object. The API docs made it look like I needed to get into the timer object and pull out the timer ID from it.