Just some clarification on how corona runs

Getting Started Newbie Questions
#1

Say I have a button with two event listeners (both for touch events, but linked to two different functions). If I add the first event listener to call on function 1 ( a large function) and then the next line is the second event listener to call on function 2, how does corona see this? Will it run through function 1 to completion before moving on to the second event listener calling on function 2? Or maybe simultaneously while it is running through function 1 will it move on to the event listener calling on function 2?

Sorry if confusing, I was just curious. Thanks for any help!

#2

Hi Nate, this seemed to have gotten posted twice, I’ve removed the duplicate post.

To answer your question, if you run this little snippet and watch the console log:

local r = display.newRect(100,100,100,100) local function b(event)      print("b", event.phase)      return true end local function a(event)      print("a", event.phase)      return true end r:addEventListener("touch", a) r:addEventListener("touch", b)

you will see printed:

2013-11-30 15:41:20.880 Corona Simulator[8163:507] a    began 2013-11-30 15:41:20.881 Corona Simulator[8163:507] b    began 2013-11-30 15:41:20.993 Corona Simulator[8163:507] a    ended 2013-11-30 15:41:20.993 Corona Simulator[8163:507] b    ended

So it runs the first function first then the second function.  But I think it’s important to understand that these are fired asynchronously.  That means it’s going to fire the began phase event to A then immediately fire the event to B.  It’s very possible that if function A takes a while that function B could fire in the middle of A’s running and depending on what all goes on, it’s possible that the B ended event could come before the A ended event.  So you may end up with A began, B began, B ended, A ended.

Rob

#3

Very helpful explanation! Thanks a bunch!

#4

Hi Nate, this seemed to have gotten posted twice, I’ve removed the duplicate post.

To answer your question, if you run this little snippet and watch the console log:

local r = display.newRect(100,100,100,100) local function b(event)      print("b", event.phase)      return true end local function a(event)      print("a", event.phase)      return true end r:addEventListener("touch", a) r:addEventListener("touch", b)

you will see printed:

2013-11-30 15:41:20.880 Corona Simulator[8163:507] a    began 2013-11-30 15:41:20.881 Corona Simulator[8163:507] b    began 2013-11-30 15:41:20.993 Corona Simulator[8163:507] a    ended 2013-11-30 15:41:20.993 Corona Simulator[8163:507] b    ended

So it runs the first function first then the second function.  But I think it’s important to understand that these are fired asynchronously.  That means it’s going to fire the began phase event to A then immediately fire the event to B.  It’s very possible that if function A takes a while that function B could fire in the middle of A’s running and depending on what all goes on, it’s possible that the B ended event could come before the A ended event.  So you may end up with A began, B began, B ended, A ended.

Rob

#5

Very helpful explanation! Thanks a bunch!