Multitouch and scaling

Audio and Graphics
#1

Hi there!

I’m new to lua and corona sdk, and I’m creating a pinch zoom library based on this tutorial:

https://coronalabs.com/blog/2013/01/22/implementing-pinch-zoom-rotate/

I was able to make it work, even made my own tweaks, but I’m stuck with making it a library, I wonder if you could help me in overcoming the error I have right now:

So what I did, is that in the multitouch.lua I added the following method:

function touchGroup:new(t)   touchGroup = t   touchGroup:addEventListener("touch")  -- listen for touches starting on the touch object   return t end

and I call it from my game.lua with:

-- include the multitouch local multitouch = require("multitouch") --some other code  multitouch:new(background)

where background is a rect.

I get the following error in multitouch.lua in the line where I set the listener:

addEventListener: listener cannot be nil: nil

I can post more code if needed, please share your thoughts, any helpd would be appreciated.  

#2

You actually need to define the touch listener.  The error message is telling you there is no touch listener to call.  So something like this will fix it:

function touchGroup:touch(event) end touchGroup:addEventListener("touch") -- listen for touches starting on the touch object
#3

You actually need to define the touch listener.  The error message is telling you there is no touch listener to call.  So something like this will fix it:

function touchGroup:touch(event) end touchGroup:addEventListener("touch") -- listen for touches starting on the touch object