Corona - Touch Events In table objects? - events

Question

I am trying to use this in a project, but I cannot figure out how to place a touch event listener to each of the icons/objects in the carousel, If someone could provide a quick answer of how to do that I'd appreciate it.
local NUM_ITEMS=20;
local radiusX= 200;
local radiusY= 40;
local centerX = 240;
local centerY = 160;
local speed = 0.05;
local perspective = 3;
local carousel = display.newGroup()
local icons = {}
local function zSort(myTable, myGroup)
table.sort(myTable,
function(a, b)
return a.depth < b.depth -- depth is your custom field
end
)
for i = 1, #myTable do
myGroup:insert(myTable[i].img)
end
end
function Icon(i)
local this = {}
local icon = display.newImage(carousel, "images/icon"..i..".png")
this.angle = (i-1) * math.rad(360/NUM_ITEMS);
this.img = icon
return this
end
function update(event)
local icon
local sin = math.sin
local cos = math.cos
for i=1, NUM_ITEMS, 1 do
icon = icons[i]
local img = icon.img
img.x = cos(icon.angle) * radiusX + centerX
img.y = sin(icon.angle) * radiusY + centerY
local s = (img.y - perspective) / (centerX + radiusY - perspective)
img.xScale = s*0.25
img.yScale = s*0.25
icon.angle = (icon.angle + speed) --%math.rad(360)
icon.depth = s
end
zSort(icons, carousel)
end
for i=1, NUM_ITEMS, 1 do
local icon = Icon(i)
icons[i] = icon
end
function onTouch(event)
if(event.phase=="moved") then
speed = (event.x - centerX) / 2000;
end
end
Runtime:addEventListener("enterFrame",update)
Runtime:addEventListener("touch", onTouch)

Answer 1

I can't exactly understood what you really need. But if you want to add individual touch to all same icons in a localGroup, then you can add the icons as an icon array and give specific tag to each and can give individual touch, as follows:
local icons = {}
for i=1,10 do
icons[i] = display.newImage(i..".png")
icons[i].tag = i
end
local function touchIt(e)
print(e.target.tag)
--[[ icons[e.target.tag] can be used to identify
and set properties to the touched icon --]]
end
for i=1,10 do
icons[i]:addEventListener("touch",touchIt)
end
OR
if you want to identify all group elements as the same and give touch, then you can use same tag/ give userdata to all icons and can give same touch action to all group elements(as follows).
local icons = {}
for i=1,10 do
icons[i] = display.newImage(i..".png")
icons[i].tag = 1 --[[ you can also use icons[i].userdata = "icons"
(or any string)--]]
end
local function touchIt(e)
print(e.target.tag) -- It willo be 1 for all icons
--[[ icons[e.target.tag] can be used to identify
whether if it is under 'icons' --]]
--[[ or use userdata as follows --]]
print(e.target.userdata)--[[ out put is a string
identifying the group/element--]]
end
for i=1,10 do
icons[i]:addEventListener("touch",touchIt)
end