Corona: slide event example

slideEvent.lua

-------------------------------------
-- group slide event
-- Erin Lin
-------------------------------------
local isActive = true
local slide = function(event) 
    if not isActive then return end
    local W = display.contentWidth * .5
    local dis = 40
    local pos = (event.xStart < W and "L") or "R"
    local len = event.xStart - event.x

    if "began" == event.phase then
        display.getCurrentStage():setFocus( group )
    elseif "moved" == event.phase then   
        if pos == "L" and len < -dis then
            print("slide", "toLeft")
            isActive = false
            -- code here
        elseif pos == "R" and len > dis then
            print("slide", "toRight")
            isActive = false
            -- code here
        end
    elseif "ended" == event.phase then
        print("click")
        display.getCurrentStage():setFocus( nil )
        if math.abs(len) < dis then
            -- code here
        end
    end
end
group:addEventListener("touch", slide)