红点提示：未读计数的点亮与熄灭

-- 错误：各处手工开关红点，状态对不上账
function afterRead()
    dot:setVisible(false)
end

local counts = {}
local function setCount(key, n)
    counts[key] = n
    local dot = panel:getChildByName("dot_" .. key)
    dot:setVisible(n > 0)
    if n > 0 then
        dot:getChildByName("num"):setString(tostring(n))
    end
    local any = false
    for _, v in pairs(counts) do
        if v > 0 then
            any = true
        end
    end
    panel:getChildByName("dot_main"):setVisible(any)
end
setCount("mail", 3)