任务追踪：主线支线的追踪面板

-- 错误：单槽位追踪，新任务顶掉旧任务
function trackQuest(q)
    panel.show = q
end

local track = {main = nil, side = {}}
local function trackQuest(q)
    if q.kind == "main" then
        track.main = q
    else
        if #track.side >= 2 then
            table.remove(track.side, 1)
        end
        table.insert(track.side, q)
    end
    refreshPanel()
end
local function refreshPanel()
    local label = panel:getChildByName("trackList")
    label:setString(buildText(track))
end