[Luzzifus]

Originally Posted by SDPhantom It really makes me cringe seeing data function calls in a sort comparison function. I would rather have the info directly in the data structure. Then again, to have it make any sense would require an update in the whole codebase to accept the new structure. It barely makes sense now.

Adapting the data structure is pretty easy:

local buttonIDs = {}
for i, button in self:IterateButtons() do
    local item = cargBags:GetItemInfo(button.bagID, button.slotID)
    if item.link then
        local _,_,tQ = GetItemInfo(item.link)
        local _,cnt = GetContainerItemInfo(button.bagID, button.slotID)
        buttonIDs[i] = { item.id, tQ, button, cnt }
    else
        buttonIDs[i] = { 0, -2, button, -1 }
    end
end
QuickSort(buttonIDs) -- sorting call

And the corresponding sort function would be this:

local QuickSort;
do
    local func = function(v1, v2)
        if not v1 or not v2 then return (v1 and true or false) end
        if v1[1] == 0 or v2[1] == 0 then
            return v1[1] > v2[1] -- empty slots last
        elseif v1[2] ~= v2[2] then
            return v1[2] > v2[2] -- higher quality first
        elseif v1[1] ~= v2[1] then
            return v1[1] > v2[1] -- group identical item ids
        else
            return v1[4] > v2[4] -- full/larger stacks first
        end
    end;
    QuickSort = function(tbl) table.sort(tbl, func) end
end