[Class] Callback

local callback
do
    local callback_id = 0
    callback = setmetatable({ }, {
        __call = function(this, eventName, x, y, w, h, hidden)
            local id = callback_id
            local action
            local hasClickableRange, range = false, 0

            local fixed = false
            local textarea = function(playerName)
                ui.addTextArea(id, "<textformat leftmargin='1' rightmargin='1'><a href='event:callback." .. eventName .. "'>" .. string.rep('\n', h / 10), playerName, x - 5, y - 5, w + 5, h + 5, 1, 1, 0, fixed)
            end

            local self = {
                callback = eventName,
                x = x,
                y = y,
                w = w,
                h = h
            }

            self.displayCallback = function(self, f)
                if type(f) == "string" then
                    return textarea(f)
                end

                for k, v in next, tfm.get.room.playerList do
                    if not f or f(k, v) then
                        textarea(k)
                    end
                end
            end

            self.fixed = function(self)
                fixed = true
                return self
            end

            self.inClickableRange = function(self, playerName)
                if hasClickableRange then
                    local x, y = tfm.get.room.playerList[playerName].x, tfm.get.room.playerList[playerName].y
                    return ((x >= (self.x - range) and x <= (self.x + self.w + range)) and (y >= (self.y - range) and y <= (self.y + self.h + range)))
                end
                return true
            end

            self.performAction = function(self, ...)
                if action then
                    action(self, ...)
                    return self, true
                end
                return self, false
            end

            self.remove = function(self, playerName)
                ui.removeTextArea(id, playerName)

                if not playerName then
                    this[eventName] = nil
                end
                return true
            end

            self.setAction = function(self, f)
                if type(f) == "function" then
                    action = f
                    this[eventName] = self
                    return true
                end
                return false
            end

            self.setClickableRange = function(self, complement)
                hasClickableRange, range = true, (complement or 0)
            end

            if not hidden then
                self.displayCallback(self)
            end

            callback_id = callback_id + 1
            return self
        end
    })
end