Added a toast feature

features/gui/toast.lua

@@ -0,0 +1,160 @@
+local Event = require 'utils.event'
+local Game = require 'utils.game'
+local Global = require 'utils.global'
+local Gui = require 'utils.gui'
+local Color = require 'resources.color_presets'
+
+local type = type
+local tonumber = tonumber
+local pairs = pairs
+local size = table.size
+
+local Public = {}
+
+local memory = {
+    id = 0,
+    active_toasts = {},
+}
+
+Global.register(memory, function (tbl) memory = tbl end)
+
+---Creates a unique ID for a toast message
+local function autoincrement()
+    local id = memory.id + 1
+    memory.id = id
+    return id
+end
+
+---Toast to a specific player
+---@param p number|string|LuaPlayer player index or object
+---@param duration number in seconds
+---@param message|nil message displayed, leave empty to have an empty LuaGuiElement
+function Public.toast_player(p, duration, message)
+    local player
+
+    if type(p) == 'string' then
+        player = Game.get_player_by_index(tonumber(p))
+    elseif type(p) == 'number' then
+        player = Game.get_player_by_index(p)
+    else
+        player = p
+    end
+
+    if not player or not player.valid then
+        return nil
+    end
+
+    local frame = player.gui.left.add({type = 'frame', direction = 'vertical', style = 'captionless_frame'})
+    frame.style.width = 300
+
+    local container = frame.add({type = 'flow', direction = 'horizontal'})
+    container.style.horizontally_stretchable = true
+
+    local progressbar = frame.add({type = 'progressbar'})
+    local style = progressbar.style
+    style.width = 290
+    style.height = 3
+    style.color = Color.grey
+    progressbar.value = 1 -- it starts full
+
+    local id = autoincrement()
+    local tick = game.tick
+    if not duration then
+        duration = 15
+    end
+
+    Gui.set_data(frame, {
+        is_toast = true,
+        toast_id = id,
+        progressbar = progressbar,
+        start_tick = tick,
+        end_tick = tick + duration * 60
+    })
+    memory.active_toasts[id] = true
+
+    if message ~= nil then
+        local label = container.add({type = 'label', caption = message})
+        label.style.single_line = false
+    end
+
+    return container
+end
+
+---Attempts to get a toast based on the element, will traverse through parents to find it.
+---@param element LuaGuiElement
+local function get_toast(element)
+    if not element or not element.valid then
+        return nil
+    end
+
+    local data = Gui.get_data(element)
+
+    if data and data.is_toast then
+        return element, data
+    end
+
+    -- no data, have to check the parent
+    return get_toast(element.parent)
+end
+
+Event.add(defines.events.on_gui_click, function (event)
+    local element = get_toast(event.element)
+    if not element then
+        return
+    end
+
+    Gui.destroy(element)
+end)
+
+Event.on_nth_tick(2, function (event)
+    local active_toasts = memory.active_toasts
+    if size(active_toasts) == 0 then
+        return
+    end
+
+    local tick = event.tick
+    local players = game.connected_players
+
+    local finished_toasts = {}
+
+    for _, player in pairs(players) do
+        for _, element in pairs(player.gui.left.children) do
+            local toast, data = get_toast(element)
+            if toast and data then
+                local toast_id = data.toast_id
+                local end_tick = data.end_tick
+
+                if tick > end_tick then
+                    Gui.destroy(element)
+                    finished_toasts[toast_id] = true
+                else
+                    local start_tick = data.start_tick
+                    local limit = end_tick - start_tick
+                    local current = end_tick - tick
+                    data.progressbar.value = current / limit
+                end
+            end
+        end
+    end
+
+    for toast_id, _ in pairs(finished_toasts) do
+        active_toasts[toast_id] = nil
+    end
+end)
+
+Event.add(defines.events.on_player_left_game, function (event)
+    local active_toasts = memory.active_toasts
+    if size(active_toasts) == 0 then
+        return
+    end
+
+    -- active toasts, do a cleanup so data remains uncorrupted
+    for _, element in pairs(Game.get_player_by_index(event.player_index).gui.left.children) do
+        local toast = get_toast(element)
+        if toast then
+            Gui.destroy(element)
+        end
+    end
+end)
+
+return Public