Added a GUI element + toasts to notify of biter evolution

config.lua

@@ -248,6 +248,10 @@ global.config = {
         ghosts_before_research = true,
         -- adds craftable loaders.
         loaders = true
+    },
+    -- adds a useless button with the biter percentage
+    evolution_progress = {
+        enabled = true,
     }
 }
 

control.lua

@@ -79,6 +79,9 @@ end
 if config.player_list.enabled then
     require 'features.gui.player_list'
 end
+if config.evolution_progress.enabled then
+    require 'features.gui.evolution_progress'
+end
 if config.poll.enabled then
     require 'features.gui.poll'
 end

features/gui/evolution_progress.lua

@@ -0,0 +1,126 @@
+local Event = require 'utils.event'
+local Gui = require 'utils.gui'
+local Game = require 'utils.game'
+local Global = require 'utils.global'
+local Toast = require 'features.gui.toast'
+local round = math.round
+local pairs = pairs
+local main_button_name = Gui.uid_name()
+
+local memory = {
+    last_percentage = 0,
+}
+
+Global.register(memory, function (tbl) memory = tbl end, 'evolution_progress')
+
+local button_sprites = {
+    ['small-biter'] = 0,
+    ['medium-biter'] = 0.2,
+    ['small-spitter'] = 0.25,
+    ['medium-spitter'] = 0.4,
+    ['big-spitter'] = 0.5,
+    ['big-biter'] = 0.501,
+    ['behemoth-spitter'] = 0.9,
+    ['behemoth-biter'] = 0.901,
+}
+
+local function get_evolution_percentage()
+    if not game then
+        return 0
+    end
+
+    local value = round(game.forces.enemy.evolution_factor * 1000) * 0.001
+    if value < 0.001 then
+        -- 0.00 won't be shown on the button as value
+        return 0.001
+    end
+
+    return value
+end
+
+local function get_alien_name(evolution_factor)
+    local last_match
+    for name, alien_threshold in pairs(button_sprites) do
+        if evolution_factor == alien_threshold then
+            return name
+        end
+
+        -- next alien evolution_factor isn't reached
+        if alien_threshold > evolution_factor then
+            return last_match
+        end
+
+        -- surpassed this alien evolution_factor
+        if alien_threshold < evolution_factor  then
+            last_match = name
+        end
+    end
+
+    -- shouldn't be reached but shouldn't crash either
+    return 'fish'
+end
+
+local function player_joined(event)
+    local player = Game.get_player_by_index(event.player_index)
+    if not player or not player.valid then
+        return
+    end
+
+    if player.gui.top[main_button_name] ~= nil then
+        return
+    end
+
+    local evolution_factor = get_evolution_percentage()
+    local alien_name = get_alien_name(evolution_factor)
+
+    player.gui.top.add({
+        name = main_button_name,
+        type = 'sprite-button',
+        sprite = 'entity/' .. alien_name,
+        number = evolution_factor * 100,
+    }).enabled = false
+end
+
+local function on_nth_tick()
+    local previous_evolution_factor = memory.last_percentage
+    local evolution_factor = get_evolution_percentage()
+
+    if previous_evolution_factor == evolution_factor then
+        return
+    end
+
+    memory.last_percentage = evolution_factor
+
+    local previous_alien = get_alien_name(previous_evolution_factor)
+    local current_alien = get_alien_name(evolution_factor)
+    local sprite
+
+    if current_alien ~= previous_alien then
+        sprite = 'entity/' .. current_alien
+        local caption = {'', 'Evolution notice: ', {'entity-name.' .. current_alien}, ' sighted!'}
+        Toast.toast_all_players_template(10, function (container)
+            container.add({type = 'sprite', sprite = sprite})
+            local text = container.add({type = 'label', caption = caption, name = Toast.close_toast_name})
+            local text_style = text.style
+            text_style.single_line = false
+            text_style.vertical_align = 'center'
+        end)
+    end
+
+    local players = game.connected_players
+    local evolution_button_number = evolution_factor * 100
+    for i = 1, #players do
+        local button = players[i].gui.top[main_button_name]
+        if button and button.valid then
+            button.number = evolution_button_number
+            if sprite then
+                button.sprite = sprite
+            end
+        end
+    end
+end
+
+Gui.allow_player_to_toggle_top_element_visibility(main_button_name)
+
+Event.add(defines.events.on_player_joined_game, player_joined)
+Event.on_nth_tick(207, on_nth_tick)

features/gui/toast.lua

@@ -1,14 +1,11 @@
 local Event = require 'utils.event'
-local Game = require 'utils.game'
 local Global = require 'utils.global'
 local Gui = require 'utils.gui'
 local Token = require 'utils.token'
 local Color = require 'resources.color_presets'
 
-local type = type
-local tonumber = tonumber
 local pairs = pairs
-local size = table.size
+local next = next
 
 local Public = {}
 

utils/event.lua

@@ -45,7 +45,7 @@
 -- Event.remove_removable(defines.events.on_built_entity, handler)
 --
 -- It's not an error to register the same token multiple times to the same event, however when
--- removing only the first occurance is removed.
+-- removing only the first occurrence is removed.
 --
 -- ** Event.add_removable_function(event_name, func) **
 --