LÖVE 11.4 Callbacks

Features

• Multiple Event Handlers

Usage Example

• New event must be registered: callbacks:registerevent(< key >)
• Such functions can be invoked as usual, via love.event.push using the table index as an argument.

local callbacks = require("callbacks"); callbacks:init()
love.handlers = callbacks.handlers

local gametime = require("gametime")
for index = 1, #gametime.__NEWEVENTS do
    callbacks:registerevent(gametime.__NEWEVENTS[index])
    -- registerevent "minutepassed"
    -- registerevent "hourpassed"
    -- registerevent "daypassed"
    -- ect.
end

callbacks:appendhandler("minutepassed", function(minute) print(minute) end)

local function hourpassed(hour) print(hour) end
callbacks:appendhandler("hourpassed", hourpassed)

function love.update(delta)
    gametime:update(delta)
end

• Example1:

local callbacks = require("callbacks"); callbacks:init()
love.handlers = callbacks.handlers

-- callbacks.handlers.mousemoved is <function> callbacks.__EMPTY

callbacks:appendhandler("mousemoved", function(x,y) print(x,y) end) -- return's function ~0x1
-- callbacks.handlers.mousemoved is <function> ~0x1

callbacks:appendhandler("mousemoved", function(x,y) print(x*y) end) -- return's function ~0x2
-- callbacks.handlers.mousemoved is <metatable>__ITERATOR {[0] = 2, ~0x1, ~0x2 }

function love.load()
    -- ...
end

function love.update()
    -- ...
end

function love.draw()
    -- ...
end

• Example2:

function love.run()    
    local callbacks = require("callbacks"); callbacks:init()
    local handlers = callbacks.handlers
    
    local quitarg = false
    local quit = function(arg) quitarg = arg or 0 end
    callbacks:appendhandler("quit", quit)
    
    local delta = love.timer.step()
    return function()
        -- Process events.
        love.event.pump()
        if quitarg then return quitarg end
        for name, a,b,c,d,e,f in love.event.poll_i do
            handlers[name](a,b,c,d,e,f)
        end

        -- Update
        delta = love.timer.step()
        -- ...

        -- Render
        love.graphics.clear()
        love.graphics.print(love.timer.getFPS(), 10, 10)
        love.graphics.present()
        
        love.timer.sleep(0.001)
    end
end

• Garbage collection:

local callbacks = require("callbacks"); callbacks:init()
love.handlers = callbacks.handlers

print(collectgarbage("count")) -- ~600 kb

for index = 1, 10^6 do -- 1'000'000
    callbacks:appendhandler("mousemoved", function(x,y) return x+y end)
end
print(collectgarbage("count")) -- ~47601 kb

callbacks:reinit()
callbacks:collectgarbage()collectgarbage()

print(collectgarbage("count")) -- ~350 kb