Initial commit

Author: tesselode

.gitattributes

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+# Auto detect text files and perform LF normalization
+* text=auto

.luacheckrc

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+return {
+	std = 'lua51+love',
+	ignore = {'212'},
+}

main.lua

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+local manager = require 'roomy'.new()
+
+local game, pause = {}, {}
+
+function game:keypressed(key)
+	if key == 'escape' then
+		manager:push(pause, 'hiya!')
+	end
+	if key == 'space' then
+		manager:switch(pause, 'switching')
+	end
+end
+
+function game:pause()
+	print 'pause'
+end
+
+function game:resume()
+	print 'unpause'
+end
+
+function game:draw()
+	love.graphics.print 'this is the gameplay state'
+end
+
+function pause:enter(previous, message)
+	print(previous, message)
+end
+
+function pause:keypressed(key)
+	manager:pop()
+end
+
+function pause:draw()
+	love.graphics.print 'paused'
+end
+
+function love.load()
+	manager:hook()
+	manager:switch(game)
+end

roomy.lua

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+local roomy = {}
+
+local Manager = {}
+Manager.__index = Manager
+
+function Manager:_switch(state, ...)
+	local previous = self.stack[#self.stack]
+	if previous then self:emit('leave', state, ...) end
+	self.stack[math.max(#self.stack, 1)] = state
+	self:emit('enter', previous or false, ...)
+end
+
+function Manager:_push(state, ...)
+	local previous = self.stack[#self.stack]
+	if previous then self:emit('pause', state, ...) end
+	self.stack[#self.stack + 1] = state
+	self:emit('enter', previous or false, ...)
+end
+
+function Manager:_pop(...)
+	if #self.stack == 0 then
+		error('No state to pop', 3)
+	end
+	if #self.stack == 1 then
+		error('Cannot pop a state when there is no state below it on the stack', 3)
+	end
+	local previous = self.stack[#self.stack]
+	self.stack[#self.stack] = nil
+	self:emit('resume', previous, ...)
+end
+
+function Manager:apply()
+	if not self.action then return end
+	if self.action.type == 'switch' then
+		self:_switch(self.action.state, unpack(self.action.args))
+	elseif self.action.type == 'push' then
+		self:_push(self.action.state, unpack(self.action.args))
+	elseif self.action.type == 'pop' then
+		self:_pop(unpack(self.action.args))
+	end
+	self.action = nil
+end
+
+function Manager:switch(state, ...)
+	self.action = {type = 'switch', state = state, args = {...}}
+end
+
+function Manager:push(state, ...)
+	self.action = {type = 'push', state = state, args = {...}}
+end
+
+function Manager:pop(...)
+	self.action = {type = 'pop', args = {...}}
+end
+
+function Manager:emit(event, ...)
+	local state = self.stack[#self.stack]
+	if not state then return end
+	if state[event] then state[event](state, ...) end
+end
+
+local defaultHookOptions = {
+	callbacks = {
+		'directorydropped',
+		'draw',
+		'filedropped',
+		'focus',
+		'keypressed',
+		'keyreleased',
+		'load',
+		'lowmemory',
+		'mousefocus',
+		'mousemoved',
+		'mousepressed',
+		'mousereleased',
+		'quit',
+		'resize',
+		'run',
+		'textedited',
+		'textinput',
+		'threaderror',
+		'touchmoved',
+		'touchpressed',
+		'touchreleased',
+		'update',
+		'visible',
+		'wheelmoved',
+	},
+	applyBefore = 'update',
+}
+
+function Manager:hook(options)
+	options = options or defaultHookOptions
+	for _, callbackName in ipairs(options.callbacks) do
+		local oldCallback = love[callbackName]
+		love[callbackName] = function(...)
+			if oldCallback then oldCallback(...) end
+			if callbackName == options.applyBefore then
+				self:apply()
+			end
+			self:emit(callbackName, ...)
+		end
+	end
+end
+
+function roomy.new()
+	local manager = setmetatable({
+		stack = {},
+		action = nil,
+	}, Manager)
+	return manager
+end
+
+return roomy