Codea codify menu system

--the main functions stay quite small
--your code needs to go into an object
--see MiGame as an example

function setup()
    --the only thing you need is
    --a variable (like pss)
    --to store a pointer to the Partition class (Parti)
    --pass it your object (MiGame)
    --and the number of rows and columns for the menu (4)
    --(4 is a 4 by 4 grid or 16 partitions)
    pss = Parti(MiGame,4)
end

function draw()
    --required (the menu draws even if you don't
    pss:draw()
end

function touched(touch)
    --required (the menu uses tocuhes even if you don't)
    pss:touched()
end


MiGame = class()

function MiGame:init()
    self.x = math.random(WIDTH)
    self.y = math.random(HEIGHT)
    self.w = math.random(WIDTH)
    self.h = math.random(HEIGHT)
end

function MiGame:draw()
    --background(0,0,0,255)
    strokeWidth(20)
    stroke(255, 0, 0, 255)
    fill(0, 0, 255, 255)
    ellipse(self.x,self.y,self.w,self.h)
end

function MiGame:Heartbeat()
    background(0,0,0,255)
    self.x = self.x + math.random(2) - 1.5
    self.y = self.y + math.random(2) - 1.5
    self.w = self.w + math.random(2) - 1.5
    self.h = self.h + math.random(2) - 1.5
end

function MiGame:touched(touch)
    self:init()
end


Parti = class()

function Parti:init(clss,np)
    self.clss = clss --the class to execute
    self.aclss = nil --active class
    self.menu = true --is the menu being displayed
    self.np = np -- number of partitions across
    self.gb = math.sqrt(5)/4 --golden border
    self.gr = (1+math.sqrt(5))/2 --golden ratio
    self.gp = WIDTH / ((self.gb * (np + 1)) + (np)) --golden partion
    self.ps = {} --table of partitions (of menu and classes)
    local i
    local j
    for i = 1, np do
        local ix = ((i)*self.gb*self.gp) + ((i - 1)*self.gp)
        self.ps[i] = {}
        for j = 1, np do
            local iy = ((j)*self.gb*self.gp) + ((j - 1)*self.gp)
            self.ps[i][j] = {x=ix,y=iy,clss=nil}
        end
    end
end

function Parti:draw()
    if self.menu == true then
        self:drawmenu()
    else
        self.aclss:Heartbeat()
        self.aclss:draw()
        self:drawreturn()
    end
end

function Parti:drawmenu()
    rect(0,0,10,10)
    background(0, 0, 0, 255)

    for i = 1, self.np do
        for j = 1, self.np do
            if self.ps[i][j].clss ~= nil then
                --print(i,j)
                pushMatrix()
                translate(self.ps[i][j].x,self.ps[i][j].y)
                scale(self.gp/WIDTH)
                self.ps[i][j].clss:draw()
                popMatrix()
            end
        end
    end

    stroke(0, 255, 0, 255)
    local gbgp = (self.gb*self.gp)
    for i = 1, self.np do
        for j = 1, self.np do
            noFill()
            strokeWidth(3)
            rect(self.ps[i][j].x,self.ps[i][j].y,self.gp,self.gp)
            noStroke()
            fill(0,0,0,255)
            rect(self.ps[i][j].x-gbgp,0,gbgp,HEIGHT)
            rect(0,self.ps[i][j].y-gbgp,WIDTH,gbgp)
        end
    end
    rect(self.ps[self.np][self.np].x+self.gp,0,gbgp,HEIGHT)
    rect(0,self.ps[self.np][self.np].x+self.gp,WIDTH,gbgp)

end

function Parti:drawreturn()
    --background(0,0,0,255)
    stroke(0, 255, 0, 255)
    fill(0,0,0,255)
    strokeWidth(7)
    rect(0,0,50*((1+math.sqrt(5))/2),50)
--ipad41001 arrows
    line(20,25,40,40)
    line(20,25,40,10)
    line(30,25,50,40)
    line(30,25,50,10)
end

function Parti:touched(touch)
    if CurrentTouch.state == BEGAN then
        if self.menu then
            self.menu = false
            for i = 1, self.np do
                for j = 1, self.np do
                    if CurrentTouch.x > self.ps[i][j].x and
                       CurrentTouch.x < self.ps[i][j].x + self.gp and
                       CurrentTouch.y > self.ps[i][j].y and
                       CurrentTouch.y < self.ps[i][j].y + self.gp then
                        if self.ps[i][j].clss == nil then
                            self.ps[i][j].clss = self.clss()
                        end --init class
                        self.aclss = self.ps[i][j].clss
                    end --touch in box
                end --j
            end --i
        else --not on menu
            if CurrentTouch.x < (50*self.gr) and CurrentTouch.y < 50 then
                self.menu = true
            else
                self.aclss:touched()
            end
        end
    end
end