SimpleMenuAPI v1.0

--[[ SimpleMenuAPI -- A Simple Menu API

--SimpleMenuAPI Guide

First, create a table variable, and make your new menu
MyMenu = {}
MyMenu[1] = menu.create('Awesome Menu', True)
The function call above sets the title of the new menu to Awesome Menu
and the True value sets it to show the titlebar

Now you need to add some items to the menu!
MyMenu[2] = menu.additem(MyMenu[1], 'New Game')
That function call adds an item to the menu you created.
MyMenu[1] tells the function the ID of the menu you want the item to add to
'New Game' sets the name of that item to New Game

Lets add one more item to the menu
MyMenu[3] = menu.additem(MyMenu[1], 'Load Game')
That function call does the same, but makes the name "Load Game" instead of "New Game"

So now you have;
MyMenu[1] -- Contains your Menu's ID
MyMenu[2] -- Contains Item 1's ID
MyMenu[3] -- Contains Item 2's ID

So, what now? Lets clear the screen!
term.clear()
Now everything is blank, right? That's okay!
We want it blank, so we can draw the menu.

Lets do that now;
menu.draw(MyMenu[1], 5, 3, 0)
This one takes some explaining.
This draws your menu(MyMenu[1]) at position (5,3) in (x,y) on the screen
And the items aren't spaced apart because the last argument is 0

Alright, that looks cool, right?

Lets set your menu to active.
menu.startselect(MyMenu[1])
This one starts the selection process of that menu.
It sets the selection cursor to your first item, which we set as "New Game"

Good, but... Nothing happened, it all looks the same.
That's because we need to draw the menu again to see the changes.

So, lets do this again;
term.clear()
menu.draw(MyMenu[1], 5, 3, 0)

And there you go! You should see this;
Awesome Menu
>New Game
Load Game

That's awesome, as the name implies.
Lets say that we already have a saved game. We need to load game, right?
So, we need to change what we have selected.

Lets do that now;
menu.down(MyMenu[1])
This moves the cursor down the list by one item. So, we now have our cursor at the right part.

Lets draw the screen again;
term.clear()
menu.draw(MyMenu[1], 5, 3, 0)

You should see this;
Awesome Menu
New Game
>Load Game

Now, lets say we changed our mind. Then we changed our mind again;

menu.up(MyMenu[1])
term.clear()
menu.draw(MyMenu[1], 5, 3, 0)

Oops, it's at New Game now.

menu.down(MyMenu[1])
term.clear()
menu.draw(MyMenu[1], 5, 3, 0)

Alright, we're back at Load Game. See, it's pretty easy to get what we want.

Now, before we make a selection, we need to make a function to figure out what we selected.

Lets do that;
function menu.choice(item)
    if item == "New Game" then
        newgame()
    elseif item == "Load Game" then
        loadgame()
    end
end
But... What does this do?

function menu.choice(item) <-- Makes a new function, that is called when you use menu.choose() later.

    if item == "New Game" then <-- This checks to see if the item you selected is "New Game"

        newgame() <-- This would be the New Game function for your game, this is outside the scope of this API

    elseif item == "Load Game" then <-- This checks to see if the item you selected is "Load Game"

        loadgame() <-- This would be the Load Game function for your game, this is outside the scope of this API

    end <-- This ends the "if" block

end <-- This ends the function

So, now you have a function that does something when you choose a menu item.

We're on the menu item that we want, so lets just go straight to selecting it;
menu.choose()
That function just selects the current item for the active menu.

Now, lets make the menu inactive again, because we don't need to select any more.
menu.stopselect()
That set menu.active to 0, and set the currently chosen menu item on your menu to the TitleBar, to hide the cursor

And there you have it. That's the scope of this menu system.
You can go incredibly complex, or incredibly lightweight.
It's all in how you use the API



See the following information for a rundown on everything we used, what it does, and what the arguments are

--VARIABLES

[menu.active]
This variable contains the ID of the active menu
If no menu is active, this variable is equal to
nil( nil = 0 )

--FUNCTIONS
[menu.create(Title, TopBar)] -- Returns ID:Integer
Title:String -- The Title bar of the menu
TopBar:Bool -- Defines whether the Title bar on this menu is visible or not

[menu.additem(ID, Name)] -- Returns ID2:Integer
ID:Integer -- The ID of the menu to add the item to
Name:String -- The name of the menu item to add

[menu.setitem(ID, ID2, Name)]
ID:Integer -- The ID of the menu containing the item
ID2:Integer -- The ID of the menu item to change the name of
Name:String -- The Name you want to set the menu item to

[menu.startselect(ID)]
ID:Integer -- The ID of the menu to start the menu selection process

[menu.stopselect(ID)]
ID:Integer -- The ID of the menu to stop the menu selection process

[menu.up(ID)] -- Moves the selection up the list
ID:Integer -- The ID of the menu to change the selected item

[menu.down(ID)] -- Moves the selection down the list
ID:Integer -- The ID of the menu to change the selected item

[menu.choose()] -- Chooses the current selection for the active menu

[menu.choice(Name)] -- Player Defined
Name:String -- Contains the name of the menu item the user chose
( To get the ID of the menu they chose from, use menu.active )
This variable is run when the user uses menu.choose()

[menu.draw(ID, X, Y, Space)]
ID:Integer -- The ID of the menu to draw
X:Integer -- The X Position to draw the Menu at
Y:Integer -- The Y Position to draw the Menu at
Space:Integer -- The amount of spaces between menu items
( Recommended; 0 or 1 )

]]--

menu = {}
menu.list = {}
menu.count = 0
menu.select = {}
menu.active = 0

function menu.create(t, b)
    local id = menu.count+1
    menu.list[id] = {}
    menu.list[id][1] = t
    menu.list[id].count = 1
    menu.list[id].topbar = b
    menu.count = id
    menu.select[id] = 1
    return id
end

function menu.additem(id,t)
    local item = menu.list[id].count + 1
    menu.list[id][item] = t
    menu.list[id].count = item
    return item
end

function menu.setitem(id, id2, t)
    menu.list[id][id2] = t
end

function menu.startselect(id)
    if menu.list[id][2] then
        menu.select[id] = 2
        menu.active = id
    end
end

function menu.stopselect(id)
    if menu.list[id][2] and menu.active == id then
        menu.select[id] = 1
        menu.active = 0
    end
end

function menu.up(id)
    if menu.active == id then
        if menu.select[id] > 2 then
            menu.select[id] = menu.select[id] - 1
        end
    end
end

function menu.down(id)
    if menu.active == id then
        if menu.select[id] < menu.list[id].count then
            menu.select[id] = menu.select[id] + 1
        end
    end
end

function menu.choose()
    if menu.active ~= 0 then
        if menu.select[menu.active] ~= 1 then
            local temp1 = menu.select[menu.active]
            local temp2 = menu.list[menu.active][temp1]
            if menu.choice ~= nil then menu.choice(temp2) end
        end
    end
end


function menu.draw(id, x, y, s)
    local h = 0
    local r = 0
    local div = 1
    for i,v in ipairs(menu.list[id]) do
        if menu.select[id] == i and i ~= 1 then
            term.setCursorPos(x,y - div + h + h*s)
            --term.clearLine()
            term.write('>')
            term.setCursorPos(x+1,y - div + h + h*s)
            term.write(menu.list[id][i])
        elseif i == 1 and menu.list[id].topbar == true then
            div = 0
            term.setCursorPos(x,y + h + h*s)
            --term.clearLine()
            term.write('--')
            term.setCursorPos(x+2,y + h + h*s)
            term.write(menu.list[id][i])
        elseif i == 1 and menu.list[id].topbar == false then
            div = 1
        elseif i ~=1 then
            term.setCursorPos(x ,y - div + h + h*s)
            --term.clearLine()
            term.write(menu.list[id][i])
        end
        h = h+1
    end
end