-- get_key_<state/pressed> usage example
-- made by antibrain

-- define list of all supported key names

keys={"1","2","3","4","5","6","7","8","9","0",
       "q","w","e","r","t","y","u","i","o","p",
       "a","s","d","f","g","h","j","k","l",
       "z","x","c","v","b","n","m",
       "[","]","shift","space","backspace"}

--define vars

currentkeyname=""
keystr=""
keyoffset=0
kpressed=true
ikd=false

-- get_key usage:

-- get_key_pressed(key) checks if key "key" is pressed and returns "true" for the frame that key "key" is pressed.
-- get_key_state(key) returns 1 if key "key" is held. if key "key" isnt held, returns "nil" 

-- "q", "1", "space", "backspace" are all valid key names.
-- "Q", "!", "^", "`" are not valid key names.

-- lowercase letters, numbers, and control keys (space, alt, backspace, etc) are all valid key names
-- uppercase letters, symbols, F keys and hotkeys are NOT valid key names.
-- if you want to use symbols (eg. shift+4=$), you can check if shift is held, then change output chars while it is.

-- an easy way to check for all keys is to make a table of all supported keynames, then iterate over it.

-- main update loop (30fps)

function _update()

    -- clear screen and reset drawing vars

    cls()
    kstrx=6
    kstry=20

    --for every key in keys, run key checking script

    for i=1,#keys do

        -- check if key "keys[i]" is held and set it to currentkey
        currentkey=get_key_state(keys[i])

        -- if current key isnt held, set it to 0 so future calculations dont die
        if currentkey==nil then currentkey=0 end    

        -- if current key is held, then set its name to currentkeyname for later
        if currentkey==1 then currentkeyname=keys[i] end

        -- if key string length in pixels is longer than screen length, move it back by 476 ish pixels
        if (kstrx-(keyoffset*5))+(#keystr*5)>480 then kstrx=6 kstry+=8 j=#keystr-keyoffset keyoffset=#keystr end
		 if (#keystr<(keyoffset)) then keyoffset-=j end
			
        -- display all keys and change its color to red if key is held
        print(keys[i],6+(i*6),6,currentkey+7)

        -- draw line at next char in keystr to show where next char will go
        line(((#keystr+1)*5)-keyoffset*5,kstry+8,(((#keystr+1)*5)+4)-keyoffset*5,kstry+8,currentkey+7)

        -- draw key string at kstrx,kstry in hyperlink blue
        print(keystr,kstrx-(keyoffset*5),kstry,28)

        -- if a key hasnt been pressed this frame
        if ikd==false then
            -- set ikd to true if one is
            ikd=get_key_pressed(keys[i])
        end

        -- if a key has been pressed this frame
        if ikd==true then

            -- set space to " " so that it doesnt just add the word "space" to keystr
            if currentkeyname=="space" then currentkeyname=" " end

            -- if backspace has been pressed, set keyname to "" so it doesnt print anything, then remove one char from end of keystr by setting keystr to substring of keystr from char 0 to char #keystr minus 1
            if currentkeyname=="backspace" then currentkeyname="" keystr=sub(keystr,0,#keystr-1) end
            keystr=keystr..currentkeyname

            --reset key vars
            currentkeyname=""
            ikd=false
        end
    end
end