frameDrawer

--Returns the valid color of a base 16 color code
local function toCol(a)
    local col = 2^(tonumber(a, 16))
    return col
end
--Returns the modified string 'str' w/ the character 'added' replaced at the string index 'n'
local function setStringIndex(str,added,n)
    return string.sub(str,1,n-1)..added..string.sub(str,n+1)
end
--Returns the modified string 'str' w/ the string 'added' replaced at the string indexs 'n' through 'n+#str'
local function writeString(str,added,n)
    return string.sub(str,1,n-1)..added..string.sub(str,n+#added)
end
--Returns the modified frame 'bf' (base frame) w/ the frame 'af' (added frame) inserted at coordinates 'x,y'
local function addFrame(x,y,bf,af)
    local endOffset = 0

    if af.w + x > bf.w then
        endOffset = af.w + x - bf.w
    end

    for i = 1, af.h do
        local baseStart = bf.w*(y-1)+x
        local addStart  = af.w*(i-1)
        local addEnd    = af.w*i-endOffset

        bf.canvas  = writeString(bf.canvas,  string.sub(af.canvas,  addStart, addEnd), baseStart)
        bf.txtCol  = writeString(bf.txtCol,  string.sub(af.txtCol,  addStart, addEnd), baseStart)
        bf.backCol = writeString(bf.backCol, string.sub(af.backCol, addStart, addEnd), baseStart)
    end
    return bf
end
--Returns a button with coordinates 'x,y', a name of 'name', and a stored function of 'function'
local function makeButton(x,y,name,doThing)
    local str = "["..name.."]"
    local txtCol = ""
    local backCol = ""
    for i = 1, #str do
        local col = "w"
        if i == 1 or i == #str then
            col = "1"
        end
        txtCol = txtCol..col
        backCol = backCol.."f"
    end
    return {
        x = x,
        y = y,
        h = 1,
        w = #name+2,
        name = name,
        canvas = str,
        txtCol = txtCol,
        backCol = backCol,
        doThing = doThing
    }
end
--Goes through a list of buttons made with the makeButton() function and checks to see whether the
--  coordinates 'x,y' overlap with any of the buttons set coordinates. Returns 'true,i' where i is
--  the index it found the first overlap. Else retuns 'false,nil' if unable to find an overlap.
local function checkForButtons(buttons,x,y)
    for i = 1, #buttons do
        local b = buttons[i]
        if b.x <= x and x <= b.x+#b.name and y == b.y then
            return true,i
        end
    end
    return false,nil
end
--Draws the frame 'frame' at coordinates 'x,y'
local function drawFrame(x,y,frame)
    local canvas  = frame.canvas
    local txtCol  = frame.txtCol
    local backCol = frame.backCol

    for i = 1, frame.h do
        local offset = frame.w*(i-1)
        term.setCursorPos(x,y+i-1)

        for j = 1, frame.w do
            local index = offset + j

            local txtC = txtCol:sub(index,index)
            local backC = backCol:sub(index,index)
            local char = canvas:sub(index,index)

            term.setTextColor( toCol( txtC ) )
            term.setBackgroundColor( toCol( backC ) )
            term.write( char )
        end
    end

    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)
end
--Draws the frame 'frame' at coordinates 'x,y' without individual character colors
local function drawFrameFast(x,y,frame,txtCol,backCol)
    local canvas  = frame.canvas

    term.setTextColor(txtCol)
    term.setBackgroundColor(backCol)

    for i = 1, frame.h do
        local startIndex = frame.w*(i-1)+1
        local endIndex = frame.w*i
        local str = canvas:sub(startIndex,endIndex)

        term.setCursorPos( x,y+i-1 )
        term.write( str )
    end

    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.black)
end
--Waits for a click, drag, or release mouse event then returns the data
local function getMouseEvent()
    local eventData = {os.pullEvent()}
    while eventData[1] ~= "mouse_click" and eventData[1] ~= "mouse_drag" and eventData[1] ~= "mouse_up" do
        eventData = {os.pullEvent()}
    end

    return eventData[1],eventData[2],eventData[3],eventData[4]
end
--Returns a frame with a width and height == 'w,h'
local function makeFrame(w,h)
        --Create an entire horizontal row
    local tempCanv    = string.rep(".",w)
    local tempTxtCol  = string.rep("0",w)
    local tempBackCol = string.rep("f",w)

         --Copy each horizontal row for the required height
    local canvas  = string.rep(tempCanv,h)
    local txtCol  = string.rep(tempTxtCol,h)
    local backCol = string.rep(tempBackCol,h)

    return {
        canvas = canvas,
        txtCol = txtCol,
        backCol = backCol,
        w = w,
        h = h
    }
end

--[[
┌┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┐
│1. Color codes: │
└┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┘

0 = white
1 = orange
2 = magenta
3 = light blue
4 = yellow
5 = lime
6 = pink
7 = gray
8 = light gray
9 = cyan
a = purple
b = blue
c = brown
d = green
e = red
f = black

┌┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┐
│2. Useful string.char's │
└┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┘

string.char()

Char 127, 129-159, 168 are block and shading characters:

127 = transluscent grid
129-159 = block patterns
168 = horizontal colon ( : )

┌┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┬┐
│3. Example use: │
└┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┴┘

--if fs.exists("frameDrawer.lua") then fs.delete("frameDrawer.lua") end

--shell.run("pastebin get FRyEWAxh frameDrawer")

local frm = require("frameDrawer")

local tw,th = term.getSize() --term width, term height
local frame = frm.makeFrame(10,10)

term.clear()

while true do
    --frm.drawFrameFast(1,1,frame,colors.white,colors.black)
    frm.drawFrame(1,1,frame)
    local _,type,x,y = frm.getMouseEvent()
    if x <= frame.w and y <= frame.h then
        local targetIndex = (y-1)*frame.w + x

        if type == 1 then
            --Left click
            --example:
            --frame.canvas = frm.pstr(frame.canvas, "HELLO WORLD!", targetIndex)
            --frame.backCol = frm.ppx(frame.backCol, "1", targetIndex)
        elseif type == 2 then
            --Right click
            --frame.canvas = frm.pstr(frame.canvas, "            ", targetIndex)
            --frame.backCol = frm.ppx(frame.backCol, "f", targetIndex)
        elseif type == 3 then
            --Middle click
        end
    end
end

]]

--Expose functions
local exposed = {
    makeButton = makeButton,
    checkForButtons = checkForButtons,

    makeFrame = makeFrame,
    drawFrame = drawFrame,
    drawFrameFast = drawFrameFast,

    getMouseEvent = getMouseEvent,

    ppx = setStringIndex,
    pstr = writeString,
}

return exposed