micropaint

--[[
    Micropaint
    A paint program that lets you utilize the new computercraft charset for detailed painting

    Written by: Nitrogen Fingers
]]--

--[[
    Operation:

    The smaller pixels allow a single ComputerCraft pixel to be divided into six subpixels, in a 3x2 pattern. For each pixel, only two colours can be used in these sub-pixels, one for the background and one for the foreground, although the program does it's best to abstract this information out when using.
    As the mouse events do not have enough precision to target these sub-pixels, and each pixel can potentially have different fore and background colours, editing of these subpixels is done by selecting the desired pixel with the 'magnify' tool, or the right mouse button on the main canvas. In the smaller canvas on the top-right, a representation of that pixel is displayed in a zoomed-in fashion. Changing the colours on this magnify tool correspondingly update the larger image.
    Images start filled with an alpha layer- this is filled by default with black when images are saved and loaded. When an image is 'cropped', as much of this as possible is removed.
    Colours can be changed with the provided pallette. There are currently no other tools to make use of.
]]
local w,h = term.getSize()

--A very quick button class, for pallette and tools
local _button = {
    x = nil;
    y = nil;
    text = nil;
    colour = nil;
    textcol = "f";

    draw = function(self)
        term.setCursorPos(self.x, self.y)
        term.blit(self.text, self.textcol:rep(#self.text), self.colour:rep(#self.text))
    end;

    is_pressed = function(self, mx, my)
        return mx >= self.x and mx < self.x + #self.text and my == self.y
    end;

    on_pressed = function() print("not implemented yet") end;
}
_button.__index = function(t, k) return _button[k] end
_button.new = function(x, y, text, colour)
    local new = { x = x; y = y; text = text; colour = colour; }
    setmetatable(new, _button)
    return new
end

--A kind of button that uses images rather than text
local _imgbutton = {
    x = nil;
    y = nil;
    img = nil;

    is_pressed = function(self, mx, my)
        return mx >= self.x and mx <= self.x + self.img.width and
                my >= self.y and my <= self.y + self.img.height
    end;

    on_pressed = function() print("not implemented yet") end;

    change_colour = function(self, old_col, new_col)
        for i=1, self.img.height do
            self.img.fg[i]:gsub(old_col, new_col)
            self.img.bg[i]:gsub(old_col, new_col)
        end
    end;
}
_imgbutton.__index = function(t, k) return _imgbutton[k] end
_imgbutton.new = function(x, y, image)
    local new = { x = x, y = y, img = image }
    setmetatable(new, _imgbutton)
    return new
end

--Draws an image format of given width and height to the screen
--This won't work for our painting image, as the lines aren't concatenated
local function drawImage(image, x, y)
    for i = 1, image.height do
        term.setCursorPos(x, y + i - 1)
        term.blit(image.text[i], image.fg[i], image.bg[i])
    end
end

_imgbutton.draw = function(self, x, y) drawImage(self.img, self.x, self.y) end

--The full image. Contains width and height information, as well as three distinct layers, stored in a 2D array:
    -- text: The character used to display the pixel. This is a char between 128 and 159, and can be nil.
    -- fg: The colouring of that character
    -- bg: The colouring of the background behind the character
local img = { }

--A map of the magnify tool. This is a 3x2 map of single-character colour codes, integer-indexed
    --Left and right are part of the painting tool.
    --pixelX and pixelY are markers to the index of the img table being edited
local magnify = { }

--The offset from the top left corner to draw the image
local imgoffX, imgoffY = 2, 2
--The offset from the top left corner to draw the magnify tool
local magoffX, magoffY = 0, 0
--The colour underlying the null characters
local alpha = "f"
--The character representing null characters
local nullchar = "\127"
--The maximum size of t a canvas. For the present- scrolling later perhaps
local maxWidth, maxHeight = w - 12, h - 4
--The minimum size of a canvas
local minWidth, minHeight = 1, 1

--The animation timer used to update 'ticking' interface elements (select boxes, magnify etc. etc.)
local tickState = 0
--The interval for the tick timer
local tickInterval = 0.5
--The tick timer
local tickTimer = os.startTimer(tickInterval)

--The name of the file being edited, if named
local filename = nil
--The file path itself
local sPath = nil
--Whether or not a saveable change has been made since the program started
local sChange = false
--Allows the run loop to proceed
local programRunning = true
--Whether or not the code should be shown
local showMagCode = false
--Whether or not the control key is down
local ctrl_down = false

--The order of our pallette. Done manually just to make it look a little nicer
local colourder = {"f", "7", "8", "0", "e", "a", "b", "c", "1", "2", "9", "d", "4", "6", "3", "5"}
--A list of buttons that can be pressed to change the colour of the paint tools
local pallette = {}
--A button drawn near the paint pallette that switches colours left and right
local pswitch = _button.new(0, 0, "\18", "8")
--Buttons for the file and edit menu
local fileButton = _button.new(2, 1, "File", "b")
fileButton.textcol = "0"
local editButton = _button.new(8, 1, "Edit", "b")
editButton.textcol = "0"
--The file and edit menu
local fMenu = { name = "File", x = fileButton.x, y = fileButton.y }
local eMenu = { name = "Edit", x = editButton.x, y = editButton.y }
--The list of each of the tool buttons, displayed on the other side of the magnifying image
local tools = {}
--The currently selected tool. A string.
local selTool = "paint"

--The select box details
local selboxX1, selboxY1 = nil, nil
local selboxX2, selboxY2 = nil, nil
--Where the cursor tool is currently working from
local cursorX, cursorY = nil, nil
--The clipboard
local clipboard = nil

--Draws a very thin 2D border around the specified rectangle. fg is the border colour, bg the background
local function drawEnclosingBorder(x, y, w, h, bg, fg)
    term.setCursorPos(x-1, y-1)
    local topborder = "\159"..("\143"):rep(w).."\144"
    term.blit(topborder, bg:rep(#topborder-1)..fg, fg:rep(#topborder-1)..bg)
    for iy = y,y+h-1 do
        term.setCursorPos(x-1, iy)
        term.blit("\149", bg, fg)
        term.setCursorPos(x+w, iy)
        term.blit("\149", fg, bg)
    end
    term.setCursorPos(x-1, y+h)
    local botborder = "\130"..("\131"):rep(w).."\129"
    term.blit(botborder, fg:rep(#botborder), bg:rep(#botborder))
end

--Tries to preserve the colour settings picked by the user- but changes them if necessary
local function updateMagColours(fg, bg, fused)
    if not fused then
        if bg ~= magnify.left and bg ~= magnify.right then return magnify.left, bg
        else return magnify.left, magnify.right end
    else
        if (bg == magnify.left or bg == magnify.right) and (fg == magnify.left or fg == magnify.right) then
            return magnify.left, magnify.right
        elseif bg == magnify.left then return magnify.left, fg
        elseif fg == magnify.left then return magnify.left, bg
        elseif bg == magnify.right then return fg, magnify.right
        elseif fg == magnify.right then return bg, magnify.right
        else return fg, bg end
    end
end

--[[The following two functions belong to the BLittle API by BombBloke, which can be viewed here:
    http://www.computercraft.info/forums2/index.php?/topic/25354-cc-176-blittle-api/
    For comments or question, please contact the author directly.
]]--
function saveBLittle()
    local output = fs.open(sPath, "wb")
    if not output then error("Can't open "..output.." for output.") end

    local function writeInt(num)
        output.write(bit.band(num, 255))
        output.write(bit.brshift(num, 8))
    end

    writeInt(img.width)
    writeInt(img.height)

    local imgComponents = {"text", "fg", "bg"}
    local defComponent = { "\128", "0", "f" }
    for ind,i in ipairs(imgComponents) do
        local thisSet = img[i]
        for y = 1, img.height do
            local thisRow = thisSet[y]
            for x = 1, img.width do
                output.write((thisRow[x] or defComponent[ind]):byte())
            end
        end
    end

    output.close()
    sChange = false
end

function loadBLittle(_filename)
    local input = fs.open(_filename, "rb")
    if not input then error("Can't open "..input.." for input.") end

    local function readInt()
        local result = input.read()
        return result + bit.blshift(input.read(), 8)
    end

    local image = {}
    image.width = readInt()
    image.height = readInt()

    local imgComponents = {"text", "fg", "bg"}
    for _,i in ipairs(imgComponents) do
        local thisSet = {}
        for y = 1, image.height do
            local thisRow = {}
            for x = 1, image.width do thisRow[x] = string.char(input.read()) end
            thisSet[y] = thisRow
        end
        image[i] = thisSet
    end

    input.close()
    sChange = false

    return image
end

--Takes a 3x2 map of colours and turns it into character with colours
local function encodeChar(magimage)
    --The binary 'score' of the iamge that determines the pixel
    local score = 0
    --We use the bottom-right colour as our baseline
    local brcol = magimage[3][2]
    local fcol = nil

    for i = 0,4 do
        if magimage[math.floor(i/2)+1][(i%2)+1] ~= brcol then
            score = score + math.pow(2,i)
            fcol = magimage[math.floor(i/2)+1][(i%2)+1]
        end
    end
    fcol = fcol or magnify.left
    return string.char(128 + score), brcol, fcol
end

--Takes a character from the image and decodes it into a 3x2 map
local function decodeChar(x, y)
    local chr, fg, bg = img.text[y][x], img.fg[y][x], img.bg[y][x]
    local score = chr and string.byte(chr) - 128 or 0
    local fused = false

    local magimage = { { }, { }, { } }
    for i = 0, 4 do
        if bit.band(score, math.pow(2, i)) == 0 then
            magimage[math.floor(i/2)+1][(i%2)+1] = bg
        else
            magimage[math.floor(i/2)+1][(i%2)+1] = fg
            fused = true
        end
    end

    magimage[3][2] = bg
    magimage.left, magimage.right = updateMagColours(fg, bg, fused)
    assert(magimage.left)
    assert(magimage.right)
    magimage.pixelX, magimage.pixelY = x, y
    return magimage
end

--Draws a single character from the image on the screen
local function drawChar(x, y)
    term.setCursorPos(imgoffX + x, imgoffY + y)
    if img.bg[y][x] == nil then
        term.blit(nullchar, "7", "f")
    else
        term.blit(img.text[y][x] and img.text[y][x] or " ",
            img.fg[y][x] and img.fg[y][x] or img.bg[y][x], img.bg[y][x])
    end
end

--Flashes to draw attention to what pixel is currently being magnified
local function drawMagnifyIcon()
    if tickState % 2 == 0 and magnify[1] then
        term.setCursorPos(imgoffX + magnify.pixelX, imgoffY + magnify.pixelY)
        local fg = string.format("%x", 15 - tonumber(img.bg[magnify.pixelY][magnify.pixelX], 16))
        local bg = img.bg[magnify.pixelY][magnify.pixelX]..""
        assert(type(nullchar) == "string")
        assert(type(fg) == "string")
        assert(type(bg) == "string")
        term.blit(nullchar, fg, bg)
    elseif magnify[1] then
        drawChar(magnify.pixelX, magnify.pixelY)
    end
end

--Draws the code used by the magnify image
local function drawMagCode()
    if not showMagCode then return end
    term.setCursorPos(magoffX + 1, magoffY + 6)
    local msg = magnify[1] and "\\"..string.byte(img.text[magnify.pixelY][magnify.pixelX]) or "    "
    term.blit(msg, ("0"):rep(#msg), ("7"):rep(#msg))
end

--Draws a graphic of the left and right paint colours beneath the magnify tool
local function drawMagColours()
    pswitch:draw()
    local mcx, mcy = magoffX + 2, magoffY + 8
    term.setCursorPos(mcx, mcy)
    local l, r = magnify.left or alpha, magnify.right or alpha
    term.blit(("\143"):rep(2).." ", "8"..r:rep(2), l:rep(2)..r)
    term.setCursorPos(mcx, mcy + 1)
    term.blit("  ".."\131", l:rep(2)..r, l:rep(2).."8")
end

--Draws the entire magnify tool, including the colour pallette and the display
local function drawMagnify()
    drawMagColours()
    if not magnify[1] then
        for y = magoffY, magoffY + 5 do
            term.setCursorPos(magoffX, y)
            term.blit(nullchar:rep(6), "777777", "ffffff")
        end
        return
    end

    for y = 1, 3 do
        for x = 1, 2 do
            local a, c = nullchar:rep(3), "fff"
            if magnify[y][x] then a, c = "   ", magnify[y][x]:rep(3) end
            term.setCursorPos(x*3 + magoffX - 3, y*2 + magoffY - 2)
            term.blit(a, "777", c)
            term.setCursorPos(x*3 + magoffX - 3, y*2 + 1 + magoffY - 2)
            term.blit(a, "777", c)
        end
    end
end

--Draws the selection box, if it's visible
local function drawSelectionBox()
    --Captures if there's no box to draw (null or too small)
    if selboxX1 == selboxX2 or selboxY1 == selboxY2 then return end

    local minX, maxX = math.min(selboxX1, selboxX2), math.max(selboxX1, selboxX2)
    local minY, maxY = math.min(selboxY1, selboxY2), math.max(selboxY1, selboxY2)

    local intv = (minX + minY + tickState) % 2 == 0

    if intv == 1 and clipboard and clipboard.projected then
        drawClipboard()
    end

    local border = ""
    term.setCursorPos(minX + imgoffX, minY + imgoffY)
    if intv then
        border = "\145"..("\129"):rep(maxX - minX - 1).."\137"
        term.blit(border, ("8"):rep(#border), ("f"):rep(#border))
    else
        border = "\134"..("\130"):rep(maxX - minX - 1).."\157"
        term.blit(border, ("8"):rep(#border-1).."f", ("f"):rep(#border-1).."8")
    end

    intv = (minX + maxY + tickState) % 2 == 0
    term.setCursorPos(minX + imgoffX, maxY + imgoffY)
    if intv then
        border = "\145"..("\144"):rep(maxX - minX - 1).."\152"
        term.blit(border, ("8"):rep(#border), ("f"):rep(#border))
    else
        border = "\155"..("\159"):rep(maxX - minX - 1).."\157"
        term.blit(border, ("f"):rep(#border), ("8"):rep(#border))
    end


    for iy = minY + 1, maxY - 1 do
        --Left side
        term.setCursorPos(minX + imgoffX, iy + imgoffY)
        intv = (iy + minX + tickState) % 2 == 0
        term.blit(intv and "\145" or "\132", "8", "f")
        --Right side
        term.setCursorPos(maxX + imgoffX, iy + imgoffY)
        intv = (iy + minX + tickState) % 2 == 0
        term.blit(intv and "\136" or "\157", intv and "8" or "f", intv and "f" or "8")
    end
end

--Helper function to draw entire image to screen
local function drawImage()
    for y = 1, img.height do
        for x = 1, img.width do
            drawChar(x, y)
        end
    end
    drawSelectionBox()
end


--Draws all the tools
local function drawTools()
    for k,v in pairs(tools) do
        v:draw()
        if k == selTool then
            drawEnclosingBorder(v.x, v.y, v.img.width, v.img.height, "8", "e")
        end
    end
end

--Updates changes to the magnify tool to the image itself
local function updateImage()
    img.text[magnify.pixelY][magnify.pixelX],
    img.bg[magnify.pixelY][magnify.pixelX],
    img.fg[magnify.pixelY][magnify.pixelX] = encodeChar(magnify)
    drawMagnifyIcon()
    drawMagCode()
end

--Updates the magnify tool by changes made to the main canvas or colour pallette
local function updateMagnify(ocol, ncol)
    if not magnify[3] or ocol == magnify.left or ocol == magnify.right then
        drawMagnify()
        return
    end

    for y = 1, 3 do
        for x = 1, 2 do
            if magnify[y][x] == ocol then magnify[y][x] = ncol end
        end
    end
    drawMagnify()
    updateImage()
end

--Copies all data currently under the selection. Can cut with optional argument
local function copySelection(cut)
    if selboxX1 == selboxX2 or selboxY1 == selboxY2 then return end
    local swidth, sheight = math.abs(selboxX2 - selboxX1), math.abs(selboxY2 - selboxY1)
    local minX, minY = math.min(selboxX1, selboxX2), math.min(selboxY1, selboxY2)
    local maxX, maxY = math.max(selboxX1, selboxX2), math.max(selboxY1, selboxY2)
    clipboard = {
        width = swidth;
        height = sheight;
        projected = false;
        text = { }; fg = { }; bg = { }; }

    for y = 1, sheight do
        clipboard.text[y] = { }
        clipboard.fg[y] = { }
        clipboard.bg[y] = { }
        for x = 1, swidth do
            clipboard.text[y][x] = img.text[y + minY - 1][x + minX - 1]
            clipboard.fg[y][x] = img.fg[y + minY - 1][x + minX - 1]
            clipboard.bg[y][x] = img.bg[y + minY - 1][x + minX - 1]
            if cut then
                img.text[y + minY - 1][x + minX - 1] = nil
                img.fg[y + minY - 1][x + minX - 1] = nil
                img.bg[y + minY - 1][x + minX - 1] = nil
            end
        end
    end
end

--Pastes data in the projected clipboard onto the screen
local function pasteSelection()
    if clipboard == nil or clipboard.projected ~= true then return end

    for x = 1, clipboard.width do
        for y = 1, clipboard.height do

        end
    end
end

--The step before pasting. This recreates the selection box and has the clipboard drawn inside-
--the user can then move the image around before deciding on where to place it and striking a key or
--changing tools.
local function projectClipboard()
    if clipboard == nil then return end

    selboxX1, selboxX2 = 1, clipboard.width
    selboxY1, selboxY2 = 1, clipboard.height
    clipboard.projected = true
end

--Applies a colour to a given index of the magnify map
local function paintMagnify(x, y, col)
    magnify[math.floor(y/2) + 1][math.floor(x/3) + 1] = col
    drawMagnify()
    updateImage()
end

--Switches the left and right paint pallette.
local function switchPaintColours()
    local bag = magnify.left
    magnify.left = magnify.right
    magnify.right = bag
    drawMagColours()
end

--Helper methods to ensure no OOB errors
local function inCanvasBounds(x, y)
    return x > imgoffX and x <= imgoffX + img.width and y > imgoffY and y <= imgoffY + img.height
end

local function inMagnifyBounds(x, y)
    return x >= magoffX and x <= magoffX + 5 and y >= magoffY and y <= magoffY + 5
end

--Draws the menu bar
local function drawMenuBar()
    term.setCursorPos(2,1)
    term.setBackgroundColour(colours.blue)
    term.clearLine()
    fileButton:draw()
    editButton:draw()
    local title = filename or "Untitled"
    term.setCursorPos(w/2 - #title/2 + 1, 1)
    term.blit(title, (filename and "0" or "3"):rep(#title), ("b"):rep(#title))
end

--Draws the entire scene fresh
local function drawScene()
    term.setBackgroundColour(colours.lightGrey)
    term.clear()
    --The canvas and magnify tool
    drawImage()
    drawMagnify()
    drawTools()
    for _, p in ipairs(pallette) do
        p:draw()
    end
    drawMenuBar()
    --The borders for each tool
    drawEnclosingBorder(magoffX, magoffY, 6, 6, "8", "7")
    drawEnclosingBorder(imgoffX + 1, imgoffY + 1, img.width, img.height, "8", "7")
    drawMagCode()
end

--Repositions the tools to be adjacent to the canvas. Avoids overlapping and so on.
local function setToolPositions()
    magoffX, magoffY = imgoffX + img.width + 4, 3
    pswitch.x, pswitch.y = imgoffX + img.width + 4, magoffY + 8
    for i,c in ipairs(colourder) do
        pallette[i].x = imgoffX + img.width + 1 + math.ceil(i/4) * 2
        pallette[i].y = magoffY + 11 + ((i-1) % 4)
    end
    local ind = 1
    for k,v in pairs(tools) do
        tools[k].x = magoffX + 9
        assert(tools[k].img)
        tools[k].y = 3 + (tools[k].img.height + 1) * (ind - 1)
        ind = ind + 1
    end
end

--Helper for resizing canvases. Shifts a table's indices left
local function shiftIndexes(val)
    local startx = val > 0 and img.width or 1
    local endx = val > 0 and 1 or img.width

    for y = 1, img.height do
        for x = startx, endx, -(val/math.abs(val)) do
            img.text[y][x + val] = img.text[y][x]
            img.text[y][x] = nil
            img.fg[y][x + val] = img.fg[y][x]
            img.fg[y][x] = nil
            img.bg[y][x + val] = img.bg[y][x]
            img.bg[y][x] = nil
        end
    end
end

local function resize(nw, nh, left, bottom)
    local wdiff, hdiff = nw - img.width, nh - img.height
    local top = hdiff - bottom
    local right = wdiff - left

    if right < 0 then
        for y = 1, img.height do
            for x = img.width, img.width + right + 1, -1 do
                img.text[y][x] = nil
                img.fg[y][x] = nil
                img.bg[y][x] = nil
            end
        end
    end
    shiftIndexes(left)

    local tablefunc = hdiff > 0 and table.insert or table.remove
    for i = 1, math.abs(top) do
        tablefunc(img.text, 1, {})
        tablefunc(img.fg, 1, {})
        tablefunc(img.bg, 1, {})
    end

    for i = 1, math.abs(bottom) do
        tablefunc(img.text, #img.text, {})
        tablefunc(img.fg, #img.fg, {})
        tablefunc(img.bg, #img.bg, {})
    end

    img.width = nw
    img.height = nh

    selboxX1, selboxX2, selboxY1, selboxY2 = nil, nil, nil, nil

    setToolPositions()
    drawScene()
end

--Resizes the canvas to be bigger or smaller, then redraws the scene
--I is the direction to preserve the piece, as an inverse numberpad.
local function resizeCanvas(nw, nh, i)
    local wdiff, hdiff = nw - img.width, nh - img.height
    local left = wdiff - math.ceil(wdiff - (wdiff/2) * ((i-1)%3))
    local bottom = math.ceil(hdiff - (hdiff/2) * math.floor((i-1)/3))

    resize(nw, nh, left, bottom)
end

--Changes the image width and height to match the area captured in the
local function cropToSelection()
    if selboxX1 == selboxX2 or selboxY1 == selboxY2 then return end

    local xmin, xmax = math.min(selboxX1, selboxX2), math.max(selboxX1, selboxX2)
    local ymin, ymax = math.min(selboxY1, selboxY2), math.max(selboxY1, selboxY2)
    local nw, nh = xmax - xmin + 1, ymax - ymin + 1

    local left = 1 - xmin
    local bottom = ymax - img.height

    resize(nw, nh, left, bottom)
end

--An off-center print function.
local function wprintOffCenter(msg, height, width, offset)
    local inc = 0
    local ops = 1
    while #msg - ops > width do
        local nextspace = 0
        while string.find(msg, " ", ops + nextspace) and
                string.find(msg, " ", ops + nextspace) - ops < width do
            nextspace = string.find(msg, " ", nextspace + ops) + 1 - ops
        end
        local ox,oy = term.getCursorPos()
        term.setCursorPos(width/2 - (nextspace)/2 + offset, height + inc)
        inc = inc + 1
        term.write(string.sub(msg, ops, nextspace + ops - 1))
        ops = ops + nextspace
    end
    term.setCursorPos(width/2 - #string.sub(msg, ops)/2 + offset, height + inc)
    term.write(string.sub(msg, ops))

    return inc + 1
end

--[[ Gets the previous file in the path, if there is one ]]--
local function getPreviousDir(_path)
    if _path == "" or _path == "/" then return path
    else
        _path = _path:reverse()
        return _path:sub(_path:find("/.*")+1):reverse()
    end
end

--Simple confirm/deny messages
local function displayConfirmDialogue(ctitle, msg, ...)
    local _doffX, _doffY = 8, 5
    local menuBG = colours.white
    --We actually print twice- once to get the lines, second time to print proper. Easier this way.
    local lines = wprintOffCenter(msg, _doffY, w - (_doffX+2) * 2, _doffX + 2)

    drawScene()

    term.setCursorPos(_doffX, _doffY - 2)
    term.setBackgroundColour(colours.blue)
    term.setTextColour(colours.white)
    term.write(string.rep(" ", w - _doffX * 2))
    term.setCursorPos(w/2 - #ctitle/2, _doffY - 2)
    term.write(ctitle)
    term.setTextColour(colours.black)
    term.setBackgroundColour(menuBG)
    term.setCursorPos(_doffX, 4)
    term.write(string.rep(" ", w - _doffX * 2))
    for i = _doffY, _doffY + lines do
        term.setCursorPos(_doffX, i)
        term.write(" "..string.rep(" ", w - (_doffX) * 2 - 2).." ")
    end
    wprintOffCenter(msg, _doffY, w - (_doffX+2) * 2, _doffX + 2)

    if arg then
        term.setCursorPos(_doffX, _doffY + lines + 1)
        term.write(string.rep(" ", w - _doffX * 2))
        term.setCursorPos(_doffX, _doffY + lines + 2)
        term.write(string.rep(" ", w - _doffX * 2))

        local _sspace = 0
        for _k,_v in ipairs(arg) do _sspace = _sspace + #_v[1] end
        _sspace = (w - (_doffX * 2) - _sspace - (2 * #arg))/(#arg)
        if _sspace <= #arg - 1 then assert(false, "Too little space: needed "..(#arg - 1)..", got ".._sspace) end
        term.setTextColour(colours.black)
        term.setCursorPos(_doffX + 1, _doffY + lines + 1)
        local _spart = false
        for i=1,#arg do
            _v = arg[i]
            arg[i][3] = term.getCursorPos()
            term.setBackgroundColour(_v[2])
            term.write(" ".._v[1].." ")
            local _vspace = math.floor(_sspace)
            if i >= #arg/2 and not _spart then _vspace = math.ceil(_sspace) _spart = true end
            local _x,_y = term.getCursorPos()
            term.setCursorPos(_x + _vspace, _y)
        end
    end

    --In the event of a message, the player hits anything to continue
    while true do
        local _id,_p1,_p2,_p3 = os.pullEvent()
        if (not arg or #arg == 0) and (id == "key" or id == "mouse_click" or id == "mouse_drag") then
            break
        elseif _id == "key" then
            if _p1 == keys.enter then return 1 end
            if _p1 == keys.backspace then return 2 end
        elseif _id == "mouse_click" and _p3 == _doffY + lines + 1 then
            for i=1,#arg do
                _v = arg[i]
                if _p2 >= _v[3] and _p2 <= _v[3] + #_v[1] + 1 then return i end
            end
        elseif _id == "timer" and _p1 == tickTimer then tickTimer = os.startTimer(tickInterval) end
    end
end

--Displays and handles events for drop-down menus
local function displayDropDown(x, y, options, noTitle)
    inDropDown = true
    if noTitle then y = y - 1 end
    local menuBG = colours.white
    --Figures out the dimensions of our thing
    local longestX = #options.name
    for i=1,#options do
        local currVal = options[i]
        if type(currVal) == "table" then currVal = currVal.name end
        longestX = math.max(longestX, #currVal)
    end
    local xOffset = math.max(0, longestX - ((w-2) - x) + 1)
    local yOffset = math.max(0, #options - ((h-1) - y))

    local clickTimes = 0
    local tid = nil
    local selection = nil
    while clickTimes < 4 do
        if not noTitle then
            term.setCursorPos(x-xOffset,y-yOffset)
            term.setBackgroundColour(colours.lightBlue)
            term.setTextColour(colours.black)
            term.write(options.name.." ")
        end

        for i=1,#options do
            term.setCursorPos(x-xOffset, y-yOffset+i)
            local currVal = options[i]
            if type(currVal.value) == "table" then
                currVal.enabled = #currVal.value > 0
            end

            if i==selection and clickTimes % 2 == 0 then
                term.setBackgroundColour(colours.blue)
                if options[selection].enabled then term.setTextColour(colours.white)
                else term.setTextColour(colours.grey) end
            else
                term.setBackgroundColour(menuBG)
                local _tcol = colours.black
                if not currVal.enabled then _tcol = colours.lightGrey end
                term.setTextColour(_tcol)
            end
            if type(currVal.value) == "table" then
                term.write(currVal.name..string.rep(" ", longestX-#currVal.name))
                term.setBackgroundColour(colours.blue)
                term.setTextColour(colours.white)
                term.write(">")
            else
                term.write(currVal.name..string.rep(" ", longestX-#currVal.name + 1))
            end

            if (i~= selection or clickTimes %2 == 1) and currVal.key and currVal.enabled then
                term.setTextColour(colours.blue)
                term.setBackgroundColour(menuBG)
                local co = currVal.name:find(currVal.key)
                if not co then co = longestX else co = co - 1 end
                term.setCursorPos(x-xOffset+co, y-yOffset + i)
                term.write(currVal.key)
            end
        end

        local id, p1, p2, p3 = os.pullEvent()
        if id == "timer" then
            if p1 == tid then
                clickTimes = clickTimes + 1
                if clickTimes > 2 then
                    break
                else
                    tid = os.startTimer(0.1)
                end
            elseif p1 == tickTimer then
                tickTimer = os.startTimer(tickInterval)
                tickState = (tickState + 1) % 4
            end
        elseif id == "key" and not tid then
            if p1 == keys.leftCtrl then
                selection = ""
                break
            elseif p1 == keys.down and (not selection or selection < #options) then
                selection = selection or 0
                _os = selection
                repeat selection = selection + 1
                until selection == #options + 1 or options[selection].enabled
                --if selection == #options + 1 then selection = _os end
            elseif p1 == keys.up and (not selection or selection > 1) then
                selection = selection or #options + 1
                _os = selection
                repeat selection = selection - 1
                until selection == 0 or options[selection].enabled
                if selection == 0 then selection = _os end
            elseif p1 == keys.enter and selection and options[selection].enabled then
                tid = os.startTimer(0.1)
                clickTimes = clickTimes - 1
            end
        elseif id == "mouse_click" and not tid then
            local _xp, _yp = x - xOffset, y - yOffset
            if p2 >= _xp and p2 <= _xp + longestX + 1 and
            p3 >= _yp+1 and p3 <= _yp+#options then
                if options[p3 - _yp].enabled then
                    selection = p3-(_yp)
                    tid = os.startTimer(0.1)
                end
            else
                selection = ""
                break
            end
        elseif id == "char" and not tid then
            for k,v in ipairs(options) do
                if v.key and v.key:lower() == p1:lower() and options[k].enabled then
                    selection = k
                    tid = os.startTimer(0.1)
                    break
                end
            end
        end
    end

    local _val = selection
    if type(selection) == "number" then
        selection = options[selection].value
    end

    if type(selection) == "string" then
        inDropDown = false
        return selection
    elseif type(selection) == "table" then
        return displayDropDown(x + longestX + 1, y + _val, selection, true)
    elseif type(selection) == "function" then
        local _rval = selection()
        if not _rval then return "" else return _rval end
    end
end

--A built-in form designed to let users create new documents of a given size
local function displaySizeSettings(_flag)
    local title = _flag == "n" and "New Image" or "Resize Image"
    local _w, _h = _flag == "n" and 16 or 24, 8
    local _x, _y = math.ceil(w/2 - _w/2), 4
    local _wopt, _hopt = { name = "Width:", y = 2, val = "", sel = false }, { name = "Height:", y = 4, val = "", sel = false }
    local _fx, _self = 9, nil
    local _fg, _bg, _hfg, _hbg = "f", "0", "0", "b"
    local _by = 6
    local _okay = _button.new(_x + 1, _y + _by, "Create", "5")
    local _invalid = _button.new(_x + 1, _y + _by, "Invalid", "8")
    _invalid.textcol = "7"
    local _cancel = _button.new(_x + #_invalid.text + 2, _y + _by, "Cancel", "e")

    drawScene()

    if _flag == "r" then
        _wopt.val = img.width..""
        _hopt.val = img.height..""
    end

    local _resizeList = { }
    for i = 1, 9 do
        _resizeList[i] = _button.new(_x + _w - (6 - ((i - 1) % 3) * 2), _y + math.ceil(i/3) * 2, " ", "7")
        _resizeList[i].textcol = "0"
    end
    _resizeList[2].text = "\24"
    _resizeList[4].text = "\27"
    _resizeList[6].text = "\26"
    _resizeList[8].text = "\25"

    _resizeList[5].colour = "5"
    _rsSel = 5

    local function drawWindow()
        local _ws = _w - #title - 1
        term.setCursorPos(_x, _y)
        term.blit((" "):rep(math.floor(_ws/2))..title..(" "):rep(math.ceil(_ws/2)).."x", ("0"):rep(_w), ("b"):rep(_w-1).."e")
        term.setCursorPos(_x, _y + 1)
        term.setBackgroundColour(colours.white)
        term.setTextColour(colours.black)
        term.write((" "):rep(_w))
        term.setCursorPos(_x, _y + 2)
        local _ws = _w - #_wopt.name - 1
        term.write(" ".._wopt.name..(" "):rep(_ws))
        term.setCursorPos(_x, _y + 3)
        term.write((" "):rep(_w))
        term.setCursorPos(_x, _y + 4)
        local _ws = _w - #_hopt.name - 1
        term.write(" ".._hopt.name..(" "):rep(_ws))
        for i=5,_h-1 do
            term.setCursorPos(_x, _y + i)
        term.write((" "):rep(_w))
        end
    end

    local function valsValid()
        local nw, nh = tonumber(_wopt.val), tonumber(_hopt.val)
        return type(nw) == "number" and type(nh) == "number" and nw >= minWidth and nw <= maxWidth and
                nh >= minHeight and nh <= maxHeight
    end

    local function drawFields()
        term.setCursorPos(_x + _fx, _y + _wopt.y)
        term.setBackgroundColour(colours.lightGrey)
        term.setTextColour(colours.black)
        term.write(_wopt.val..(" "):rep(3 - #_wopt.val))
        term.setCursorPos(_x + _fx, _y + _hopt.y)
        term.write(_hopt.val..(" "):rep(3 - #_hopt.val))
    end

    local function updateBlink()
        if _self == nil then
            term.setCursorBlink(false)
        else
            term.setCursorPos(_x + _fx + #_self.val, _y + _self.y)
            term.setCursorBlink(true)
        end
    end

    local function drawButtons()
        term.setCursorPos(_x + 1, _y + _by)
        term.setBackgroundColour(colours.white)
        term.write((" "):rep(#_invalid.text))
        if valsValid() then
            _okay:draw()
        else
            _invalid:draw()
        end
        _cancel:draw()
    end

    local function displayResizePositions()
        for i,b in ipairs(_resizeList) do
            b.colour = i == _rsSel and "5" or "7"
            b:draw()
        end
    end

    drawWindow()
    drawFields()
    drawButtons()
    if _flag == "r" then displayResizePositions() end

    _menuComplete = false
    repeat
        local _id, _p1, _p2, _p3 = os.pullEvent()

        if _id == "timer" then
            if _p1 == tickTimer then tickTimer = os.startTimer(tickInterval) end
        elseif _id == "mouse_click" then
            if _cancel:is_pressed(_p2, _p3) or (_p2 == _x + _w - 1 and _p3 == _y) then
                _menuComplete = true
            elseif _okay:is_pressed(_p2, _p3) and valsValid() then
                term.setCursorBlink(false)
                return tonumber(_wopt.val), tonumber(_hopt.val), _rsSel
            elseif _p2 >= _x + _fx and _p2 <= _x + _fx + 3 and _p3 == _y + _wopt.y then
                _self = _wopt
                updateBlink()
            elseif _p2 >= _x + _fx and _p2 <= _x + _fx + 3 and _p3 == _y + _hopt.y then
                _self = _hopt
                updateBlink()
            elseif _flag == "r" then
                local pressed = false
                for i, b in ipairs(_resizeList) do
                    if b:is_pressed(_p2, _p3) then
                        _rsSel = i
                        pressed = true
                        break
                    end
                end
                displayResizePositions()

                if not pressed then
                    _self = nil
                end
                updateBlink()
            else
                _self = nil
                updateBlink()
            end
        elseif _id == "char" then
            if _self and #_self.val < 2 then
                _self.val = _self.val.._p1
                drawFields()
                drawButtons()
                updateBlink()
            end
        elseif _id == "key" then
            if _self and _p1 == keys.backspace then
                _self.val = _self.val:sub(0, #_self.val-1)
                drawFields()
                drawButtons()
                updateBlink()
            end
        end
    until _menuComplete
    term.setCursorBlink(false)
end

--A more elaborate save menu than my first effort. Directory navigation and election. It works well enough.
local function displayFileBrowser(_flag,_h,_w,_y,_x)
    local _mt = { ["-s"] = "Save As", ["-b"] = "Browse Files", ["-l"] = "Load File" }
    if not _h then _h = math.floor(h/2) else _h = math.floor(_h) end
    if not _w then _w = math.floor(w/2) else _w = math.floor(_w) end
    if not _x then _x = math.floor(w/2-_w/2) + 1 else _x = math.floor(_x) end
    if not _y then _y = math.floor(h/2-_h/2) end
    local _bc,_tc = colours.white, colours.black
    local _btc,_ttc = colours.blue, colours.white
    local _bfc,_tfc,_tdc = colours.black, colours.white, colours.green
    local _fname = sName or ""
    --This is a nasty timesaver.
    local _cpath = sPath or "/"..shell.resolve(".")
    if _cpath == "/" then _cpath = "" end
    if not _cpath:find("/") then
        _cpath = ""
    elseif sPath then
        _cpath = "/"..getPreviousDir(_cpath)
    end
    local _rlist = fs.list(_cpath)
    if _cpath ~= "/" and _cpath ~= "" then table.insert(_rlist, 1, "..") end

    local _scr = 0
    local _abmsg = { ["-l"] = " Open ", ["-s"] = " Save As ",
            [1] = " Invalid ", [2] = " Overwrite " }
    local _labmsg = ""
    local _winh = _h - 7
    local _cpos = 0

    drawScene()

    --Some dedicated internal draw functions (to speed things up)
    local function _drawWindow()
        --Permanent parts of the window
        term.setBackgroundColour(_btc)
        term.setTextColour(_ttc)
        term.setCursorPos(_x,_y)
        term.write(string.rep(" ", math.floor(_w/2) - math.floor(#_mt[_flag]/2))
                .._mt[_flag]..string.rep(" ", math.ceil(_w/2) -
                math.ceil(#_mt[_flag]/2)-1))
        term.setBackgroundColour(colours.red)
        term.setTextColour(colours.white)
        term.write("x")
        term.setBackgroundColour(_bc)
        term.setTextColour(_tc)
        for i=1,_h do
            term.setCursorPos(_x,_y+i)
            term.write(string.rep(" ", _w))
        end

        term.setTextColour(colours.black)
        term.setBackgroundColour(colours.red)
        term.setCursorPos(_x + _w - 10, _y + _h - 1)
        term.write(" Cancel ")
    end

    local function _drawBrowser()
        term.setBackgroundColour(_bc)
        term.setTextColour(_tc)
        local _dpath = _cpath
        if #_dpath > _w-4 then
            while _dpath:find("/") do
                local _ind = _dpath:find("/") + 1
                _dpath = _dpath:sub(_ind)
                if #_dpath < _w-7 then
                    _dpath = "...".._dpath
                    break
                end
            end
        end
        if #_dpath > _w-4 then _dpath = "...".._dpath:sub(_w-4-#_dpath)
        elseif #_dpath == 0 then _dpath = "/" end
        term.setCursorPos(_x+2,_y+2)
        term.write(_dpath..string.rep(" ", _w-4-#_dpath))

        term.setBackgroundColour(_bfc)
        for i = 1 + _scr, _winh + _scr do
            _pth = _rlist[i] or ""
            if #_pth > _w - 5 then _pth = _pth:sub(1,(_w - 8)).."..." end
            term.setCursorPos(_x + 2, _y + 2 + i - _scr)
            if fs.isDir(_cpath.."/".._pth) then
                term.setTextColour(_tdc)
            else term.setTextColour(_tfc) end
            term.write(" ".._pth..string.rep(" ", _w - 5 - #_pth))
        end
    end

    local function _drawActivationButton()
        _owrite = 0
        local _val = _cpath.."/".._fname
        if (not fs.exists(_val) and _flag == "-l") or
                (fs.exists(_val) and fs.isDir(_val)) then
            _owrite = 1
        elseif fs.exists(_val) and _flag == "-s" then _owrite = 2 end
        term.setTextColour(colours.black)
        term.setCursorPos(_x + 2, _y + _h - 1)
        if _owrite == 1 and _flag ~= "-b" then
            term.setBackgroundColour(colours.lightGrey)
            term.setTextColour(colours.grey)
            _labmsg = " Invalid "
        elseif _owrite == 2 then
            term.setBackgroundColour(colours.orange)
            _labmsg = " Overwrite "
        elseif _flag == "-s" then
            term.setBackgroundColour(colours.green)
            _labmsg = " Save "
        elseif _flag == "-l" then
            term.setBackgroundColour(colours.green)
            _labmsg = " Open "
        end
        term.write(_labmsg)
        term.setBackgroundColour(_bc)
        term.write(string.rep(" ", #" Overwrite " - #_labmsg))
    end

    local function _drawWriteBar()
        term.setCursorPos(_x + 2, _y + _h - 3)
        term.setTextColour(colours.black)
        term.setBackgroundColour(colours.white)
        local _pm = "Save As "
        if _flag == "-l" then _pm = "Open " end
        term.write(_pm)

        local _msg = _fname
        if #_msg > _w - 8 - #_pm then _msg = _msg:sub(#_msg - (_w - 8 - #_pm)) end
        term.setBackgroundColour(colours.lightGrey)
        term.write(" ".._msg)
        _cpos = term.getCursorPos()
        term.write(string.rep(" ", math.max(_w - 5 - #_pm - #_msg, 1)))
    end

    _drawWindow()
    _drawActivationButton()
    _drawBrowser()
    _drawWriteBar()

    while true do
        term.setTextColour(colours.black)
        term.setCursorPos(_cpos, _y + _h - 3)
        term.setCursorBlink(true)
        local _id,_p1,_p2,_p3 = os.pullEvent()

        if _id == "key" then
            if _p1 == keys.backspace and #_fname > 0 then
                _fname = _fname:sub(1,#_fname-1)
                _drawActivationButton()
                _drawWriteBar()
            elseif _p1 == keys.up and _scr > 0 then
                _scr = _scr - 1
                _drawBrowser()
            elseif _p1 == keys.down and _scr < #_rlist - _winh then
                _scr = _scr + 1
                _drawBrowser()
            elseif _p1 == keys.enter then
                local _val = _cpath.."/".._fname
                if (_flag == "-l" and fs.exists(_val) and not fs.isDir(_val))
                        or(_flag == "-s" and not fs.isDir(_val)) then
                    break
                end
            end
        elseif _id == "char" then
            _fname = _fname.._p1
            _drawActivationButton()
            _drawWriteBar()
        elseif _id == "mouse_click" then
            if _p2 == _x + _w - 1 and _p3 == _y then
                _fname = nil
                break
            elseif _p2 >= _x + 2 and _p2 <= _x + _w - 2 and _p3 >= _y + 3 and
                    _p3 < _y + 3 + _winh then
                _p3 = _p3 - _y - 2
                local _val = _rlist[_p3 + _scr]
                if _val == ".." then
                    --Wow why is there no reverse find
                    _cpath = getPreviousDir(_cpath)
                    _rlist = fs.list(_cpath)
                    if _cpath ~= "/" and _cpath ~= "" then table.insert(_rlist, 1, "..") end
                    _scr = 0
                    _drawBrowser()
                    _drawActivationButton()
                elseif fs.isDir(_cpath.."/".._val) then
                    if _cpath == "/" then _cpath = _cpath.._val
                    else _cpath = _cpath.."/".._val end
                    _rlist = fs.list(_cpath)
                    if _cpath ~= "/" and  _cpath ~= "" then table.insert(_rlist, 1, "..") end
                    _scr = 0
                    _drawBrowser()
                    _drawActivationButton()
                else
                    _fname = _val or _fname
                    _drawActivationButton()
                    _drawWriteBar()
                end
            elseif _p3 == _y + _h - 1 and _p2 >= _x + 2 and _p2 < _x + 2 + #        _labmsg and _labmsg ~= _abmsg[1] then
                break
            elseif _p3 == _y + _h - 1 and _p2 >= _x + _w - 2 - #" Cancel " and
                    _p2 < _x + _w - 2 then
                _fname = nil
                term.setCursorBlink(false)
                return false
            end
        elseif _id == "mouse_scroll" then
            _scr = math.min(_scr, #_rlist - _winh - 1)
            _scr = math.max(_scr + _p1, 0)
            _drawBrowser()
        elseif _id == "timer" and _p1 == tickTimer then
            tickTimer = os.startTimer(tickInterval)
        end
    end
    term.setCursorBlink(false)
    if _fname then return (_cpath.."/".._fname):sub(2),_fname else return nil end
end

--Sets up canvas features etc. for a loaded image
local function createLoadedImage(path)
    path = path or sPath
    img = loadBLittle(path)

    magnify = {
        left = "0";
        right = "f";
        pixelX = nil;
        pixelY = nil;
    }
    setToolPositions()

    drawScene()
end

--Starts a blank canvas.
local function createNewImage(iw, ih)
    img = {
        width = iw or 20;
        height = ih or 15;

        text = { };
        fg = { };
        bg = { };
    }

    for y = 1, img.height do
        img.text[y] = { }
        img.fg[y] = { }
        img.bg[y] = { }
    end

    magnify = {
        left = "0";
        right = "f";
        pixelX = nil;
        pixelY = nil;
    }
    setToolPositions()

    sPath = nil
    sChange = false
    filename = nil

    drawScene()
end

--Save a document from the menu
local function menuSaveAs()
    local _sp,sn = displayFileBrowser("-s", 14, 24, 3)
    if _sp then
        sPath = _sp
        sName = _sn
        saveBLittle(img, sPath)
    end
end


--Checks to ensure no changes have been made that are unsaved
local function checkSave()
    if not sChange then return true end
    drawScene()
    local _val = displayConfirmDialogue("Unsaved Changes", "Your document contains unsaved changes. Are you sure you want to do this?", { [1] = "Save"; [2] = colours.green }, { [1] = "Discard"; [2] = colours.orange; }, { [1] = "Cancel";
    [2] = colours.red; })
    if _val == 1 then
        if sPath then saveBLittle()
        else menuSaveAs() end
        return true
    elseif _val == 2 then
        return true
    else
        return false
    end
end

--Handles the events for the program
local function run()
    while programRunning do
        local id, p1, p2, p3 = os.pullEvent()
        if id == "key" then
            if p1 == keys.leftCtrl then
                ctrl_down = true
            elseif ctrl_down then
                local found = false
                for _, option in ipairs(fMenu) do
                    if p1 == keys[string.lower(option.key or "-")] and option.enabled then
                        found = true
                        option.value()
                        drawScene()
                        break
                    end
                end
                if not found then for _, option in ipairs(eMenu) do
                    if p1 == keys[string.lower(option.key or "-")] and option.enabled then
                        found = true
                        option.value()
                        drawScene()
                        break
                    end
                end end
                ctrl_down = false
            end
        elseif id == "key_up" then
            if p1 == keys.leftCtrl then
                ctrl_down = false
            end
        elseif id == "timer" then
            if p1 == tickTimer then
                tickTimer = os.startTimer(tickInterval)
                tickState = (tickState + 1) % 4
                drawMagnifyIcon()
                drawSelectionBox()
            end
        elseif id == "mouse_click" or id == "mouse_drag" then
            local ix, iy = p2 - imgoffX, p3 - imgoffY
            local mx, my = p2 - magoffX, p3 - magoffY
            if p1 == 1 then
                --Canvas
                if inCanvasBounds(p2, p3) then
                    if selTool == "paint" then
                        img.text[iy][ix] = "\128"
                        img.fg[iy][ix] = magnify.left
                        img.bg[iy][ix] = magnify.left
                        drawChar(ix, iy)
                        if ix == magnify.pixelX and iy == magnify.pixelY then
                            magnify = decodeChar(ix, iy)
                            drawMagnify()
                            drawMagCode()
                        end
                        sChange = true
                    elseif selTool == "magnify" and img.text[iy][ix] ~= nil then
                        local ox, oy = magnify.pixelX, magnify.pixelY
                        magnify = decodeChar(ix, iy)
                        drawMagnify()
                        drawMagCode()
                        if ox and oy then drawChar(ox, oy) end
                        drawMagnifyIcon()
                    elseif selTool == "selectbox" then
                        if id == "mouse_click" then
                            selboxX1, selboxY1 = ix, iy
                        end
                        selboxX2, selboxY2 = ix, iy
                        drawImage()
                    elseif selTool == "cursor" then
                        if id == "mouse_drag" and selboxX1 ~= selboxX2 and selboxY1 ~= selboxY2 then
                            local diffX, diffY = ix - cursorX, iy - cursorY
                            local bwidth, bheight = math.abs(selboxX2 - selboxX1), math.abs(selboxY2 - selboxY1)
                            if selboxX2 then
                                selboxX2 = math.max(math.min(selboxX2 + diffX, img.width), bwidth + 1)
                                selboxX1 = math.max(math.min(selboxX1 + diffX, img.width - bwidth ), 1)
                                selboxY2 = math.max(math.min(selboxY2 + diffY, img.height), bheight + 1)
                                selboxY1 = math.max(math.min(selboxY1 + diffY, img.height - bheight), 1)
                                drawImage()
                            end
                        end
                        cursorX, cursorY = ix, iy
                    end
                elseif magnify[1] and inMagnifyBounds(p2, p3) then
                    paintMagnify(mx, my, magnify.left)
                    sChange = true
                elseif pswitch:is_pressed(p2, p3) then pswitch:on_pressed()
                elseif fileButton:is_pressed(p2, p3) then fileButton:on_pressed()
                elseif editButton:is_pressed(p2, p3) then editButton:on_pressed()
                else
                    local _pressed = false
                    for _, cbutton in ipairs(pallette) do
                        if cbutton:is_pressed(p2, p3) then
                            cbutton:on_pressed(p1)
                            _pressed = true
                            break
                        end
                    end
                    --if _pressed then break end
                    for _, tbutton in pairs(tools) do
                        if tbutton:is_pressed(p2, p3) then
                            tbutton:on_pressed()
                            _pressed = true
                            break
                        end
                    end
                end
            elseif p1 == 2 then
                if inCanvasBounds(p2, p3) then
                    if selTool == "paint" then
                        img.text[iy][ix] = "\128"
                        img.fg[iy][ix] = magnify.right
                        img.bg[iy][ix] = magnify.right
                        drawChar(ix, iy)
                        if ix == magnify.pixelX and iy == magnify.pixelY then
                            magnify = decodeChar(ix, iy)
                            drawMagnify()
                            drawMagCode()
                        end
                        sChange = true
                    elseif selTool == "magnify" and img.text[iy][ix] ~= nil  then
                        local ox, oy = magnify.pixelX, magnify.pixelY
                        magnify = decodeChar(ix, iy)
                        drawMagnify()
                        drawMagCode()
                        if ox and oy then drawChar(ox, oy) end
                        drawMagnifyIcon()
                    elseif selTool == "selectbox" then

                    elseif selTool == "cursor" then

                    end
                elseif magnify[1] and inMagnifyBounds(p2, p3) then
                    paintMagnify(mx, my, magnify.right)
                    sChange = true
                else
                    local bpressed = false
                    for _, cbutton in ipairs(pallette) do
                        if cbutton:is_pressed(p2, p3) then
                            cbutton:on_pressed(p1)
                            bpressed = true
                            break
                        end
                    end

                    if not bpressed and id ~= "mouse_drag" then
                        local ox, oy = magnify.pixelX, magnify.pixelY
                        magnify = { left = magnify.left, right = magnify.right }
                        drawMagnify()
                        drawMagCode()
                        if ox and oy then drawChar(ox, oy) end
                    end
                end
            end
        elseif id == "mouse_scroll" then
            switchPaintColours()
        end

        if selTool == "paint" or selTool == "magnify" and selboxX1 then
            selboxX1, selboxY1, selboxX2, selboxY2 = nil, nil, nil
            drawImage()
        end
    end
end

--Interface specifications etc.
local pallette_pressed = function(self, mb)
    local ocol = (mb == 1 and magnify.left or magnify.right)
    if mb == 1 then magnify.left = self.colour
    else magnify.right = self.colour end
    updateMagnify(ocol, self.colour)
end
for i,c in ipairs(colourder) do
    nb = _button.new(w-1, i, "  ", c)
    nb.on_pressed = pallette_pressed
    table.insert(pallette, nb)
end
pswitch.on_pressed = switchPaintColours

fileButton.on_pressed = function()
    fMenu[3].enabled = sChange and sPath
    fMenu[4].enabled = sChange and sPath
    displayDropDown(fMenu.x, fMenu.y, fMenu)
    drawScene()
end
editButton.on_pressed = function()
    displayDropDown(eMenu.x, eMenu.y, eMenu)
    drawScene()
end

table.insert(fMenu, { name = "New", key = "N", enabled = true, value = function()
    if checkSave() then
        local nw, nh = displaySizeSettings("n")
        if nw and nh then createNewImage(nw, nh)
        end end end })
table.insert(fMenu, { name = "Open", key = "O", enabled = true, value = function()
    if checkSave() then
        local _sp,_sn = displayFileBrowser("-l", 14, 24, 3)
        if _sp then
            createLoadedImage(_sp)
            sPath = _sp
            filename = _sn
            assert(sPath)
    end end end })
table.insert(fMenu, { name = "Revert", key = "R", enabled = false, value = function()
    createLoadedImage(sPath)
end })
table.insert(fMenu, { name = "Save", key = "S", enabled = false, value = saveBLittle })
table.insert(fMenu, { name = "Save As", key = "A", enabled = true, value = menuSaveAs })
table.insert(fMenu, { name = "-------", enabled = false })
--table.insert(fMenu, { name = "About", key = "b", enabled = false, value = nil })
table.insert(fMenu, { name = "Quit", key = "Q", enabled = true, value = function()
    if checkSave() then programRunning = false end end })

table.insert(eMenu, { name = "Cut", key = 'x', enabled = false })
table.insert(eMenu, { name = "Copy", key = 'C', enabled = false })
table.insert(eMenu, { name = "Paste", key = 'v', enabled = false })
table.insert(eMenu, { name = "---------", enabled = false })
table.insert(eMenu, { name = "Resize", key = "R", enabled = true, value = function()
    local nw, nh, i = displaySizeSettings("r")
    if nw and nh then resizeCanvas(nw, nh, i) end
end})
table.insert(eMenu, { name = "Crop", key = "p", enabled = true, value = cropToSelection })
table.insert(eMenu, { name = "Show Code", enabled = true, value = function()
        showMagCode = not showMagCode
        eMenu[#eMenu].name = showMagCode and "Hide Code" or "Show Code"
    end
})

--A list of the images we use for each tool
local toolImages = {
    paint = {
        width = 3, height = 2,
        text = { "\128\135\135", "\142\133\128" },
        fg = { "00c", "ff0" },
        bg = { "0c0", "000" }
    },
    magnify = {
        width = 3, height = 2,
        text = { "\151\128\148", "\128\131\146" },
        fg = { "033", "090" },
        bg = { "930", "00f" }
    },
    selectbox = {
        width = 3, height = 2,
        text = { "\136\136\144", "\130\132\132" },
        fg = { "888", "888" },
        bg = { "000", "000" }
    },
    cursor = {
        width = 3, height = 2,
        text = { "\128\143\144", "\128\135\132" },
        fg = { "00f", "0ff" },
        bg = { "0f0", "000" }
    }
}

for k,v in pairs(toolImages) do
    local newButton = _imgbutton.new(1, 1, v)
    newButton.name = k
    newButton.on_pressed = function(self)
        if tools[selTool] then tools[selTool]:change_colour("4", "0") end
        local oldSel = tools[selTool]
        drawEnclosingBorder(oldSel.x, oldSel.y, oldSel.img.width, oldSel.img.height, "8", "8")

        selTool = self.name
        self:change_colour("0", "4")
        drawTools()
    end
    tools[k] = newButton
end

local tArgs = {...}
if tArgs[1] then
    filename = tArgs[1]
    sPath = shell.resolve(tArgs[1])
    if fs.exists(sPath) then
        createLoadedImage(sPath)
    else
        createNewImage(10,10)
    end
else
    createNewImage(10,10)
end

run()
term.setBackgroundColour(colours.black)
shell.run("clear")