Scroller

--By CoolisTheName007

local mon=peripheral.wrap'back'
mon.setTextScale(1)
local delay=1
local textPath='text'

local function getText()
    local f=fs.open(textPath,'r')
    local text=f.readAll()
    f.close()
    return text
end

local function write( sText)
    local term=mon
    local w,h = term.getSize()
    local x,y = term.getCursorPos()

    local nLinesPrinted = 0
    local function newLine()
        if y + 1 <= h then
            term.setCursorPos(1, y + 1)
        else
            term.setCursorPos(1, h)
            term.scroll(1)
        end
        x, y = term.getCursorPos()
        nLinesPrinted = nLinesPrinted + 1
    end

    -- Print the line with proper word wrapping
    while string.len(sText) > 0 do
        local whitespace = string.match( sText, "^[ \t]+" )
        if whitespace then
            -- Print whitespace
            term.write( whitespace )
            x,y = term.getCursorPos()
            sText = string.sub( sText, string.len(whitespace) + 1 )
        end

        local newline = string.match( sText, "^\n" )
        if newline then
            -- Print newlines
            newLine()
            sText = string.sub( sText, 2 )
        end

        local text = string.match( sText, "^[^ \t\n]+" )
        if text then
            sText = string.sub( sText, string.len(text) + 1 )
            if string.len(text) > w then
                -- Print a multiline word
                while string.len( text ) > 0 do
                    if x > w then
                        newLine()
                    end
                    term.write( text )
                    text = string.sub( text, (w-x) + 2 )
                    x,y = term.getCursorPos()
                end
            else
                -- Print a word normally
                if x + string.len(text) - 1 > w then
                    newLine()
                end
                term.write( text )
                x,y = term.getCursorPos()
            end
        end
    end

    return nLinesPrinted
end

local function wrap(text, limit) --from Kingdaroo
        local lines = {''}
        for word, space in text:gmatch('(%S+)(%s*)') do
                local temp = lines[#lines] .. word .. space:gsub('\n','')
                if #temp > limit then
                        table.insert(lines, '')
                end
                if space:find('\n') then
                        lines[#lines] = lines[#lines] .. word

                        space = space:gsub('\n', function()
                                table.insert(lines, '')
                                return ''
                        end)
                else
                        lines[#lines] = lines[#lines] .. word .. space
                end
        end
        return lines
end

local function extract(t,s,l)
    local c={}
    for k=s,s+l-1 do
        c[k-s+1]=t[k%(#t)+1]
    end
    return c
end

local function print_screen(t)
    mon.clear()
    mon.setCursorPos(1,1)
    local x,y=mon.getSize()


    for i,line in ipairs(t) do
        if (line:sub(1,1)=='#') then
            local tc=colors[line:match'^#([^-#]+)']
            mon.setTextColor(tc or colors.white)
            local bc=colors[line:match'^#[^-#]+%-([^#]+)#']
            mon.setBackgroundColor(bc or colors.black)
            local l=line:match'^#[^#]+#'
            line=line:sub(l:len()+1)
        end
        c=' '
        if (line:sub(-2,-2)=='&') then
            c=line:sub(-1,-1)
            line=line:sub(1,-3)
        end
        line=line..string.rep(c,math.max(x-#line,0))
        write(line..(i~=#t and '\n' or ''))
    end
end

local function main()
    local x,y=mon.getSize()
    local text
    local c=-1
    repeat

        local ok,r=pcall(getText)
        if ok then text=r else error(r) end
        local tText=wrap(text,x)
        c=(c+1)%(#tText)
        mon.setTextColor(colors.white)
        mon.setBackgroundColor(colors.black)
        local t=tText
        for i=1,(c+1) do
            local line=t[i]
            if (line:sub(1,1)=='#') then
                local tc=colors[line:match'^#([^-#]+)']
                mon.setTextColor(tc or colors.white)
                local bc=colors[line:match'^#[^-#]+%-([^#]+)#']
                mon.setBackgroundColor(bc or colors.black)
            end
        end
        print_screen(extract(tText,c,y))

        sleep(delay)
    until false
end
parallel.waitForAny(main,function() shell.run'shell' end)