terminal draft

--[[Not yet finished: Not advised for real use just now and subject to heavy change]]

function dPadMenu(t, yStart, yEnd, indent, highlight, background)
    if yStart == nil or yStart < 1 then
        yStart = 1
    elseif yStart >= mY then
        yStart = mY-1
    end
    if yEnd == nil or yEnd > mY then
        yEnd = mY
    end
    indent = indent or 3
    highlight = highlight or colors.magenta
    background = background or colors.black
    local menu = compileListIntoPages(t, yStart, yEnd)
    local pageS = 1 -- The default selected page
    local unitS = 1 -- The default selected item in the page
    local numberOfPages = #menu
    local returnVal = nil
    while true do
        menu[pageS][unitS]["selected"] = true -- Sets the default selection
        writeListWithHighlights(menu[pageS], indent, mX, yStart, yEnd, highlight, background)
        local event = {os.pullEvent("key")}
        if event[2] == 200 then -- up arrow. Shift unitS down if room. Shift original unitS to false
            if unitS > 1 then
                menu[pageS][unitS]["selected"] = false
                unitS = unitS - 1
            elseif pageS > 1 and unitS == 1 then
                menu[pageS][unitS]["selected"] = false
                pageS = pageS - 1
                unitS = #menu[pageS]
            end
        elseif event[2] == 208 then -- down arrow. Shift unitS up if room. Shift original unitS to false
            if unitS < #menu[pageS] then
                menu[pageS][unitS]["selected"] = false
                unitS = unitS + 1
            elseif pageS < numberOfPages and unitS == #menu[pageS] then
                menu[pageS][unitS]["selected"] = false
                pageS = pageS + 1
                unitS = 1
            end
        elseif event[2] == 203 then -- left arrow. Shift pageS down if room and reset unitS to one. Shift original unitS to false and original pageS to false
            if pageS > 1 then
                menu[pageS][unitS]["selected"] = false
                pageS = pageS - 1
                unitS = 1
            end
        elseif event[2] == 205 then -- right arrow. Shift pageS up if room and reset unitS to one. Shift original unitS to false and original pageS to false
            if pageS < numberOfPages then
                menu[pageS][unitS]["selected"] = false
                pageS = pageS + 1
                unitS = 1
            end
        elseif event[2] == 28 then -- enter. Set returnVal to current menu[pageS][unitS]["data"] and break
            returnVal = menu[pageS][unitS]["data"]
            term.setBackgroundColor(background)
            break
        end
        term.setBackgroundColor(background)
    end
    return returnVal
end

-- Add a menu option to your menu with this function.

function constructSelectionPart(targetSelectionMenu, message, data)
    local tLength = #targetSelectionMenu
    data = data or message
    targetSelectionMenu[tLength+1] = {
        ["message"] = message,
        ["data"] = data,
        ["key"] = targetSelectionMenu,
        ["selected"] = false,
        }
    table.insert(targetSelectionMenu, 0, t)
end

-- You could just make the table yourself, which is better probably, but this is here for the sake of completeness

function constructSelectionMenu()
    local t = {}
    return t
end

function clearScreenAtLineRange(minY, maxY)
    if minY == nil then
        minY = 1
    end
    if maxY == nil then

        maxY = mY
    end
    for i = minY, maxY do
        term.setCursorPos(1,i)
        term.clearLine()
    end
    term.setCursorPos(1,minY)
end

function stringToPointInLine(point, char, prefix, suffix, start) -- tweak
    prefix = prefix or ""
    suffix = suffix or ""
    char = char or " "
    local cX = start
    if start == nil then
        local x,y = term.getCursorPos()
        cX = x
    end
    local length = mX - ((2*cX) + string.len(prefix..suffix))
    prefix = prefix..(string.rep(char, length))..suffix
    return prefix
end

function writeListWithHighlights(list, indent, tWidth, yStart, yEnd, highlight, background, track, withHold) -- tweak
    local yShift = 0
    clearScreenAtLineRange(yStart, yEnd)
    for i,v in pairs(list) do
        term.setCursorPos(indent, yShift + yStart)
        yShift = yShift + 1
        if track == true then
            local x, y = term.getCursorPos()
            v["pos"] = {["x"] = x, ["y"] = y}
        end
        if withHold ~= true then
            term.setBackgroundColor(background)
            if v["selected"] == true then
                term.setBackgroundColor(highlight)
            end
            local str = stringToPointInLine(tWidth-(1+indent), nil, "   "..v["message"])
            write(str)
        end
    end
    return list
end

function compileListIntoPages(list, yStart, yEnd) -- tweak
    local pageNumber = 1
    local menu = {}
    for i,v in pairs(list) do
            if menu[pageNumber] == nil then
                menu[pageNumber] = {}
            end
            table.insert(menu[pageNumber], 0, v)
            if #menu[pageNumber] == (yEnd - yStart) then
                pageNumber = pageNumber + 1
            end
    end
    return menu
end