How to use the mouse_scroll event

In conjuction with jasperdekiller's database, I have made a client for it. One of the downsides is that the log might be 50 lines long and the height limit is 19. I am trying to make it so that whenever i scroll down, it will show the rest of the log and vice versa.

I will be happy if I can get a simple but clever answer.

Best bet is to bung each line into a separate table index, then just print lines x through to x+18, where x is whatever position you've scrolled to.

I've got some code for a menu that should give you some idea as to how to go about it.

Bomb Bloke, on 14 February 2015 - 10:47 PM said:

Best bet is to bung each line into a separate table index, then just print lines x through to x+18, where x is whatever position you've scrolled to.

I've got some code for a menu that should give you some idea as to how to go about it.

OK….. No idea what I'm doing here.

All I want is a simple system that if I scroll down, it goes down and if i scroll up, it goes up.

Well… what have you got?

Heres the Main: Rxx5WNPW

Heres the API: SfXFSh0a

Im gonna post the part that i want to be edited here:

						    term.setBackgroundColour(colours.black)
							term.clear()
							term.setTextColour(colours.white)
							Log = db.getAllLogs(tonumber(serverID), serverName, serverPass)
							local yPos = 1
							term.setCursorPos(1, yPos)
							for k, v in pairs(Log) do
								if v[2] == "Info" then
									term.setTextColour(colours.blue)
									term.write("[ "..v[2].." ] ")
									term.setTextColour(colours.lightGrey)
									term.write(v[1])
									yPos = yPos + 1
									term.setCursorPos(1, yPos)
								elseif v[2] == "Success" then
									term.setTextColour(colours.green)
									term.write("[ "..v[2].. " ] ")
									term.setTextColour(colours.lightGrey)
									term.write(v[1])
									yPos = yPos + 1
									term.setCursorPos(1, yPos)
								elseif v[2] == "Warning" or v[2] == "Error" or v[2] == "Alert" then
									term.setTextColour(colours.red)
									term.write("[ "..v[2].." ] ")
									term.setTextColour(colours.lightGrey)
									term.write(v[1])
									yPos = yPos + 1
									term.setCursorPos(1, yPos)
								end
							end
							event, key = os.pullEvent("key")
							pageLayout()

Don't have time to go through all your code, but this is basically what I would do

items = {
  "This is the first line",
  "This is the second line",
  "This is the third line"
}  --#You probably have more than three lines

local w,h = term.getSize()
local offset = 0

term.setCursorPos(1,1)
if #items > h then
  for i = 1, h do
    term.write(items[#items-(h+offset)+i])
  end
else
  for i = 1, h do
    term.write(items[i])
  end
end

Change 'offset' to move the list up or down.

Like I said, that's the basic idea, you will have to play with it to get it to work.

This isn't as elegant as the other solutions, and it's not based on your code, but it's what I use in my programs. It views/scrolls a page at a time instead of a line at a time. You'll need to make changes to suit your needs. Note that this only works for ordered tables, not sparse tables…

local testData = { "Line 1", "Line 2", "Line 3", "Line 4", "Line 5", "Line 6", "Line 7", "Line 8", "Line 9", "Line 10", "Line 11", "Line 12" } --#substitute this with your actual data

local linesPerPage = 10 --# the number of lines per page (change this to suit your needs)
local pageNum = 1	--# which page we're currently on - we're starting at the first page
local numPages = math.ceil(#testData / linesPerPage) --# total number of pages based on number of entries

local function listPage()
  term.clear()	   --# this is just for this example, you may wish to clear just the area the data fills
  local xPos = 1   --# cursor X position (change this to be your actual 'top' x position)
  local yPos = 1   --# cursor Y position (change this to be your actual 'top' y position)
  local startY = 1 --# this should be equal to the initial yPos value
  local currentEntry = ((pageNum - 1) * (linesPerPage - 1)) + pageNum
  for i = currentEntry, #testData do --# start the listing loop from the current entry
    term.setCursorPos(xPos, yPos)    --# set the cursor position
    term.write(testData[i])	     --# write the data to screen
    yPos = yPos + 1	             --# increment the Y position so the next entry is written on the next display line
    if yPos = startY + linesPerPage then break end --# we've listed the set number of entries per page so stop the loop
  end
end

local function getInput()
  while true do
    local _, scroll = os.pullEvent("mouse_scroll")
    if scroll == 1 then
      pageNum = math.min(pageNum + 1, numPages) --# if the user scrolls down, increment the page number
    elseif scroll == -1 then
      pageNum = math.max(1, pageNum - 1)        --# if the user scrolls up, decrement the page number
    end
    listPage()
  end
end

listPage()
getInput()

I understand nothing of what all of you have said.

It doesn't matter because I found a function that scrolls through already.