Help with read() and input box - ComputerCraft Forums (archive)

funkey100 #1

58 posts

Location Mars

Posted 27 August 2012 - 09:06 PM

I am making a new operating system (which will be released soon as alpha :D/>/> ) which opens an input box when you want to rename or make a new file/directory. Here is the input box with an example of the new directory box:

|------------------------------------------------|
|New directory's name:				 |
|	  					 |
|------------------------------------------------|

The read() is on the third line. My problem is that because read() reads the whole line after it's called, it deletes the right |, even if you didn't type anything long enough to reach it. Is there any way I can make it not go past the |, like make it only go 48 spaces? Thanks.

Grim Reaper #2

504 posts

Location Seattle, WA

Posted 27 August 2012 - 10:42 PM

I believe this is in the wrong section, but I help you anyways :D/>/>

I wrote a function a while ago that lets your read a limited amount of characters and can have a replacement character.
However, this function doesn't delete the whole line, rather it only erases the length of the currently entered string.

Here it is:

Spoiler


function limitRead( nLength, cReplaceChar )
  term.setCursorBlink( true )
  local nLength = nLength or -1 -- -1 is unlimited
  local sReturnString = ""
  local xPos, yPos = term.getCursorPos()
  local while true do
           local event, char = os.pullEvent()
		   if nLength ~= -1 and string.len( sReturnString ) >= nLength then term.setCursorBlink( false ); return sReturnString end -- Length	  check
				if event == "char" then sReturnString = sReturnString .. char
				elseif event == "key" and char == 28 then term.setCursorBlink( false ); return sReturnString -- Enter
				elseif event == "key" and char == 14 then -- Backspace
						term.setCursorPos( xPos, yPos )
						term.write( string.rep( " ", string.len( sReturnString ) ) )
						sReturnString = string.sub( sReturnString, 1, string.len( sReturnString )-1 )
						term.setCursorPos( xPos, yPos )
						if not cReplaceChar then term.write( sReturnString )
						else term.write( string.rep( cReplaceChar, string.len( sReturnString ) ) ) end
				end
				term.setCursorPos( xPos, yPos )
				term.write( string.rep( " ", string.len( sReturnString ) ) )
				term.setCursorPos( xPos, yPos )
				if not cReplaceChar then term.write( sReturnString )
				else term.write( string.rep( cReplaceChar, string.len( sReturnString ) ) ) end
		end
end

If you use this, please give me credit.

Hope I helped! :P/>/>

Jan #3

137 posts

Location the Netherlands

Posted 27 August 2012 - 10:46 PM

This is the read-function from the rom:

Spoiler


function read( _sReplaceChar, _tHistory )
term.setCursorBlink( true )
    local sLine = ""
local nHistoryPos = nil
local nPos = 0
    if _sReplaceChar then
  _sReplaceChar = string.sub( _sReplaceChar, 1, 1 )
end

local w, h = term.getSize()
local sx, sy = term.getCursorPos()
local function redraw()
  local nScroll = 0
  if sx + nPos >= w then
   nScroll = (sx + nPos) - w
  end
  
  term.setCursorPos( sx, sy )
  term.write( string.rep(" ", w - sx + 1) )
  term.setCursorPos( sx, sy )
  if _sReplaceChar then
   term.write( string.rep(_sReplaceChar, string.len(sLine) - nScroll) )
  else
   term.write( string.sub( sLine, nScroll + 1 ) )
  end
  term.setCursorPos( sx + nPos - nScroll, sy )
end

while true do
  local sEvent, param = os.pullEvent()
  if sEvent == "char" then
   sLine = string.sub( sLine, 1, nPos ) .. param .. string.sub( sLine, nPos + 1 )
   nPos = nPos + 1
   redraw()
  
  elseif sEvent == "key" then
	  if param == keys.enter then
    -- Enter
    break
   
   elseif param == keys.left then
    -- Left
    if nPos > 0 then
	 nPos = nPos - 1
	 redraw()
    end
   
   elseif param == keys.right then
    -- Right   
    if nPos < string.len(sLine) then
	 nPos = nPos + 1
	 redraw()
    end
  
   elseif param == keys.up or param == keys.down then
			    -- Up or down
    if _tHistory then
	 if param == keys.up then
	  -- Up
	  if nHistoryPos == nil then
	   if #_tHistory > 0 then
	    nHistoryPos = #_tHistory
	   end
	  elseif nHistoryPos > 1 then
	   nHistoryPos = nHistoryPos - 1
	  end
	 else
	  -- Down
	  if nHistoryPos == #_tHistory then
	   nHistoryPos = nil
	  elseif nHistoryPos ~= nil then
	   nHistoryPos = nHistoryPos + 1
	  end	 
	 end
	
	 if nHistoryPos then
					 sLine = _tHistory[nHistoryPos]
					 nPos = string.len( sLine )
				    else
	  sLine = ""
	  nPos = 0
	 end
	 redraw()
			    end
   elseif param == keys.backspace then
    -- Backspace
    if nPos > 0 then
	 sLine = string.sub( sLine, 1, nPos - 1 ) .. string.sub( sLine, nPos + 1 )
	 nPos = nPos - 1	
	 redraw()
    end
   end
  end
end

term.setCursorBlink( false )
term.setCursorPos( w + 1, sy )
print()

return sLine
end

You could try to add a modified edition of this in your program.
In the 'redraw' function, just add some lines that write your '|'

funkey100 #4

58 posts

Location Mars

Posted 27 August 2012 - 10:54 PM

I do not understand how I do that…

Grim Reaper #5

504 posts

Location Seattle, WA

Posted 27 August 2012 - 11:59 PM

Y U NO USE MY FUNCTION?

funkey100 #6

58 posts

Location Mars

Posted 28 August 2012 - 01:35 AM

Haha, I'm sorry I didn't see that before! Thanks! Gonna test it later.

funkey100 #7

58 posts

Location Mars

Posted 28 August 2012 - 09:48 PM

One problem, when it hits 48 characters, it gets bugged up while in the normal read(), it only scrolls so you can put more and scrolls back if you use backspace. I'll try to find a solution…