Plugin to show recent scrollback activity

<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE muclient>

<muclient>
<plugin
   name="Current_Output_Window"
   author="Nick Gammon"
   id="391192793248409895090099"
   language="Lua"
   purpose="Redirects recent output to a miniwindow"
   date_written="2009-02-05 17:00"
   requires="4.37"
   version="1.0"
   >

</plugin>

<timers>
  <timer second="0.50" 
         enabled="y" 
         script="heartbeat"
         >
  </timer>
</timers>


<!--  Script  -->


<script>
<![CDATA[

-- configuration

-- window size in pixels
MAX_LINES = 20

-- font
FONT_NAME = "Lucida Console"
FONT_SIZE = 9

-- where to put the window
WINDOW_POSITION = 6  -- see below (6 is top right)

--[[
Useful positions:

4 = top left
5 = center left-right at top
6 = top right
7 = on right, center top-bottom
8 = on right, at bottom
9 = center left-right at bottom
--]]


-- colours
WINDOW_BACKGROUND_COLOUR = ColourNameToRGB ("khaki")
WINDOW_TEXT_COLOUR = ColourNameToRGB ("black")

-- offset of text from edge
TEXT_INSET = 5

-- where to store the scrollback line
lines = {}  -- table of recent scrollback lines

-- display one line
function Display_Line (line, text)

  local left = TEXT_INSET
  local top = (line - 1) * font_height + TEXT_INSET
  
  WindowText (win, "f", text, left, top, window_width - TEXT_INSET, 0, WINDOW_TEXT_COLOUR)
  
end -- Display_Line

function add_line (line)
  -- remove first line if filled up
  if #lines >= MAX_LINES then
    table.remove (lines, 1)
  end -- if 

  -- add new line
  table.insert (lines, line)

end -- add_line

-- here on new output
function OnPluginScreendraw (type, log, line)

  -- blank existing window contents
  WindowRectOp (win, 2, 0, 0, 0, 0, WINDOW_BACKGROUND_COLOUR)
  
  -- wrap long lines
  while #line > wrap_column do
    add_line (line:sub (1, wrap_column))
    line = line:sub (wrap_column + 1) 
  end -- while line > max
  
  -- add remainder of line
  add_line (line)
  
  -- display all lines
  for k, v in ipairs (lines) do
    Display_Line (k, v)
  end -- for
  
end -- end OnPluginScreendraw


-- hide window on removal
function OnPluginClose ()
  WindowShow (win,  false)  -- hide it
end -- OnPluginClose

-- hide window on disable
function OnPluginDisable ()
  WindowShow (win,  false)  -- hide it
end -- OnPluginDisable

-- show window on enable
function OnPluginEnable ()
  if #lines > 0 then
    WindowShow (win,  true)  -- show it
  end -- if
end -- OnPluginEnable

function heartbeat (timername)
  
  -- display window if output window paused and we have something to show
  WindowShow (win,  GetInfo (114) and #lines > 0)

end -- heartbeat

-- startup stuff

win = GetPluginID ()  -- get a unique name

-- make the window
WindowCreate (win, 0, 0, 1, 1, WINDOW_POSITION, 0, 
                         WINDOW_BACKGROUND_COLOUR)  -- create window
               
-- grab a font
WindowFont (win, "f", FONT_NAME, FONT_SIZE) -- define font

-- work out how high and wide it is
font_height = WindowFontInfo (win, "f", 1)   -- height of the font  
wrap_column = GetOption ("wrap_column")

window_width = wrap_column * WindowFontInfo (win, "f", 6) + TEXT_INSET * 2
window_height = MAX_LINES * font_height + TEXT_INSET * 2 

-- remake the window with the correct width
WindowCreate (win, 0, 0, window_width, window_height, WINDOW_POSITION, 0, 
                         WINDOW_BACKGROUND_COLOUR)  -- create window

]]>
</script>

</muclient>

WINDOW_BACKGROUND_COLOUR = ColourNameToRGB ("khaki")
WINDOW_TEXT_COLOUR = ColourNameToRGB ("black")

function heartbeat (timername)
  
  if GetInfo (113) then
    -- display window if output window paused and we have something to show
    WindowShow (win,  GetInfo (114) and #lines > 0)
  end -- if world active
  
end -- heartbeat

  -- wrap long lines
  while #line > wrap_column do
    add_line (line:sub (1, wrap_column))
    line = line:sub (wrap_column + 1) 
  end -- while line > max

  -- wrap long lines, at a space if possible
  while #line > wrap_column do
  
    local col = wrap_column
    if line:match (' ', 3) then  -- if a space past column 2
      while line:sub (col, col) ~= ' ' do  -- find a space
        col = col - 1
      end -- while finding a space, going backwards
      col = col - 1  -- use space in new line, to indent it
    end -- any spaces

    add_line (line:sub (1, col))
    line = line:sub (col + 1) 
    
  end -- while line > max

  -- wrap long lines, at a space if possible
  while #line > wrap_column do
  
    -- find a space not followed by a space, closest to the end of the line
    local col = string.find (line:sub (1, wrap_column), "%s%S*$")
    
    if col and col > 2 then
      col = col - 1  -- use the space to indent
    else
      col = wrap_column  -- just cut off at wrap_column
    end -- if

    add_line (line:sub (1, col))
    line = line:sub (col + 1) 
    
  end -- while line > max