--******************************************************************************
--*                                                                            *
--*  File:        TkLua_00a.lua                         Revision:  1.0         *
--*                                                                            *
--*  Contents:    similar to 'TkLua_00', but with a console window             *
--*                                                                            *
--*  Creation:    07.03.2002                   Last Modification:  07.03.2002  *
--*                                                                            *
--*  Platform:    IBM-compatible PC running Windows 98SE                       *
--*                                                                            *
--*  Environment: Lua 4.0, TkLua 4.0                                           *
--*                                                                            *
--*  Author:      Andreas Rozek           Phone:  ++49 (711) 6770682           *
--*               Kirschblütenweg 15      Fax:    -                            *
--*             D-70569 Stuttgart         EMail:  Andreas.Rozek@T-Online.De    *
--*               Germany                                                      *
--*                                                                            *
--*  URL:         http://www.Andreas-Rozek.de/                                 *
--*                                                                            *
--*  Copyright:   the software is published under the "GNU Lesser General Pub- *
--*               lic  License" (see "http://www.fsf.org/copyleft/lesser.html" *
--*               for additional information)                                  *
--*                                                                            *
--*  Comments:    (none)                                                       *
--*                                                                            *
--******************************************************************************

  dofile("Lua_02_Lib.lua");     -- provides an extended 'tostring' function etc.

  local Icon     = "./Lua.gif";-- specifying the file name is already sufficient
  local Title    = "TkLua_00a";
  local Subtitle = "a simple TkLua application";
  local Status   = "(watch the console window)";

--******************************************************************************
--*                                                                            *
--*               tkconsole - a simple console window for TkLua                *
--*                                                                            *
--******************************************************************************

  _TkConsole = nil;                    -- global reference to the console window

--**** redefine the built-in write function ('writeln' and 'print' rely on it) ****

  local _write = write;             -- preserve the old version of this function

  function write (...)
--  call(%_write,arg);                   -- as a backup, send a copy to "stdout"
    call(tkWrite,arg);                      -- and now write onto the Tk console
  end;

--**** additionally redirect any error messages to the Tk console as well ****

  local __ALERT = _ALERT;                       -- preserve the original setting

  function _ALERT (...)
    call(tkWrite,arg);                 -- send all error messages to the console
    call(%_ALERT,arg);          -- as a backup, call the former '_ALERT' as well
  end;

--**** tkWrite actually does most of the work ****

  function tkWrite (...)
    if (_TkConsole == nil) then                -- build console, if not yet done
      local Console = tktext{
        font="-*-courier-medium-r-*--11", width=80, height=25, wrap="none",
        borderwidth=0,
--      state="disabled",                      -- disables editing of the output
--      xscrollcommand="print('XScrollbar:set', arg); self.XScrollbar:set(arg)",
--      yscrollcommand="print('YScrollbar:set', arg); self.YScrollbar:set(arg)",
        xscrollcommand="tremove(arg,1); tinsert(arg,1,self.XScrollbar); call(self.XScrollbar.set,arg);",
        yscrollcommand="tremove(arg,1); tinsert(arg,1,self.YScrollbar); call(self.YScrollbar.set,arg);",
      };
      local XScrollbar = tkscrollbar{
        orient="horizontal", command="tremove(arg,1); tinsert(arg,1,self.Console); call(self.Console.xview,arg);"
      };
      local YScrollbar = tkscrollbar{
        orient="vertical",   command="tremove(arg,1); tinsert(arg,1,self.Console); call(self.Console.yview,arg);"
      };

      Console.XScrollbar = XScrollbar;  XScrollbar.Console = Console;
      Console.YScrollbar = YScrollbar;  YScrollbar.Console = Console;

      _TkConsole = tktoplevel{
        tkframe{
          Console, YScrollbar, "/", XScrollbar;
          relief="sunken", borderwidth=2, geoman="grid"
        }, {fill="both", expand=1};
--      title=%Title.." Console Window",                 -- doesn't seem to work
      };

      _TkConsole:show();
--    _TkConsole:title(%Title.." Console Window");  -- removed for library usage
      _TkConsole:title("Console Window");    -- this even works within a library

      _TkConsole.Console = Console;             -- remember 'Console' for output

    --**** fine-tune the window layout ****

      tkeval('grid configure '..Console.tkname..'    -sticky "news"');
      tkeval('grid configure '..YScrollbar.tkname..' -sticky "ns"');
      tkeval('grid configure '..XScrollbar.tkname..' -sticky "ew"');

    --**** let the "Console" consume all the space within its cell ****

      tkeval('grid rowconfigure    '.._TkConsole.objects[1].tkname..' 0 -weight 1');
      tkeval('grid columnconfigure '.._TkConsole.objects[1].tkname..' 0 -weight 1');

    --**** prevent console window from being removed by the user ****

      _TkConsole:protocol("WM_DELETE_WINDOW", "_TkConsole:iconify()");
    end;

    for i = 1,getn(arg) do
      ArgType = type(arg[i]);

      if     (ArgType == "nil") then
        _TkConsole.Console:insert("end","(nil)");
      elseif (ArgType == "number") then
        _TkConsole.Console:insert("end",tostring(arg[i]));
      elseif (ArgType == "string") then
        _TkConsole.Console:insert("end",arg[i]);
      elseif (ArgType == "function") then
        _TkConsole.Console:insert("end","(function)");
      elseif (ArgType == "userdata") then
        _TkConsole.Console:insert("end","(userdata)");
      else -- ArgType == "table"
        _TkConsole.Console:insert("end",tostring(arg[i]));
      end;

      _TkConsole.Console:see("end");               -- makes the new text visible

    --**** limit console content to (approx.) 400 lines ****

      local LineCount = _TkConsole.Console:index("end")[1];
      if (LineCount > 400) then
        _TkConsole.Console:delete("1.0",tostring(LineCount-399)..".0");
      end;
    end;
  end;

--******************************************************************************
--*                                                                            *
--*                                main program                                *
--*                                                                            *
--******************************************************************************

--**** define window components ****

  local IconLabel      = tklabel{image=Icon, anchor="center", width=32, height=32};
  local TitleLabel     = tklabel{Title;      anchor="e", font="-*-helvetica-bold-o-*--16"};
  local SubtitleLabel  = tklabel{Subtitle;   anchor="e", font="-*-helvetica-bold-r-*--12"};
  local UpperSeparator = tkframe{relief="sunken", borderwidth=2,            height=2};
  local Placeholder    = tkframe{relief="sunken", borderwidth=2, width=320, height=240, background="darkgray"};
  local LowerSeparator = tkframe{relief="sunken", borderwidth=2,            height=2};
  local StatusBar      = tklabel{Status;     anchor="w", font="-*-helvetica-medium-r-*--11"};

--**** construct application window ****

  local MainWindow = tkmain{
    tkframe{
      IconLabel,     {side="left"},
      TitleLabel,    {side="top", fill="x"},
      SubtitleLabel, {side="top", fill="x"}
    },               {side="top", fill="x"},
    UpperSeparator,  {side="top", fill="x"},
    Placeholder,     {side="top", fill="both", expand=1, pady=2},
    LowerSeparator,  {side="top", fill="x"},
    StatusBar,       {side="top", fill="x"}
  };

--**** display application window ****

  MainWindow:title(Title.." - "..Subtitle);
  MainWindow:show();                            -- also triggers a window layout
--MainWindow:resizable(0,0);                     -- disables window size changes
--MainWindow:raise();                   -- brings the window into the foreground

--**** pop up the console window ****

  print("Hello, World!");

--**** periodically print some text ****

  tktimer(1000,function() print(date()); end);

--**** provide an explicit method to terminate this program! ****

  MainWindow:protocol("WM_DELETE_WINDOW", "print('done...'); tkexit()");

--**** test error redirection ****

  error("explicitly generated error message");