--******************************************************************************
--*                                                                            *
--*  File:        TkLua_06.lua                          Revision:  1.0         *
--*                                                                            *
--*  Contents:    a simple ASCII table display                                 *
--*                                                                            *
--*  Creation:    12.03.2002                   Last Modification:  12.03.2002  *
--*                                                                            *
--*  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:    event binding is not yet possible, and characters like \, {  *
--*               and } cause hefty crashes (within Tcl/Tk)                    *
--*                                                                            *
--******************************************************************************

  dofile("Lua_02_Lib.lua");     -- provides an extended 'tostring' function etc.
  dofile("TkLua_00_Lib.lua");    -- provides a simple console for TkLua programs

  local Icon     = "./Lua.gif";-- specifying the file name is already sufficient
  local Title    = "TkLua_06";
  local Subtitle = "a simple ASCII table display";
  local Status   = "click on a character to see its ASCII code";

--**** list of names for all ASCII control characters ****

  ControlSet = {
    "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
    "BS",  "HT",  "LF",  "VT",  "FF",  "CR",  "SO",  "SI",
    "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
    "CAN", "EM",  "SUB", "ESC", "FS",  "GS",  "RS",  "US"
  };

--**** list of hexadecimal digits ****

  HexDigit = {
    [0]='0';'1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
  };

--******************************************************************************
--*                                                                            *
--* CellSize      calculates cell size required to display any ASCII character *
--*                                                                            *
--******************************************************************************

  function CellSize (CellFont, CellMetrics)
    local Width,Height = 0,0;

  --**** calculate required cell width from the foreseen content ****

    for Col = 0,15 do
      Width = max(Width,tonumber(tkeval("font measure "..CellFont.." {-"..HexDigit[Col].."}")[1]));
    end;

--  for Row = 0,15 do
--    Width = max(Width,tonumber(tkeval("font measure "..CellFont.." {-"..HexDigit[Row].."}")[1]));
--  end;

    for Code = 1,getn(ControlSet) do
      Width = max(Width,tonumber(tkeval("font measure "..CellFont.." {"..ControlSet[Code].."}")[1]));
    end;

    for Code = getn(ControlSet),255 do
      local Character = strchar(Code);
        if (Character == "{")  then Character = " "; end;     -- causes problems
        if (Character == "}")  then Character = " "; end;     -- causes problems
        if (Character == "\\") then Character = " "; end;     -- causes problems
      Width = max(Width,tonumber(tkeval("font measure "..CellFont.." {"..Character.."}")[1]));
    end;

  --**** getting the cell height is easy ****

    Height = CellMetrics.linespace;

  --**** that's it! ****

    return Width, Height;
  end;

--******************************************************************************
--*                                                                            *
--* MetricsFrom      constructs a "FontMetrics" structure from 'tkeval' result *
--*                                                                            *
--******************************************************************************

  function MetricsFrom (ArgList)
    local Result = {};
      for i = 1,getn(ArgList)-1,2 do
        Result[strsub(ArgList[i],2)] = tonumber(ArgList[i+1]);
      end;
    return Result;
  end;

--******************************************************************************
--*                                                                            *
--* processClick                processes mouse clicks on an ASCII table entry *
--*                                                                            *
--******************************************************************************

  function processClick (ArgList)
print("ArgList = ", ArgList);
  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 ContentArea = tkcanvas{};                        -- will be filled later
    local CellFont    = tkeval("font create -family {Helvetica} -size 11 -weight {normal}")[1];
    local CellMetrics = MetricsFrom(tkeval("font metrics "..CellFont));

    local CellWidth,CellHeight = CellSize(CellFont,CellMetrics);

    local CanvasWidth  = CellWidth+3+(16*CellWidth+15)+3+CellWidth;    local dW = CellWidth/2;
    local CanvasHeight = CellHeight+3+(16*CellHeight+15)+3+CellHeight; local dH = CellHeight/2;
  ContentArea.width,ContentArea.height=CanvasWidth,CanvasHeight;

  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"},
    ContentArea,     {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

--**** it's time to fill the 'ContentArea' ****

  ContentArea:create("line",CellWidth+2,0,             CellWidth+2,CanvasHeight-1);
  ContentArea:create("line",CanvasWidth-CellWidth-2,0, CanvasWidth-CellWidth-2,CanvasHeight-1);

  ContentArea:create("line",0,CellHeight+2,              CanvasWidth-1,CellHeight+2);
  ContentArea:create("line",0,CanvasHeight-CellHeight-2, CanvasWidth-1,CanvasHeight-CellHeight-2);

  local BoldFont = "Helvetica 9 bold";--does not conflict with actual cell sizes
  for Row = 0,15 do
    local Label = "-"..HexDigit[Row];
    ContentArea:create("text",              dW,CellHeight+3+Row*(CellHeight+1)+dH, "-text", Label, "-font", BoldFont);
    ContentArea:create("text",CanvasWidth-1-dW,CellHeight+3+Row*(CellHeight+1)+dH, "-text", Label, "-font", BoldFont);
  end;

  for Col = 0,15 do
    local Label = "-"..HexDigit[Col];
    ContentArea:create("text",CellWidth+3+Col*(CellWidth+1)+dW,dH,                "-text", Label, "-font", BoldFont);
    ContentArea:create("text",CellWidth+3+Col*(CellWidth+1)+dW,CanvasHeight-1-dH, "-text", Label, "-font", BoldFont);
  end;

  for Code = 0,getn(ControlSet)-1 do
    local Row,Col = floor(Code/16),mod(Code,16);
    local Tag     = format("code_0x%02X", Code);

    ContentArea:create("text",                -- x position is moved by +1 pixel
      CellWidth+3+Col*(CellWidth+1)+dW+1, CellHeight+3+Row*(CellHeight+1)+dH,
      "-text", ControlSet[Code+1], "-tags", Tag
    );
--  ContentArea:bind(Tag, "<ButtonPress-1>", "processClick(arg)"); -- not yet possible
  end;

  for Code = getn(ControlSet),255 do
    local Row,Col = floor(Code/16),mod(Code,16);
    local Tag     = format("code_0x%02X", Code);

    local Character = strchar(Code);
      if (Character == "{")  then Character = " "; end;       -- causes problems
      if (Character == "}")  then Character = " "; end;       -- causes problems
      if (Character == "\\") then Character = " "; end;       -- causes problems
    ContentArea:create("text",                -- x position is moved by +1 pixel
      CellWidth+3+Col*(CellWidth+1)+dW+1, CellHeight+3+Row*(CellHeight+1)+dH,
      "-text", Character, "-tags", Tag
    );
--  ContentArea:bind(Tag, "<ButtonPress-1>", "processClick(arg)"); -- not yet possible
  end;

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

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