getkey

 GETKEY - get a single keypress
   CH = GETKEY waits for a keypress and returns the ASCII code. Accepts
   all ascii characters, including backspace (8), space (32), enter (13),
   etc, that can be typed on the keyboard. CH is a double.

   CH = GETKEY('non-ascii') uses non-documented matlab 6.5 features to
   return a string describing the key pressed so keys like ctrl, alt, tab
   etc. can also be used. CH is a string.

   This function is kind of a workaround for getch in C. It uses a modal, but
   non-visible window, which does show up in the taskbar.
   C-language keywords: KBHIT, KEYPRESS, GETKEY, GETCH

   Examples:

    fprintf('\nPress any key: ') ;
    ch = getkey ;
    fprintf('%c\n',ch) ;

    fprintf('\nPress the Ctrl-key: ') ;
    if strcmp(getkey('non-ascii'),'control'),
      fprintf('OK\n') ;
    else
      fprintf(' ... wrong key ...\n') ;
    end

  See also INPUT, CHAR

0001 function ch = getkey(m) 
0002 
0003 % GETKEY - get a single keypress
0004 %   CH = GETKEY waits for a keypress and returns the ASCII code. Accepts
0005 %   all ascii characters, including backspace (8), space (32), enter (13),
0006 %   etc, that can be typed on the keyboard. CH is a double.
0007 %
0008 %   CH = GETKEY('non-ascii') uses non-documented matlab 6.5 features to
0009 %   return a string describing the key pressed so keys like ctrl, alt, tab
0010 %   etc. can also be used. CH is a string.
0011 %
0012 %   This function is kind of a workaround for getch in C. It uses a modal, but
0013 %   non-visible window, which does show up in the taskbar.
0014 %   C-language keywords: KBHIT, KEYPRESS, GETKEY, GETCH
0015 %
0016 %   Examples:
0017 %
0018 %    fprintf('\nPress any key: ') ;
0019 %    ch = getkey ;
0020 %    fprintf('%c\n',ch) ;
0021 %
0022 %    fprintf('\nPress the Ctrl-key: ') ;
0023 %    if strcmp(getkey('non-ascii'),'control'),
0024 %      fprintf('OK\n') ;
0025 %    else
0026 %      fprintf(' ... wrong key ...\n') ;
0027 %    end
0028 %
0029 %  See also INPUT, CHAR
0030 
0031 % (c) 2005 Jos
0032 % email jos @ jasen .nl
0033 % Feel free to (ab)use, modify or change this contribution
0034 
0035 
0036 % Determine the callback string to use
0037 if nargin == 1,
0038     if strcmp(lower(m),'non-ascii'),
0039         callstr = ['set(gcbf,''Userdata'',get(gcbf,''Currentkey'')) ; uiresume '] ;
0040     else       
0041         error('Argument should be the string ''non-ascii''') ;
0042     end
0043 else
0044     callstr = ['set(gcbf,''Userdata'',double(get(gcbf,''Currentcharacter''))) ; uiresume '] ;
0045 end
0046 
0047 % Set up the figure
0048 % May be the position property  should be individually tweaked to avoid visibility
0049 fh = figure('keypressfcn',callstr, ...
0050     'windowstyle','modal',...    
0051     'position',[0 0 1 1],...
0052     'Name','GETKEY', ...
0053     'userdata','timeout') ; 
0054 try
0055     % Wait for something to happen
0056     uiwait ;
0057     ch = get(fh,'Userdata') ;
0058 catch
0059     % Something went wrong, return and empty matrix.
0060     ch = [] ;
0061 end
0062 close(fh) ;