% QINFO   Prints Q structure information 
%
%    This function prints field information for a "Q-structure" if the
%    format described in *qcheck* is followed. 
%
%    Some examples:
%    Assuming that *qdef* provides needed information, information for 
%    field DUMMY is obrtained by:
%       qinfo(@qdef,'DUMMY');
%    To create a file qdoc.txt with information for all fields:
%       qinfo(@qdef,'all',''qdoc.txt');
%
% FORMAT   qinfo( qfun, field, fid )
%        
% IN    qfun   Pointer to function providing default structure.
%       field  Field name, or 'all'.
% OPT   fid    File identifier(s) for output. Or name on file to create.
%              Default is to only print on screen.

% 2004-09-07   Created by Patrick Eriksson.

function qinfo( qfun, field, fid )

if nargin < 3
  fid = 1;
end

if ischar(fid)
  fid = fileopen( fid, 'w' );
  filetoclose = 1;
else
  filetoclose = 0;
end


[Q,INFO] = feval( qfun );


f1 = fieldnames( Q ); 
f2 = fieldnames( INFO ); 

ok = 1;

for i = 1 : length(f1)
  if ~isfield( INFO, f1{i} )
    fprintf('The Q-field %s is not found in INFO.\n', f1{i} );
    ok = 0;
  end
end


if length(f1) ~= length(f2)  | ~ok
  for i = 1 : length(f2)
    if ~isfield( Q, f2{i} )
      fprintf('The INFO-field %s is not defined in Q.\n', f1{i} );
      ok = 0;
    end
  end
end


if ~ok
  fprintf('\n');
  error('Inconsistency found when comparing Q and INFO.');
end


if strcmp( field, 'all' )

  fields = fieldnames( INFO );

  out(0,1,fid);
  for i = 1 : length(fields)  
    printfield( fields{i}, getfield( INFO, fields{i} ), fid );
    if i < length(fields)
      out(0,0,fid);
    end
  end
  out(0,-1,fid);


else

  if ~isfield( INFO, field )
    error(sprintf('The field %s is not recognised.', field));
  end

  s = getfield( INFO, field );

  if ~ischar( s )
    error(sprintf('Information for field %s is not a string.', field));
  end

  out(0,1,fid);
  printfield( field, s, fid );
  out(0,-1,fid);

end


if  filetoclose 
  fileclose( fid );
end



%----------------------------------------------------------------------------

function printfield( field, s, fid )
  %
  atmlab( 'require', {'SCREEN_WIDTH'} );
  ncols = atmlab( 'SCREEN_WIDTH' ) - 4;
  ls = length( s );
  %
  ind = [find( s == ' ' ) ls+1 ];
  ready = 0;
  i = 1;
  %
  out(0,sprintf('Field: %s',field),fid);
  out(0,'-',fid);
  while ~ready
    j = ind(max(find( ind <= i+ncols )))-1;
    out(0,s(i:j),fid);
    i = j + 2;
    if i > ls
      ready = 1;
    end
  end
return