Preliminary inclusion of uixx objects properties in the manual (bug #46076) * doc/interpreter/genpropdoc.m: add uixx objects to the list of supported graphics objects * doc/interpreter/genpropdoc.m (get_doc): add uixx objects and their specific properties (currently empty documentation) * doc/interpreter/plot.txi("Interacting with Plots"): add a note and a reference about ui* family of functions. * doc/interpreter/plot.txi("Interacting with Plots"): for consistency, remove "uimenu" reference. All the other uixx are already in the gui section * doc/interpreter/plot.txi("graphics data structure"): add uixx objects * doc/interpreter/gui.txi("UI Elements"): add "uimenu" function reference * doc/module.mk: add rules to build uixx properties texi files. * graphics.in.h: make uixx "__object__" property (Octave internal) hidden so that it does not appear in the documentation.

function r = __trace__ (t)
  persistent history

  if (isempty (history))
    history = {};
  end
  if (nargin == 0)
    if (nargout == 0)
      history = {};
    else
      r = history;
    end
  elseif (nargin == 1);
    history = [history; t];
  else
    error ('incorrect call to __trace__');
  end

end