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##
## Copyright (C) 2014-2021 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or .
##
## This file is part of Octave.
##
## Octave is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
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## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
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## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING. If not, see
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########################################################################
## -*- texinfo -*-
## @deftypefn {} {} zoom
## @deftypefnx {} {} zoom (@var{factor})
## @deftypefnx {} {} zoom on
## @deftypefnx {} {} zoom off
## @deftypefnx {} {} zoom xon
## @deftypefnx {} {} zoom yon
## @deftypefnx {} {} zoom out
## @deftypefnx {} {} zoom reset
## @deftypefnx {} {} zoom (@var{hfig}, @var{option})
## Zoom the current axes object or control the interactive zoom mode of a
## figure in the GUI.
##
## Given a numeric argument greater than zero, zoom by the given factor. If
## the zoom factor is greater than one, zoom in on the plot. If the factor
## is less than one, zoom out. If the zoom factor is a two- or three-element
## vector, then the elements specify the zoom factors for the x, y, and z
## axes respectively.
##
## Given the option @qcode{"on"} or @qcode{"off"}, set the interactive zoom
## mode on or off.
##
## With no arguments, toggle the current zoom mode on or off.
##
## Given the option @qcode{"xon"} or @qcode{"yon"}, enable zoom mode for the
## x or y-axis only.
##
## Given the option @qcode{"out"}, zoom to the initial zoom setting.
##
## Given the option @qcode{"reset"}, store the current zoom setting so that
## @code{zoom out} will return to this zoom level.
##
## If the first argument @var{hfig} is a figure, then operate on the given
## figure rather than the current figure as returned by @code{gcf}.
##
## @seealso{pan, rotate3d}
## @end deftypefn
## Eventually we need to also support these features:
## @deftypefnx {} {zoom_object_handle =} zoom (@var{hfig})
function zoom (varargin)
nargs = nargin;
if (nargs > 2)
print_usage ();
endif
if (nargs == 1 && nargout > 0 && isfigure (varargin{1}))
error ("zoom: syntax 'handle = zoom (hfig)' not implemented");
endif
hfig = NaN;
if (nargs == 2)
hfig = varargin{1};
if (isfigure (hfig))
varargin(1) = [];
nargs -= 1;
else
error ("zoom: invalid figure handle HFIG");
endif
endif
if (isnan (hfig))
hfig = gcf ();
endif
if (nargs == 0)
zm = get (hfig, "__zoom_mode__");
if (strcmp (zm.Enable, "on"))
zm.Enable = "off";
else
zm.Enable = "on";
endif
set (hfig, "__zoom_mode__", zm);
update_mouse_mode (hfig, zm.Enable);
elseif (nargs == 1)
arg = varargin{1};
if (isnumeric (arg))
factor = arg;
switch (numel (factor))
case 2
xfactor = factor(1);
yfactor = factor(2);
case 1
xfactor = yfactor = factor;
otherwise
error ("zoom: invalid FACTOR");
endswitch
if (xfactor < 0 || yfactor < 0)
error ("zoom: FACTOR must be greater than 1");
elseif (xfactor == 1 && yfactor == 1)
return;
endif
cax = get (hfig, "currentaxes");
if (! isempty (cax))
if (xfactor != 1)
if (yfactor != 1)
mode = "both";
else
mode = "horizontal";
endif
else
if (yfactor != 1)
mode = "vertical";
endif
endif
__zoom__ (cax, mode, factor);
endif
elseif (ischar (arg))
switch (arg)
case {"on", "off", "xon", "yon"}
zm = get (hfig, "__zoom_mode__");
switch (arg)
case {"on", "off"}
zm.Enable = arg;
zm.Motion = "both";
case "xon"
zm.Enable = "on";
zm.Motion = "horizontal";
case "yon"
zm.Enable = "on";
zm.Motion = "vertical";
endswitch
set (hfig, "__zoom_mode__", zm);
update_mouse_mode (hfig, arg);
case "out"
cax = get (hfig, "currentaxes");
if (! isempty (cax))
__zoom__ (cax, "out");
endif
case "reset"
cax = get (hfig, "currentaxes");
if (! isempty (cax))
__zoom__ (cax, "reset");
endif
otherwise
error ("zoom: unrecognized OPTION '%s'", arg);
endswitch
else
error ("zoom: wrong type argument '%s'", class (arg));
endif
endif
endfunction
function update_mouse_mode (hfig, arg)
if (strcmp (arg, "off"))
set (hfig, "__mouse_mode__", "none");
else
## FIXME: Is there a better way other than calling these functions
## to set the other mouse mode Enable fields to "off"?
pan ("off");
rotate3d ("off");
set (hfig, "__mouse_mode__", "zoom");
endif
endfunction
%!demo
%! clf;
%! sombrero ();
%! title ("zoom() demo #1");
%! pause (1);
%! ## zoom in by a factor of 2
%! zoom (2);
%! pause (1);
%! ## return to original zoom level
%! zoom out;
%! pause (1);
%! ## zoom in by a factor of 2
%! zoom (2);
%! pause (1);
%! ## set this zoom level as the "initial zoom level"
%! ## and zoom in some more
%! zoom reset;
%! zoom (2);
%! pause (1);
%! ## return to zoom level set by last call to "zoom reset"
%! zoom out;