## Copyright (C) 2014-2015 Pantxo Diribarne
##
## This program 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.
##
## This program is distributed in the hope that it will be useful,
## but 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.
##
## You should have received a copy of the GNU General Public License
## along with this program.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {@var{retval} =} genpropdoc (@var{OBJNAME}, @var{FILENAME})
##
## Print FILENAME texinfo source file associated to OBJNAME objects.  This
## function is meant to be run for generating octave documentation
## (see doc/interpreter/graphics_properties.mk).
##
## All the hard coded documentation is written in getdoc function.  See the
## comments in getdoc bellow for instruction on how to document a graphics
## property.
##
## @seealso{}
## @end deftypefn

function genpropdoc (objname, fname)
  objnames = {"root", "figure", "axes", "line", ...
              "text", "image", "patch", "surface"};

  ## Base properties
  base = getstructure ("base");

  ## Object properties
  if (any (strcmp (objname, objnames)))
    obj = getstructure (objname, base);
  else
    error ("genpropdoc: unknown object %s", objname);
  endif

  ## Docstring
  str = printdoc (objname, obj);

  if (nargin == 2)
    fid = fopen (fname,  "w+");
    if (fid < 0)
      error ("genpropdoc: couldn't open %s.", fname);
    endif
  else
    fid = stdout;
  endif

  fprintf (fid, str);

  if (nargin == 2)
    fclose (fid);
  endif

endfunction

function s = getdoc (objname, field, base)
  ## Properties are represented by a struct with fields :
  ##
  ## -"doc": string to be printed verbatim after being expanded
  ##   through expand_doc function.  Special keywords are:
  ##   "__objname__" : replaced by the current object name;
  ##   "__prop__"    : replaced by the current property name;
  ##   "__modemsg__" : replaced by a message explaining that
  ##                   the propmode will be toggled to "manual".
  ##   You may also cross reference properties using the label format
  ##   OBJNAMEPROPERTY, e.g, "@xref{XREFaxescolor, , axes color property}."
  ##
  ## -"valid": string that describes valid values for the current property.
  ##   Use "packopt" function to join options with " | " separator
  ##   and "markdef" to mark default among valid values between curly braces.
  ##   If not provided, valid values for radio properties are automatically
  ##   retrieved using set function.
  ##
  ## -"default": string.  If not provided the default value is automatically
  ##   retrieved using get function.
  ##
  ## -"printdefault": a boolean (def. true) that specifies whether the
  ##   default value should be printed.  It is useful for properties
  ##   like root "screendepth" that default to screen dependant values.

  packopt = @(c) strjoin (c, " | ");
  markdef = @(s) ["@{" s "@}"];

  ## Some generic templates:
  valid_color = "colorspec";
  valid_handle = "graphics handle";
  valid_string = "string";
  valid_fcn = packopt ({"string", "function handle"});
  valid_cellstring = packopt ({"string", "cell array of strings"});
  valid_2elvec = "two-element vector";
  valid_3elvec = "three-element vector";
  valid_4elvec = "four-element vector";
  valid_vecmat = packopt ({"vector", "matrix"});
  valid_scalmat = packopt ({"scalar", "matrix"});

  doc_notimpl = "%s is not yet implemented for __objname__ objects.  \
__prop__ is unused.";
  doc_unused =  "__prop__ is unused.";

  ## Initialize structure
  if (isfield (base, field))
    s = base.(field);
  else
    s = struct ("valid", "", "default", "", "doc", "", "printdefault", true);
  endif

  ## Base properties: Write generic documentation because it will be included
  ## in the list of each graphics object.  If a given graphics object
  ## interprets the property differently than others, then the doc will have
  ## to be rewritten for this object.
  if (strcmp (objname, "base"))
    switch (field)
      case "beingdeleted"
      case "busyaction"
      case "buttondownfcn"
        s.valid = valid_fcn;
      case "children"
        s.doc = "Graphics handles of the __objname__'s children.";
        s.valid = "vector of graphics handles";

      case "clipping"
        s.doc = "If __prop__ is @qcode{\"on\"}, the __objname__ is \
clipped in its parent axes limits.";

      case "createfcn"
        s.doc = "Callback function executed immediately after __objname__ \
has been created.  Function is set by using default property on root object, \
e.g., @code{set (0, \"default__objname__createfcn\", \
'disp (\"__objname__ created!\")')}.";
        s.valid = valid_fcn;

      case "deletefcn"
        s.doc = "Callback function executed immediately before __objname__ \
is deleted.";
        s.valid = valid_fcn;

      case "handlevisibility"
        s.doc = "If __prop__ is @qcode{\"off\"}, the __objname__'s \
handle is not visible in its parent's \"children\" property.";

      case "hittest"
      case "interruptible"
      case "parent"
        s.doc = "Handle of the parent graphics object.";
        s.valid = valid_handle;

      case "selected"
      case "selectionhighlight"
      case "tag"
        s.doc = "A user-defined string to label the graphics object.";
        s.valid = valid_string;

      case "type"
        s.doc = "Class name of the graphics object.  __prop__ is \
always @qcode{\"__objname__\"}";
        s.valid = valid_string;
        s.printdefault = false;

      case "uicontextmenu"
        s.doc = "Graphics handle of the uicontextmenu object that is \
currently associated to this __objname__ object.";
        s.valid = valid_handle;
        
      case "userdata"
        s.doc = "User-defined data to associate with the graphics object.";
        s.valid = "Any Octave data";

      case "visible"
        s.doc = "If __prop__ is @qcode{\"off\"}, the __objname__ is \
not rendered on screen.";
    endswitch

  ## Root properties:
  elseif (strcmp (objname, "root"))
    switch (field)
      ## Overridden shared properties
      case {"beingdeleted", "busyaction", "buttondownfcn", ...
            "clipping", "createfcn", "deletefcn", "handlevisibility", ...
            "hittest", "interruptible", "selected", ...
            "selectionhighlight", "uicontextmenu", "visible"}
        s.doc = doc_unused;

      case "parent"
        s.doc = "Root figure has no parent graphics object.  __prop__ \
is always empty.";

      ## Specific properties
      case "callbackobject"
        s.valid = valid_handle;

      case "commandwindowsize"
      case "currentfigure"
        s.doc = "Graphics handle of the current figure.";
        s.valid = valid_handle;

      case "diary"
        s.doc = "If __prop__ is @qcode{\"on\"}, the Octave command window \
session is saved to file.  @xref{XREFrootdiaryfile, , @w{diaryfile property}}.";

      case "diaryfile"
        s.doc = "The name of the diary file.  \
@xref{XREFdiary, , @w{diary function}}.";
        s.valid = valid_string;

      case "echo"
        s.doc = "Control whether Octave displays commands executed from \
scripts.  @xref{XREFecho, , @w{echo function}}.";

      case "errormessage"
        s.doc = "The last error message raised.  \
@xref{XREFlasterr, , @w{lasterr function}}.";
        s.valid = valid_string;

      case "fixedwidthfontname"
        s.valid = valid_string;

      case "format"
        s.doc = "This property is a wrapper around the @code{format} function.\
  @xref{XREFformat, , @w{format function}}.";

      case "formatspacing"
        s.doc = "This property is a wrapper around the @code{format} function.\
  @xref{XREFformat, , @w{format function}}.";

      case "language"
        s.valid = valid_string;

      case "monitorpositions"
        s.doc = doc_unused;
        s.printdefault = false;

      case "pointerlocation"
        s.doc = doc_unused;
        s.valid = valid_2elvec;

      case "pointerwindow"
        s.doc = doc_unused;
        s.valid = valid_handle;

      case "recursionlimit"
        s.doc = "The maximum number of times a function can be called \
recursively.  \
@xref{XREFmax_recursion_depth, , @w{max_recursion_depth function}}.";
        s.valid = "double";

      case "screendepth"
        s.valid = "double";
        s.printdefault = false;

      case "screenpixelsperinch"
        s.valid = "double";
        s.printdefault = false;

      case "screensize"
        s.valid = valid_4elvec;
        s.printdefault = false;

      case "showhiddenhandles"
        s.doc = "If __prop__ is @qcode{\"on\"}, all graphics objects handles \
are visible in their parents' children list, regardless of the value of their \
@code{handlevisibility} property.";

      case "units"
    endswitch

  ## Figure properties
  elseif (strcmp (objname, "figure"))
    switch (field)
      ## Overridden shared properties
      case "clipping"
        s.doc = doc_unused;

      ## Specific properties
      case "alphamap"
        s.doc = sprintf (doc_notimpl, "Transparency");
      case "closerequestfcn"
        s.valid = valid_fcn;

      case "color"
        s.doc = "Color of the figure background.  \
@xref{Colors, , colorspec}.";
        s.valid = valid_color;

      case "colormap"
        s.doc = "A matrix containing the RGB color map for the current axes.";
        s.valid = "N-by-3 matrix";

      case "currentaxes"
        s.doc = "Handle to the graphics object of the current axes.";
        s.valid = valid_handle;

      case "currentcharacter"
        s.doc = doc_unused;

      case "currentobject"
        s.valid = valid_handle;

      case "currentpoint"
        s.doc = "A 1-by-2 matrix which holds the coordinates of the point \
over which the mouse pointer was when a mouse event occurred.  The X and Y \
coordinates are in units defined by the figure's @code{units} property \
and their origin is the lower left corner of the plotting area.\n\
\n\
Events which set @code{currentpoint} are\n\
@table @asis\n\
@item A mouse button was pressed\n\
always\n\
@item A mouse button was released\n\
only if the figure's callback @code{windowbuttonupfcn} is defined\n\
@item The pointer was moved while pressing the mouse button (drag)\n\
only if the figure's callback @code{windowbuttonmotionfcn} is defined\n\
@end table";
        s.valid = valid_2elvec;

      case "dockcontrols"
        s.doc = doc_unused;

      case "doublebuffer"
      case "filename"
        s.doc = "The filename used when saving the plot figure";
        s.valid = valid_string;

      case "integerhandle"
        s.doc = "Assign the next lowest unused integer as the Figure number.";

      case "inverthardcopy"
      case "keypressfcn"
        s.valid = valid_fcn;

      case "keyreleasefcn"
        s.doc = "With @code{keypressfcn}, the keyboard callback functions.  \
These callback functions are called when a key is pressed/released \
respectively.  The functions are called with two input arguments.  The first \
argument holds the handle of the calling figure.  The second argument holds \
an event structure which has the following members:\n\
@table @code\n\
@item Character:\n\
The ASCII value of the key\n\
@item Key:\n\
Lowercase value of the key\n\
@item Modifier:\n\
A cell array containing strings representing the modifiers pressed with the \
key.\n\
@end table";
        s.valid = valid_fcn;

      case "menubar"
        s.doc = "Control the display of the figure menu bar in the upper \
left of the figure.";  

      case "name"
        s.doc = "Name to be displayed in the figure title bar.  The name is \
displayed to the right of any title determined by the @code{numbertitle} \
property.";
        s.valid = valid_string;

      case "nextplot"

      case "numbertitle"
        s.doc = "Display \"Figure\" followed by the numerical figure handle \
value in the figure title bar.";

      case "outerposition"
        s.valid = valid_4elvec;

      case "paperorientation"
      case "paperposition"
        s.doc = "Vector @code{[x0 y0 width height]} defining the position of \
the figure (in @code{paperunits} units) on the printed page.\
  __modemsg__.";
        s.valid = valid_4elvec;

      case "paperpositionmode"
        s.doc = "If __prop__ is set to @qcode{\"auto\"}, the \
@code{paperposition} property is automatically computed: the printed \
figure will have the same size as the on-screen figure and will be centered \
on the output page.";

      case "papersize"
        s.doc = "Vector @code{[width height]} defining the size of the \
paper for printing.  Setting this property forces the @code{papertype} \
property to be set to @qcode{\"<custom>\"}.";
        s.valid = valid_2elvec;

      case "papertype"
        s.doc = "Name of the paper used for printed output.  \
Setting __prop__ also changes @code{papersize} accordingly.";

      case "paperunits"
        s.doc = "The unit used to compute the @code{paperposition} property.";

      case "pointer"
        s.doc = doc_unused;
      case "pointershapecdata"
        s.doc = doc_unused;
      case "pointershapehotspot"
        s.doc = doc_unused;

      case "position"
        s.valid = valid_4elvec;

      case "renderer"
      case "renderermode"
      case "resize"
      case "resizefcn"
        s.valid = valid_fcn;

      case "selectiontype"
        s.doc = doc_unused;

      case "toolbar"
        s.doc = doc_unused;

      case "units"
        s.doc = "The unit used to compute the @code{position} and \
@code{outerposition} properties.";

      case "windowbuttondownfcn"
        s.doc = "@xref{XREFfigurewindowbuttonupfcn, , \
@w{windowbuttonupfcn property}}.";
        s.valid = valid_fcn;

      case "windowbuttonmotionfcn"
        s.doc = "@xref{XREFfigurewindowbuttonupfcn, , \
@w{windowbuttonupfcn property}}.";
        s.valid = valid_fcn;

      case "windowbuttonupfcn"
        s.doc = "With @code{windowbuttondownfcn} and \
@code{windowbuttonmotionfcn}, the mouse callback functions.  These \
callback functions are called when a mouse button is pressed, dragged, or \
released respectively.  When these callback functions are executed, the \
@code{currentpoint} property holds the current coordinates of the cursor.";
        s.valid = valid_fcn;

      case "windowkeypressfcn"
        s.valid = valid_fcn;

      case "windowkeyreleasefcn"
        s.valid = valid_fcn;

      case "windowscrollwheelfcn"
        s.valid = valid_fcn;

      case "windowstyle"
      case "wvisual"
      case "wvisualmode"
      case "xdisplay"
      case "xvisual"
      case "xvisualmode"

    endswitch

  ## Axes properties
  elseif (strcmp (objname, "axes"))
    switch (field)
      ## Overridden shared properties
      case "clipping"
        s.doc = doc_unused;

      ## Specific properties
      case "activepositionproperty"
      case "alim"
        s.doc = sprintf (doc_notimpl, "Transparency");
      case "alimmode"
      case "ambientlightcolor"
        s.doc = sprintf (doc_notimpl, "Light");
      case "box"
        s.doc = "Control whether the axes has a surrounding box.";

      case "cameraposition"
        s.valid = valid_3elvec;

      case "camerapositionmode"
      case "cameratarget"
        s.valid = valid_3elvec;

      case "cameratargetmode"
      case "cameraupvector"
        s.valid = valid_3elvec;

      case "cameraupvectormode"
      case "cameraviewangle"
        s.valid = "scalar";

      case "cameraviewanglemode"
      case "clim"
        s.doc = "Define the limits for the color axis of image children.  \
__modemsg__.  @xref{XREFpcolor, , @w{pcolor function}}.";
        s.valid = valid_2elvec;

      case "climmode"

      case "color"
        s.doc = "Color of the axes background.  @xref{Colors, , colorspec}.";
        s.valid = valid_color;

      case "colororder"
        s.doc = "RGB values used by plot function for automatic line \
coloring.";
        s.valid = "N-by-3 RGB matrix";

      case "currentpoint"
        s.doc = "Matrix @code{[xf, yf, zf; xb, yb, zb]} which holds the \
coordinates (in axes data units) of the point over which the mouse pointer \
was when the mouse button was pressed.  If a mouse callback function is \
defined, @code{currentpoint} holds the pointer coordinates at the time \
the mouse button was pressed.  For 3-D plots, the first row of the returned \
matrix specifies the point nearest to the current camera position and the \
second row the furthest point.  The two points forms a line which is \
perpendicular to the screen.";
        s.valid = "2-by-3 matrix";

      case "dataaspectratio"
        s.doc = "Specify the relative height and width of the data \
displayed in the axes.  Setting @code{dataaspectratio} to \
@w{@code{[1, 2]}} causes the length of one unit as displayed on the x-axis \
to be the same as the length of 2 units on the y-axis.  __modemsg__.";
        s.valid = valid_3elvec;

      case "dataaspectratiomode"
      case "drawmode"
      case "fontangle"
      case "fontname"
        s.doc = "Name of the font used for axes annotations.";
        s.valid = valid_string;

      case "fontsize"
        s.doc = "Size of the font used for axes annotations.  \
@xref{XREFaxesfontunits, , @w{fontunits property}}.";
        s.valid = "scalar";

      case "fontunits"
        s.doc = "Unit used to interpret @code{fontsize} property.";

      case "fontweight"

      case "gridlinestyle"
      case "interpreter"

      case "layer"
        s.doc = "Control whether the axes is drawn below child graphics \
objects (ticks, labels, etc. covered by plotted objects) or above.";

      case "linestyleorder"

      case "linewidth"
      case "minorgridlinestyle"
      case "mousewheelzoom"
        s.doc = "Fraction of axes limits to zoom for each wheel movement."; 
        s.valid = "scalar in the range (0, 1)";

      case "nextplot"
      case "outerposition"
        s.doc = "Specify the position of the plot including titles, \
axes, and legend.  The four elements of the vector are the \
coordinates of the lower left corner and width and height of the \
plot, in units normalized to the width and height of the plot \
window.  For example, @code{[0.2, 0.3, 0.4, 0.5]} sets the lower \
left corner of the axes at @math{(0.2, 0.3)} and the width and \
height to be 0.4 and 0.5 respectively.  \
@xref{XREFaxesposition, , @w{position property}}.";
        s.valid = valid_4elvec;

      case "plotboxaspectratio"
      case "plotboxaspectratiomode"
      case "position"
        s.doc = "Specify the position of the plot excluding titles, \
axes, and legend.  The four elements of the vector are the \
coordinates of the lower left corner and width and height of the \
plot, in units normalized to the width and height of the plot \
window.  For example, @code{[0.2, 0.3, 0.4, 0.5]} sets the lower \
left corner of the axes at @math{(0.2, 0.3)} and the width and \
height to be 0.4 and 0.5 respectively.  \
@xref{XREFaxesouterposition, , @w{outerposition property}}.";
        s.valid = valid_4elvec;

      case "projection"

      case "tickdir"
        s.doc = "Control whether axes tick marks project \"in\" to the plot \
box or \"out\".";

      case "tickdirmode"

      case "ticklength"
        s.doc = "Two-element vector @code{[2Dlen 3Dlen]} specifying the \
length of the tickmarks relative to the longest visible axis.";
        s.valid = valid_2elvec;

      case "tightinset"
      case "title"
        s.doc = "Graphics handle of the title text object.";
        s.valid = valid_handle;

      case "units"
      case "view"
        s.doc = "Two-element vector @code{[azimuth elevation]} specifying \
the viewpoint for three-dimensional plots";
        s.valid = valid_2elvec;

      case "xaxislocation"
      case "xcolor"
        s.doc = "Color of the x-axis.  @xref{Colors, , colorspec}.";
        s.valid = packopt ({markdef(valid_color), "@qcode{\"none\"}"});

      case "xdir"
      case "xgrid"
        s.doc = "Control whether major x grid lines are displayed.";

      case "xlabel"
        s.doc = "Graphics handle of the x label text object.";
        s.valid = valid_handle;

      case "xlim"
        s.doc = "Two-element vector @code{[xmin xmax]} specifying the limits \
for the x-axis.  __modemsg__.  @xref{XREFxlim, , @w{xlim function}}.";
        s.valid = valid_2elvec;

      case "xlimmode"
      case "xminorgrid"
        s.doc = "Control whether minor x grid lines are displayed.";

      case "xminortick"
      case "xscale"
      case "xtick"
        s.doc = "Position of x tick marks.  __modemsg__.";
        s.valid = "vector";

      case "xticklabel"
        s.doc = "Labels of x tick marks.  __modemsg__.";
        s.valid = valid_cellstring;

      case "xticklabelmode"
      case "xtickmode"
      case "yaxislocation"
      case "ycolor"
        s.doc = "Color of the y-axis.  @xref{Colors, , colorspec}.";
        s.valid = packopt ({markdef(valid_color), "@qcode{\"none\"}"});

      case "ydir"
      case "ygrid"
        s.doc = "Control whether major y grid lines are displayed.";

      case "ylabel"
        s.doc = "Graphics handle of the y label text object.";
        s.valid = valid_handle;

      case "ylim"
        s.doc = "Two-element vector @code{[ymin ymax]} specifying the limits \
for the y-axis.  __modemsg__.  @xref{XREFylim, , @w{ylim function}}.";
        s.valid = valid_2elvec;

      case "ylimmode"
      case "yminorgrid"
        s.doc = "Control whether minor y grid lines are displayed.";

      case "yminortick"
      case "yscale"
      case "ytick"
        s.doc = "Position of y tick marks.  __modemsg__.";
        s.valid = "vector";

      case "yticklabel"
        s.doc = "Labels of y tick marks.  __modemsg__.";
        s.valid = valid_cellstring;

      case "yticklabelmode"
      case "ytickmode"
      case "zcolor"
        s.doc = "Color of the z-axis.  @xref{Colors, , colorspec}.";
        s.valid = packopt ({markdef(valid_color), "@qcode{\"none\"}"});

      case "zdir"
      case "zgrid"
        s.doc = "Control whether major z grid lines are displayed.";

      case "zlabel"
        s.doc = "Graphics handle of the z label text object.";
        s.valid = valid_handle;

      case "zlim"
        s.doc = "Two-element vector @code{[zmin zmaz]} specifying the limits \
for the z-axis.  __modemsg__.  @xref{XREFzlim, , @w{zlim function}}.";
        s.valid = valid_2elvec;

      case "zlimmode"
      case "zminorgrid"
        s.doc = "Control whether minor z grid lines are displayed.";

      case "zminortick"
      case "zscale"
      case "ztick"
        s.doc = "Position of z tick marks.  __modemsg__.";
        s.valid = "vector";

      case "zticklabel"
        s.doc = "Labels of z tick marks.  __modemsg__.";
        s.valid = valid_cellstring;

      case "zticklabelmode"
      case "ztickmode"
    endswitch

  ## Line properties
  elseif (strcmp (objname, "line"))
    switch (field)
      ## Overridden shared properties
      case "children"
        s.doc = doc_unused;

      ## Specific properties
      case "color"
        s.doc = "Color of the line object.  @xref{Colors, , colorspec}.";
        s.valid = valid_color;

      case "displayname"
        s.doc = "Text for the legend entry corresponding to this line.";
        s.valid = valid_cellstring;

      case "erasemode"
        s.doc = doc_unused;

      case "interpreter"
      case "linestyle"
        s.doc = "@xref{Line Styles}.";

      case "linewidth"
        s.doc = "Width of the line object measured in points.";

      case "marker"
        s.doc = "Shape of the marker for each data point.  \
@xref{Marker Styles}.";

      case "markeredgecolor"
        s.doc = "Color of the edge of the markers.  When set to \
@qcode{\"auto\"}, the marker edges have the same color as the line.  If set \
to @qcode{\"none\"}, no marker edges are displayed.  This property can also \
be set to any color.  @xref{Colors, , colorspec}.";

      case "markerfacecolor"
        s.doc = "Color of the face of the markers.  When set to \
@qcode{\"auto\"}, the marker faces have the same color as the line.  If set \
to @qcode{\"none\"}, the marker faces are not displayed.  This property \
can also be set to any color.  @xref{Colors, , colorspec}.";

      case "markersize"
        s.doc = "Size of the markers measured in points.";
        s.valid = "scalar";

      case "xdata"
        s.doc = "Vector of x data to be plotted.";
        s.valid = "vector";

      case "xdatasource"
        s.doc = "Name of a vector in the current base workspace to use as \
x data.";
        s.valid = valid_string;

      case "ydata"
        s.doc = "Vector of y data to be plotted.";
        s.valid = "vector";

      case "ydatasource"
        s.doc = "Name of a vector in the current base workspace to use as \
y data.";
        s.valid = valid_string;

      case "zdata"
        s.doc = "Vector of z data to be plotted.";
        s.valid = "vector";

      case "zdatasource"
        s.doc = "Name of a vector in the current base workspace to use as \
z data.";
        s.valid = valid_string;

    endswitch

  ## Text properties
  elseif (strcmp (objname, "text"))
    switch (field)
      ## Overridden shared properties
      case "children"
        s.doc = doc_unused;

      ## Specific properties
      case "backgroundcolor"
        s.doc = sprintf (doc_notimpl, "Background area");
        s.valid = valid_color;

      case "color"
        s.doc = "Color of the text.  @xref{Colors, ,colorspec}.";
        s.valid = valid_color;

      case "displayname"
      case "edgecolor"
        s.doc = sprintf (doc_notimpl, "Background area");
        s.valid = valid_color;

      case "editing"
      case "erasemode"
        s.doc = doc_unused;

      case "extent"
      case "fontangle"
        s.doc = "Flag whether the font is italic or normal.  \
@code{fontangle} is currently unused.";

      case "fontname"
        s.doc = "The font used for the text.";
        s.valid = valid_string;

      case "fontsize"
        s.doc = "The font size of the text as measured in \
@code{fontunits}.";
        s.valid = "scalar";

      case "fontunits"
        s.doc = "The units used to interpret @code{fontsize} property.";

      case "fontweight"
        s.doc = "Control variant of base font used: bold, light, normal, etc.";

      case "horizontalalignment"
      case "interpreter"
      case "linestyle"
        s.doc = sprintf (doc_notimpl, "Background area");

      case "linewidth"
        s.doc = sprintf (doc_notimpl, "Background area");
        s.valid = "scalar";

      case "margin"
        s.doc = sprintf (doc_notimpl, "Background area");
        s.valid = "scalar";

      case "position"
        s.doc = "Vector @code{[X0 Y0 Z0]} where X0, Y0 and Z0 indicate the \
position of the text anchor as defined by @code{verticalalignment} and \
@code{horizontalalignment}.";
        s.valid = valid_4elvec;

      case "rotation"
        s.doc = "The angle of rotation for the displayed text, \
measured in degrees.";
        s.valid = "scalar";

      case "string"
        s.doc = "The text object string content.";
        s.valid = valid_string;

      case "units"
      case "verticalalignment"
    endswitch

  ## Image properties
  elseif (strcmp (objname, "image"))
    switch (field)
      ## Overridden shared properties
      case "children"
        s.doc = doc_unused;

      ## Specific properties
      case "alphadata"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "alphadatamapping"
        s.doc = sprintf (doc_notimpl, "Transparency");

      case "cdata"
        s.valid = "matrix";

      case "cdatamapping"
      case "displayname"
        s.doc = "Text for the legend entry corresponding to this image.";
        s.valid = valid_cellstring;

      case "erasemode"
        s.doc = doc_unused;

      case "xdata"
        s.doc = "Two-element vector @code{[xmin xmax]} specifying the x \
coordinates of the first and last columns of the image.\n\
\n\
Setting @code{xdata} to the empty matrix ([]) will restore the default value \
of @code{[1 columns(image)]}.";
        s.valid = valid_2elvec;

      case "ydata"
        s.doc = "Two-element vector @code{[ymin ymax]} specifying the y \
coordinates of the first and last rows of the image.\n\
\n\
Setting @code{ydata} to the empty matrix ([]) will restore the default value \
of @code{[1 rows(image)]}.";
        s.valid = valid_2elvec;

    endswitch

  ## Surface properties
  elseif (strcmp (objname, "surface"))
    switch (field)
      ## Overridden shared properties
      case "children"
        s.doc = doc_unused;

      ## Specific properties
      case "alphadata"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "alphadatamapping"
        s.doc = sprintf (doc_notimpl, "Transparency");

      case "ambientstrength"
        s.doc = sprintf (doc_notimpl, "Light");

      case "backfacelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "cdata"
        s.valid = "matrix";

      case "cdatamapping"
      case "cdatasource"
      case "diffusestrength"
        s.doc = sprintf (doc_notimpl, "Light");

      case "displayname"
        s.doc = "Text for the legend entry corresponding to this surface.";

      case "edgealpha"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = "scalar";

      case "edgecolor"
      case "edgelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "erasemode"
        s.doc = doc_unused;
      case "facealpha"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "facecolor"
      case "facelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "interpreter"
      case "linestyle"
        s.doc = "@xref{Line Styles}.";

      case "linewidth"
        s.doc = "@xref{XREFlinelinewidth, , @w{line linewidth property}}.";

      case "marker"
        s.doc = "@xref{Marker Styles}.";

      case "markeredgecolor"
        s.doc = "@xref{XREFlinemarkeredgecolor, , \
@w{line markeredgecolor property}}.";

      case "markerfacecolor"
        s.doc = "@xref{XREFlinemarkerfacecolor, , \
@w{line markerfacecolor property}}.";

      case "markersize"
        s.doc = "@xref{XREFlinemarkersize, , \
@w{line markersize property}}.";
        s.valid = "scalar";

      case "meshstyle"
      case "normalmode"
      case "specularcolorreflectance"
        s.doc = sprintf (doc_notimpl, "Light");

      case "specularexponent"
        s.doc = sprintf (doc_notimpl, "Light");

      case "specularstrength"
        s.doc = sprintf (doc_notimpl, "Light");

      case "vertexnormals"
      case "xdata"
        s.valid = "matrix";

      case "xdatasource"
      case "ydata"
        s.valid = "matrix";

      case "ydatasource"
      case "zdata"
        s.valid = "matrix";

      case "zdatasource"
    endswitch

  ## Patch properties
  elseif (strcmp (objname, "patch"))
    switch (field)
      ## Overridden shared properties
      case "children"
        s.doc = doc_unused;

      ## Specific properties
      case "alphadatamapping"
        s.doc = sprintf (doc_notimpl, "Transparency");

      case "ambientstrength"
        s.doc = sprintf (doc_notimpl, "Light");
        s.valid = "scalar";

      case "backfacelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "cdata"
        s.doc = "Data defining the patch object color.\n\
Patch color can be defined for faces or for vertices.\n\
\n\
If @code{cdata} is a scalar index into the current colormap or a RGB triplet, \
it defines the color of all faces.\n\
\n\
If @code{cdata} is an N-by-1 vector of indices or an N-by-3 (RGB) matrix, \
it defines the color of each one of the N faces.\n\
\n\
If @code{cdata} is an N-by-M or an N-by-M-by-3 (RGB) matrix, \
it defines the color at each vertex.";
        s.valid = valid_scalmat;

      case "diffusestrength"
        s.doc = sprintf (doc_notimpl, "Light");
        s.valid = "scalar";

      case "displayname"
        s.doc = "Text of the legend entry corresponding to this patch.";

      case "edgealpha"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "edgecolor"
      case "edgelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "erasemode"
        s.doc = doc_unused;

      case "facealpha"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "facecolor"
        ## Don't provide a default value, and mark colorspec with
        ## braces, this forces the default rgb triplet to be displayed
        s.valid = packopt ({markdef(valid_color), ...
                            "@qcode{\"none\"}", ...
                            "@qcode{\"flat\"}", ...
                            "@qcode{\"interp\"}"});

      case "facelighting"
        s.doc = sprintf (doc_notimpl, "Light");

      case "faces"
      case "xdata"
        s.valid = valid_vecmat;

      case "facevertexalphadata"
        s.doc = sprintf (doc_notimpl, "Transparency");
        s.valid = valid_scalmat;

      case "facevertexcdata"
      case "interpreter"
        s.doc = doc_unused;

      case "linestyle"
      case "linewidth"
      case "marker"
        s.doc = "@xref{XREFlinemarker, , @w{line marker property}}.";

      case "markeredgecolor"
        s.doc = "@xref{XREFlinemarkeredgecolor, , \
@w{line markeredgecolor property}}.";

      case "markerfacecolor"
        s.doc = "@xref{XREFlinemarkerfacecolor, , \
@w{line markerfacecolor property}}.";

      case "markersize"
        s.doc = "@xref{XREFlinemarkersize, , @w{line markersize property}}.";
        s.valid = "scalar";

      case "normalmode"
      case "specularcolorreflectance"
        s.doc = sprintf (doc_notimpl, "Light");
        s.valid = "scalar";

      case "specularexponent"
        s.doc = sprintf (doc_notimpl, "Light");
        s.valid = "scalar";

      case "specularstrength"
        s.doc = sprintf (doc_notimpl, "Light");
        s.valid = "scalar";

      case "vertexnormals"
      case "vertices"
        s.valid = valid_vecmat;

      case "xdata"
        s.valid = valid_vecmat;

      case "ydata"
        s.valid = valid_vecmat;

      case "zdata"
        s.valid = valid_vecmat;

    endswitch
  endif

  ## Replace keywords
  if (! isempty (s.doc) && ! strcmp (objname, "base"))
    s.doc = expand_doc (s.doc, field, objname);
  endif

endfunction

function strout = expand_doc (strin, field, objname)
  strout = strrep (strin, "__objname__", objname);
  strout = strrep (strout, "__prop__", ["@code{" field "}"]);

  modemsg = "Setting @code{%s} also forces the @code{%smode} \
property to be set to @qcode{\"manual\"}";
  modemsg = sprintf (modemsg, field, field);
  strout = strrep (strout, "__modemsg__", modemsg);
endfunction

function s = getstructure (objname, base = [])
  hf = [];
  if (! strcmp (objname, "root"))
    ## Use an improbable number to avoid ishandle to return true for 1
    hf = figure (2265465, "visible", "off");
  endif

  ## Build a default object to extract its properties list and default values.
  if (strcmp (objname, "base"))
    ## Base properties are extracted from hggroup that only have 2 additional
    ## regular (non-hidden) properties, "displayname" and "erasemode".
    h = hggroup ();
  elseif (strcmp (objname, "root"))
    h = 0;
  elseif (strcmp (objname, "figure"))
    h = hf;
  else
    eval (["h = " objname " ();"]);
  endif

  gprop = get (h);
  sprop = set (h);

  fields = fieldnames (gprop);
  nf = numel (fields);
  args = cell (2*nf, 1);
  for ii = 1:nf
    field = fields{ii};

    ## Get hard coded documentation
    val = getdoc (objname, field, base);

    ## Extract the default values that are not hard coded in getdoc
    if (isempty (val.default) && val.printdefault)
      val.default = getdefault (h, objname, field);
    endif

    val.isreadonly = ! isfield (sprop, field);

    ## Extract the valid values that are not hard coded in getdoc
    if (! val.isreadonly && isempty (val.valid))
      val.valid = sprop.(field);
      if (! isempty (val.valid) && iscellstr (val.valid))
        ## Add double quotes around string radio properties
        val.valid = cellfun (@(s) ["@qcode{\"" s "\"}"], val.valid,
                             "uniformoutput", false);
        val.valid = strjoin (val.valid, " | ");
      endif
    endif

    args{2*(ii-1)+1} = field;
    args{2*ii} = val;
  endfor

  ## Build struct and remove unused fields in base properties
  s = struct (args{:});

  if (strcmp (objname, "base"))
    s = rmfield (s, {"displayname", "erasemode"});
  endif

  if (isfigure (hf))
    close (hf)
  endif

endfunction

function def = getdefault (h, objname, field)
  ## This function is meant to be run without initialization file so
  ## that the properties we get are the default.
  def = get (h, field);

  ## Don't print default values for graphics handles
  if (isscalar (def) && def != 0 && ishandle (def))
    def = "";
  else
    if (ischar (def))
      def = ['@qcode{"' def '"}'];
    else
      if ((isvector (def) && numel (def) < 5) || isempty (def))
        ## Use disp to print the default value for short vectors and
        ## empty values
        str = disp (def);
        str(end) = [];          # remove linefeed
        str = strtrim (str);    # remove leading space

        ## Add [] around vector values
        if (ismatrix (def) && numel (def) > 1)
          str = ["[" str "]"];
          ## Add ";" between columns vector values
          if (rows (def) != 1)
            str = strrep (str, "\n", "; ");
          endif
        endif

        ## Replace texinfo reserved characters
        def = strrep (str, "{", "@{");
        def = strrep (def, "}", "@}");
        def = strrep (def, "@", "@@");

        def = ["@code{" def "}"];
      else
        args = arrayfun (@(x) num2str (x), size (def), "uniformoutput", false);
        def = [strjoin(args, "-by-") " " class(def)];
      endif
    endif
  endif

endfunction

function str = printdoc (objname, obj)
  ## Sort fields so that they appear in alphabetic order in the manual
  fields = sort (fieldnames (obj));
  nf = numel (fields);

  ## File header and begining of properties table
  str = [warn_autogen() "\n\n@table @asis"];

  for ii = 1:nf
    field = fields{ii};
    str = sprintf ("%s\n\n", str);

    ## @anchor: cross reference using XREFobjnamefield label
    ## Concept index: call info from octave with 'doc ("objname field")'
    str = sprintf ("%s@anchor{XREF%s%s}\n@cindex %s %s\n",
                   str, objname, field, objname, field);

    ## Item
    str = sprintf ("%s@item @code{%s}", str, field);

    ## Mark item read-only if needed
    if (obj.(field).isreadonly)
      str = sprintf ("%s (read-only):", str);
    else
      str = sprintf ("%s:", str);
    endif

    ## Print valid and default values
    tmp = print_options (obj.(field).valid,
                         obj.(field).default);
    if (! isempty (tmp))
      str = sprintf ("%s %s\n", str, tmp);
    else
      str = sprintf ("%s\n", str);
    endif

    ## Print documentation
    str = sprintf ("%s%s\n", str, obj.(field).doc);
  endfor

  ## End of properties table
  str = sprintf ("%s\n@end table", str);

endfunction

function str = warn_autogen ()
  str = "@c DO NOT EDIT!  Generated automatically by genpropdoc.m.\n\
\n\
@c Copyright (C) 2014-2015 Pantxo Diribarne\n\
@c\n\
@c This file is part of Octave.\n\
@c\n\
@c Octave is free software; you can redistribute it and/or modify it\n\
@c under the terms of the GNU General Public License as published by the\n\
@c Free Software Foundation; either version 3 of the License, or (at\n\
@c your option) any later version.\n\
@c\n\
@c Octave is distributed in the hope that it will be useful, but WITHOUT\n\
@c ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or\n\
@c FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License\n\
@c for more details.\n\
@c\n\
@c You should have received a copy of the GNU General Public License\n\
@c along with Octave; see the file COPYING.  If not, see\n\
@c <http://www.gnu.org/licenses/>.";
endfunction

function str = print_options (val, default)
  str = "";
  if (! isempty (val))
    tmp = strrep (val, default, ["@{" default "@}"]);
    if (length (tmp) == length (val) && ! isempty (default))
      str = [tmp ", def. " default];
    else
      str = tmp;
    endif
  elseif (! isempty (default))
    str = ["def. " default];
  endif
endfunction
