[dia] PyDia: allow to implement DiaRenderer::is_capabale_to() ...

[Hans Breuer <hans src gnome org>]

commit 1e456ba06433cd447bcad90b93c1b488ca7ea0eb
Author: Hans Breuer <hans breuer org>
Date:   Fri Apr 25 12:44:34 2014 +0200

    PyDia: allow to implement DiaRenderer::is_capabale_to() ...
    
    ... and use that for diasvg.py. The latter is necessary to avoid some
    recently implemented fallbacks of the DiaRenderer base class, i.e.
    render-alpha, render-affine and render-holes are all supported with
    diasvg.py, but the core was applying some fallbacks.

 plug-ins/python/diasvg.py      |   16 +++++++++++++---
 plug-ins/python/pydia-render.c |   40 ++++++++++++++++++++++++++++++++++++++--
 2 files changed, 51 insertions(+), 5 deletions(-)
---
diff --git a/plug-ins/python/diasvg.py b/plug-ins/python/diasvg.py
index bf8b759..a02bb7d 100644
--- a/plug-ins/python/diasvg.py
+++ b/plug-ins/python/diasvg.py
@@ -53,6 +53,16 @@ class SvgRenderer :
        def end_render (self) :
                self.f.write('</svg>')
                self.f.close()
+       def is_capable_to (self, cap) :
+               if cap == 1 : # RENDER_HOLES
+                       return 1
+               elif cap == 2 : # RENDER_ALPHA
+                       return 1
+               elif cap == 4 : #  RENDER_AFFINE
+                       return 1
+               elif cap == 8 : # RENDER_PATTERN
+                       return 0
+               return 0
        def draw_object (self, object, matrix) :
                self.f.write("<!-- " + object.type.name + " -->\n")
                odict = object.properties["meta"].value
@@ -62,8 +72,8 @@ class SvgRenderer :
                        attrs = ''
                        if matrix :
                                attrs += 'transform="matrix' + str(matrix) + '" '
-               if odict.has_key("id") :
-                       attrs += 'id="' + self._escape(odict['id']) + '"'
+                       if odict.has_key("id") :
+                               attrs += 'id="' + self._escape(odict['id']) + '"'
                        self.f.write('<g ' + attrs + '>\n')
                # don't forget to render the object
                object.draw (self)
@@ -72,7 +82,7 @@ class SvgRenderer :
                if odict.has_key("url") :
                        self.f.write('</a>\n')
        def set_linewidth (self, width) :
-               if width < 0.001 : # zero line width is invisble ?
+               if width < 0.001 : # zero line width is invisible ?
                        self.line_width = 0.001
                else :
                        self.line_width = width
diff --git a/plug-ins/python/pydia-render.c b/plug-ins/python/pydia-render.c
index ede92a8..f8a235b 100644
--- a/plug-ins/python/pydia-render.c
+++ b/plug-ins/python/pydia-render.c
@@ -411,6 +411,40 @@ set_font(DiaRenderer *renderer, DiaFont *font, real height)
 static gpointer parent_class = NULL;
 
 /*!
+ * \brief Advertise the renderer's capabilities
+ * \memberof _DiaTransformRenderer
+ */
+static gboolean
+is_capable_to (DiaRenderer *renderer, RenderCapability cap)
+{
+  PyObject *func, *res, *arg, *self = PYDIA_RENDERER (renderer);
+  gboolean bRet = FALSE;
+
+  func = PyObject_GetAttrString (self, "is_capable_to");
+  if (func && PyCallable_Check(func)) {
+    Py_INCREF(self);
+    Py_INCREF(func);
+    arg = Py_BuildValue ("(i)", cap);
+    if (arg) {
+      res = PyEval_CallObject (func, arg);
+      if (res && PyInt_Check(res)) {
+        bRet = (PyInt_AsLong(res) != 0);
+        Py_DECREF (res);
+      } else {
+        ON_RES(res, FALSE);
+      }
+    }
+    Py_XDECREF(arg);
+    Py_DECREF(func);
+    Py_DECREF(self);
+  } else {
+    PyErr_Clear(); /* member optional */
+    return DIA_RENDERER_CLASS (parent_class)->is_capable_to (renderer, cap);
+  }
+  return bRet;
+}
+
+/*!
  * \brief Draw object
  *
  * Optional on the PyDia side. If not implemented the base class method
@@ -420,7 +454,7 @@ static gpointer parent_class = NULL;
  * object information in the drawing. It is also necessary if the PyDia 
  * renderer should support transformations.
  *
- * If implementing a drawing exposrt filter and overwriting draw_object()
+ * If implementing a drawing export filter and overwriting draw_object()
  * the following code shall be used. Otherwise no draw/fill method will
  * be called at all.
  *
@@ -429,7 +463,7 @@ static gpointer parent_class = NULL;
        object.draw (self)
  * \endcode
  *
- * Not calling the object draw method is only usefull when a non-drawing
+ * Not calling the object draw method is only useful when a non-drawing
  * export - e.g. code generation \sa codegen.py - is implemented.
  *
  * @param renderer Self
@@ -1240,5 +1274,7 @@ dia_py_renderer_class_init (DiaPyRendererClass *klass)
   /* highest level functions */
   renderer_class->draw_rounded_rect = draw_rounded_rect;
   renderer_class->fill_rounded_rect = fill_rounded_rect;
+  /* other */
+  renderer_class->is_capable_to = is_capable_to;
 }