I'm evaluating the use of Cluttermm or Cairomm for the development of an
aesthetically pleasing budgeting program, and while it wasn't too difficult
for me to get Cairomm up an running, as well as drawing SVG images to gtkmm
widgets, I have not been so fortunate with Cluttermm. I am developing this
for GTK2, so gtkmm 2.4, Cluttermm 1.1.3, and clutter-gtkmm 0.10.
The problem is when I was trying to get SVG into Cluttermm. There was a
project called Dax, which could be used to import SVG files, but it did not
have a stable release available. However, there was the option in Cluttermm
to produce a Clutter::Cairo::Texture, which is a special type of
Clutter::Texture that one can create a Cairo::Context to perform Cairo
drawing operations on. From here, I figured I could just use the same
librsvgmm that I had used to get SVG files drawn in Cairomm. Here's the
code:
Glib::RefPtr<Clutter::Actor> get_svg_from_file(char const *filename, guint
width, guint height)
{
std::string str(filename);
Glib::RefPtr<Clutter::Actor> ret_actor;
try
{
Glib::RefPtr<Rsvg::Handle> handle = Rsvg::Handle::create_from_file(str);
Glib::RefPtr<Clutter::Cairo::Texture> cairo_texture =
Clutter::Cairo::Texture::create(width, height);
Glib::RefPtr<Cairo::Context> draw_context =
cairo_texture->create_context();
handle->render(draw_context);
ret_actor = cairo_texture;
}
catch (Rsvg::Error e)
{
// Return the failure actor.
Glib::ustring error_str("Bad Filename!");
ret_actor = Clutter::Text::create(ERROR_FONT, error_str, ERROR_COLOR);
}
return ret_actor;
}
The problem here is that Rsvg::Handle::render() doesn't take a
Glib::RefPtr<Cairo::Context>, instead it takes a
Cairo::RefPtr<Cairo::Context>! This seems like a trivial issue, as it would
be sensible for Cluttermm to return a Cairo::RefPtr instead of a
Glib::RefPtr in this particular instance, but it does not. Either this was
intentional, for reasons I cannot fathom, or it's an oversight, which I
suppose makes sense considering the disparate libraries I'm connecting. To
make my point more pronounced, it's clear this causes an error, as it's my
first build problem:
zeke@GoddamnPC:~/Projects/C/abe/abe/clutter_drawing$ g++ TryDrawSVG.cpp -o
try `pkg-config --libs --cflags cluttermm-1.0 gtkmm-2.4 clutter-gtkmm-1.0
librsvgmm-2.0`
TryDrawSVG.cpp: In function ‘Glib::RefPtr<Clutter::Actor>
get_svg_from_file(const char*, guint, guint)’:
TryDrawSVG.cpp:61: error: no matching function for call to
‘Rsvg::Handle::render(Glib::RefPtr<Cairo::Context>&)’
/usr/local/include/librsvgmm-2.0/librsvgmm/rsvg.h:328: note: candidates are:
bool Rsvg::Handle::render(const Cairo::RefPtr<Cairo::Context>&) const
I was hoping someone on this mailing list has encountered these kinds of
issues before, namely the interchanging of different libraries RefPtrs and
how to go about changing it from a Glib::RefPtr to a Cairo::RefPtr. If this
isn't an option, could someone give me another choice or method to import
SVG files for drawing onto a Clutter::Stage?
Thank you for any assistance.
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