Re: Crash when calling Gdk::Drawable::draw_pixbuf

[Falk Schilling <falk schilling gmx net>]

Dear Mark,

of course you’re right, accessing a method of a non-existing object is a
very suboptimal idea… ^^

But nevertheless, if I do the following, I still get a segmentation
fault when calling Gdk::Drawable::draw_pixbuf().

m_drawable = Gdk::Drawable::create();

Maybe I have somewhere overlooked something in the documentation, but I
assume that this is the right way to instantiate an Gdk::Drawable object.

Greetings,
Falk Schilling


P.S.: Sorry Mark, I unfortunately replied your mail to your personal
account, but it was intended to let the list also take part at the
discussion.


Mark Roberts schrieb:
> Dear Falk!
> 
>> • have the following member variables (m_pixbuf, m_gc, m_dim are
>> initialized and work properly, m_drawable and m_gdk_image are NULL ):
>>
>> Glib::RefPtr<Gdk::GC> m_gc;
>> Glib::RefPtr<Gdk::Drawable> m_drawable;
>> Glib::RefPtr<Gdk::Image> m_gdk_image;
>> Glib::RefPtr<Gdk::Pixbuf> m_pixbuf;
>> rdcnnsim::Dimension m_dim;
>>
>> /* rdcnnsim::Dimension
>> * simple class that contains width and height as integers
>> */
>>
>> • take the Gdk::Pixbuf of the Gtk::Image and call:
>>
>> m_drawable->draw_pixbuf(m_gc,
>>                 m_pixbuf,
>>                 0,0,
>>             0,0,
>>             m_dim.get_width(),
>>             m_dim.get_height(),
>>             Gdk::RGB_DITHER_NONE,
>>             0,0);
> 
> You just said that m_drawable was NULL...
> 
>> At this point I am getting an extraordinary annoying segfault when
>> starting the application.
> 
> All the best,
> Mark Roberts