Re: OffscreenWindow returns empty pixbuf

[Phil Wolff <adiabat centurylink net>]

I saw that, but it's now clear I over-interpreted the "re" part of 
"redrawn"...

Good catch!!

Phil

On 09/03/2014 07:56 AM, Kjell Ahlstedt wrote:
> The documentation of OffscreenWindow says: "When contained offscreen 
> widgets are redrawn, OffscreenWindow will emit a "damage-event" signal."
>
> I connected a signal handler to signal_damage_event(), like so:
>
>     m_pw.signal_damage_event().connect(
>       sigc::mem_fun(*this, &Test::on_offscreen_window_damage_event));
>
>  And it worked, when I called get_pixbuf() in the signal handler!
>
> Kjell
>
> Den 2014-09-03 15:32, Phil Wolff skrev:
> > Yes, I discovered that yesterday, but my end use for this cannot rely 
> > on user intervention.
> >
> > I derived my own OffscreenWindow class so I could trap events. 
> > Following the show_all(), I see signal_realize, and I see signal_map, 
> > but (contrary to the documentation: "The signal_map_event() signal 
> > will be emitted when the widget's window is mapped. A window is 
> > mapped when it becomes visible on the screen.") I never see 
> > signal_map_event, which is the one that would tell me when to call 
> > get_pixbuf().
> >
> > ???
> >
> > Phil
> >
> > On 09/03/2014 01:46 AM, Kjell Ahlstedt wrote:
> > > Den 2014-09-02 01:23, Phil Wolff skrev:
> > > > Can anybody tell me why this code returns a properly sized Pixbuf 
> > > > with no image data?
> > > When Gtk::OffscreenWindow::get_pixbuf() is called in Test::Test, the 
> > > OffscreenWindow has not yet been drawn. Try my modified version of 
> > > your code. When it's started, the window is empty. If you press a 
> > > mouse button in the window, Test::on_button_press_event() is called, 
> > > and the label's text is shown.
> > >
> > > Kjell