Re: displaying an image

[Robert Pearce <rob bdt-home demon co uk>]

Hi Harry,

On Thu, 23 Dec 2010 18:39:16 +0000 you wrote:
> 
> Bear in mind I have no experience with ::Inage, but ask why the pointer?
> Gtk::Image iconImage("Positive-48.png");    // this should work too I think

That depends entirely on the context. If you were to write, say:

MyWindow::make_display(void)
{
    Gtk::Image iconImage("Positive-48.png");
    vertical_box->pack_start ( iconImage, Gtk::PACK_SHRINK, 0);
}

then it would absolutely NOT work. The image thus created is a
temporary object allocated on the stack frame of the make_display
method, and ceases to exist as soon as that method completes. As this
will ALWAYS be before the image is actually drawn (since that happens
in the Gtk::mainloop iteration) the result will be no image on the
screen.

Cheers,
Rob