Re: Bring a widget to the foreground

[John Emmas <johne53 tiscali co uk>]

On 2 Jan 2011, at 21:00, jcupitt gmail com wrote:

> On 2 January 2011 15:39, John Emmas <johne53 tiscali co uk> wrote:
> > To be honest, all I'm trying to do is create a button whose label font can be changed on demand.  I've 
> > managed to achieve it by using an empty button with a label on top, except that the label doesn't always 
> > stay on top!
>
> Ah, OK, yes, there's a much simpler technique.
>
> Try something like this:
>
>  txt = "some text to display";
>  font = "sans 12";
>
>  snprintf (button_text, 256,
>     "<span font_desc=\"%s\" size=\"medium\">%s</span>",
>     font, txt);
>  gtk_label_set_markup (
>    GTK_LABEL (gtk_bin_get_child (GTK_BIN (button))),
>    button_text);
>
> Assuming 'button' is a regular gtk button containing a label.

Thanks for the suggestion John.  I needed to modify your code slightly because strictly speaking, I'm using 
gtkmm rather than gtk+ but the basic technique worked.  In fact, once I realised that I could obtain a 
pointer to the button's label object, I found that I could simply call Gtk::Label_modify_font() to modify the 
font too (assuming I had a suitable Pango::FontDescription object).  The best thing though is that I managed 
to get rid of my clumsy composite widget, so I now have a button whose font can be changed on demand PLUS the 
button's label is always visible, exactly as it's supposed to be!  So success all round, I'd say!  However, 
there's a minor problem with both strategies....

Although I can now change the button's label font, the new font seems to be quite transitory and certain 
operations seem to reset it.  For example if (later) I change the label's text (e.g. if it currently says 
"This message" and I change it to say "That message") the font will immediately revert back to whatever it 
was when the button got created.  I could get around this by maintaining a persistent object somewhere that 
described the last font that I set but it would be neater and more intelligent if I could "get" the label's 
current font (immediately prior to changing its text) and then "set" it back to what it should be.

And therein lies the problem....  I can't see any obvious method of retrieving a widget's current font.  
gtk_widget_modify_font() allows me to set a new font but it doesn't return anything that would describe the 
widget's previous font.  Nor does there seem to be any other way of retrieving a widget's current font 
AFAICT.  Am I missing something obvious?

John