Re: why gtk_label_set_attributes not change anything?

[Owen Taylor <otaylor redhat com>]

"chen.shengqi" <chen shengqi connet com tw> writes:

> Dear sirs:
>     I'm using gnome 2.0 on solaris, the follow code did not change any thing, the label is always black 
> font on screen. What's the correct method to change property of GtkLabel? thanks.
>
>  PangoAttribute *pa;
>  PangoAttrList *tmpattr,*oldattr=NULL;
>  guint16 r,g,b;
>  int rgb;
>  GtkLabel *DestLabel=NULL;
>  tmpattr = pango_attr_list_new();
>  rgb = COLORS[2];
>    r=((rgb>>16)&0x000000FF)*255;

Note that you should use 257 here, not 255.

>    g=((rgb>>8)&0x000000FF)*255;
>    b=((rgb)&0x000000FF)*255;
>  pa = pango_attr_foreground_new(r,g,b);

When you create an attribute, you need to set attr->start_index
and attr->end_index, or it won't apply to any characters.

>  pango_attr_list_insert(tmpattr,pa);
>    rgb = COLORS[9];
>    r=((rgb>>16)&0x000000FF)*255;
>    g=((rgb>>8)&0x000000FF)*255;
>    b=((rgb)&0x000000FF)*255;
>    pa = pango_attr_background_new(r,g,b);
>    pango_attr_list_insert(tmpattr,pa);
>  
>  DestLabel = (GtkLabel *)lookup_widget(drawingcanvas->parent,
>                                         "sware_work_name");
>  if (DestLabel==NULL) return;
>  gtk_label_set_label(DestLabel,"hello");
>  if (DestLabel)
>  {
>   oldattr = gtk_label_get_attributes(DestLabel);
>   if (oldattr) pango_attr_list_unref(oldattr);
>   else debug(1)("no oldattr \n");
>   gtk_label_set_attributes(DestLabel,tmpattr);
>  }

You could make things easier by yourself by just doing:

 gtk_label_set_attributes (DestLabel, tmpattr);
 pango_attr_list_unref (tmpattr)

Then you can just forget about attribute list and it
will be freed with the label or when you set a new
attribute list.

You might want to consider using gtk_widget_modify_fg()
gtk_widget_modify_bg() instead ... they are easier to use.
But note that the GtkLabel widget doesn't have a background
so you'll have to put it inside a different widget (like
a GtkEventBox) and set the backgrourd on that.

Regards,
                                        Owen