However, there are some additional things to keep in mind.
First, you can use either
GtkStatusbar or GnomeAppBar
as a statusbar. Second, you probably want to use the
statusbar to display help about menu items as the user
moves over them; Gnome comes with convenience functions to
do this. This section describes the two status bar widgets;
the section called Online
Help discusses using the statusbar to display menu
There's no real reason to prefer
GtkStatusbar; they simply have different APIs. The
GnomeAppBar widget was written
later, with several goals in mind:
To simplify the
To support an optional progress bar next to the
status bar, similar to Netscape's.
Eventual support for "interactive" use in the
tradition of the Emacs "minibuffer." This is
unfinished in Gnome 1.0, however.
To create a GnomeAppBar, use
gnome_appbar_new() (Figure 6). The constructor
lets you configure the capabilities of GnomeAppBar: it can have a progress bar
(or not), have a status text area (or not), and be
interactive (or not). You must have either a status text
area or a progress bar.
GnomePreferencesType is a kind of extended boolean
GNOME_PREFERENCES_NEVER means the bar is never
GNOME_PREFERENCES_USER means the bar is
interactive if the user has activated that feature as
a Gnome-wide preference.
GNOME_PREFERENCES_ALWAYS means the bar is
In Gnome 1.0, interactivity is incompletely implemented;
GNOME_PREFERENCES_ALWAYS. There are some
experimental Gnome functions which provide an abstraction
of certain user interactions, allowing users to choose
between dialogs and the Emacs-style minibuffer approach;
when these are more developed,
GNOME_PREFERENCES_USER will make sense even if you
don't explicitly use the interactivity. So GNOME_PREFERENCES_USER is the
GtkWidget* gnome_appbar_new(gboolean has_progress, gboolean
Figure 6. GnomeAppBar
Using a GnomeAppBar is
simple. The progress-bar element presents a GtkProgress interface; to use it, simply
extract the GtkProgress with
gnome_appbar_get_progress() (Figure 7) and use
the GtkProgress functions.
Note that you should not make assumptions about the
particular subclass of
GtkProgress; in particular, do not cast it to GtkProgressBar.
Figure 7. Extracting
Status texts are stored in a stack; when the bar is
refreshed, the top item of the stack is displayed. The
bar is refreshed anytime you manipulate the stack. So
pushing some text onto the status stack will display that
There are two other sources for the status text. You can
set some "default" text; this is displayed if the stack
is empty. The default default text is "". You can also set the status text
without changing the stack; this "transient" text is
immediately displayed, but not stored. On the next
refresh (the next time you push, pop, or set the
default), the text disappears forever, replaced by the
top of the stack.
Figure 8 lists the
functions to manipulate the status text. gnome_appbar_set_status() is used to set
the transient status text;
gnome_appbar_refresh() forces a refresh without
changing the stack---this is useful to be sure any
transient text has been cleared. The other functions
should be obvious.
Note that you can use the
GnomeAppBar as a simple label---one message at a
time, always replacing the previous message---just stick
to either setting the default or setting the transient
text, and never use the stack.
gnome_appbar_set_status(GnomeAppBar* appbar, const gchar*
gnome_appbar_set_default(GnomeAppBar* appbar, const gchar*
Figure 8. Setting