A GtkWidget instance looks
like this:
typedef struct _GtkWidget GtkWidget;
struct _GtkWidget
{
GtkObject object;
guint16 private_flags;
guint8 state;
guint8 saved_state;
gchar *name;
GtkStyle *style;
GtkRequisition requisition;
GtkAllocation allocation;
GdkWindow *window;
GtkWidget *parent;
};
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The private_flags, state, and saved_state fields should all be
accessed with macros, if at all. Some of these macros
will come up as we discuss widget implementations. The
state field stores the
widget's state as described in the section called Widget
States in the chapter called GTK+ Basics.
saved_state is used to
save the widget's previous state when the current state
is GTK_STATE_INSENSITIVE;
when the widget is re-sensitized, its original state is
restored. As the
section called Widget States in the chapter called
GTK+ Basics explains, the current state can be
accessed with the
GTK_WIDGET_STATE() macro.
The name of a widget is
used in a gtkrc file to group
widgets together for customization purposes. By default,
the name of a widget is the type name registered with the
object system (in GTK+, this type name is always the name
of the instance struct, such as
"GtkLabel"). Particular widgets can be given a
different name with
gtk_widget_set_name(); for example, if you want a
particular label to appear in a different font, you can
give it a name like "FunkyFontLabel" and then specify a
different font for that name in a
gtkrc shipped with your application.
The requisition and allocation fields store the
last requested and allocated size of the widget,
respectively. the section called
Size Negotiation will have more to say about
this.
The window field stores
the widget's GdkWindow,
or the widget's parent's
GdkWindow if the widget has none. The parent field is a pointer to the
widget's parent container; it will be NULL if the widget is not inside a
container.
