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void | add | Run First |
void | check-resize | Run Last |
void | remove | Run First |
void | set-focus-child | Run First |
GObject ╰── GInitiallyUnowned ╰── GtkWidget ╰── GtkContainer ├── GtkBin ├── GtkActionBar ├── GtkBox ├── GtkExpander ├── GtkFixed ├── GtkFlowBox ├── GtkGrid ├── GtkHeaderBar ├── GtkIconView ├── GtkLayout ├── GtkListBox ├── GtkMenuShell ├── GtkNotebook ├── GtkPaned ├── GtkStack ├── GtkTextView ├── GtkToolbar ╰── GtkTreeView
A GTK+ user interface is constructed by nesting widgets inside widgets. Container widgets are the inner nodes in the resulting tree of widgets: they contain other widgets. So, for example, you might have a GtkWindow containing a GtkFrame containing a GtkLabel. If you wanted an image instead of a textual label inside the frame, you might replace the GtkLabel widget with a GtkImage widget.
There are two major kinds of container widgets in GTK+. Both are subclasses of the abstract GtkContainer base class.
The first type of container widget has a single child widget and derives from GtkBin. These containers are decorators, which add some kind of functionality to the child. For example, a GtkButton makes its child into a clickable button; a GtkFrame draws a frame around its child and a GtkWindow places its child widget inside a top-level window.
The second type of container can have more than one child; its purpose is to manage layout. This means that these containers assign sizes and positions to their children. For example, a horizontal GtkBox arranges its children in a horizontal row, and a GtkGrid arranges the widgets it contains in a two-dimensional grid.
For implementations of GtkContainer the virtual method GtkContainerClass.forall()
is always required, since it's used for drawing and other internal operations
on the children.
If the GtkContainer implementation expect to have non internal children
it's needed to implement both GtkContainerClass.add()
and GtkContainerClass.remove()
.
If the GtkContainer implementation has internal children, they should be added
with gtk_widget_set_parent()
on init()
and removed with gtk_widget_unparent()
in the GtkWidgetClass.destroy()
implementation.
See more about implementing custom widgets at https://wiki.gnome.org/HowDoI/CustomWidgets
GtkContainer introduces child properties. These are object properties that are not specific to either the container or the contained widget, but rather to their relation. Typical examples of child properties are the position or pack-type of a widget which is contained in a GtkBox.
Use gtk_container_class_install_child_property()
to install child properties
for a container class and gtk_container_class_find_child_property()
or
gtk_container_class_list_child_properties()
to get information about existing
child properties.
To set the value of a child property, use gtk_container_child_set_property()
,
gtk_container_child_set()
or gtk_container_child_set_valist()
.
To obtain the value of a child property, use
gtk_container_child_get_property()
, gtk_container_child_get()
or
gtk_container_child_get_valist()
. To emit notification about child property
changes, use gtk_widget_child_notify()
.
The GtkContainer implementation of the GtkBuildable interface supports a <packing> element for children, which can contain multiple <property> elements that specify child properties for the child.
Child properties can also be marked as translatable using the same “translatable”, “comments” and “context” attributes that are used for regular properties.
Containers can have a <focus-chain> element containing multiple <widget> elements, one for each child that should be added to the focus chain. The ”name” attribute gives the id of the widget.
An example of these properties in UI definitions:
<object class="GtkBox"> <child> <object class="GtkEntry" id="entry1"/> <packing> <property name="pack-type">start</property> </packing> </child> <child> <object class="GtkEntry" id="entry2"/> </child> <focus-chain> <widget name="entry1"/> <widget name="entry2"/> </focus-chain> </object>
#define GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID(object, property_id, pspec)
This macro should be used to emit a standard warning about unexpected
properties in set_child_property()
and get_child_property()
implementations.
void gtk_container_add (GtkContainer *container
,GtkWidget *widget
);
Adds widget
to container
. Typically used for simple containers
such as GtkWindow, GtkFrame, or GtkButton; for more complicated
layout containers such as GtkBox or GtkGrid, this function will
pick default packing parameters that may not be correct. So
consider functions such as gtk_box_pack_start()
and
gtk_grid_attach()
as an alternative to gtk_container_add()
in
those cases. A widget may be added to only one container at a time;
you can’t place the same widget inside two different containers.
Note that some containers, such as GtkScrolledWindow or GtkListBox, may add intermediate children between the added widget and the container.
void gtk_container_remove (GtkContainer *container
,GtkWidget *widget
);
Removes widget
from container
. widget
must be inside container
.
Note that container
will own a reference to widget
, and that this
may be the last reference held; so removing a widget from its
container can destroy that widget. If you want to use widget
again, you need to add a reference to it before removing it from
a container, using g_object_ref()
. If you don’t want to use widget
again it’s usually more efficient to simply destroy it directly
using gtk_widget_destroy()
since this will remove it from the
container and help break any circular reference count cycles.
void gtk_container_add_with_properties (GtkContainer *container
,GtkWidget *widget
,const gchar *first_prop_name
,...
);
Adds widget
to container
, setting child properties at the same time.
See gtk_container_add()
and gtk_container_child_set()
for more details.
void gtk_container_foreach (GtkContainer *container
,GtkCallback callback
,gpointer callback_data
);
Invokes callback
on each non-internal child of container
.
See gtk_container_forall()
for details on what constitutes
an “internal” child. For all practical purposes, this function
should iterate over precisely those child widgets that were
added to the container by the application with explicit add()
calls.
Most applications should use gtk_container_foreach()
,
rather than gtk_container_forall()
.
GList *
gtk_container_get_children (GtkContainer *container
);
Returns the container’s non-internal children. See
gtk_container_forall()
for details on what constitutes an "internal" child.
GtkWidgetPath * gtk_container_get_path_for_child (GtkContainer *container
,GtkWidget *child
);
Returns a newly created widget path representing all the widget hierarchy
from the toplevel down to and including child
.
GtkAdjustment *
gtk_container_get_focus_vadjustment (GtkContainer *container
);
Retrieves the vertical focus adjustment for the container. See
gtk_container_set_focus_vadjustment()
.
void gtk_container_set_focus_vadjustment (GtkContainer *container
,GtkAdjustment *adjustment
);
Hooks up an adjustment to focus handling in a container, so when a
child of the container is focused, the adjustment is scrolled to
show that widget. This function sets the vertical alignment. See
gtk_scrolled_window_get_vadjustment()
for a typical way of obtaining
the adjustment and gtk_container_set_focus_hadjustment()
for setting
the horizontal adjustment.
The adjustments have to be in pixel units and in the same coordinate system as the allocation for immediate children of the container.
GtkAdjustment *
gtk_container_get_focus_hadjustment (GtkContainer *container
);
Retrieves the horizontal focus adjustment for the container. See
gtk_container_set_focus_hadjustment()
.
void gtk_container_set_focus_hadjustment (GtkContainer *container
,GtkAdjustment *adjustment
);
Hooks up an adjustment to focus handling in a container, so when a child
of the container is focused, the adjustment is scrolled to show that
widget. This function sets the horizontal alignment.
See gtk_scrolled_window_get_hadjustment()
for a typical way of obtaining
the adjustment and gtk_container_set_focus_vadjustment()
for setting
the vertical adjustment.
The adjustments have to be in pixel units and in the same coordinate system as the allocation for immediate children of the container.
GType
gtk_container_child_type (GtkContainer *container
);
Returns the type of the children supported by the container.
Note that this may return G_TYPE_NONE
to indicate that no more
children can be added, e.g. for a GtkPaned which already has two
children.
void gtk_container_child_get (GtkContainer *container
,GtkWidget *child
,const gchar *first_prop_name
,...
);
Gets the values of one or more child properties for child
and container
.
void gtk_container_child_set (GtkContainer *container
,GtkWidget *child
,const gchar *first_prop_name
,...
);
Sets one or more child properties for child
and container
.
void gtk_container_child_get_property (GtkContainer *container
,GtkWidget *child
,const gchar *property_name
,GValue *value
);
Gets the value of a child property for child
and container
.
void gtk_container_child_set_property (GtkContainer *container
,GtkWidget *child
,const gchar *property_name
,const GValue *value
);
Sets a child property for child
and container
.
void gtk_container_child_get_valist (GtkContainer *container
,GtkWidget *child
,const gchar *first_property_name
,va_list var_args
);
Gets the values of one or more child properties for child
and container
.
void gtk_container_child_set_valist (GtkContainer *container
,GtkWidget *child
,const gchar *first_property_name
,va_list var_args
);
Sets one or more child properties for child
and container
.
void gtk_container_child_notify (GtkContainer *container
,GtkWidget *child
,const gchar *child_property
);
Emits a “child-notify” signal for the
child property
child_property
on the child.
This is an analogue of g_object_notify()
for child properties.
Also see gtk_widget_child_notify()
.
container |
the GtkContainer |
|
child |
the child widget |
|
child_property |
the name of a child property installed on
the class of |
void gtk_container_child_notify_by_pspec (GtkContainer *container
,GtkWidget *child
,GParamSpec *pspec
);
Emits a “child-notify” signal for the
child property specified by
pspec
on the child.
This is an analogue of g_object_notify_by_pspec()
for child properties.
container |
the GtkContainer |
|
child |
the child widget |
|
pspec |
the GParamSpec of a child property instealled on
the class of |
void gtk_container_forall (GtkContainer *container
,GtkCallback callback
,gpointer callback_data
);
Invokes callback
on each direct child of container
, including
children that are considered “internal” (implementation details
of the container). “Internal” children generally weren’t added
by the user of the container, but were added by the container
implementation itself.
Most applications should use gtk_container_foreach()
, rather
than gtk_container_forall()
.
[virtual forall]
gboolean gtk_container_get_focus_chain (GtkContainer *container
,GList **focusable_widgets
);
Retrieves the focus chain of the container, if one has been
set explicitly. If no focus chain has been explicitly
set, GTK+ computes the focus chain based on the positions
of the children. In that case, GTK+ stores NULL
in
focusable_widgets
and returns FALSE
.
container |
||
focusable_widgets |
location
to store the focus chain of the
container, or |
[element-type GtkWidget][out][transfer container] |
void gtk_container_set_focus_chain (GtkContainer *container
,GList *focusable_widgets
);
Sets a focus chain, overriding the one computed automatically by GTK+.
In principle each widget in the chain should be a descendant of the container, but this is not enforced by this method, since it’s allowed to set the focus chain before you pack the widgets, or have a widget in the chain that isn’t always packed. The necessary checks are done when the focus chain is actually traversed.
void
gtk_container_unset_focus_chain (GtkContainer *container
);
Removes a focus chain explicitly set with gtk_container_set_focus_chain()
.
GParamSpec * gtk_container_class_find_child_property (GObjectClass *cclass
,const gchar *property_name
);
Finds a child property of a container class by name.
void gtk_container_class_install_child_property (GtkContainerClass *cclass
,guint property_id
,GParamSpec *pspec
);
Installs a child property on a container class.
void gtk_container_class_install_child_properties (GtkContainerClass *cclass
,guint n_pspecs
,GParamSpec **pspecs
);
Installs child properties on a container class.
GParamSpec ** gtk_container_class_list_child_properties (GObjectClass *cclass
,guint *n_properties
);
Returns all child properties of a container class.
struct GtkContainerClass { GtkWidgetClass parent_class; void (*add) (GtkContainer *container, GtkWidget *widget); void (*remove) (GtkContainer *container, GtkWidget *widget); void (*check_resize) (GtkContainer *container); void (*forall) (GtkContainer *container, GtkCallback callback, gpointer callback_data); void (*set_focus_child) (GtkContainer *container, GtkWidget *child); GType (*child_type) (GtkContainer *container); void (*set_child_property) (GtkContainer *container, GtkWidget *child, guint property_id, const GValue *value, GParamSpec *pspec); void (*get_child_property) (GtkContainer *container, GtkWidget *child, guint property_id, GValue *value, GParamSpec *pspec); GtkWidgetPath * (*get_path_for_child) (GtkContainer *container, GtkWidget *child); };
Base class for containers.
Signal emitted when a widget is added to container. |
||
Signal emitted when a widget is removed from container. |
||
Signal emitted when a size recalculation is needed. |
||
Invokes callback on each child of container. |
||
Sets the focused child of container. |
||
Returns the type of the children supported by the container. |
||
Set a property on a child of container. |
||
Get a property from a child of container. |
||
Get path representing entire widget hierarchy
from the toplevel down to and including |
“add”
signalvoid user_function (GtkContainer *container, GtkWidget *widget, gpointer user_data)
Flags: Run First
“check-resize”
signalvoid user_function (GtkContainer *container, gpointer user_data)
Flags: Run Last
“remove”
signalvoid user_function (GtkContainer *container, GtkWidget *widget, gpointer user_data)
Flags: Run First
“set-focus-child”
signalvoid user_function (GtkContainer *container, GtkWidget *widget, gpointer user_data)
Flags: Run First