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GtkContainer

GtkContainer — Base class for widgets which contain other widgets

Functions

#define GTK_IS_RESIZE_CONTAINER()
#define GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID()
void gtk_container_add ()
void gtk_container_remove ()
void gtk_container_add_with_properties ()
GtkResizeMode gtk_container_get_resize_mode ()
void gtk_container_set_resize_mode ()
void gtk_container_check_resize ()
void gtk_container_foreach ()
void gtk_container_foreach_full ()
GList * gtk_container_get_children ()
void gtk_container_set_reallocate_redraws ()
GtkWidget * gtk_container_get_focus_child ()
void gtk_container_set_focus_child ()
GtkAdjustment * gtk_container_get_focus_vadjustment ()
void gtk_container_set_focus_vadjustment ()
GtkAdjustment * gtk_container_get_focus_hadjustment ()
void gtk_container_set_focus_hadjustment ()
void gtk_container_resize_children ()
GType gtk_container_child_type ()
void gtk_container_child_get ()
void gtk_container_child_set ()
void gtk_container_child_get_property ()
void gtk_container_child_set_property ()
void gtk_container_child_get_valist ()
void gtk_container_child_set_valist ()
void gtk_container_forall ()
guint gtk_container_get_border_width ()
void gtk_container_set_border_width ()
void gtk_container_propagate_expose ()
gboolean gtk_container_get_focus_chain ()
void gtk_container_set_focus_chain ()
void gtk_container_unset_focus_chain ()
GParamSpec * gtk_container_class_find_child_property ()
void gtk_container_class_install_child_property ()
GParamSpec ** gtk_container_class_list_child_properties ()

Properties

guint border-width Read / Write
GtkWidget * child Write
GtkResizeMode resize-mode Read / Write

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GtkObject
            ╰── GtkWidget
                ╰── GtkContainer
                    ├── GtkBin
                    ├── GtkBox
                    ├── GtkCList
                    ├── GtkFixed
                    ├── GtkPaned
                    ├── GtkIconView
                    ├── GtkLayout
                    ├── GtkList
                    ├── GtkMenuShell
                    ├── GtkNotebook
                    ├── GtkSocket
                    ├── GtkTable
                    ├── GtkTextView
                    ├── GtkToolbar
                    ├── GtkToolItemGroup
                    ├── GtkToolPalette
                    ├── GtkTree
                    ╰── GtkTreeView

Implemented Interfaces

GtkContainer implements AtkImplementorIface and GtkBuildable.

Includes

#include <gtk/gtk.h>

Description

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 GtkHBox arranges its children in a horizontal row, and a GtkTable arranges the widgets it contains in a two-dimensional grid.

To fulfill its task, a layout container must negotiate the size requirements with its parent and its children. This negotiation is carried out in two phases, size requisition and size allocation.

Size Requisition

The size requisition of a widget is it's desired width and height. This is represented by a GtkRequisition.

How a widget determines its desired size depends on the widget. A GtkLabel, for example, requests enough space to display all its text. Container widgets generally base their size request on the requisitions of their children.

The size requisition phase of the widget layout process operates top-down. It starts at a top-level widget, typically a GtkWindow. The top-level widget asks its child for its size requisition by calling gtk_widget_size_request(). To determine its requisition, the child asks its own children for their requisitions and so on. Finally, the top-level widget will get a requisition back from its child.


Size Allocation

When the top-level widget has determined how much space its child would like to have, the second phase of the size negotiation, size allocation, begins. Depending on its configuration (see gtk_window_set_resizable()), the top-level widget may be able to expand in order to satisfy the size request or it may have to ignore the size request and keep its fixed size. It then tells its child widget how much space it gets by calling gtk_widget_size_allocate(). The child widget divides the space among its children and tells each child how much space it got, and so on. Under normal circumstances, a GtkWindow will always give its child the amount of space the child requested.

A child's size allocation is represented by a GtkAllocation. This struct contains not only a width and height, but also a position (i.e. X and Y coordinates), so that containers can tell their children not only how much space they have gotten, but also where they are positioned inside the space available to the container.

Widgets are required to honor the size allocation they receive; a size request is only a request, and widgets must be able to cope with any size.


Child properties

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().


GtkContainer as GtkBuildable

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.

Example 44. Child properties in UI definitions

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<object class="GtkVBox">
  <child>
    <object class="GtkLabel"/>
    <packing>
      <property name="pack-type">start</property>
    </packing>
  </child>
</object>

Since 2.16, child properties can also be marked as translatable using the same "translatable", "comments" and "context" attributes that are used for regular properties.

Functions

GTK_IS_RESIZE_CONTAINER()

#define GTK_IS_RESIZE_CONTAINER(widget) (GTK_IS_CONTAINER (widget) && ((GtkContainer*) (widget))->resize_mode != GTK_RESIZE_PARENT)


GTK_CONTAINER_WARN_INVALID_CHILD_PROPERTY_ID()

#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.

Parameters

object

the GObject on which set_child_property() or get_child_property() was called

 

property_id

the numeric id of the property

 

pspec

the GParamSpec of the property

 

gtk_container_add ()

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 GtkTable, this function will pick default packing parameters that may not be correct. So consider functions such as gtk_box_pack_start() and gtk_table_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.

Parameters

container

a GtkContainer

 

widget

a widget to be placed inside container

 

gtk_container_remove ()

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 while it's not inside 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.

Parameters

container

a GtkContainer

 

widget

a current child of container

 

gtk_container_add_with_properties ()

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.

Parameters

container

a GtkContainer

 

widget

a widget to be placed inside container

 

first_prop_name

the name of the first child property to set

 

gtk_container_get_resize_mode ()

GtkResizeMode
gtk_container_get_resize_mode (GtkContainer *container);

Returns the resize mode for the container. See gtk_container_set_resize_mode().

Parameters

container

a GtkContainer

 

Returns

the current resize mode


gtk_container_set_resize_mode ()

void
gtk_container_set_resize_mode (GtkContainer *container,
                               GtkResizeMode resize_mode);

Sets the resize mode for the container.

The resize mode of a container determines whether a resize request will be passed to the container's parent, queued for later execution or executed immediately.

Parameters

container

a GtkContainer

 

resize_mode

the new resize mode

 

gtk_container_check_resize ()

void
gtk_container_check_resize (GtkContainer *container);


gtk_container_foreach ()

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. Most applications should use gtk_container_foreach(), rather than gtk_container_forall().

Parameters

container

a GtkContainer

 

callback

a callback.

[scope call]

callback_data

callback user data

 

gtk_container_foreach_full ()

void
gtk_container_foreach_full (GtkContainer *container,
                            GtkCallback callback,
                            GtkCallbackMarshal marshal,
                            gpointer callback_data,
                            GDestroyNotify notify);

gtk_container_foreach_full is deprecated and should not be used in newly-written code.

Use gtk_container_foreach() instead.


gtk_container_get_children ()

GList *
gtk_container_get_children (GtkContainer *container);

gtk_container_get_children is deprecated and should not be used in newly-written code.

Returns the container's non-internal children. See gtk_container_forall() for details on what constitutes an "internal" child.

Parameters

container

a GtkContainer

 

Returns

a newly-allocated list of the container's non-internal children.

[element-type GtkWidget][transfer container]


gtk_container_set_reallocate_redraws ()

void
gtk_container_set_reallocate_redraws (GtkContainer *container,
                                      gboolean needs_redraws);

Sets the reallocate_redraws flag of the container to the given value.

Containers requesting reallocation redraws get automatically redrawn if any of their children changed allocation.

Parameters

container

a GtkContainer

 

needs_redraws

the new value for the container's reallocate_redraws flag

 

gtk_container_get_focus_child ()

GtkWidget *
gtk_container_get_focus_child (GtkContainer *container);

Returns the current focus child widget inside container . This is not the currently focused widget. That can be obtained by calling gtk_window_get_focus().

Parameters

container

a GtkContainer

 

Returns

The child widget which will receive the focus inside container when the conatiner is focussed, or NULL if none is set.

[transfer none]

Since: 2.14


gtk_container_set_focus_child ()

void
gtk_container_set_focus_child (GtkContainer *container,
                               GtkWidget *child);

Sets, or unsets if child is NULL, the focused child of container .

This function emits the GtkContainer::set_focus_child signal of container . Implementations of GtkContainer can override the default behaviour by overriding the class closure of this signal.

This is function is mostly meant to be used by widgets. Applications can use gtk_widget_grab_focus() to manualy set the focus to a specific widget.

Parameters

container

a GtkContainer

 

child

a GtkWidget, or NULL.

[allow-none]

gtk_container_get_focus_vadjustment ()

GtkAdjustment *
gtk_container_get_focus_vadjustment (GtkContainer *container);

Retrieves the vertical focus adjustment for the container. See gtk_container_set_focus_vadjustment().

Parameters

container

a GtkContainer

 

Returns

the vertical focus adjustment, or NULL if none has been set.

[transfer none]


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.

Parameters

container

a GtkContainer

 

adjustment

an adjustment which should be adjusted when the focus is moved among the descendents of container

 

gtk_container_get_focus_hadjustment ()

GtkAdjustment *
gtk_container_get_focus_hadjustment (GtkContainer *container);

Retrieves the horizontal focus adjustment for the container. See gtk_container_set_focus_hadjustment().

Parameters

container

a GtkContainer

 

Returns

the horizontal focus adjustment, or NULL if none has been set.

[transfer none]


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.

Parameters

container

a GtkContainer

 

adjustment

an adjustment which should be adjusted when the focus is moved among the descendents of container

 

gtk_container_resize_children ()

void
gtk_container_resize_children (GtkContainer *container);


gtk_container_child_type ()

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.

Parameters

container

a GtkContainer

 

Returns

a GType.


gtk_container_child_get ()

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 .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

first_prop_name

the name of the first property to get

 

gtk_container_child_set ()

void
gtk_container_child_set (GtkContainer *container,
                         GtkWidget *child,
                         const gchar *first_prop_name,
                         ...);

Sets one or more child properties for child and container .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

first_prop_name

the name of the first property to set

 

gtk_container_child_get_property ()

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 .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

property_name

the name of the property to get

 

value

a location to return the value

 

gtk_container_child_set_property ()

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 .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

property_name

the name of the property to set

 

value

the value to set the property to

 

gtk_container_child_get_valist ()

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 .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

first_property_name

the name of the first property to get

 

var_args

return location for the first property, followed optionally by more name/return location pairs, followed by NULL

 

gtk_container_child_set_valist ()

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 .

Parameters

container

a GtkContainer

 

child

a widget which is a child of container

 

first_property_name

the name of the first property to set

 

var_args

a NULL-terminated list of property names and values, starting with first_prop_name

 

gtk_container_forall ()

void
gtk_container_forall (GtkContainer *container,
                      GtkCallback callback,
                      gpointer callback_data);

Invokes callback on each 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().

Parameters

container

a GtkContainer

 

callback

a callback

 

callback_data

callback user data

 

gtk_container_get_border_width ()

guint
gtk_container_get_border_width (GtkContainer *container);

Retrieves the border width of the container. See gtk_container_set_border_width().

Parameters

container

a GtkContainer

 

Returns

the current border width


gtk_container_set_border_width ()

void
gtk_container_set_border_width (GtkContainer *container,
                                guint border_width);

Sets the border width of the container.

The border width of a container is the amount of space to leave around the outside of the container. The only exception to this is GtkWindow; because toplevel windows can't leave space outside, they leave the space inside. The border is added on all sides of the container. To add space to only one side, one approach is to create a GtkAlignment widget, call gtk_widget_set_size_request() to give it a size, and place it on the side of the container as a spacer.

Parameters

container

a GtkContainer

 

border_width

amount of blank space to leave outside the container. Valid values are in the range 0-65535 pixels.

 

gtk_container_propagate_expose ()

void
gtk_container_propagate_expose (GtkContainer *container,
                                GtkWidget *child,
                                GdkEventExpose *event);

When a container receives an expose event, it must send synthetic expose events to all children that don't have their own GdkWindows. This function provides a convenient way of doing this. A container, when it receives an expose event, calls gtk_container_propagate_expose() once for each child, passing in the event the container received.

gtk_container_propagate_expose() takes care of deciding whether an expose event needs to be sent to the child, intersecting the event's area with the child area, and sending the event.

In most cases, a container can simply either simply inherit the “expose” implementation from GtkContainer, or, do some drawing and then chain to the ::expose implementation from GtkContainer.

Note that the ::expose-event signal has been replaced by a ::draw signal in GTK+ 3, and consequently, gtk_container_propagate_expose() has been replaced by gtk_container_propagate_draw(). The GTK+ 3 migration guide for hints on how to port from ::expose-event to ::draw.

Parameters

container

a GtkContainer

 

child

a child of container

 

event

a expose event sent to container

 

gtk_container_get_focus_chain ()

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.

Parameters

container

a GtkContainer

 

focusable_widgets

location to store the focus chain of the container, or NULL. You should free this list using g_list_free() when you are done with it, however no additional reference count is added to the individual widgets in the focus chain.

[element-type GtkWidget][out][transfer container]

Returns

TRUE if the focus chain of the container has been set explicitly.


gtk_container_set_focus_chain ()

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.

Parameters

container

a GtkContainer

 

focusable_widgets

the new focus chain.

[transfer none][element-type GtkWidget]

gtk_container_unset_focus_chain ()

void
gtk_container_unset_focus_chain (GtkContainer *container);

Removes a focus chain explicitly set with gtk_container_set_focus_chain().

Parameters

container

a GtkContainer

 

gtk_container_class_find_child_property ()

GParamSpec *
gtk_container_class_find_child_property
                               (GObjectClass *cclass,
                                const gchar *property_name);

Finds a child property of a container class by name.

Parameters

cclass

a GtkContainerClass.

[type GtkContainerClass]

property_name

the name of the child property to find

 

Returns

the GParamSpec of the child property or NULL if class has no child property with that name.

[transfer none]


gtk_container_class_install_child_property ()

void
gtk_container_class_install_child_property
                               (GtkContainerClass *cclass,
                                guint property_id,
                                GParamSpec *pspec);

Installs a child property on a container class.

Parameters

cclass

a GtkContainerClass

 

property_id

the id for the property

 

pspec

the GParamSpec for the property

 

gtk_container_class_list_child_properties ()

GParamSpec **
gtk_container_class_list_child_properties
                               (GObjectClass *cclass,
                                guint *n_properties);

Returns all child properties of a container class.

Parameters

cclass

a GtkContainerClass.

[type GtkContainerClass]

n_properties

location to return the number of child properties found

 

Returns

a newly allocated NULL-terminated array of GParamSpec*. The array must be freed with g_free().

[array length=n_properties][transfer container]

Types and Values

struct GtkContainer

struct GtkContainer;


gtk_container_border_width

#define gtk_container_border_width		gtk_container_set_border_width

gtk_container_border_width is deprecated and should not be used in newly-written code.

Use gtk_container_set_border_width() instead.

Does the same as gtk_container_set_border_width().


gtk_container_children

#define gtk_container_children gtk_container_get_children

gtk_container_children is deprecated and should not be used in newly-written code.

Use gtk_container_get_children() instead.

Does the same as gtk_container_get_children().

Property Details

The “border-width” property

  “border-width”             guint

The width of the empty border outside the containers children.

Flags: Read / Write

Allowed values: <= 65535

Default value: 0


The “child” property

  “child”                    GtkWidget *

Can be used to add a new child to the container.

Flags: Write


The “resize-mode” property

  “resize-mode”              GtkResizeMode

Specify how resize events are handled.

Flags: Read / Write

Default value: GTK_RESIZE_PARENT

Signal Details

The “add” signal

void
user_function (GtkContainer *container,
               GtkWidget    *widget,
               gpointer      user_data)

Parameters

container

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “check-resize” signal

void
user_function (GtkContainer *container,
               gpointer      user_data)

Parameters

container

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last


The “remove” signal

void
user_function (GtkContainer *container,
               GtkWidget    *widget,
               gpointer      user_data)

Parameters

container

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First


The “set-focus-child” signal

void
user_function (GtkContainer *container,
               GtkWidget    *widget,
               gpointer      user_data)

Parameters

container

the object which received the signal.

 

user_data

user data set when the signal handler was connected.

 

Flags: Run First

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