## GtkBox

GtkBox — Base class for box containers

## Synopsis

    #include <gtk/gtk.h>

    struct              GtkBox;
    GtkWidget *         gtk_box_new                         (GtkOrientation orientation,
                                                             gint spacing);
    void                gtk_box_pack_start                  (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding);
    void                gtk_box_pack_end                    (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding);
    gboolean            gtk_box_get_homogeneous             (GtkBox *box);
    void                gtk_box_set_homogeneous             (GtkBox *box,
                                                             gboolean homogeneous);
    gint                gtk_box_get_spacing                 (GtkBox *box);
    void                gtk_box_set_spacing                 (GtkBox *box,
                                                             gint spacing);
    void                gtk_box_reorder_child               (GtkBox *box,
                                                             GtkWidget *child,
                                                             gint position);
    void                gtk_box_query_child_packing         (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean *expand,
                                                             gboolean *fill,
                                                             guint *padding,
                                                             GtkPackType *pack_type);
    void                gtk_box_set_child_packing           (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding,
                                                             GtkPackType pack_type);

## Object Hierarchy

      GObject
       +----GInitiallyUnowned
             +----GtkWidget
                   +----GtkContainer
                         +----GtkBox
                               +----GtkAppChooserWidget
                               +----GtkButtonBox
                               +----GtkVBox
                               +----GtkHBox

## Implemented Interfaces

GtkBox implements AtkImplementorIface, GtkBuildable and GtkOrientable.

## Properties

      "homogeneous"              gboolean              : Read / Write
      "spacing"                  gint                  : Read / Write

## Child Properties

      "expand"                   gboolean              : Read / Write
      "fill"                     gboolean              : Read / Write
      "pack-type"                GtkPackType           : Read / Write
      "padding"                  guint                 : Read / Write
      "position"                 gint                  : Read / Write

## Description

GtkBox is an widget which encapsulates functionality for a particular kind of container, one that organizes a variable number of widgets into a rectangular area. GtkBox has a number of derived classes, e.g. GtkHBox and GtkVBox.

The rectangular area of a GtkBox is organized into either a single row or a single column of child widgets depending upon whether the box is of type GtkHBox or GtkVBox, respectively. Thus, all children of a GtkBox are allocated one dimension in common, which is the height of a row, or the width of a column.

GtkBox uses a notion of packing. Packing refers to adding widgets with reference to a particular position in a GtkContainer. For a GtkBox, there are two reference positions: the start and the end of the box. For a GtkVBox, the start is defined as the top of the box and the end is defined as the bottom. For a GtkHBox the start is defined as the left side and the end is defined as the right side.

Use repeated calls to `gtk_box_pack_start()` to pack widgets into a GtkBox from start to end. Use `gtk_box_pack_end()` to add widgets from end to start. You may intersperse these calls and add widgets from both ends of the same GtkBox.

Because GtkBox is a GtkContainer, you may also use `gtk_container_add()` to insert widgets into the box, and they will be packed with the default values for "expand" and "fill". Use `gtk_container_remove()` to remove widgets from the GtkBox.

Use `gtk_box_set_homogeneous()` to specify whether or not all children of the GtkBox are forced to get the same amount of space.

Use `gtk_box_set_spacing()` to determine how much space will be minimally placed between all children in the GtkBox. Note that spacing is added between the children, while padding added by `gtk_box_pack_start()` or `gtk_box_pack_end()` is added on either side of the widget it belongs to.

Use `gtk_box_reorder_child()` to move a GtkBox child to a different place in the box.

Use `gtk_box_set_child_packing()` to reset the "expand", "fill" and "padding" child properties. Use `gtk_box_query_child_packing()` to query these fields.

### Note

Note that a single-row or single-column GtkGrid provides exactly the same functionality as GtkBox.

## Details

### struct GtkBox

    struct GtkBox;

### gtk_box_new ()

    GtkWidget *         gtk_box_new                         (GtkOrientation orientation,
                                                             gint spacing);

Creates a new GtkBox.

`orientation` : | the box's orientation.
`spacing` : | the number of pixels to place by default between children.
Returns : | a new GtkBox.

Since 3.0

### gtk_box_pack_start ()

    void                gtk_box_pack_start                  (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding);

Adds `child` to `box`, packed with reference to the start of `box`. The `child` is packed after any other child packed with reference to the start of `box`.

`box` : | a GtkBox
`child` : | the GtkWidget to be added to `box`
`expand` : | `TRUE` if the new child is to be given extra space allocated to `box`. The extra space will be divided evenly between all children that use this option
`fill` : | `TRUE` if space given to `child` by the `expand` option is actually allocated to `child`, rather than just padding it. This parameter has no effect if `expand` is set to `FALSE`. A child is always allocated the full height of a GtkHBox and the full width of a GtkVBox. This option affects the other dimension
`padding` : | extra space in pixels to put between this child and its neighbors, over and above the global amount specified by "spacing" property. If `child` is a widget at one of the reference ends of `box`, then `padding` pixels are also put between `child` and the reference edge of `box`

### gtk_box_pack_end ()

    void                gtk_box_pack_end                    (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding);

Adds `child` to `box`, packed with reference to the end of `box`. The `child` is packed after (away from end of) any other child packed with reference to the end of `box`.

`box` : | a GtkBox
`child` : | the GtkWidget to be added to `box`
`expand` : | `TRUE` if the new child is to be given extra space allocated to `box`. The extra space will be divided evenly between all children of `box` that use this option
`fill` : | `TRUE` if space given to `child` by the `expand` option is actually allocated to `child`, rather than just padding it. This parameter has no effect if `expand` is set to `FALSE`. A child is always allocated the full height of a GtkHBox and the full width of a GtkVBox. This option affects the other dimension
`padding` : | extra space in pixels to put between this child and its neighbors, over and above the global amount specified by "spacing" property. If `child` is a widget at one of the reference ends of `box`, then `padding` pixels are also put between `child` and the reference edge of `box`

### gtk_box_get_homogeneous ()

    gboolean            gtk_box_get_homogeneous             (GtkBox *box);

Returns whether the box is homogeneous (all children are the same size). See `gtk_box_set_homogeneous()`.

`box` : | a GtkBox
Returns : | `TRUE` if the box is homogeneous.

### gtk_box_set_homogeneous ()

    void                gtk_box_set_homogeneous             (GtkBox *box,
                                                             gboolean homogeneous);

Sets the "homogeneous" property of `box`, controlling whether or not all children of `box` are given equal space in the box.

`box` : | a GtkBox
`homogeneous` : | a boolean value, `TRUE` to create equal allotments, `FALSE` for variable allotments

### gtk_box_get_spacing ()

    gint                gtk_box_get_spacing                 (GtkBox *box);

Gets the value set by `gtk_box_set_spacing()`.

`box` : | a GtkBox
Returns : | spacing between children

### gtk_box_set_spacing ()

    void                gtk_box_set_spacing                 (GtkBox *box,
                                                             gint spacing);

Sets the "spacing" property of `box`, which is the number of pixels to place between children of `box`.

`box` : | a GtkBox
`spacing` : | the number of pixels to put between children

### gtk_box_reorder_child ()

    void                gtk_box_reorder_child               (GtkBox *box,
                                                             GtkWidget *child,
                                                             gint position);

Moves `child` to a new `position` in the list of `box` children. The list is the `children` field of GtkBox, and contains both widgets packed GTK_PACK_START as well as widgets packed GTK_PACK_END, in the order that these widgets were added to `box`.

A widget's position in the `box` children list determines where the widget is packed into `box`. A child widget at some position in the list will be packed just after all other widgets of the same packing type that appear earlier in the list.

`box` : | a GtkBox
`child` : | the GtkWidget to move
`position` : | the new position for `child` in the list of children of `box`, starting from 0. If negative, indicates the end of the list

### gtk_box_query_child_packing ()

    void                gtk_box_query_child_packing         (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean *expand,
                                                             gboolean *fill,
                                                             guint *padding,
                                                             GtkPackType *pack_type);

Obtains information about how `child` is packed into `box`.

`box` : | a GtkBox
`child` : | the GtkWidget of the child to query
`expand` : | pointer to return location for "expand" child property. [out]
`fill` : | pointer to return location for "fill" child property. [out]
`padding` : | pointer to return location for "padding" child property. [out]
`pack_type` : | pointer to return location for "pack-type" child property. [out]

### gtk_box_set_child_packing ()

    void                gtk_box_set_child_packing           (GtkBox *box,
                                                             GtkWidget *child,
                                                             gboolean expand,
                                                             gboolean fill,
                                                             guint padding,
                                                             GtkPackType pack_type);

Sets the way `child` is packed into `box`.

`box` : | a GtkBox
`child` : | the GtkWidget of the child to set
`expand` : | the new value of the "expand" child property
`fill` : | the new value of the "fill" child property
`padding` : | the new value of the "padding" child property
`pack_type` : | the new value of the "pack-type" child property

## Property Details

### The `"homogeneous"` property

      "homogeneous"              gboolean              : Read / Write

Whether the children should all be the same size.

Default value: FALSE

### The `"spacing"` property

      "spacing"                  gint                  : Read / Write

The amount of space between children.

Allowed values: >= 0

Default value: 0

## Child Property Details

### The `"expand"` child property

      "expand"                   gboolean              : Read / Write

Whether the child should receive extra space when the parent grows.

Note that the default value for this property is `FALSE` for GtkBox, but GtkHBox, GtkVBox and other subclasses use the old default of `TRUE`.

Note that the "halign", "valign", "hexpand" and "vexpand" properties are the preferred way to influence child size allocation in containers.

Default value: FALSE

### The `"fill"` child property

      "fill"                     gboolean              : Read / Write

Whether the child should receive extra space when the parent grows.

Note that the "halign", "valign", "hexpand" and "vexpand" properties are the preferred way to influence child size allocation in containers.

Default value: TRUE

### The `"pack-type"` child property

      "pack-type"                GtkPackType           : Read / Write

A GtkPackType indicating whether the child is packed with reference to the start or end of the parent.

Default value: GTK_PACK_START

### The `"padding"` child property

      "padding"                  guint                 : Read / Write

Extra space to put between the child and its neighbors, in pixels.

Allowed values: <= G_MAXINT

Default value: 0

### The `"position"` child property

      "position"                 gint                  : Read / Write

The index of the child in the parent.

Allowed values: >= G_MAXULONG

Default value: 0

## See Also

GtkHBox, GtkVBox, GtkFrame, GtkTable, GtkLayout