Box#

The box is a generic container for widgets, allowing you to construct layouts.

Usage#

A box can be instantiated with no children and the children added later:

import toga

box = toga.Box('box1')

button = toga.Button('Hello world', on_press=button_handler)
box.add(button)

To create boxes within boxes, use the children argument:

import toga

box_a = toga.Box('box_a')
box_b = toga.Box('box_b')

box = toga.Box('box', children=[box_a, box_b])

Box Styling#

Styling of boxes can be done during instantiation of the Box:

import toga
from toga.style import Pack
from toga.style.pack import COLUMN

box = toga.Box(id='box', style=Pack(direction=COLUMN, padding_top=10))

Styles can be also be updated on an existing instance:

import toga
from toga.style import Pack
from toga.style.pack import COLUMN

box = toga.Box(id='box', style=Pack(direction=COLUMN))

box.style.update(padding_top=10)

Reference#

class toga.widgets.box.Box(id=None, style=None, children=None, factory=None)#

This is a Widget that contains other widgets, but has no rendering or interaction of its own.

Parameters:

id (str) – An identifier for this widget.
( (style) – class:~colosseum.CSSNode`): An optional style object. If no style is provided then a new one will be created for the widget.
children (list of Widget) – An optional list of child Widgets that will be in this box.

add(*children)#

Add the provided widgets as children of this widget.

If a node already has a different parent, it will be moved over. This does nothing if a node already is a child of this node.

Raises ValueError if this widget cannot have children.

Parameters:: children – The widgets to add as children of this widget.

property app#

The App to which this widget belongs.

When setting the app for a widget, all children of this widget will be recursively assigned to the same app.

Raises ValueError if the widget is already associated with another app.

property can_have_children#

Determine if the node can have children.

This does not resolve whether there actually are any children; it only confirms whether children are theoretically allowed.

property children#

The children of this node. This always returns a list, even if the node is a leaf and cannot have children.

Returns:: A list of the children for this widget.

property enabled#: Is the widget currently enabled? i.e., can the user interact with the widget?

focus()#: Set this widget to have the current input focus.

property id#: The node identifier. This id can be used to target styling directives.

insert(index, child)#

Insert a widget as a child of this widget.

If the node already has a parent, ownership of the widget will be transferred.

Raises ValueError if this node cannot have children.

Parameters:

index – The position in the list of children where the new widget should be added.
child – The child to insert as a child of this node.

property parent#

The parent of this node.

Returns:: The parent of this node. Returns None if this node is the root node.

refresh()#: Refresh the layout and appearance of the tree this node is contained in.

refresh_sublayouts()#

remove(*children)#

Remove the provided widgets as children of this node.

This does nothing if a given node is not a child of this node.

Raises ValueError if this node is a leaf, and cannot have children.

Parameters:: children – The child nodes to remove.

property root#

The root of the tree containing this node.

Returns:: The root node. Returns self if this node is the root node.

property tab_index#: The position of the widget in the focus chain for the window.

property window#

The window to which this widget belongs.

When setting the window for a widget, all children of this widget will be recursively assigned to the same window.