Widget#

The base class of all widgets. This class should not be be instantiated directly.

Reference#

class toga.widgets.base.Widget(id=None, enabled=True, style=None, factory=None)#

This is the base widget implementation that all widgets in Toga derive from.

It defines the interface for core functionality for children, styling, layout and ownership by specific App and Window.

Apart from the above, this is an abstract implementation which must be made concrete by some platform-specific code for the _apply_layout method.

Parameters:

id (str) – An identifier for this widget.
enabled (bool) – Whether or not interaction with the button is possible, defaults to True.
style – An optional style object. If no style is provided then a new one will be created for the widget.

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.

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.

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

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.

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.

property root#

The root of the tree containing this 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.