Tree#

The tree widget is still under development.

Usage#

import toga

tree = toga.Tree(['Navigate'])

tree.insert(None, None, 'root1')

root2 = tree.insert(None, None, 'root2')

tree.insert(root2, None, 'root2.1')
root2_2 = tree.insert(root2, None, 'root2.2')

tree.insert(root2_2, None, 'root2.2.1')
tree.insert(root2_2, None, 'root2.2.2')
tree.insert(root2_2, None, 'root2.2.3')

Reference#

class toga.widgets.tree.Tree(headings, id=None, style=None, data=None, accessors=None, multiple_select=False, on_select=None, on_double_click=None, factory=None)#

Tree Widget.

Parameters:

headings – The list of headings for the interface.
id – An identifier for this widget.
style – An optional style object. If no style is provided then a new one will be created for the widget.
data –
The data to display in the widget. Can be an instance of TreeSource, a list, dict or tuple with data to display in the tree widget, or a class instance which implements the interface of TreeSource. Entries can be:
- any Python object value with a string representation. This string will be shown in the widget. If value has an attribute icon, instance of (Icon), the icon will be shown in front of the text.
- a tuple (icon, value) where again the string representation of value will be used as text.
accessors – Optional; a list of attributes to access the value in the columns. If not given, the headings will be taken.
multiple_select – Boolean; if True, allows for the selection of multiple rows. Defaults to False.
on_select – A handler to be invoked when the user selects one or multiple rows.
on_double_click – A handler to be invoked when the user double clicks a row.

MIN_HEIGHT = 100#

MIN_WIDTH = 100#

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 data#

The data source of the tree :rtype: dict

Type:: returns

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 multiple_select#: Does the table allow multiple rows to be selected?

property on_double_click#

The callable function for when a node on the Tree is selected. The provided callback function has to accept two arguments tree (Tree) and node (Node or None).

Return type:: callable

property on_select#

The callable function for when a node on the Tree is selected. The provided callback function has to accept two arguments tree (Tree) and node (Node or None).

Return type:: callable

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 selection#

The current selection of the table.

A value of None indicates no selection. If the tree allows multiple selection, returns a list of selected data nodes. Otherwise, returns a single data 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.