Source¶

Base abstraction of managed data.

Usage¶

Data sources are abstractions that allow you to define the data being managed by your application independent of the GUI representation of that data. For details on the use of data sources, see the topic guide.

The base class referenced on this page, Source, isn't useful on its own. It provides an implementation of the notification API that data sources must provide, and is subclassed by:

It can also be used by custom data source implementations.

Reference¶

toga.sources.Source ¶

Source()

Bases: Generic[ListenerT]

A base class for data sources, providing an implementation of data notifications.

listeners `property` ¶

listeners: list[ListenerT]

The listeners of this data source.

RETURNS	DESCRIPTION
`list[ListenerT]`	A list of objects that are listening to this data source.

add_listener ¶

add_listener(listener: ListenerT) -> None

Add a new listener to this data source.

If the listener is already registered on this data source, the request to add is ignored.

PARAMETER	DESCRIPTION
`listener`	The listener to add TYPE: `ListenerT`

notify ¶

notify(notification: str, **kwargs: object) -> None

Notify all listeners an event has occurred.

PARAMETER	DESCRIPTION
`notification`	The notification to emit. TYPE: `str`
`kwargs`	The data associated with the notification. TYPE: `object` DEFAULT: `{}`

remove_listener ¶

remove_listener(listener: ListenerT) -> None

Remove a listener from this data source.

PARAMETER	DESCRIPTION
`listener`	The listener to remove. TYPE: `ListenerT`