In what cases does an activity or component transition to a deactivated state?

In Flutter, there is no activity (Activity) as such, since it is an Android concept. However, when talking about the widget lifecycle, the deactivation state occurs when a widget is removed from the widget tree but can still be reinserted elsewhere in the tree. This state allows for cleanup or preparation before the widget is removed.

For example, the deactivate() method is called before a widget is removed or moved. If the widget is not reinserted, dispose() is called after deactivate(), where final resource cleanup occurs.

Thus, deactivation occurs when a widget ceases to be part of the current widget tree but has not yet been completely destroyed.