Readonly
currentA signal emitted when the current instance changes.
If the last instance being tracked is disposed, null
will be emitted.
Readonly
currentThe current widget is the most recently focused or added widget.
It is the most recently focused widget, or the most recently added widget if no widget has taken focus.
Readonly
isReadonly
restoredA promise that is resolved when the widget tracker has been restored from a serialized state.
Most client code will not need to use this, since they can wait for the whole application to restore. However, if an extension wants to perform actions during the application restoration, but after the restoration of another widget tracker, they can use this promise.
Readonly
sizeThe number of instances held by the tracker.
Readonly
widgetA signal emitted when a widget is added.
Readonly
widgetA signal emitted when a widget is updated.
Dispose of the resources held by the object.
If the object's dispose
method is called more than once, all
calls made after the first will be a no-op.
It is undefined behavior to use any functionality of the object after it has been disposed unless otherwise explicitly noted.
Filter the instances in the tracker based on a predicate.
The function by which to filter.
Find the first instance in the tracker that satisfies a filter function.
The filter function to call on each instance.
If nothing is found, the value returned is undefined
.
Iterate through each instance in the tracker.
The function to call on each instance.
Check if this tracker has the specified instance.
The object whose existence is being checked.
Inject an instance into the widget tracker without the tracker handling its restoration lifecycle.
The instance to inject into the tracker.
A class that tracks HTML viewer widgets.