Retrieves all open widgets that have been opened by this handler.
all open widgets for this open handler.
Closes all widgets that have been opened by this open handler.
the close options that should be applied to all widgets.
a promise of all closed widgets that resolves after they have been closed.
Tries to get an existing widget for the given uri.
the uri of the widget.
a promise that resolves to the existing widget or undefined if no widget for the given uri exists.
Return an existing widget for the given uri or creates a new one.
It does not open a widget, use {@link WidgetOpenHandler#open} instead.
uri of the widget.
a promise of the existing or newly created widget.
Emit when a new widget is created.