BackButtonDispatcher class abstract
Report to a Router when the user taps the back button on platforms that support back buttons (such as Android).
When Router widgets are nested, consider using a ChildBackButtonDispatcher, passing it the parent BackButtonDispatcher, so that the back button requests get dispatched to the appropriate Router. To make this work properly, it's important that whenever a Router thinks it should get the back button messages (e.g. after the user taps inside it), it calls takePriority on its BackButtonDispatcher (or ChildBackButtonDispatcher) instance.
The class takes a single callback, which must return a Future<bool>. The callback's semantics match WidgetsBindingObserver.didPopRoute's, namely, the callback should return a future that completes to true if it can handle the pop request, and a future that completes to false otherwise.
- Implementers
Constructors
Properties
- hasCallbacks → bool
-
Whether a callback is currently registered.
no setter
- hashCode → int
-
The hash code for this object.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
addCallback(
ValueGetter< Future< callback) → voidbool> > -
Register the callback to be called when the object changes.
inherited
-
createChildBackButtonDispatcher(
) → ChildBackButtonDispatcher - Creates a ChildBackButtonDispatcher that is a direct descendant of this back button dispatcher.
-
deferTo(
ChildBackButtonDispatcher child) → void - Mark the given child as taking priority over this object and the other children.
-
forget(
ChildBackButtonDispatcher child) → void - Causes the given child to be removed from the list of children to which this object might defer, as if deferTo had never been called for that child.
-
invokeCallback(
Future< bool> defaultValue) → Future<bool> - Handles a pop route request.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
removeCallback(
ValueGetter< Future< callback) → voidbool> > -
Remove a previously registered callback.
inherited
-
takePriority(
) → void - Make this BackButtonDispatcher take priority among its peers.
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited