SheetPopScope<T> class

Manages the back navigation gesture for the current modal sheet.

This widget is a wrapper around PopScope, providing additional control over the swipe-to-dismiss gesture in a modal sheet. The behavior of the modal sheet is determined by the canPop property and whether onPopInvokedWithResult is provided. The table below describes how the sheet behaves based on these properties:

Behavior	Implementation
Can pop; Gesture is enabled	`SheetPopScope(canPop: true)`
Cannot pop; Gesture is enabled	`SheetPopScope(canPop: false, onPopInvokedWithResult: nonNullCallback)`
Cannot pop; Gesture is disabled	`SheetPopScope(canPop: false, onPopInvokedWithResult: null)`

Note that the gesture is always disabled if ModalSheetRouteMixin.swipeDismissible on the parent route is false.

Typically, this widget is placed above a sheet widget:

ModalSheetRoute(
  swipeDismissible: true,
  builder: (context) => SheetPopScope(
    canPop: false,
    onPopInvokedWithResult: (didPop, result) {...},
    child: Sheet(child: Container()),
  ),
);

However, it can also be placed deeper within the sheet's widget tree. This is useful when you want to dynamically control gesture availability in a widget's build method:

class SheetContent extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // If false, the modal cannot be popped, and the gesture is also disabled
    // (and vice versa).
    final canPopByGesture = ...;
    return SheetPopScope(
      canPop: canPopByGesture,
      onPopInvokedWithResult: canPopByGesture
        ? (didPop, result) {...}
        : null,
      child: Sheet(child: Container()),
    );
  }
}

Compatibility with PopScope

While SheetPopScope offers fine-grained control, the standard PopScope widget can also manage a modal sheet's dismissibility. However, PopScope lacks the ability to control the swipe-to-dismiss gesture.

Assuming ModalSheetRouteMixin.swipeDismissible is true, PopScope behaves similarly to SheetPopScope in the following cases:

Behavior	Implementation
Can pop; Gesture is enabled	`PopScope(canPop: true)`
Cannot pop; Gesture is enabled	`PopScope(canPop: false)`
Cannot pop; Gesture is disabled	❌ Not possible

Note that the first two cases are equivalent to SheetPopScope, but the third is not possible with PopScope.

Inheritance

Constructors

SheetPopScope({required Widget child, Key? key, bool canPop = true, PopInvokedWithResultCallback<T>? onPopInvokedWithResult}): Creates a widget that controls the pop behavior of a modal sheet.
const

Properties

canPop → bool: When false, blocks the current route from being popped.
final
child → Widget: The widget below this widget in the tree.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
onPopInvokedWithResult → PopInvokedWithResultCallback<T>?: A callback that is called when a pop is attempted on the current route, including when the swipe gesture is performed.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<SheetPopScope<T>>: Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>: Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void: Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode: Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String: A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String: Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String: Returns a one-line detailed description of the object.
inherited
toStringShort() → String: A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited