BackdropScaffold class

Implements the basic functionality of backdrop.

This class internally uses Scaffold. It allows to set a back layer and a front layer and manage the switching between the two. The implementation is inspired by the material backdrop component.

Usage example:

Widget build(BuildContext context) {
  return MaterialApp(
    title: 'Backdrop Demo',
    home: BackdropScaffold(
      appBar: BackdropAppBar(
        title: Text("Backdrop Example"),
        actions: <Widget>[
          BackdropToggleButton(
            icon: AnimatedIcons.list_view,
          )
        ],
      ),
      backLayer: Center(
        child: Text("Back Layer"),
      ),
      frontLayer: Center(
        child: Text("Front Layer"),
      ),
    ),
  );
}

See also:

  • Scaffold, which is the plain scaffold used in material apps.
Inheritance

Constructors

BackdropScaffold({Key? key, AnimationController? animationController, required Widget backLayer, required Widget frontLayer, Widget? subHeader, bool subHeaderAlwaysActive = true, double? headerHeight, ShapeBorder frontLayerShape = const RoundedRectangleBorder(borderRadius: BorderRadius.only(topLeft: Radius.circular(16), topRight: Radius.circular(16))), BorderRadius? frontLayerBorderRadius, double frontLayerElevation = 1, bool stickyFrontLayer = false, bool revealBackLayerAtStart = false, Curve animationCurve = Curves.ease, Curve? reverseAnimationCurve, Color? frontLayerBackgroundColor, double frontLayerActiveFactor = 1, Color? backLayerBackgroundColor, Color frontLayerScrim = Colors.white70, Color backLayerScrim = Colors.black54, VoidCallback? onBackLayerConcealed, VoidCallback? onBackLayerRevealed, bool maintainBackLayerState = true, bool concealBacklayerOnBackButton = true, GlobalKey<ScaffoldState>? scaffoldKey, PreferredSizeWidget? appBar, Widget? floatingActionButton, FloatingActionButtonLocation? floatingActionButtonLocation, FloatingActionButtonAnimator? floatingActionButtonAnimator, List<Widget>? persistentFooterButtons, Widget? drawer, DrawerCallback? onDrawerChanged, Widget? endDrawer, DrawerCallback? onEndDrawerChanged, Widget? bottomNavigationBar, Widget? bottomSheet, Color? backgroundColor, bool? resizeToAvoidBottomInset, bool primary = true, DragStartBehavior drawerDragStartBehavior = DragStartBehavior.start, bool extendBody = false, bool extendBodyBehindAppBar = false, Color? drawerScrimColor, double? drawerEdgeDragWidth, bool drawerEnableOpenDragGesture = true, bool endDrawerEnableOpenDragGesture = true, String? restorationId})
Creates a backdrop scaffold to be used as a material widget.

Properties

animationController → AnimationController?
Can be used to customize the behaviour of the backdrop animation.
final
animationCurve → Curve
The animation curve used for the backdrop animation.
final
appBar → PreferredSizeWidget?
See Scaffold.appBar and BackdropAppBar.
final
backgroundColor → Color?
See Scaffold.backgroundColor.
final
backLayer → Widget
Content that should be displayed on the back layer.
final
backLayerBackgroundColor → Color?
Background Color for the back layer.
final
backLayerScrim → Color
Scrim over backLayer when active (back layer concealed).
final
bottomNavigationBar → Widget?
See Scaffold.bottomNavigationBar.
final
bottomSheet → Widget?
See Scaffold.bottomSheet.
final
concealBacklayerOnBackButton → bool
Specifiy whether to conceal backLayer when back button pressed.
final
drawer → Widget?
See Scaffold.drawer.
final
drawerDragStartBehavior → DragStartBehavior
See Scaffold.drawerDragStartBehavior.
final
drawerEdgeDragWidth → double?
See Scaffold.drawerEdgeDragWidth.
final
drawerEnableOpenDragGesture → bool
See Scaffold.drawerEnableOpenDragGesture.
final
drawerScrimColor → Color?
See Scaffold.drawerScrimColor.
final
endDrawer → Widget?
See Scaffold.endDrawer.
final
endDrawerEnableOpenDragGesture → bool
See Scaffold.endDrawerEnableOpenDragGesture.
final
extendBody → bool
See Scaffold.extendBody.
final
extendBodyBehindAppBar → bool
See Scaffold.extendBodyBehindAppBar.
final
floatingActionButton → Widget?
See Scaffold.floatingActionButton.
final
floatingActionButtonAnimator → FloatingActionButtonAnimator?
See Scaffold.floatingActionButtonAnimator.
final
floatingActionButtonLocation → FloatingActionButtonLocation?
See Scaffold.floatingActionButtonLocation.
final
frontLayer → Widget
The widget that is shown on the front layer.
final
frontLayerActiveFactor → double
Fraction of available height the frontLayer will occupy when active (back layer concealed).
final
frontLayerBackgroundColor → Color?
Background Color for the front layer.
final
frontLayerBorderRadius → BorderRadius?
Defines the BorderRadius applied to the front layer.
final
frontLayerElevation → double
Defines the elevation applied to the front layer.
final
frontLayerScrim → Color
Scrim over frontLayer when minimized (back layer revealed) and animating.
final
frontLayerShape → ShapeBorder
Defines the ShapeBorder applied to the front layer.
final
hashCode → int
The hash code for this object.
no setterinherited
headerHeight → double?
Defines the front layer's height when minimized (back layer revealed).
final
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
maintainBackLayerState → bool
Specifies whether the state of the backLayer should be maintained.
final
onBackLayerConcealed → VoidCallback?
Will be called when backLayer has been concealed.
final
onBackLayerRevealed → VoidCallback?
Will be called when backLayer has been revealed.
final
onDrawerChanged → DrawerCallback?
See Scaffold.onDrawerChanged.
final
onEndDrawerChanged → DrawerCallback?
See Scaffold.onEndDrawerChanged.
final
persistentFooterButtons → List<Widget>?
See Scaffold.persistentFooterButtons.
final
primary → bool
See Scaffold.primary.
final
resizeToAvoidBottomInset → bool?
See Scaffold.resizeToAvoidBottomInset.
final
restorationId → String?
See Scaffold.restorationId.
final
revealBackLayerAtStart → bool
Indicates whether the back layer should be revealed at the beginning.
final
reverseAnimationCurve → Curve?
The reverse animation curve used for the backdrop animation.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
scaffoldKey → GlobalKey<ScaffoldState>?
A key to use when building the Scaffold.
final
stickyFrontLayer → bool
Indicates the front layer should minimize to the back layer's bottom edge.
final
subHeader → Widget?
The widget shown at the top of the front layer.
final
subHeaderAlwaysActive → bool
Keeps subHeader active when minimized (back layer revealed).
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → BackdropScaffoldState
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}) → 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