FadeThroughTransition class

Defines a transition in which outgoing elements fade out, then incoming elements fade in and scale up.

The fade through pattern provides a transition animation between UI elements that do not have a strong relationship to one another. As an example, the BottomNavigationBar may use this animation to transition the currently displayed content when a new BottomNavigationBarItem is selected.

Scale is only applied to incoming elements to emphasize new content over old.

Consider using FadeThroughPageTransitionsBuilder within a PageTransitionsTheme if you want to apply this kind of transition to MaterialPageRoute transitions within a Navigator (see FadeThroughPageTransitionsBuilder for some example code). Or use this transition directly in a PageTransitionSwitcher.transitionBuilder to transition from one widget to another as seen in the following example:

 int _selectedIndex = 0;

 final List<Color> _colors = [Colors.blue, Colors.red, Colors.yellow];

 @override
 Widget build(BuildContext context) {
   return Scaffold(
     appBar: AppBar(
       title: const Text('Switcher Sample'),
     ),
     body: PageTransitionSwitcher(
       transitionBuilder: (
         Widget child,
         Animation<double> primaryAnimation,
         Animation<double> secondaryAnimation,
       ) {
         return FadeThroughTransition(
           child: child,
           animation: primaryAnimation,
           secondaryAnimation: secondaryAnimation,
         );
       },
       child: Container(
         key: ValueKey<int>(_selectedIndex),
         color: _colors[_selectedIndex],
       ),
     ),
     bottomNavigationBar: BottomNavigationBar(
       items: const <BottomNavigationBarItem>[
         BottomNavigationBarItem(
           icon: Icon(Icons.home),
           title: Text('Blue'),
         ),
         BottomNavigationBarItem(
           icon: Icon(Icons.business),
           title: Text('Red'),
         ),
         BottomNavigationBarItem(
           icon: Icon(Icons.school),
           title: Text('Yellow'),
         ),
       ],
       currentIndex: _selectedIndex,
       selectedItemColor: Colors.amber[800],
       onTap: (int index) {
         setState(() {
           _selectedIndex = index;
         });
       },
     ),
   );
 }
Inheritance

Constructors

FadeThroughTransition({Key? key, required Animation<double> animation, required Animation<double> secondaryAnimation, Color? fillColor, Widget? child})
Creates a FadeThroughTransition.
const

Properties

animation → Animation<double>
The animation that drives the child's entrance and exit.
final
child → Widget?
The widget below this widget in the tree.
final
fillColor → Color?
The color to use for the background color during the transition.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
secondaryAnimation → Animation<double>
The animation that transitions child when new content is pushed on top of it.
final

Methods

build(BuildContext context) → Widget
Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement
Creates a StatelessElement to manage this widget's location in the tree.
inherited
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