The part of a material design AppBar that expands and collapses.

Most commonly used in in the SliverAppBar.flexibleSpace field, a flexible space bar expands and contracts as the app scrolls so that the AppBar reaches from the top of the app to the top of the scrolling contents of the app.

The widget that sizes the AppBar must wrap it in the widget returned by FlexibleSpaceBar.createSettings, to convey sizing information down to the FlexibleSpaceBar.

See also:

Inheritance

Constructors

FlexibleSpaceBar({Key key, Widget title, Widget background, bool centerTitle })
Creates a flexible space bar. [...]
const

Properties

background Widget
Shown behind the title when expanded. [...]
final
centerTitle bool
Whether the title should be centered. [...]
final
title Widget
The primary contents of the flexible space bar when expanded. [...]
final
hashCode int
The hash code for this object. [...]
read-only, inherited
key Key
Controls how one widget replaces another widget in the tree. [...]
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

createState() → _FlexibleSpaceBarState
Creates the mutable state for this widget at a given location in the tree. [...]
createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder description) → void
Add additional properties associated with the node. [...]
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent 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 toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns 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 ==(other) bool
The equality operator. [...]
inherited

Static Methods

createSettings({double toolbarOpacity, double minExtent, double maxExtent, double currentExtent, Widget child }) Widget
Wraps a widget that contains an AppBar to convey sizing information down to the FlexibleSpaceBar. [...]