NavigationToolbar is a layout helper to position 3 widgets or groups of widgets along a horizontal axis that's sensible for an application's navigation bar such as in Material Design and in iOS.

The leading and trailing widgets occupy the edges of the widget with reasonable size constraints while the middle widget occupies the remaining space in either a center aligned or start aligned fashion.

Either directly use the themed app bars such as the Material AppBar or the iOS CupertinoNavigationBar or wrap this widget with more theming specifications for your own custom app bar.

Inheritance

Constructors

Creates a widget that lays out its children in a manner suitable for a toolbar.
const

Properties

centerMiddle bool
Whether to align the middle widget to the center of this widget or next to the leading widget when false.
final
leading Widget
Widget to place at the start of the horizontal toolbar.
final
middle Widget
Widget to place in the middle of the horizontal toolbar, occupying as much remaining space as possible.
final
middleSpacing double
The spacing around the middle widget on horizontal axis. [...]
final
trailing Widget
Widget to place at the end of the horizontal toolbar.
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

build(BuildContext context) Widget
Describes the part of the user interface represented by this widget. [...]
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. [...]
@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

Constants

kMiddleSpacing double
The default spacing around the middle widget in dp.
16.0