Banner class Null safety
Displays a diagonal message above the corner of another widget.
Useful for showing the execution mode of an app (e.g., that asserts are enabled.)
See also:
- CheckedModeBanner, which the WidgetsApp widget includes by default in debug mode, to show a banner that says "DEBUG".
- Inheritance
Constructors
- Banner({Key? key, Widget? child, required String message, TextDirection? textDirection, required BannerLocation location, TextDirection? layoutDirection, Color color = _kColor, TextStyle textStyle = _kTextStyle})
-
Creates a banner.
const
Properties
- child → Widget?
-
The widget to show behind the banner.
final
- color → Color
-
The color of the banner.
final
- hashCode → int
- The hash code for this object.
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- layoutDirection → TextDirection?
-
The directionality of the layout.
final
- location → BannerLocation
-
Where to show the banner (e.g., the upper right corner).
final
- message → String
-
The message to show in the banner.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- textDirection → TextDirection?
-
The directionality of the text.
final
- textStyle → TextStyle
-
The style of the text shown on the banner.
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.protected">@protectedinherited -
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
override
-
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 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.
nonVirtual">@nonVirtualinherited