RichText class

A paragraph of rich text.

The RichText widget displays text that uses multiple different styles. The text to display is described using a tree of TextSpan objects, each of which has an associated style that is used for that subtree. The text might break across multiple lines or might all be displayed on the same line depending on the layout constraints.

Text displayed in a RichText widget must be explicitly styled. When picking which style to use, consider using DefaultTextStyle.of the current BuildContext to provide defaults. For more details on how to style text in a RichText widget, see the documentation for TextStyle.

Consider using the Text widget to integrate with the DefaultTextStyle automatically. When all the text uses the same style, the default constructor is less verbose. The Text.rich constructor allows you to style multiple spans with the default text style while still allowing specified styles per span.

{@tool snippet}

This sample demonstrates how to mix and match text with different text styles using the RichText Widget. It displays the text "Hello bold world," emphasizing the word "bold" using a bold font weight.

RichText(
  text: TextSpan(
    text: 'Hello ',
    style: DefaultTextStyle.of(context).style,
    children: const <TextSpan>[
      TextSpan(text: 'bold', style: TextStyle(fontWeight: FontWeight.bold)),
      TextSpan(text: ' world!'),
    ],
  ),
)

{@end-tool}

Selections

To make this RichText Selectable, the RichText needs to be in the subtree of a SelectionArea or SelectableRegion and a SelectionRegistrar needs to be assigned to the RichText.selectionRegistrar. One can use SelectionContainer.maybeOf to get the SelectionRegistrar from a context. This enables users to select the text in RichTexts with mice or touch events.

The selectionColor also needs to be set if the selection is enabled to draw the selection highlights.

{@tool snippet}

This sample demonstrates how to assign a SelectionRegistrar for RichTexts in the SelectionArea subtree.

RichText(
  text: const TextSpan(text: 'Hello'),
  selectionRegistrar: SelectionContainer.maybeOf(context),
  selectionColor: const Color(0xAF6694e8),
)

{@end-tool}

See also:

• TextStyle, which discusses how to style text.
• TextSpan, which is used to describe the text in a paragraph.
• Text, which automatically applies the ambient styles described by a DefaultTextStyle to a single string.
• Text.rich, a const text widget that provides similar functionality as RichText. Text.rich will inherit TextStyle from DefaultTextStyle.
• SelectableRegion, which provides an overview of the selection system.

Inheritance

• Object
• DiagnosticableTree
• Widget
• RenderObjectWidget
• MultiChildRenderObjectWidget
• RichText

Constructors

RichText({Key? key, required InlineSpan text, TextAlign textAlign = TextAlign.start, TextDirection? textDirection, bool softWrap = true, TextOverflow overflow = TextOverflow.clip, @Deprecated('Use textScaler instead. ' 'Use of textScaleFactor was deprecated in preparation for the upcoming nonlinear text scaling support. ' 'This feature was deprecated after v3.12.0-2.0.pre.') double textScaleFactor = 1.0, TextScaler textScaler = TextScaler.noScaling, int? maxLines, Locale? locale, StrutStyle? strutStyle, TextWidthBasis textWidthBasis = TextWidthBasis.parent, TextHeightBehavior? textHeightBehavior, SelectionRegistrar? selectionRegistrar, Color? selectionColor})

Creates a paragraph of rich text.

Properties

children → List<Widget>

The widgets below this widget in the tree.

final, inherited

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

locale → Locale?

Used to select a font when the same Unicode character can be rendered differently, depending on the locale.

final

maxLines → int?

An optional maximum number of lines for the text to span, wrapping if necessary. If the text exceeds the given number of lines, it will be truncated according to overflow.

final

overflow → TextOverflow

How visual overflow should be handled.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

selectionColor → Color?

The color to use when painting the selection.

final

selectionRegistrar → SelectionRegistrar?

The SelectionRegistrar this rich text is subscribed to.

final

softWrap → bool

Whether the text should break at soft line breaks.

final

strutStyle → StrutStyle?

The strut style to use. Strut style defines the strut, which sets minimum vertical layout metrics.

final

text → InlineSpan

The text to display in this widget.

final

textAlign → TextAlign

How the text should be aligned horizontally.

final

textDirection → TextDirection?

The directionality of the text.

final

textHeightBehavior → TextHeightBehavior?

Defines how to apply TextStyle.height over and under text.

final

textScaleFactor → double

Deprecated. Will be removed in a future version of Flutter. Use textScaler instead.

no setter

textScaler → TextScaler

The font scaling strategy to use when laying out and rendering the text.

final

textWidthBasis → TextWidthBasis

Defines how to measure the width of the rendered text.

final

Methods

createElement() → MultiChildRenderObjectElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

inherited

createRenderObject(BuildContext context) → RenderParagraph

Creates an instance of the RenderObject class that this RenderObjectWidget represents, using the configuration described by this RenderObjectWidget.

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.

override

didUnmountRenderObject(covariant RenderObject renderObject) → void

A render object previously associated with this widget has been removed from the tree. The given RenderObject will be of the same type as returned by this object's createRenderObject.

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, int wrapWidth = 65}) → 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

updateRenderObject(BuildContext context, covariant RenderParagraph renderObject) → void

Copies the configuration described by this RenderObjectWidget to the given RenderObject, which will be of the same type as returned by this object's createRenderObject.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited