RichText class Null safety

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.

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!'),
    ],
  ),
)

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.

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),
)

Constructors

RichText({Key? key, required InlineSpan text, TextAlign textAlign = TextAlign.start, TextDirection? textDirection, bool softWrap = true, TextOverflow overflow = TextOverflow.clip, double textScaleFactor = 1.0, 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.
finalinherited
hashCode → int: The hash code for this object.
nonVirtual">@nonVirtualread-onlyinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
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.
read-onlyinherited
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: The number of font pixels for each logical pixel.
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.
protected">@protectedinherited
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.
protected">@protectedinherited
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
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.
nonVirtual">@nonVirtualinherited

Flutter
widgets
RichText class