WidgetSpan class Null safety

An immutable widget that is embedded inline within text.

The child property is the widget that will be embedded. Children are constrained by the width of the paragraph.

The child property may contain its own Widget children (if applicable), including Text and RichText widgets which may include additional WidgetSpans. Child Text and RichText widgets will be laid out independently and occupy a rectangular space in the parent text layout.

WidgetSpans will be ignored when passed into a TextPainter directly. To properly layout and paint the child widget, WidgetSpan should be passed into a Text.rich widget.

A card with Hello World! embedded inline within a TextSpan tree.
const Text.rich(
    children: <InlineSpan>[
      TextSpan(text: 'Flutter is'),
        child: SizedBox(
          width: 120,
          height: 50,
          child: Card(
            child: Center(
              child: Text('Hello World!')
      TextSpan(text: 'the best!'),

WidgetSpan contributes the semantics of the WidgetSpan.child to the semantics tree.

See also:



WidgetSpan({required Widget child, PlaceholderAlignment alignment = ui.PlaceholderAlignment.bottom, TextBaseline? baseline, TextStyle? style})
Creates a WidgetSpan with the given values.


alignment PlaceholderAlignment
How the placeholder aligns vertically with the text.
final, inherited
baseline TextBaseline?
The TextBaseline to align against when using ui.PlaceholderAlignment.baseline, ui.PlaceholderAlignment.aboveBaseline, and ui.PlaceholderAlignment.belowBaseline.
final, inherited
child Widget
The widget to embed inline within text.
hashCode int
The hash code for this object.
read-only, override
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
style TextStyle?
The TextStyle to apply to this span.
final, inherited


build(ParagraphBuilder builder, {double textScaleFactor = 1.0, List<PlaceholderDimensions>? dimensions}) → void
Adds a placeholder box to the paragraph builder if a size has been calculated for the widget.
codeUnitAt(int index) int?
Returns the UTF-16 code unit at the given index in the flattened string.
codeUnitAtVisitor(int index, Accumulator offset) int?
Performs the check at each InlineSpan for if the index falls within the range of the span and returns the corresponding code unit. Returns null otherwise.
compareTo(InlineSpan other) RenderComparison
Describe the difference between this span and another, in terms of how much damage it will make to the rendering. The comparison is deep.
computeSemanticsInformation(List<InlineSpanSemanticsInformation> collector) → void
Walks the InlineSpan tree and accumulates a list of InlineSpanSemanticsInformation objects.
computeToPlainText(StringBuffer buffer, {bool includeSemanticsLabels = true, bool includePlaceholders = true}) → void
PlaceholderSpans are flattened to a 0xFFFC object replacement character in the plain text representation when includePlaceholders is true.
debugAssertIsValid() bool
In debug mode, throws an exception if the object is not in a valid configuration. Otherwise, returns true.
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
describeSemantics(Accumulator offset, List<int> semanticsOffsets, List semanticsElements) → void
Populates the semanticsOffsets and semanticsElements with the appropriate data to be able to construct a SemanticsNode.
getSemanticsInformation() List<InlineSpanSemanticsInformation>
Flattens the InlineSpan tree to a list of InlineSpanSemanticsInformation objects.
getSpanForPosition(TextPosition position) InlineSpan?
Returns the text span that contains the given position in the text.
getSpanForPositionVisitor(TextPosition position, Accumulator offset) InlineSpan?
Performs the check at each InlineSpan for if the position falls within the range of the span and returns the span if it does.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
toPlainText({bool includeSemanticsLabels = true, bool includePlaceholders = true}) String
Flattens the InlineSpan tree into a single string.
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) String
A string representation of this object.
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants.
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object.
toStringShort() String
A brief description of this object, usually just the runtimeType and the hashCode.
visitChildren(InlineSpanVisitor visitor) bool
Calls visitor on this WidgetSpan. There are no children spans to walk.


operator ==(Object other) bool
The equality operator.