ChartLegendScope class

Composes any chart with a tappable legend that toggles series visibility.

Pass your full dataSets, render the chart inside builder using the filtered list that the builder receives. Tapping a legend item hides or shows the corresponding series without you having to touch the underlying chart widget.

Example

ChartLegendScope(
  dataSets: myDataSets,
  builder: (context, visibleDataSets) {
    return LineChartWidget(dataSets: visibleDataSets);
  },
)

With an external controller

final controller = ChartVisibilityController();

ChartLegendScope(
  controller: controller,
  dataSets: myDataSets,
  position: LegendPosition.top,
  builder: (context, visible) => BarChartWidget(dataSets: visible),
)

Inheritance

Constructors

ChartLegendScope({Key? key, required List<ChartDataSet> dataSets, required Widget builder(BuildContext context, List<ChartDataSet> visibleDataSets), ChartVisibilityController? controller, LegendPosition position = LegendPosition.bottom, double spacing = 12.0, ChartTheme? theme, String seriesLabelFor(Color color, List<ChartDataSet> group)?, bool showLegend = true}): const

Properties

builder → Widget Function(BuildContext context, List<ChartDataSet> visibleDataSets): Renders the chart. Receives the filtered (visible) list of datasets.
final
controller → ChartVisibilityController?: Optional external controller. If omitted, the scope creates its own.
final
dataSets → List<ChartDataSet>: The full list of datasets. Not mutated.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
position → LegendPosition: Where to place the legend relative to the chart.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
seriesLabelFor → String Function(Color color, List<ChartDataSet> group)?: Optional custom label resolver (see ChartLegend.fromDataSets).
final
showLegend → bool: Set to false to hide the legend but still render the chart; useful when you want to manage toggling via your own UI.
final
spacing → double: Gap between the chart and the legend.
final
theme → ChartTheme?: Theme used for label colors. Falls back to the ambient Material theme.
final

Methods

createElement() → StatefulElement: Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<ChartLegendScope>: Creates the mutable state for this widget at a given location in the tree.
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.
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

Operators

operator ==(Object other) → bool: The equality operator.
inherited