MapLegend class

Shows legend for the bubbles or shapes.

Information provided in the legend helps to identify the data rendered in the map shapes or bubbles.

Defaults to null.

By default, legend will not be shown.

Legend for shape

Set MapLegend.source to MapElement.shape to show legend for shapes.

If MapShapeSource.shapeColorMappers is not null, then MapColorMapper.color and MapColorMapper.text will be used for the legend item's icon and the legend item's text respectively.

If MapShapeSource.shapeColorMappers is null, the color returned in the MapShapeSource.shapeColorValueMapper will be applied to the legend item's icon and the legend item's text will be taken from the MapShapeSource.shapeDataField.

In a rare case, if both the MapShapeSource.shapeColorMappers and the MapShapeSource.shapeColorValueMapper properties are null, the legend item's text will be taken from the MapShapeSource.shapeDataField property and the legend item's icon will have the default color.

Legend for bubbles

Set MapLegend.source to MapElement.bubble to show legend for bubbles.

If MapShapeSource.bubbleColorMappers is not null, then MapColorMapper.color and MapColorMapper.text will be used for the legend item's icon and the legend item's text respectively.

If MapShapeSource.bubbleColorMappers is null, the color returned in the MapShapeSource.bubbleColorValueMapper will be applied to the legend item's icon and the legend item's text will be taken from the MapShapeSource.shapeDataField.

If both the MapShapeSource.bubbleColorMappers and the MapShapeSource.bubbleColorValueMapper properties are null, the legend item's text will be taken from the MapShapeSource.shapeDataField property and the legend item's icon will have the default color.

The below code snippet represents how to setting default legend to the shape.

late List<DataModel> _data;
late MapShapeSource _mapSource;

 @override
 void initState() {
   super.initState();

   _data = <DataModel>[
     DataModel('India', 280, "Low"),
     DataModel('United States of America', 190, "High"),
     DataModel('Pakistan', 37, "Low"),
   ];

   _mapSource = MapShapeSource.asset(
     "assets/world_map.json",
     shapeDataField: "name",
     dataCount: _data.length,
     primaryValueMapper: (int index) {
       return _data[index].country;
     },
     shapeColorValueMapper: (int index) {
       return _data[index].storage;
     },
     shapeColorMappers: [
       MapColorMapper(value: "Low", color: Colors.red),
       MapColorMapper(value: "High", color: Colors.green)
     ],
   );
 }

 @override
 Widget build(BuildContext context) {
   return Scaffold(
     appBar: AppBar(
       title: Text('Default legend'),
     ),
     body: Center(
       child: SfMaps(
         layers: [
           MapShapeLayer(
             source: _mapSource,
             legend: MapLegend(MapElement.shape),
           )
         ],
       ),
     ),
   );
 }

class DataModel {
  const DataModel(this.country, this.count, this.storage);

  final String country;
  final double count;
  final String storage;
}

The below code snippet represents how to setting bar legend to the shape.

late List<DataModel> _data;
late MapShapeSource _mapSource;

 @override
 void initState() {
   super.initState();

   _data = <DataModel>[
     DataModel('India', 280, "Low"),
     DataModel('United States of America', 190, "High"),
     DataModel('Pakistan', 37, "Low"),
   ];

   _mapSource = MapShapeSource.asset(
     "assets/world_map.json",
     shapeDataField: "name",
     dataCount: _data.length,
     primaryValueMapper: (int index) {
       return _data[index].country;
     },
     shapeColorValueMapper: (int index) {
       return _data[index].storage;
     },
     shapeColorMappers: [
       MapColorMapper(value: "Low", color: Colors.red),
       MapColorMapper(value: "High", color: Colors.green)
     ],
   );
 }

 @override
 Widget build(BuildContext context) {
   return Scaffold(
     appBar: AppBar(
       title: Text('Bar legend'),
     ),
     body: Center(
       child: SfMaps(
         layers: [
           MapShapeLayer(
             source: _mapSource,
             legend: MapLegend.bar(MapElement.shape),
           )
         ],
       ),
     ),
   );
 }

class DataModel {
  const DataModel(this.country, this.count, this.storage);

  final String country;
  final double count;
  final String storage;
}

Inheritance

• Object
• DiagnosticableTree
• MapLegend

Annotations

• @immutable

Constructors

MapLegend(MapElement source, {bool shouldAlwaysShowScrollbar = false, Widget? title, MapLegendPosition position = MapLegendPosition.top, Offset? offset, MapLegendOverflowMode overflowMode = MapLegendOverflowMode.wrap, Axis? direction, EdgeInsetsGeometry? padding = const EdgeInsets.all(10.0), double spacing = 10.0, MapIconType iconType = MapIconType.circle, Size iconSize = const Size(8.0, 8.0), TextStyle? textStyle, bool enableToggleInteraction = false, Color? toggledItemColor, Color? toggledItemStrokeColor, double toggledItemStrokeWidth = 1.0, double toggledItemOpacity = 0.5})

Creates a legend with different styles like circle, rectangle, triangle and square for the bubbles or shapes.

const

MapLegend.bar(MapElement source, {bool shouldAlwaysShowScrollbar = false, Widget? title, MapLegendOverflowMode overflowMode = MapLegendOverflowMode.scroll, EdgeInsetsGeometry? padding = const EdgeInsets.all(10.0), MapLegendPosition position = MapLegendPosition.top, Offset? offset, double spacing = 2.0, Size? segmentSize, TextStyle? textStyle, Axis? direction, MapLegendLabelsPlacement? labelsPlacement, MapLegendEdgeLabelsPlacement edgeLabelsPlacement = MapLegendEdgeLabelsPlacement.inside, MapLabelOverflow labelOverflow = MapLabelOverflow.visible, MapLegendPaintingStyle segmentPaintingStyle = MapLegendPaintingStyle.solid, bool showPointerOnHover = false, MapLegendPointerBuilder? pointerBuilder, Color? pointerColor, Size pointerSize = const Size(16, 12)})

Creates a bar type legend for the bubbles or shapes.

const

Properties

direction → Axis?

Arranges the legend items in either horizontal or vertical direction.

final

edgeLabelsPlacement → MapLegendEdgeLabelsPlacement

Place the edge labels either inside or outside of the bar legend.

final

enableToggleInteraction → bool

Enables the toggle interaction for the legend.

final

hashCode → int

The hash code for this object.

no setter, override

iconSize → Size

Customizes the size of the icon.

final

iconType → MapIconType

Specifies the shape of the legend icon.

final

labelOverflow → MapLabelOverflow

Trims or removes the legend text when it is overflowed from the bar legend. Defaults to MapLabelOverflow.hide.

final

labelsPlacement → MapLegendLabelsPlacement?

Place the labels either between the segments or on the segments.

final

offset → Offset?

Places the legend in custom position.

final

overflowMode → MapLegendOverflowMode

Wraps or scrolls the legend items when it overflows.

final

padding → EdgeInsetsGeometry?

Sets the padding around the legend.

final

pointerBuilder → MapLegendPointerBuilder?

Returns a widget for the given value.

final

pointerColor → Color?

Customizes the color of the pointer.

final

pointerSize → Size

Customizes the size of the pointer.

final

position → MapLegendPosition

Positions the legend in the different directions.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

segmentPaintingStyle → MapLegendPaintingStyle

Applies gradient or solid color for the bar segments.

final

segmentSize → Size?

Customizes the size of the bar segments.

final

shouldAlwaysShowScrollbar → bool

Toggles the scrollbar visibility.

final

showPointerOnHover → bool

Specifies whether the pointer should be shown while hovering on the MapLegend segments.

final

source → MapElement

Shows legend for the bubbles or shapes.

final

spacing → double

Specifies the space between the each legend items.

final

textStyle → TextStyle?

Customizes the legend item's text style.

final

title → Widget?

Sets a title for the legend.

final

toggledItemColor → Color?

Fills the toggled legend item's icon and the respective shape or bubble by this color.

final

toggledItemOpacity → double

Sets the toggled legend item's text opacity.

final

toggledItemStrokeColor → Color?

Stroke color for the toggled legend item's respective shape or bubble.

final

toggledItemStrokeWidth → double

Stroke width for the toggled legend item's respective shape or bubble.

final

Methods

copyWith({Axis? direction, EdgeInsetsGeometry? padding, MapLegendPosition? position, Widget? title, Offset? offset, double? spacing, MapIconType? iconType, TextStyle? textStyle, Size? iconSize, Size? segmentSize, MapLegendOverflowMode? overflowMode, bool? enableToggleInteraction, Color? toggledItemColor, Color? toggledItemStrokeColor, double? toggledItemStrokeWidth, double? toggledItemOpacity, MapElement? source, MapLegendLabelsPlacement? labelsPlacement, MapLegendEdgeLabelsPlacement? edgeLabelsPlacement, MapLabelOverflow? labelOverflow, MapLegendPaintingStyle? segmentPaintingStyle, bool? showPointerOnHover, MapLegendPointerBuilder? pointerBuilder, Color? pointerColor, Size? pointerSize}) → MapLegend

Creates a copy of this class but with the given fields replaced with the new values.

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

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}) → 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 brief description of this object, usually just the runtimeType and the hashCode.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

override