BarGroupInfo class

Metadata for positioning and composing a bar series within category slots.

When multiple bar slots share the same X-values, they need to be positioned side-by-side. Stacked series intentionally share a slot index while grouped series receive distinct indices.

Usage:

// For the second bar series out of three total bar series:
final groupInfo = BarGroupInfo(
  index: 1,
  count: 3,
  gap: 2.0,
);

// Calculate X-offset for a 20px wide bar
final offset = groupInfo.calculateOffset(20.0);

Immutability: All fields are final and the class has a const constructor.

See also:

  • SeriesElement, which stores bar group metadata during rendering
Annotations
  • @ChartSurfaceExempt.new('Render-time layout result, not an authoring config: the bar layout engine ' 'computes index/count and the stacked start, end and percentage maps per ' 'frame and hands them to the renderer. Consumers compose bars through ' 'BarChartSeries. index and count are additionally assert-coupled ' '(index < count), so individual setters could only build an invalid slot.')

Constructors

BarGroupInfo({required int index, required int count, double gap = 2.0, BarLayoutMode layoutMode = BarLayoutMode.grouped, String? groupId, double stackBaseline = 0.0, Map<int, double> startValues = const {}, Map<int, double> endValues = const {}, Map<int, double> percentages = const {}, Set<int> outerPointIndices = const {}, bool drawTrack = true})
Creates bar group positioning metadata.
const

Properties

count → int
Total number of side-by-side category slots in the chart.
final
drawTrack → bool
Whether this series owns the shared track behind its composition slot.
final
endValues → Map<int, double>
Rendered segment end values keyed by point index.
final
gap → double
Pixel spacing between adjacent bars within a group.
final
groupId → String?
Named stack ID, when supplied by the series.
final
hashCode → int
Returns a hash code based on index, count, and gap.
no setteroverride
index → int
0-based index of this series' category slot.
final
isDiverging → bool
no setter
isOverlaid → bool
no setter
isStacked → bool
no setter
isWaterfall → bool
no setter
layoutMode → BarLayoutMode
Composition mode resolved for this series.
final
outerPointIndices → Set<int>
Point indices exposed at the positive or negative end of a stack.
final
percentages → Map<int, double>
Signed normalized percentages keyed by point index.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stackBaseline → double
Common baseline used by a stack.
final
startValues → Map<int, double>
Rendered segment start values keyed by point index.
final

Methods

calculateOffset(double barWidth) → double
Calculate the X-offset for this bar within its group.
copyWith({int? index, int? count, double? gap, BarLayoutMode? layoutMode, String? groupId, bool clearGroupId = false, double? stackBaseline, Map<int, double>? startValues, Map<int, double>? endValues, Map<int, double>? percentages, Set<int>? outerPointIndices, bool? drawTrack}) → BarGroupInfo
Creates a copy with optional field overrides.
endValueFor(int pointIndex, double fallback) → double
isOuterPoint(int pointIndex) → bool
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
percentageFor(int pointIndex) → double?
startValueFor(int pointIndex, double fallback) → double
toString() → String
Returns a string representation of this BarGroupInfo.
override

Operators

operator ==(Object other) → bool
Compares two BarGroupInfo instances for value equality.
override