BarChartPainter class
A custom painter for rendering bar charts with animations and interactions.
This painter handles the rendering of bar charts including:
- Single and grouped bar layouts
- Smooth animations with staggered effects
- Interactive selection and hover states
- Rounded corners and gradient fills
- Professional grid and axis rendering
The painter extends BaseChartPainter to inherit common chart rendering functionality like grid, axes, and labels.
See also:
- BarChartWidget for the widget that uses this painter
- Inheritance
-
- Object
- Listenable
- CustomPainter
- BaseChartPainter
- BarChartPainter
Constructors
-
BarChartPainter({required ChartTheme theme, required List<
ChartDataSet> dataSets, bool showGrid = true, bool showAxis = true, bool showLabel = true, double barWidth = 20.0, double borderRadius = 8.0, bool isGrouped = false, double animationProgress = 1.0, ChartInteractionResult? selectedBar, ChartInteractionResult? hoveredBar}) - Creates a bar chart painter.
Properties
- animationProgress → double
-
The animation progress value between 0.0 and 1.0.
final
- barWidth → double
-
The width of each bar in pixels.
final
- borderRadius → double
-
The border radius for rounded bar corners.
final
-
dataSets
→ List<
ChartDataSet> -
finalinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- hoveredBar → ChartInteractionResult?
-
The currently hovered bar interaction result.
final
- isGrouped → bool
-
Whether bars should be grouped when multiple data sets are provided.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- selectedBar → ChartInteractionResult?
-
The currently selected bar interaction result.
final
- semanticsBuilder → SemanticsBuilderCallback?
-
Returns a function that builds semantic information for the picture drawn
by this painter.
no setterinherited
- showAxis → bool
-
finalinherited
- showGrid → bool
-
finalinherited
- showLabel → bool
-
finalinherited
- theme → ChartTheme
-
finalinherited
Methods
-
addListener(
VoidCallback listener) → void -
Register a closure to be notified when it is time to repaint.
inherited
-
drawAxes(
Canvas canvas, Size size, double minX, double maxX, double minY, double maxY) → void -
Draw axes
inherited
-
drawAxisLabels(
Canvas canvas, Size size, double minX, double maxX, double minY, double maxY) → void -
Draw axis labels (optimized with text style caching)
inherited
-
drawGrid(
Canvas canvas, Size size, double minX, double maxX, double minY, double maxY) → void -
Draw grid lines (optimized with batched operations)
inherited
-
getDataBounds(
double getValue(ChartDataPoint), double combine(double, double)) → void -
Get data bounds
inherited
-
hitTest(
Offset position) → bool? -
Called whenever a hit test is being performed on an object that is using
this custom paint delegate.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
paint(
Canvas canvas, Size size) → void -
Called whenever the object needs to paint. The given Canvas has its
coordinate space configured such that the origin is at the top left of the
box. The area of the box is the size of the
sizeargument.override -
pointToCanvas(
ChartDataPoint point, Size size, double minX, double maxX, double minY, double maxY) → Offset -
Convert data point to canvas coordinates (optimized)
inherited
-
removeListener(
VoidCallback listener) → void -
Remove a previously registered closure from the list of closures that the
object notifies when it is time to repaint.
inherited
-
shouldRebuildSemantics(
covariant CustomPainter oldDelegate) → bool -
Called whenever a new instance of the custom painter delegate class is
provided to the RenderCustomPaint object, or any time that a new
CustomPaint object is created with a new instance of the custom painter
delegate class (which amounts to the same thing, because the latter is
implemented in terms of the former).
inherited
-
shouldRepaint(
covariant BarChartPainter oldDelegate) → bool -
Called whenever a new instance of the custom painter delegate class is
provided to the RenderCustomPaint object, or any time that a new
CustomPaint object is created with a new instance of the custom painter
delegate class (which amounts to the same thing, because the latter is
implemented in terms of the former).
override
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited