HeatmapChart class

A 2D heatmap widget that maps grid values to colours via a ChartRamp.

Each cell in the grid is expected to be in the [0..1] range and is rendered as a coloured terminal cell.

HeatmapChart(
  grid: [
    [0.1, 0.4, 0.8],
    [0.3, 0.6, 0.9],
    [0.5, 0.7, 1.0],
  ],
  width: 30,
  height: 10,
  ramp: ChartRamp.thermal(),
)
Inheritance

Constructors

HeatmapChart({required List<List<double>> grid, int? width, int? height, ChartRamp? ramp, bool useBackground = true, String glyph = ' ', bool showGrid = false, int gridRows = 3, int gridCols = 3, UvStyle? gridStyle, List<String>? xLabels, List<String>? yLabels, UvStyle? labelStyle, List<ChartLegendEntry>? legendEntries, int legendColumns = 1, int legendRowGap = 0, ChartLegendPosition legendPosition = ChartLegendPosition.topRight, int legendPadding = 1, int? crosshairX, int? crosshairY, UvStyle? crosshairStyle, Key? key})
Creates a HeatmapChart with the given grid data and display options.

Properties

accessibilityLabel → String?
Optional accessibility label.
no setterinherited
accessibilityRole → String
Optional accessibility role.
no setterinherited
children → List<Widget>
Child widgets that receive forwarded messages.
no setterinherited
crosshairStyle → UvStyle?
Style for the crosshair lines.
final
crosshairX → int?
X coordinate for crosshair overlay, or null to hide.
final
crosshairY → int?
Y coordinate for crosshair overlay, or null to hide.
final
debugRenderObjectPassthrough → bool
Whether this widget is intentionally transparent to render-object layouts.
no setterinherited
degradationSignal → WidgetDegradationSignal
Signal that controls this widget's render budget behavior.
no setterinherited
focusable → bool
Whether this widget can receive keyboard focus.
no setterinherited
glyph → String
Character placed in each cell (visible only when useBackground is false).
final
grid → List<List<double>>
The 2D array of values, each in [0..1].
final
gridCols → int
Number of vertical grid lines.
final
gridRows → int
Number of horizontal grid lines.
final
gridStyle → UvStyle?
Style for grid overlay lines.
final
hashCode → int
The hash code for this object.
no setterinherited
height → int?
The chart height in terminal rows, or null to fill available space.
final
id → String
Unique identifier for this widget.
no setterinherited
key → Key?
Key for preserving widget identity.
finalinherited
labelStyle → UvStyle?
Style for axis labels.
final
legendColumns → int
Number of legend columns.
final
legendEntries → List<ChartLegendEntry>?
Optional legend entries rendered inside chart bounds.
final
legendPadding → int
Inner padding from chart edges to legend area.
final
legendPosition → ChartLegendPosition
Legend placement within chart bounds.
final
legendRowGap → int
Empty rows inserted between legend rows.
final
ramp → ChartRamp?
Colour ramp for value-to-colour mapping.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
showGrid → bool
Whether to draw a grid overlay.
final
theme → Theme
Access the current theme.
no setterinherited
useBackground → bool
If true, applies colour as background; otherwise as foreground.
final
width → int?
The chart width in terminal columns, or null to fill available space.
final
xLabels → List<String>?
Labels along the bottom (X) axis.
final
yLabels → List<String>?
Labels along the left (Y) axis.
final

Methods

buildCachedView<T>(T builder(), Object? cacheKey) → T
Returns a cached view if the cache key matches.
inherited
createRenderObject() → RenderObject
override
didUnmountRenderObject(RenderObject renderObject) → void
inherited
handleInit() → Cmd?
Override this instead of init for widget-specific initialization.
inherited
handleIntercept(Msg msg) → (Widget, Cmd?)
Override this to handle messages before they reach children.
inherited
handleUpdate(Msg msg) → (Widget, Cmd?)
Override this to handle messages specific to this widget.
inherited
init() → Cmd?
Called once when the widget is first mounted.
inherited
invalidateCachedView() → void
Clears any cached view for this widget.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
shouldRenderAt(DegradationLevel degradationLevel, {required bool subtreeHasFocusedWidget}) → bool
Whether this widget should participate in the current render when degradationLevel is active.
inherited
toString() → String
A string representation of this object.
inherited
update(Msg msg) → (Model, Cmd?)
Handles messages by forwarding to children then calling handleUpdate.
inherited
updateRenderObject(RenderObject renderObject) → void
override
view() → Object
Renders the widget to a string or View.
override

Operators

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