charting library

Charting primitives for terminal-native visualizations.

Provides reusable renderers for sparklines, histograms, heatmaps, and ribbon/area charts that draw into UV buffers.

Classes

ChartCanvas

A convenience canvas for rendering charts into UV buffers.

ChartLegendEntry

A single entry in a chart legend.

ChartRamp

Discrete color ramp for mapping normalized 0..1 values to colors.

Functions

clamp01(double value) → double

Clamps value to the range 0..1, treating NaN as 0.

drawAxisLabels(Screen screen, Rectangle area, {List<String>? xLabels, List<String>? yLabels, UvStyle style = const UvStyle()}) → void

Draws axis labels along the X and/or Y edges of area.

drawCrosshair(Screen screen, Rectangle area, int x, int y, {UvStyle style = const UvStyle(), String hChar = '─', String vChar = '│', String intersectionChar = '┼', bool drawOnEmpty = true}) → void

Draws a crosshair overlay at (x, y) within area.

drawGrid(Screen screen, Rectangle area, {int rows = 3, int cols = 3, UvStyle style = const UvStyle(), String hChar = '┄', String vChar = '┆', String intersectionChar = '┼', bool preserveBackground = false}) → void

Draws a grid of horizontal and vertical guide lines within area.

drawHeatmap(Screen screen, Rectangle area, List<List<double>> grid, {ChartRamp? ramp, bool useBackground = true, String glyph = ' ', bool showGrid = false, int gridRows = 3, int gridCols = 3, UvStyle gridStyle = const UvStyle(), List<String>? xLabels, List<String>? yLabels, UvStyle labelStyle = const UvStyle()}) → void

Draws a heatmap of the 2-D grid values into area on screen.

drawHistogram(Screen screen, Rectangle area, List<double> values, {UvStyle barStyle = const UvStyle(), UvStyle axisStyle = const UvStyle(), UvStyle gridStyle = const UvStyle(), UvStyle labelStyle = const UvStyle(), bool showAxis = true, bool showGrid = false, int gridRows = 3, int gridCols = 0, List<String>? xLabels, List<String>? yLabels, String barChar = '█', int barGap = 1}) → void

Draws a vertical bar histogram of values into area on screen.

drawLegend(Screen screen, Rectangle area, List<ChartLegendEntry> entries, {int columns = 1, int rowGap = 0}) → void

Draws a legend for the given entries within area.

drawLineChart(Screen screen, Rectangle area, List<double> values, {UvStyle lineStyle = const UvStyle(), UvStyle gridStyle = const UvStyle(), UvStyle labelStyle = const UvStyle(), bool showGrid = false, int gridRows = 3, int gridCols = 3, bool showMarkers = true, String markerChar = '●', String lineChar = '•', List<String>? xLabels, List<String>? yLabels}) → void

Draws a line chart of values into area on screen.

drawPieChart(Screen screen, Rectangle area, List<double> values, {List<UvStyle>? styles, bool useBackground = true, bool donut = false, double innerRadiusRatio = 0.45, double cellAspect = 2.0, String glyph = ' '}) → void

Draws a pie (or donut) chart of values into area on screen.

drawRibbonChart(Screen screen, Rectangle area, List<List<double>> series, {List<UvStyle>? styles, bool normalizeTotals = true, String fillChar = '█', bool showGrid = false, int gridRows = 3, int gridCols = 0, UvStyle gridStyle = const UvStyle()}) → void

Draws a stacked ribbon chart of multiple series into area on screen.

drawSparkline(Screen screen, Rectangle area, List<double> values, {UvStyle style = const UvStyle(), bool showGrid = false, UvStyle gridStyle = const UvStyle()}) → void

Draws a compact sparkline of values into area on screen.

normalize(double value, double min, double max) → double

Normalizes value into the 0..1 range between min and max.

putText(Screen screen, Rectangle area, int x, int y, String text, UvStyle style) → void

renderChartLines(int width, int height, ChartPainter painter) → List<String>

Renders a chart into a list of lines.

sampleSeries(List<double> values, int width) → List<double>

Down-samples or up-samples values to fit the given width.

uvColorFromHex(String hex, {UvColor fallback = const UvBasic16(7)}) → UvColor

Parses a hex color string (e.g. '#ff0000') into a UvColor.

uvStyleFromHex(String hex, {String? backgroundHex, int attrs = 0}) → UvStyle

Creates a UvStyle from hex color strings for foreground and optional background.

Typedefs

ChartPainter = void Function(Screen screen, Rectangle area)

Signature for chart painters.