BarChart

Multi-series stacked bar chart with optional y-axis, grid, value labels, and legend. Bars render vertically (default) or horizontally.

Constructor: NewBarChart(id, class string) *BarChart

Configure data, axes, and orientation via the setter methods after construction.

Data types

type BarSeries struct {
    Label  string    // legend label; may be empty
    Values []float64 // one value per category, all >= 0
}

Methods

• SetSeries(s []BarSeries) — replace all series
• AddSeries(s BarSeries) — append a series
• Series() []BarSeries — current series
• SetCategories(labels []string) — category labels (one per index of Values)
• Categories() []string — current category labels
• SetAbsolute(v bool) — when true, values are drawn as absolute heights instead of stacked
• SetMax(v float64) — explicit y-axis max (zero means auto)
• SetHorizontal(v bool) — flip to horizontal orientation
• SetShowAxis(v bool) — toggle y-axis labels
• SetShowGrid(v bool) — toggle background grid
• SetShowValues(v bool) — toggle per-bar value labels
• SetLegend(v bool) — toggle legend
• SetBarWidth(w int) — width of each bar in cells (≥ 1)
• SetBarGap(g int) — gap between bars (≥ 0)
• SetTicks(n int) — number of y-axis ticks (≥ 2)
• Select(index int) — set focused category; fires EvtSelect
• Selected() int — current focused category

Events

Event	Data	Description
"select"	int	Focused category index changed
"activate"	int	Enter pressed or category clicked twice

Notes

Flags: "focusable".

Keyboard: ←/→ (or ↑/↓ when horizontal) move the selection by one category; Home/End jump to the first/last; Enter activates. Single mouse click selects, double click activates.