Module select 

Selection policy — Selectable and the chart elements that implement it.

Selectable objects expose their interaction-policy pixel bounds (bounds); what selection does is fixed by the trait’s default methods so it applies uniformly to every element: a blue highlight box around the bounds (selection_box) and point hit-testing (contains). The renderer draws the box with skia (axis_render::draw_selection_boxes); the model only states the policy.

Placement formulas shared with the renderer consume glyph extents through the MeasureText contract. Tick labels intentionally use a representative strip instead of reproducing renderer-owned tick generation, formatting, pruning, or the exact union of rendered labels.

Structs

AxisElement

One of the four axes — the axis line plus its tick band.

AxisLabelElement

One axis’s tick-value labels — the band the numeric labels live in, between the tick ends and the outer chart edge.

AxisTitleElement

One axis title (rotated 90° on Left/Right sides).

ChartTitleElement

The chart title in the top band.

ColorBarAxisElement

The colourbar axis line plus its major/minor tick band.

ColorBarElement

The colourbar strip.

ColorBarLabelElement

The colourbar’s tick-value label band.

ColorBarTitleElement

The colourbar title, rotated on vertical bars.

DataAreaElement

The data plotting area (everything inside the margins).

HitId

Id of an entry registered in a HitMap. Stable for the map’s lifetime.

HitMap

Registry of selectable elements for one chart panel + point hit-testing.

LegendElement

The legend box in one corner of the data area.

SelectionBox

The blue box drawn around a selected element. Produced by Selectable::selection_box; consumed by the renderer’s skia pass.

Constants

SELECTION_COLOR

Selection highlight color (blue).

SELECTION_PADDING

Gap between the element bounds and the highlight box, px.

SELECTION_STROKE_WIDTH

Stroke width of the highlight box, px.

Traits

Selectable

An object the user can select on the chart.