Add hover effects to gg2d3 widget — d3

Enables hover highlighting for a gg2d3 widget. When hovering over an element, other elements are dimmed (reduced opacity) and the hovered element can optionally receive a highlight stroke.

Usage

d3_hover(widget, opacity = 0.3, stroke = NULL, stroke_width = NULL)

Arguments

widget: A gg2d3 widget object created by gg2d3()
opacity: Numeric opacity value (0-1) for non-hovered elements. Default is 0.3, which strongly dims other elements so the hovered one stands out. The hovered element always has opacity 1.0.
stroke: Optional stroke color for hovered element (e.g., "black", "#ff0000"). If NULL, no highlight stroke is added.
stroke_width: Optional stroke width in pixels for hovered element. Only used if stroke is provided. Default is NULL.

Value

Modified gg2d3 widget with hover effects enabled. Returns the widget to enable pipe chaining.

Details

For ordinary geom_polygon() paths and geom_sf() polygon-family, point-family, line-family, geom_sf_text(), and geom_sf_label() marks, hover uses the existing shared event handling path and exposes sanitized source-row payloads without renderer-private fields.

Examples

if (FALSE) { # \dontrun{
library(ggplot2)
p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()

# Basic hover with default dimming
gg2d3(p) |> d3_hover()

# Custom opacity
gg2d3(p) |> d3_hover(opacity = 0.3)

# Add highlight stroke
gg2d3(p) |> d3_hover(stroke = "red", stroke_width = 2)

# Combine with tooltips
gg2d3(p) |> d3_tooltip() |> d3_hover(opacity = 0.5)
} # }