Interactive focus-map viewer — focus

Renders spatial features as a smooth, interactive SVG map. Click any polygon to zoom in and lift it from the map with a "toast" effect; right-click or press Escape to reset. Camera transitions use D3's optimal zoom interpolation for fluid 60 fps motion with zero server round-trips.

Usage

focus_map(
  x,
  label_col = NULL,
  id_col = NULL,
  group_col = NULL,
  simplify = TRUE,
  fill = "#2d6ea3",
  fill_opacity = 0.58,
  stroke = "#ffffff",
  lift_scale = 1.16,
  focus_padding = 40,
  focus_size = 0.76,
  max_zoom = NULL,
  font_size = 14,
  show_labels = TRUE,
  show_sidebar = TRUE,
  performance_mode = NULL,
  info_cols = NULL,
  info_labels = NULL,
  info_title = NULL,
  info_position = c("top-right", "top-left", "bottom-right", "bottom-left"),
  info_card_scale = 1,
  area_min = 5000,
  width_min = 95,
  height_min = 28,
  width = "100%",
  height = "600px",
  elementId = NULL
)

focusmapOutput(outputId, width = "100%", height = "600px")

renderFocusmap(expr, env = parent.frame(), quoted = FALSE)

Arguments

x: An sf, exploded_map, or grouped_exploded_map object.
label_col: Character. Column name for polygon labels. Auto-detected if NULL.
id_col: Optional stable feature ID column for Shiny selection events. Defaults to row order if NULL.
group_col: Character. Optional column for region/group colouring. Polygons sharing a group value share a hue.
simplify: Controls geometry simplification for rendering performance. TRUE (default) applies a sensible tolerance (dTolerance = 0.001 in WGS 84 degrees, \(\approx\) 100 m). A positive number sets a custom tolerance. FALSE disables simplification. Only affects the widget copy — the original data is never modified.
fill: Fill colour (used when group_col is NULL). Default "#2d6ea3".
fill_opacity: Fill opacity. Default 0.58.
stroke: Stroke colour. Default "#ffffff".
lift_scale: Initial toast lift scale. Default 1.16. Increase this to make the lifted feature larger.
focus_padding: Extra screen-space padding in pixels around the lifted feature during focus. Increase this if large lifted features feel too close to the map edge.
focus_size: Target fraction of the map viewport the lifted feature may occupy. Increase this to make selected areas appear larger while preserving focus_padding.
max_zoom: Optional maximum camera zoom. If NULL, a density-aware default is used.
font_size: Label font size in px. Default 14.
show_labels: Show labels on lifted shapes? Default TRUE.
show_sidebar: Show control sidebar? Default TRUE.
performance_mode: Logical or NULL. If NULL, dense layers automatically use shorter camera transitions and lighter in-flight rendering. Set TRUE to force it or FALSE to disable it.
info_cols: Optional character vector of columns to show in a non-blocking focus card when a feature is selected.
info_labels: Optional named character vector or list for display labels in the focus card. Names should match info_cols.
info_title: Optional column to use as the focus card title. Defaults to label_col.
info_position: Position for the focus card: "top-right", "top-left", "bottom-right", or "bottom-left".
info_card_scale: Relative size for the focus card. Values above 1 make the card larger; values below 1 make it more compact.
area_min: Min screen area (px^2) for label visibility.
width_min: Min screen width (px) for label visibility.
height_min: Min screen height (px) for label visibility.
width: Widget width. Default "100%".
height: Widget height. Default "600px".
elementId: Optional element ID.
outputId: Shiny output ID.
expr: Expression that returns a focus_map() widget.
env: Environment in which to evaluate expr.
quoted: Logical. Is expr already quoted?

Value

An htmlwidgets object.

Details

Accepts raw sf objects, exploded_map results from explode_sf, or grouped_exploded_map results from explode_grouped. For exploded objects, the displaced (WGS 84) geometry is used automatically.

Examples

if (FALSE) { # \dontrun{
focus_map(nj_counties, label_col = "NAME")

result <- explode_sf(nj_counties, region_col = "region")
focus_map(result)
focus_map(result, group_col = "region")
} # }