The layers control is a native map control: it stacks alongside other
controls (navigation, fullscreen, etc.) in its corner rather than
overlapping them, following the order in which controls are added to the
map. Its default appearance matches the other map controls (white
background, dark monochrome items). To restore the blue active style from
earlier versions of mapgl, set active_color = "#4a90e2" and
active_text_color = "#ffffff".
Usage
add_layers_control(
map,
position = "top-left",
layers = NULL,
collapsible = TRUE,
use_icon = TRUE,
background_color = NULL,
active_color = NULL,
hover_color = NULL,
active_text_color = NULL,
inactive_text_color = NULL,
margin_top = NULL,
margin_right = NULL,
margin_bottom = NULL,
margin_left = NULL,
mode = c("multiple", "single")
)Arguments
- map
A map object.
- position
The position of the control on the map (one of "top-left", "top-right", "bottom-left", "bottom-right").
- layers
Either a character vector of layer IDs to include in the control, a named list/vector where names are labels and values are layer IDs, or a named list where values can be vectors to group multiple layers together. If NULL, all layers will be included.
- collapsible
Whether the control should be collapsible.
- use_icon
Whether to use a stacked layers icon instead of the "Layers" text when collapsed. Only applies when collapsible = TRUE.
- background_color
The background color for the layers control; this will be the color used for inactive layer items.
- active_color
The background color for active layer items.
- hover_color
The background color for layer items when hovered.
- active_text_color
The text color for active layer items.
- inactive_text_color
The text color for inactive layer items.
- margin_top
Optional top margin in pixels, applied to the control within the native control stack. Rarely needed now that the control no longer overlaps other controls; NULL (the default) uses standard control spacing.
- margin_right
Optional right margin in pixels. Default is NULL.
- margin_bottom
Optional bottom margin in pixels. Default is NULL.
- margin_left
Optional left margin in pixels. Default is NULL.
- mode
How many entries can be visible at once. In
"multiple"mode (the default), entries toggle independently. In"single"mode, activating an entry turns the others off — useful for flipping through alternative analytical layers or raster imagery where only one should show at a time. Clicking the active entry does nothing. When the control is created in"single"mode with several entries visible, the first visible entry stays on and the rest are turned off. To combine both behaviors on one map, add two controls: one"single"-mode control for the alternatives and one"multiple"-mode control for independent overlays.
Examples
if (FALSE) { # \dontrun{
library(tigris)
options(tigris_use_cache = TRUE)
rds <- roads("TX", "Tarrant")
tr <- tracts("TX", "Tarrant", cb = TRUE)
cty <- counties("TX", cb = TRUE)
maplibre() |>
fit_bounds(rds) |>
add_fill_layer(
id = "Census tracts",
source = tr,
fill_color = "purple",
fill_opacity = 0.6
) |>
add_line_layer(
"Local roads",
source = rds,
line_color = "pink"
) |>
add_layers_control(
position = "top-left",
background_color = "#ffffff",
active_color = "#4a90e2"
)
# With custom labels
maplibre() |>
add_fill_layer(id = "tract-fill", source = tr) |>
add_line_layer(id = "tract-line", source = tr) |>
add_layers_control(
layers = list(
"Census Tracts" = "tract-fill",
"Tract Borders" = "tract-line"
)
)
# Group multiple layers together
maplibre(bounds = cty) |>
add_fill_layer(id = "county-fill", source = cty, fill_opacity = 0.3) |>
add_line_layer(
id = "county-outline",
source = cty,
line_color = "yellow",
line_width = 3
) |>
add_line_layer(
id = "roads-layer",
source = rds,
line_color = "blue"
) |>
add_layers_control(
layers = list(
"Counties" = c("county-fill", "county-outline"),
"Roads" = "roads-layer"
)
)
} # }