Geometries module

GeometriesModule draws polygons on the map, each with a fill, a border and a label. They can be administrative boundaries from the geometry data service, or any GeoJSON Polygon and MultiPolygon features of your own.

• It owns the fills, borders and labels it draws and how they look, through color, fill, line, the labels, the fill style and the palette.
• It never restyles the base map, which belongs to the Styling Foundations module. Styling knobs never reach geometry layers, and a geometry with no colour takes the map's accent. Who owns what draws the line for every module.

Showing geometries

Initializing geometry module

import { TomTomConfig } from '@tomtom-org/maps-sdk/core';
import { TomTomMap, GeometriesModule } from '@tomtom-org/maps-sdk/map';

TomTomConfig.instance.put({ apiKey: 'YOUR_API_KEY' });
const map = new TomTomMap({ mapLibre: { container: 'map' } });

const geometryModule = await GeometriesModule.create(map);

Displaying administrative boundaries

import { geocode, geometryData } from '@tomtom-org/maps-sdk/services';

const place = (await geocode({ query: 'Amsterdam, Netherlands' })).features[0];
const geometryResponse = await geometryData({ geometries: [place] });

await geometryModule.show(geometryResponse);

show replaces the geometries shown, and clear removes them.

Custom styling configuration

One top-level color sets the fill and the border together:

const geometryModule = await GeometriesModule.create(map, { color: '#E63312' });

The colours resolve in this order, and the first match wins:

• The accent applies when a theme sets one.
• The default follows the map style: navy #0A3653 on light styles, sky blue #5FA8D8 on dark ones.
• With fill.style: 'outline', the border is a neutral grey, #555555, instead of the accent or the default.

fill and line configure the fill and the border separately. The fill takes fill: { color, opacity }, or a palette instead of one colour. The border takes line: { color, width, opacity }:

const geometryModule = await GeometriesModule.create(map, {
    fill: { color: '#007cbf', opacity: 0.3 },
    line: { color: '#005a8b', width: 2, opacity: 0.8 },
    beforeLayerConfig: 'lowestLabel' // below all the map's labels
});

For anything else, layers takes a partial MapLibre layer, without id or source, for each of the module's layers: fill, line (the border), label (the center labels) and lineLabel (the border labels). An entry can set any property of its layer. Its paint and layout merge per property onto the module's own and override the curated fields:

const geometryModule = await GeometriesModule.create(map, {
    line: { color: '#00A65E', width: 2 },
    layers: {
        line: {
            paint: {
                'line-offset': 2,          // inset/outset border, in pixels
                'line-blur': 4,            // glow, in pixels
                'line-dasharray': [2, 2],  // dash pattern in line-width units
                'line-gap-width': 3        // hollow casing
            },
            layout: { 'line-cap': 'round' }
        },
        label: { layout: { 'text-transform': 'uppercase' } }
    }
});

• beforeLayerConfig alone positions the layers, so a beforeID in an entry is ignored.
• A layer hidden through layout.visibility stays hidden while the module is shown.
• updateConfig({ layers }) repaints the geometries shown without preparing them again.

Restyling shown geometries

A config change to the colours, fill style, labels or transformFeaturesForDisplay updates the geometries on the map without a new show(). applyConfig replaces the whole config, updateConfig changes only what you pass, and resetConfig restores the defaults:

await geometryModule.show(cityBoundaries);

geometryModule.updateConfig({ fill: { style: 'outline', palette: ['#e63312', '#f5a000'] } });
geometryModule.updateConfig({ label: { title: ['get', 'name'] } }); // keeps the palette and fill style
geometryModule.resetConfig(); // default colours, fill style and labels

getConfig() returns the settings to store. All of it survives JSON except the transformFeaturesForDisplay function. GeometriesModuleSerializableConfig types what you parse back, and you add the function in code:

import type { GeometriesModuleSerializableConfig } from '@tomtom-org/maps-sdk/map';

const saved: GeometriesModuleSerializableConfig = JSON.parse(JSON.stringify(geometryModule.getConfig()));
geometryModule.applyConfig({ ...saved, transformFeaturesForDisplay: addAreaLabels });

Hovered and clicked geometries

Once a handler covers the geometries, a hovered or clicked geometry draws a denser fill and a wider border in its own colour. The module's event state methods set that state from your own UI:

geometryModule.events.on('click', (geometry) => console.log(geometry.properties.name));
geometryModule.setEventState({ index: 0, state: 'click' });

An id is the properties.id that getShown() and the handlers return. The module generates one for a feature that has none, so a geometry data result's top-level id matches nothing.

highlight sets how much denser the fill gets and how much wider the border. Try it in the geometry config playground:

• By default, the fill opacity doubles, up to fully opaque, and the border width grows 1.75 times.
• The factors multiply the current opacity and width, including a fill.opacity or line.width you set.
• A factor of 1 draws a hovered geometry like any other, keeping its look fixed.
• A width you set through layers.line stays the same in every state.

geometryModule.applyConfig({
    fill: { opacity: 0.3 },
    highlight: { fill: { opacityFactor: 3 }, line: { widthFactor: 1 } }, // 0.9 while hovered, the border as is
});

Events

events covers the geometries and all their labels, and a handler receives the feature as drawn. Two named scopes each cover one surface, with the same handlers and event states. events.geometry covers the fills, borders and border labels, and events.geometryLabel covers the center labels.

geometryModule.events.on('click', (geometry, lngLat) => console.log(geometry.properties.title, lngLat));
geometryModule.events.geometry.on('hover', (geometry) => showTooltip(geometry.properties.title));

The user events guide covers the event types and their timings.

Showing and hiding

setVisible hides and shows the fills, borders, center labels and border labels together. To start the module hidden, pass visible: false at creation. show() and clear() never change visibility, so geometries shown while hidden appear on setVisible(true). The state survives a style change.

function toggleGeometry() {
    geometryModule.setVisible(!geometryModule.isVisible());
}

Layer positioning and styling

A single beforeLayerConfig positions all geometry layers together. The record form { all?, fill?, line? } places the fill and the border separately:

• Each part uses its own entry, otherwise all, otherwise its default place just below the geometry titles.
• 'top' keeps the titles above everything else.
• updateConfig({ beforeLayerConfig }) moves the layers by the same rules, so a part with no target in the new value returns to its default place.

const geometryModule = await GeometriesModule.create(map, {
    fill: { color: '#87CEEB', opacity: 0.5 },
    line: { color: '#4682B4', width: 1.5 },
    // Fill slips below the road network, the border below the map's labels
    beforeLayerConfig: { fill: 'lowestRoadLine', line: 'lowestLabel' }
});

Labels

Each polygon whose feature has a title property gets a center label, which label styles. lineLabel repeats it along the border, but only when you set it. Pass {} for the defaults.

• Both take a title, a string or a MapLibre expression that defaults to the feature's title.
• Both take the styling fields every module's labels share: size, color, haloColor, haloWidth, opacity and font.
• lineLabel adds minZoom, symbolSpacing and offset.
• Colours you don't set follow the map style, with dark text on a white halo on light styles and the reverse on dark ones.

const module = await GeometriesModule.create(map, {
    label: { title: ['get', 'name'], size: 18, color: '#FFFFFF', haloColor: '#000000' },
    lineLabel: { title: ['get', 'name'], minZoom: 10, size: 13, offset: [0, 1], symbolSpacing: 350 },
});

// Later: restyle the center labels of the shown geometries, keeping their other settings
module.updateConfig({ label: { ...module.getConfig()?.label, size: 20 } });

Deriving display properties

transformFeaturesForDisplay receives what you passed to show() and returns the features to draw, so a label or a colour can come from your own domain data. It runs on every show(), and again whenever a config change alters what is drawn:

const module = await GeometriesModule.create(map, {
    transformFeaturesForDisplay: (geometries) => ({
        ...geometries,
        features: geometries.features.map((feature) => ({
            ...feature,
            properties: { ...feature.properties, title: `${feature.properties?.name} (${feature.properties?.population})` },
        })),
    }),
});

Fill styles

Setting the fill style at config level

fill.style applies one fill style to every feature, and a feature's own fillStyle property overrides it:

import { GeometriesModule } from '@tomtom-org/maps-sdk/map';

// Highlight "rest of the world" outside a country
const module = await GeometriesModule.create(map, {
    fill: { style: 'inverted', color: 'black', opacity: 0.5 },
});
await module.show(countryGeometry);

Using fillStyledGeometryConfig for mixed fill styles

For features in one module with different fill styles, fillStyledGeometryConfig({ palette?, beforeLayerConfig? }) returns a config whose expressions read each feature's fillStyle property. beforeLayerConfig defaults to 'lowestLabel', and the config draws the border labels too.

import { GeometriesModule, fillStyledGeometryConfig } from '@tomtom-org/maps-sdk/map';

const module = await GeometriesModule.create(map, fillStyledGeometryConfig({ palette: ['#0077b6', '#90e0ef'] }));

await module.show({
    type: 'FeatureCollection',
    features: [
        { ...featureA, properties: { fillStyle: 'filled', title: 'Zone A' } },
        { ...featureB, properties: { fillStyle: 'outline', title: 'Zone B' } },
    ],
});

Color palettes

fill.palette is a list of CSS colours that the features take in turn, starting over after the last, so neighbouring polygons stay distinct without a colour assigned to each.

• An empty list counts as unset. Without a palette, every feature draws in one colour, the map's accent or the default.
• The precedence table shows where fill.palette sits among the colours.
• To match the map, take the palette from the colours the map is themed from. The map-theme plugin's deriveMapColors returns them by role.

import { fillStyledGeometryConfig, GeometriesModule } from '@tomtom-org/maps-sdk/map';
import { deriveMapColors } from '@tomtom-org/maps-sdk-plugin-map-theme';

const regions = await GeometriesModule.create(map, {
    fill: { palette: ['#ffadad', '#ffd6a5', '#caffbf', '#a0c4ff'], opacity: 0.3 },
});

// fillStyledGeometryConfig takes it as its `palette` option
const { accent, water, roadMajor } = deriveMapColors(['#1d3f8a', '#e63312', '#f5d000', '#f4f1ea']);
const zones = await GeometriesModule.create(map, fillStyledGeometryConfig({ palette: [accent, water, roadMajor] }));

Reachable ranges have their own reachable ranges module. It titles each band from its budget, nests each origin's bands and colours them from the map.

Every setting as data

geometriesKnobCatalogue lists every plain-valued display setting of the module with its kind, its range or options, and its default where one value holds everywhere. Each id is the setting's path in the config, so a UI can build its controls from it with no map loaded:

import { geometriesKnobCatalogue } from '@tomtom-org/maps-sdk/map';

const borderKnobs = geometriesKnobCatalogue.filter(({ id }) => id.startsWith('line.'));
// [{ id: 'line.color', kind: 'color', description: '…' }, …,
//  { id: 'line.width', kind: 'number', description: '…', range: { min: 0, max: 20, step: 0.5, bounds: 'hard-min' } }]

• Opacities and widths have no default entry where the fill style decides them, and colours have none where the accent or the map style does.
• Setting any lineLabel knob draws the border labels.
• A font knob takes its options from mapFonts. Order matters, since the first font the map has wins. Unset, the labels are in Noto-Bold set in their typeface, and getKnob returns undefined.
• lineLabel.offset is in ems, x along the line and y across it, and defaults to [0, 1].
• geometriesKnobIds lists the ids in catalogue order, GeometriesKnobId is their union, and GeometriesKnobValueOf<ID> is the plain value one takes.
• It leaves out beforeLayerConfig, layers, the labels' title and transformFeaturesForDisplay, which take structured, MapLibre or function values, and events.
• Its entries share their shape, KnobEntry, with every module's catalogue.

Multiple module instances

Each instance has its own sources, layers and configuration, so several can show different sets of geometries side by side:

const countryBorders = await GeometriesModule.create(map, {
    fill: { color: '#E74C3C', opacity: 0.2 },
    line: { color: '#C0392B', width: 3 }
});

const cityBounds = await GeometriesModule.create(map, {
    fill: { color: '#3498DB', opacity: 0.3 },
    line: { color: '#2980B9', width: 2 }
});

await countryBorders.show(countryData);
await cityBounds.show(cityData);

Reading shown data

getShown() returns what the module draws, as prepared for display:

• geometry - The polygons with the colours, fill styles and titles the config gave them. An inverted one covers the area outside it.
• geometryLabel - The points where their center labels sit.

const { geometry } = geometryModule.getShown();
console.log(`Geometries: ${geometry.features.length}`);

Related guides and examples

Services integration

• Geometry data service - Boundary and shape data for administrative areas and places
• Search services - Finding places and administrative areas that have geometry data

Related examples

• Basic geometry - Simple geometry display and styling
• Multiple geometries - Several geometry layers and data sets
• Multiple geometry modules - Several modules managed side by side
• Geometry config playground - Fill and border colours, layer-stack positions, visibility and the clicked look
• Places in geometry - Geometry boundaries combined with place markers
• Geometry search playground - Searching inside a geometry

Related map modules

• Reachable ranges module - Ranges calculated by budget, drawn as bands nested around their origins
• Places module - Places and POIs within or around geometric boundaries
• Routing module - Routes through geometric areas
• User interaction events - User interactions with geometric shapes and boundaries