Layers
LineLayer
The LineLayer component is used to render lines on your map, ideal for displaying paths, borders, routes, or any other linear features.
It works in conjunction with a data source, such as GeojsonSource, which provides the geographic data for the lines.
Reference: Line
Usage
The LineLayer component is typically used within a parent source component, such as GeojsonSource, which supplies the line geometries.
Style customization
You can also configure the appearance and behavior of the layer using the layout and paint options, similar to other layers in libregl.
Also, the component exposes a paint() method, which allows you to modify the paint properties of the layer programmatically.
This makes it easy to dynamically adjust styles, such as circle color or size, based on user input or other conditions.
Toggle layer visibility
You can programmatically control the visibility of the line layer on the map using the exposed toggle() method.
This method toggles the layer’s visibility by interacting with MapLibre’s setLayoutProperty() function.
Behind the scenes, it adjusts the visibility property of the line layer between visible and none.
Without source component
And of course, when using CircleLayer without a parent source component, you can pass a source prop directly to the layer, here is an example.
Rerendering data
The data prop in the GeojsonSource is reactive, once the data changes, libregl automatically rerenders the layer like a charm, ensuring your map always reflects the latest data, here is an example.
Listening to events
You can listen to layer’s events once you pass the event name like @click, @mousemove and more, to learn more about supported events please visit the offical documentation at MapLayerEventType.
API
Events
The LineLayer component’s events.
| Prop | Description | Type |
|---|---|---|
| click | Fired when a pointing device (usually a mouse) is pressed and released contains a visible portion of the specified layer. | MapLayerMouseEvent |
| contextmenu | Fired when the right button of the mouse is clicked or the context menu key is pressed within visible portion of the specified layer. | MapLayerMouseEvent |
| dblclick | Fired when a pointing device (usually a mouse) is pressed and released twice contains a visible portion of the specified layer. | MapLayerMouseEvent |
| mousedown | Fired when a pointing device (usually a mouse) is pressed while inside a visible portion of the specified layer. | MapLayerMouseEvent |
| mouseenter | Fired when a pointing device (usually a mouse) enters a visible portion of a specified layer from outside that layer or outside the map canvas. | MapLayerMouseEvent |
| mouseleave | Fired when a pointing device (usually a mouse) leaves a visible portion of a specified layer, or leaves the map canvas. | MapLayerMouseEvent |
| mousemove | Fired when a pointing device (usually a mouse) is moved while the cursor is inside a visible portion of the specified layer. As you move the cursor across the layer, the event will fire every time the cursor changes position within that layer. | MapLayerMouseEvent |
| mouseout | Fired when a point device (usually a mouse) leaves the visible portion of the specified layer. | MapLayerMouseEvent |
| mouseover | Fired when a pointing device (usually a mouse) is moved inside a visible portion of the specified layer. | MapLayerMouseEvent |
| mouseup | Fired when a pointing device (usually a mouse) is released while inside a visible portion of the specified layer. | MapLayerMouseEvent |
| touchcancel | Fired when a touchstart event occurs within the visible portion of the specified layer. | MapLayerMouseEvent |
| touchend | Fired when a touchend event occurs within the visible portion of the specified layer. | MapLayerMouseEvent |
| touchstart | Fired when a touchstart event occurs within the visible portion of the specified layer. | MapLayerMouseEvent |
Props
The Heatmap component’s props.
While an id is typically required for MapLibre layers, the HeatmapLayer component automatically generates a unique id if none is provided.
| Prop | Description | Type |
|---|---|---|
| id | The id for the source. Must not be used by any existing source. | Optional string |
| metadata | Arbitrary properties useful to track with the layer, but do not influence rendering. Properties should be prefixed to avoid collisions, like ‘maplibre:’. | Optional |
| source | Name of a source description to be used for this layer. | Optional GeoJSONSourceSpecification or string |
| minzoom | The minimum zoom level for the layer. At zoom levels less than the minzoom, the layer will be hidden. | Optional number in range [0, 24]. |
| maxzoom | The maximum zoom level for the layer. At zoom levels equal to or greater than the maxzoom, the layer will be hidden. | Optional number in range [0, 24]. |
| filter | A expression specifying conditions on source features. Only features that match the filter are displayed. Zoom expressions in filters are only evaluated at integer zoom levels. The feature-state expression is not supported in filter expressions. | Optional filter |
| layout | Layout properties for the layer. | Optional HeatmapSpecification[‘layout’] |
| paint | Default paint properties for this layer. | Optional HeatmapSpecification[‘paint’] |