---
title: "Add an animated icon to the map | JavaScript maps SDK"
description: "Add animated icons generated at runtime using Canvas API."
---
> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.
# Add an animated icon to the map
Add an animated icon to the map that was generated at runtime with the [Canvas API](https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API).
### NPM module setup
```bash
npm install --save @maptiler/sdk
```
#### main.js
```js
import { Map, MapStyle, config } from '@maptiler/sdk';
import '@maptiler/sdk/dist/maptiler-sdk.css';
config.apiKey = 'YOUR_MAPTILER_API_KEY_HERE';
const map = new Map({
container: 'map',
style: MapStyle.STREETS,
center: [-80.19, 25.76],
zoom: 12
});
const size = 200;
// implementation of CustomLayerInterface to draw a pulsing dot icon on the map
// see https://docs.maptiler.com/sdk-js/api/properties/#customlayerinterface for more info
const pulsingDot = {
width: size,
height: size,
data: new Uint8Array(size * size * 4),
// get rendering context for the map canvas when layer is added to the map
onAdd: function () {
const canvas = document.createElement('canvas');
canvas.width = this.width;
canvas.height = this.height;
this.context = canvas.getContext('2d');
},
// called once before every frame where the icon will be used
render: function () {
const duration = 1000;
const t = (performance.now() % duration) / duration;
const radius = (size / 2) * 0.3;
const outerRadius = (size / 2) * 0.7 * t + radius;
const context = this.context;
// draw outer circle
context.clearRect(0, 0, this.width, this.height);
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
outerRadius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 200, 200,' + (1 - t) + ')';
context.fill();
// draw inner circle
context.beginPath();
context.arc(
this.width / 2,
this.height / 2,
radius,
0,
Math.PI * 2
);
context.fillStyle = 'rgba(255, 100, 100, 1)';
context.strokeStyle = 'white';
context.lineWidth = 2 + 4 * (1 - t);
context.fill();
context.stroke();
// update this image's data with data from the canvas
this.data = context.getImageData(
0,
0,
this.width,
this.height
).data;
// continuously repaint the map, resulting in the smooth animation of the dot
map.triggerRepaint();
// return `true` to let the map know that the image was updated
return true;
}
};
map.on('load', function () {
map.addImage('pulsing-dot', pulsingDot, { pixelRatio: 2 });
map.addSource('points', {
'type': 'geojson',
'data': {
'type': 'FeatureCollection',
'features': [
{
'type': 'Feature',
'geometry': {
'type': 'Point',
'coordinates': [-80.19, 25.76]
}
}
]
}
});
map.addLayer({
'id': 'points',
'type': 'symbol',
'source': 'points',
'layout': {
'icon-image': 'pulsing-dot'
}
});
});
```
#### index.html
```html
Add an animated icon to the map
```
#### style.css
```css
body {margin: 0; padding: 0;}
#map {position: absolute; top: 0; bottom: 0; width: 100%;}
```
### Basic JavaScript setup
```html
Add an animated icon to the map
```
## Related examples
### [Animate a line](https://docs.maptiler.com/sdk-js/examples/animate-a-line/)
Examples
Animate lines by updating GeoJSON sources on every frame.
### [Animate a marker](https://docs.maptiler.com/sdk-js/examples/animate-marker/)
Examples
Animate map marker positions by updating locations each frame.
### [Animate a point along a route](https://docs.maptiler.com/sdk-js/examples/animate-point-along-route/)
Examples
Smoothly animate a point along a route using Turf.