* Add VideoOverlay class based on ImageOverlay * Make linter happy * Move VideoOverlay include to layer/index * Fix mapbox tokens
4.2 KiB
layout | title |
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tutorial_v2 | Leaflet on Mobile |
Video on webpages
Video used to be a hard task when building a webpage, until the <video>
HTML element was made available.
Nowadays, we can use the following HTML code:
<video width="500" controls>
<source src="https://www.mapbox.com/bites/00188/patricia_nasa.webm" type="video/webm">
<source src="https://www.mapbox.com/bites/00188/patricia_nasa.mp4" type="video/mp4">
</video>
To display this video:
If a video can be shown in a webpage in this way, then Leaflet can display it inside a map. It is important that the videos are prepared in such a way that they will fit the map: The video should have a "north-up" orientation, and its proportions should fit the map. If not, it will look out of place.
Bounds of an image overlay
First of all, create a Leaflet map and add a background L.TileLayer
in the usual way:
var map = L.map('map').setView([37.8, -96], 4);
L.tileLayer('https://api.tiles.mapbox.com/v4/{id}/{z}/{x}/{y}.png?access_token=' + mapboxAccessToken, {
id: 'mapbox.satellite',
attribution: ...
}).addTo(map);
Then, we'll define the geographical bounds that the video will cover. This is an instance of L.LatLngBounds
, which is a rectangular shape:
var bounds = L.latLngBounds([[ 32, -130], [ 13, -100]]);
If you want to see the area covered by a LatLngBounds
, use a L.Rectangle
:
L.rectangle(bounds).addTo(map);
map.fitBounds(bounds);
{% include frame.html url="example-bounds.html" %}
Adding the video overlay
Adding a video overlay works very similar to adding a image overlay. For just one image, L.ImageOverlay
s is used like this:
var overlay = L.imageOverlay( imageUrl, bounds, options );
For a video overlay, just:
- Use
L.videoOverlay
instead ofL.imageOverlay
- Instead of the image URL, specify one video URL or an array of video URLs
var videoUrls = [
'https://www.mapbox.com/bites/00188/patricia_nasa.webm',
'https://www.mapbox.com/bites/00188/patricia_nasa.mp4'
];
var bounds = L.latLngBounds([[ 32, -130], [ 13, -100]]);
var videoOverlay = L.videoOverlay( videoUrls, bounds, {
opacity: 0.8
}).addTo(map);
And just like that, you'll get the video on your map:
{% include frame.html url="example-nocontrols.html" %}
Video overlays behave like any other Leaflet layer - you can add and remove them, let the user select from several videos using a layers control, etc.
A bit of control over the video
If you read the API documentation, you'll notice that the L.VideoOverlay
class does not have a play()
or pause()
method.
For this, the getElement()
method of the video overlay is useful. It returns the HTMLVideoElement
(which inherits from HTMLMediaElement
) for the overlay - and that has methods like play()
and pause()
, e.g.
videoOverlay.getElement().pause();
This allows us to build custom interfaces. For example, we can build a small subclass of L.Control
to play/pause this video overlay once it's loaded:
videoOverlay.on('load', function () {
var MyPauseControl = L.Control.extend({
onAdd: function() {
var button = L.DomUtil.create('button');
button.innerHTML = '⏸';
L.DomEvent.on(button, 'click', function () {
videoOverlay.getElement().pause();
});
return button;
}
});
var MyPlayControl = L.Control.extend({
onAdd: function() {
var button = L.DomUtil.create('button');
button.innerHTML = '⏵';
L.DomEvent.on(button, 'click', function () {
videoOverlay.getElement().play();
});
return button;
}
});
var pauseControl = (new MyPauseControl()).addTo(map);
var playControl = (new MyPlayControl()).addTo(map);
});
{% include frame.html url="example.html" %}