Leaflet/docs/examples/video-overlay/index.md
Andrew 748905cbf5 Fix docs redirects (#5824)
* use redirected.html instead of jekyll-redirect-from

* modify redirected.html to preserve url hases

* fix links in zoom-levels example

- use relative links instead of absolute
- remove hardcoded version in lins and refer to latest version docs instead

* fix hash in choropleth example

* fix links in geojson example

 - use relative links instead of absolute

* fix absolute link in quick-start example

* fix link in video-overlay example

* fix link in map-panes example

* fix link in wms example

* fix link in geojson example

* fix relative reference links
2017-10-05 15:34:04 +02:00

123 lines
4.2 KiB
Markdown

---
layout: tutorial_v2
title: Leaflet on Mobile
---
## Video on webpages
Video used to be a hard task when building a webpage, until the [`<video>` HTML element](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video) 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:
<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>
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`](/reference.html#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`](/reference.html#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](/reference.html#imageoverlay) is used like this:
var overlay = L.imageOverlay( imageUrl, bounds, options );
For a video overlay, just:
* Use `L.videoOverlay` instead of `L.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](../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`](https://developer.mozilla.org/docs/Web/API/HTMLImageElement) (which inherits from [`HTMLMediaElement`](https://developer.mozilla.org/docs/Web/API/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" %}