Responsive controls

One thing you’ll quickly notice is that Media Chrome is not responsive out of the box. This is by design, there are way too many permutations possible to provide one configuration for a responsive media player.

There are different techniques available to make your Media Chrome controls responsive. We’ll show you a future facing method using Container Queries (CQ) and a simple but cross browser method using a ResizeObserver and CSS classes.

Lets create a basic layout for our Media Chrome player.

<style>
  media-controller {
    display: block;
    aspect-ratio: 16 / 9;
  }
  video {
    width: 100%;
  }
</style>
<media-controller>
  <video
    playsinline
    slot="media"
    src="https://stream.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/high.mp4"
    poster="https://image.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/thumbnail.jpg?time=56"
  ></video>
  <media-control-bar>
    <media-play-button></media-play-button>
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
    <media-mute-button></media-mute-button>
    <media-volume-range></media-volume-range>
    <media-time-display></media-time-display>
    <media-time-range></media-time-range>
    <media-duration-display></media-duration-display>
    <media-playback-rate-button></media-playback-rate-button>
    <media-fullscreen-button></media-fullscreen-button>
  </media-control-bar>
</media-controller>

That looks pretty good but the controls are static no matter the size of the player. Lets change that, for this exercise we’ll make a big center play button when the player width is smaller than 484px and only show the timerange at the bottom of the player.

You might already be familiar with Media Queries in CSS. They allow you to have different CSS selectors depending on the size of the page itself. However, since we’re building a video player, that doesn’t help us much. Instead, we are finally getting Container Queries, which allows us to create CSS selectors that apply depending on the size of an element itself, which is exactly what we want for a responsive video player, where the dimensions of the player itself are what matters rather than the dimensions of the page that the player is on.

Since CQ is quite new, it’s not available everywhere yet. Depending on the browsers that you need to support, that may not be an issue. However, to support the most users, it’s recommended to write your styles in a progressive enhancement approach, which we will go over, and consider including the Containuer Queries Polyfill as well.

Let’s make a simple responsive layout. In addition to the media-control-bar above, we want to add some center controls.

<div class="center" slot="centered-chrome">
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-play-button></media-play-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
</div>

When the player dimensions are small, we can hide the control bar and only show these center controls. When the player is medium sized, we can keep the control bar but hide the buttons that are available in the center controls. In a large player size, we can show just the control bar.

The combined HTML for the player should look like this:

<media-controller>
  <video
    playsinline
    slot="media"
    src="https://stream.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/high.mp4"
    poster="https://image.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/thumbnail.jpg?time=56"
  ></video>
  <div class="center" slot="centered-chrome">
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-play-button></media-play-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
  </div>
  <media-control-bar class="bottom">
    <media-play-button></media-play-button>
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
    <media-mute-button></media-mute-button>
    <media-volume-range></media-volume-range>
    <media-time-display></media-time-display>
    <media-time-range></media-time-range>
    <media-duration-display></media-duration-display>
    <media-playback-rate-button></media-playback-rate-button>
    <media-fullscreen-button></media-fullscreen-button>
  </media-control-bar>
</media-controller>

Now, we have a working player, but the center controls are always showing up. We only want them to show up in some specific cases, so, let’s hide them by default.

.center {
  display: none;
}

This would also help for progressive enhancement, because then on browsers without CQ, we’ll have a player that only has the bottom control bar, which looks better.

Now, let’s make it responsive with container queries.

First, we need to declare the media-controller as a container

media-controller {
  container: media-chrome / inline-size;
}

This marks media-controller as a container named media-chrome should we have multiple containers that we need to refer to by name. We also tell CQ that we only care about the inline-size of this element, in this case it’s the width of the player.

For the smaller player, we want to show the center controls, since they are hidden by default, and then hide the control bar.

@container (inline-size < 420px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: none;
  }
}

This tells CSS that apply display: block to the .center class if the inline-size, aka the width player, is less than 420px. This range syntax is brand new and may not be supported everywhere yet. We can use max-width instead, like so:

@container (max-width: 420px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: none;
  }
}

This isn’t a big difference yet, but the new syntax will be especially nice in the medium player size.

For the medium player, we want to show the center controls and control bar. However, because space is a bit cramped, we’ll hide the controls available in the center controls from the control bar.

@container (420px <= inline-size <= 590px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: flex;
  }
  media-control-bar media-play-button,
  media-control-bar media-seek-backward-button,
  media-control-bar media-seek-forward-button {
    display: none;
  }
}

Once again, since the new range syntax isn’t available yet, you can use min-width, max-width, and and, but it’s not quite as nice as the range syntax.

@container (min-width: 420px) and (max-width: 590px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: flex;
  }
  media-control-bar media-play-button,
  media-control-bar media-seek-backward-button,
  media-control-bar media-seek-forward-button {
    display: none;
  }
}

Now, since we already have a default that hides the center controls in the cases where the player isn’t small or medium, we don’t strictly need another container query, but let’s add one for the sake of completeness.

@container (inline-size > 590px) {
  .center {
    display: none;
  }
  media-control-bar {
    display: flex;
  }
}

.center {
  display: none;
}

/* declare media-controller as a containuer for CQ */
media-controller {
  container: media-chrome / inline-size;
}

/* small player size */
@container (inline-size < 420px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: none;
  }
}

/* medium player size */
@container (420px <= inline-size <= 590px) {
  .center {
    display: block;
  }
  media-control-bar {
    display: flex;
  }
  media-control-bar media-play-button,
  media-control-bar media-seek-backward-button,
  media-control-bar media-seek-forward-button {
    display: none;
  }
}

/* large (default) player size */
@container (inline-size > 590px) {
  .center {
    display: none;
  }
  media-control-bar {
    display: flex;
  }
}

Together, it’ll give you a player like this. You can resize the page and see how the player responds to the page width. Or select a width with the following radio buttons.

Since we’re still waiting for CSS Container Queries to get wider adoption, this will require ResizeObserver to detect any size changes to the container of the player.

You might be tempted to use media queries for this but that solution will probably backfire because a media query listens to the browser viewport dimensions, not the player container dimensions.

<script>
  const breakpoints = { xs: 396, sm: 484, md: 576, lg: 768, xl: 960 };
  const resizeObserver = new ResizeObserver(function (entries) {
    entries.forEach((entry) => {
      const classNames = getBreakpoints(breakpoints, entry.contentRect);
      console.log(classNames);
    });
  });
  resizeObserver.observe(document.querySelector('media-controller'));

  function getBreakpoints(breakpoints, rect) {
    return Object.keys(breakpoints).filter((key) => {
      return rect.width >= breakpoints[key];
    });
  }
</script>

This little snippet will output the defined breakpoints as class names whenever the width of the player is smaller than the defined breakpoint.

Now it’s as simple as adding some CSS classes and CSS properties to hide and show controls based on the breakpoints.

<style>
  media-controller {
    display: block;
    aspect-ratio: 16 / 9;
  }
  video {
    width: 100%;
  }

  /* Hide most of the bottom controls on a tiny player. */
  media-controller:not(.sm) .bottom :not(media-time-range) {
    display: none;
  }

  /* Hide the big center play button on a larger player. */
  media-controller.sm .center {
    display: none;
  }
</style>
<media-controller id="mc2">
  <video
    playsinline
    slot="media"
    src="https://stream.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/high.mp4"
    poster="https://image.mux.com/O6LdRc0112FEJXH00bGsN9Q31yu5EIVHTgjTKRkKtEq1k/thumbnail.jpg?time=56"
  ></video>
  <div class="center" slot="centered-chrome">
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-play-button></media-play-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
  </div>
  <media-control-bar class="bottom">
    <media-play-button></media-play-button>
    <media-seek-backward-button seek-offset="15"></media-seek-backward-button>
    <media-seek-forward-button seek-offset="15"></media-seek-forward-button>
    <media-mute-button></media-mute-button>
    <media-volume-range></media-volume-range>
    <media-time-display></media-time-display>
    <media-time-range></media-time-range>
    <media-duration-display></media-duration-display>
    <media-playback-rate-button></media-playback-rate-button>
    <media-fullscreen-button></media-fullscreen-button>
  </media-control-bar>
</media-controller>
<script>
  const breakpoints = { xs: 396, sm: 484, md: 576, lg: 768, xl: 960 };
  const mc = document.querySelector('#mc2');
  const resizeObserver = new ResizeObserver(function (entries) {
    entries.forEach((entry) => {
      const classNames = getBreakpoints(breakpoints, entry.contentRect);
      entry.target.className = classNames.join(' ');
    });
  });
  resizeObserver.observe(mc);

  function getBreakpoints(breakpoints, rect) {
    return Object.keys(breakpoints).filter((key) => {
      return rect.width >= breakpoints[key];
    });
  }
</script>

Try changing the size of the player embed below to see if the controls show and hide like expected.