Brightcove Player Sample: Display Thumbnails on Hover

In this topic, you will learn how to display a set of four thumbnail images when the user hovers over the Brightcove Player. These images are taken at different points in the video to give the user an idea of what to expect in the video.

Player example

This example uses the ModalDialog to display four thumbnail images taken from various points in the video. This allows the user to get a sneak peek at what is in the video. The ModalDialog is only displayed before the video begins playback.

See the Pen Display Thumbnails Hover by Brightcove Learning Services (@bcls1969) on CodePen.

Source code

View the complete solution on GitHub.

Using the CodePen

Here are some tips to effectively use the above CodePen:

  • Toggle the actual display of the player by clicking the Result button.
  • Click the HTML/CSS/JS buttons to display ONE of the code types.
  • Later in this document the logic, flow and styling used in the application will be discussed in the Player/HTML configuration, Application flow and Application styling sections. The best way to follow along with the information in those sections is to:
    1. Click the EDIT ON CODEPEN button in the CodePen and have the code available in one browser/browser tab.
    2. In CodePen, adjust what code you want displayed. You can change the width of different code sections within CodePen.
    3. View the Player/HTML configuration, Application flow and/or Application styling sections in another browser/browser tab. You will now be able to follow the code explanations and at the same time view the code.

Development sequence

Here is the recommended development sequence:

  1. Use the In-Page embed player implementation to test the functionality of your player, plugin and CSS (if CSS is needed)
  2. Put the plugin's JavaScript and CSS into separate files for local testing
  3. Deploy the plugin code and CSS to your server once you have worked out any errors
  4. Use Studio to add the plugin and CSS to your player
  5. Replace the In-Page embed player implementation if you determine that the iframe implementation is a better fit (detailed in next section)

For details about these steps, review the Step-by-Step: Plugin Development guide.

iframe or In-Page embed

When developing enhancements for the Brightcove Player you will need to decide if the code is a best fit for the iframe or In-Page embed implementation. The best practice recommendation is to build a plugin for use with an iframe implementation. The advantages of using the iframe player are:

  • No collisions with existing JavaScript and/or CSS
  • Automatically responsive
  • The iframe eases use in social media apps (or whenever the video will need to "travel" into other apps)

Although integrating the In-Page embed player can be more complex, there are times when you will plan your code around that implementation. To generalize, this approach is best when the containing page needs to communicate to the player. Specifically, here are some examples:

  • Code in the containing page needs to listen for and act on player events
  • The player uses styles from the containing page
  • The iframe will cause app logic to fail, like a redirect from the containing page

Even if your final implementation does not use the iframe code, you can still use the In-Page embed code with a plugin for your JavaScript and a separate file for your CSS. This encapsulates your logic so that you can easily use it in multiple players.

API/Plugin resources used

API Methods API Events ModalDialog Methods
addChild() loadstart open()
el()   close()
play()   dispose()

Some advantages of using the ModalDialog component include the following:

  • It covers the entire player by default
  • It has methods to easily open and close the modal window

Player/HTML configuration

This section details any special configuration needed during player creation. In addition, other HTML elements that must be added to the page, beyond the in-page embed player implementation code, are described.

Player configuration

No special configuration is required for the Brightcove Player you create for this sample.

Video configuration

This sample uses an array of thumbnail image URLs that are stored in the video's Long Description field. We will then access the currently loaded video's metadata through the mediainfo object. Alternatively, you can create a custom field to store the URL array.

Here is the thumbnail array added to the Long Description property in Video Cloud Studio's Media module:

Thumbnail array
Thumbnail array

Here is the more nicely formatted thumbnail array code:

  "thumbs": [{
      "image": ""
    }, {
      "image": ""
    }, {
      "image": ""
    }, {
      "image": ""

Other HTML

Remember to add the id attribute to the video-js tag in the player embed code.

<video-js id="myPlayerID"

Application flow

The basic logic behind this application is:

  • Get the player DOM element.
  • Get the thumbnail array.
  • Format the overlay content with the thumbnails for different sections within the video content.
  • Show the thumbnails on user hover.
  • Hide the thumbnails on user mouseout.
  • Play the video when the user clicks on the thumbnails ModalDialog.

Get the player DOM element

Find the code which is labeled:

// +++ Get the player DOM element +++

Get a reference to the player's DOM element. We will use this to add the ModalDialog to the player.

Get the thumbnail array

Find the code which is labeled:

// +++ Get the thumbnail array +++

Get the thumbnail URL array from the video's Long Description property. For details about adding this metadata to your video, see the Video configuration section.

Format the overlay content

Find the code which is labeled:

// +++ Format the overlay content +++

To format the overlay content, do the following:

  1. Get the thumbnail URLs from the video Long Description field and add to modal dialog content.
  2. Configure and create the Modal Dialog.
  3. Add the Modal Dialog to the player.

Show the thumbnails

Find the code which is labeled:

// +++ Show the thumbnails +++

Listen for the mouseover event on the player. When triggered, display the Modal Dialog with the video section thumbnail images.

Hide the thumbnails

Find the code which is labeled:

// +++ Hide the thumbnails +++

Listen for the mouseout event on the player. When triggered, hide the Modal Dialog with the video section thumbnail images.

Play the video

Find the code which is labeled:

// +++ Play the video +++

When the thumbnail ModalDialog is clicked, remove the event listeners, close and dispose of the ModalDialog and start video playback.

Application styling

The CSS styles the videos thumbnail images in the ModalDialog.

Plugin code

Normally when converting the JavaScript into a Brightcove Player plugin nominal changes are needed. One required change is to replace the standard use of the ready() method with the code that defines a plugin.

Here is the very commonly used start to JavaScript code that will work with the player:

videojs.getPlayer('myPlayerID').ready(function() {
  var myPlayer = this;

You will change the first line to use the standard syntax to start a Brightcove Player plugin:

videojs.registerPlugin('pluginName', function(options) {
  var myPlayer = this;

As mentioned earlier, you can see the plugin's JavaScript code in this document's corresponding GitHub repo: thumbnail-hover.js.

Using the plugin with a player

Once you have the plugin's CSS and JavaScript files stored in an Internet accessible location, you can use the plugin with a player. In Studio's PLAYERS module you can choose a player, then in the PLUGINS section add the URLs to the CSS and JavaScript files, and also add the Name and Options, if options are needed.