Slideshow app can display web pages and HTML files on the screen using a WebView component of Android.

The WebView component can be updated separately from Android system and Slideshow app by updating Android System WebView app from Google Play Store or other sources. Keeping the WebView component up-to-date is important for displaying web pages that require the most recent version of the web browser. The default WebView component is based on Chrome browser, you can change the provider via Android settings – Developer options – WebView implementation.

User-Agent HTTP header used for requesting external web pages can be changed with a setting “User agent for HTTP requests”. The default User-Agent based on the actual browser core (which is used if the setting is empty) is the best option for most use-cases.

Displaying web page using URL file

Entire web pages from the internet can be displayed using a file with .url file extension. If Slideshow detects such a file, it will read the URL address and display the containing website on the screen.

Format of the .url file can be:

  • Plain text file with a single line containing the URL address of the website
  • URL file created by Slideshow’s file manager (right click – New file – URL) and edited (right click – Edit file – Enter web page)
  • URL file created in Windows (see https://fileinfo.com/extension/url)

Online websites can be displayed on the screen only if the device running Slideshow app is connected to the internet. Only pages which are successfully loaded are displayed on the screen. If you are an IT specialist, you can use this functionality for example for displaying Zabbix or Grafana dashboards.

Displaying HTML file

Slideshow can directly render files with .html file extension. The HTML file can contain regular HTML code, including iframes and JavaScript, which gives you vast posibilities. The exact supported set HTML/CSS/JavaScript features depend on the version of Android System WebView app.

The default background is transparent, in order to allow HTML overlay. If you would like to have a non-transparent background, add style="background-color: white" to tagorin the HTML file.

HTML files can be also directly edited in a WYSIWYG editor via the web interface – menu File Manager – right click a HTML file – Edit fileCKEditor. Other editors are available as well, including plain-text editor TextArea.

Displaying HTML widgets

As an example, using Twitter Publish, you can create an HTML snippet with your Twitter feed, save it as an HTML file to Slideshow and display the Twitter feed on the screen. You can find example with Slideshow’s Twitter bellow: content of the HTML file on the left and the result as rendered by Slideshow app on the screen on the right

<html>
<style>body, html {margin: 0}</style>
<body>
<a class="twitter-timeline" data-lang="en" data-width="960" data-height="1080" data-theme="dark" href="https://twitter.com/SlideshowPlay?ref_src=twsrc%5Etfw">Tweets by SlideshowPlay</a>
<script async src="https://platform.twitter.com/widgets.js" charset="utf-8"></script>
</body>
</html>

 

Video tutorial