How to check if an element is in fullscreen mode?

Answers:

• To check if an element is in fullscreen mode in a web page, you can use the Fullscreen API provided by the browser. Specifically, you can check if a particular element is currently in fullscreen mode by accessing the document.fullscreenElement property.

  Here's a simple way to check if a specific element is in fullscreen mode:

  1. Using document.fullscreenElement: This property returns the element that is currently in fullscreen mode, or null if no elements are in fullscreen.

  2. Using Element.requestFullscreen() and document.exitFullscreen(): You can toggle fullscreen mode on the element.

  Here is a code example:

  // Assume you have an element with the ID 'myElement'
  const myElement = document.getElementById('myElement');
  
  // Function to check if the element is in fullscreen mode
  function isElementInFullscreen(element) {
      return document.fullscreenElement === element;
  }
  
  // Example usage
  if (isElementInFullscreen(myElement)) {
      console.log('The element is in fullscreen mode.');
  } else {
      console.log('The element is NOT in fullscreen mode.');
  }
  
  // Optional: Toggle fullscreen
  function toggleFullscreen(element) {
      if (!isElementInFullscreen(element)) {
          // Request fullscreen for the element
          element.requestFullscreen().catch(err => {
              console.error(`Error attempting to enable fullscreen mode: ${err.message}`);
          });
      } else {
          // Exit fullscreen mode
          document.exitFullscreen();
      }
  }
  

  Key Points:

  • Use document.fullscreenElement to check if a specific element is currently in fullscreen mode.
  • You can toggle fullscreen by calling requestFullscreen() on the element and exitFullscreen() on the document.

  Notes:

  • Ensure that your code is executed in an environment where the Fullscreen API is supported (most modern browsers).
  • Remember that fullscreen actions usually require a user gesture, such as a click.

Related Questions:

• What properties indicate an element is in fullscreen mode?
• How can I toggle fullscreen mode on a specific element?
• What methods can I use to exit fullscreen mode programmatically?
• How to detect when an element enters or exits fullscreen mode?
• What is the difference between browser fullscreen and element fullscreen?
• How do I use the Fullscreen API in JavaScript?
• Can I apply CSS styles specifically for fullscreen elements?
• What browsers support the Fullscreen API?
• How to detect fullscreen mode changes in different browsers?
• What events are triggered when entering or exiting fullscreen mode?