make an element full screen in the web page

Question

Any idea to make an element in the page full screen?

For example,a div or an img?

With "full screen" I mean that it should take all the space of user's screen,just like when we watch a video with the full screen model. I do not want the task bar/menu bar of the browser window display.

Any idea?

  div.fullscreen{
    display:block;

    /*set the div in the top-left corner of the screen*/
    position:absolute;
    top:0;
    left:0;

    /*set the width and height to 100% of the screen*/
    width:100%;
    height:100%;
    background-color:red
  }

I have tried the above code,however it is not what I want,it juse take all the space of the browser's content area rather than the user's computer'screen.

Solution 1

HTML elements can't break out of the bounds of the browser document window. The menu and tool bar are outside of the document window (which is a child of the browser window), so you can't "reach" them.

I think the only solution is to trigger full screen mode with JavaScript.

This answer shows how you can do that: How to make the window full screen with Javascript (stretching all over the screen)

Solution 2

There is a relatively new fullscreen JavaScript api which can make an element full screen.

It has to be called as the result of user input to prevent possible abuse, but it's relatively straight-forward to use:

Code from MDN article:

document.addEventListener("keydown", function(e) {
  if (e.keyCode == 13) {
    toggleFullScreen();
  }
}, false);

function toggleFullScreen() {
  if (!document.fullscreenElement &&    // alternative standard method
      !document.mozFullScreenElement && !document.webkitFullscreenElement) {  // current working methods
    if (document.documentElement.requestFullscreen) {
      document.documentElement.requestFullscreen();
    } else if (document.documentElement.mozRequestFullScreen) {
      document.documentElement.mozRequestFullScreen();
    } else if (document.documentElement.webkitRequestFullscreen) {
      document.documentElement.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
    }
  } else {
    if (document.cancelFullScreen) {
      document.cancelFullScreen();
    } else if (document.mozCancelFullScreen) {
      document.mozCancelFullScreen();
    } else if (document.webkitCancelFullScreen) {
      document.webkitCancelFullScreen();
    }
  }
}