Set An Html5 Video To Pause When Video Player Is Out Of View

I'd like to do this with javascript. I'm building a presentation using Hakim El Hattab's Reveal.js as a foundation. The way Reveal.js works is the current slide you are viewing has

Solution 1:

Now that you posted your code, it makes it easier to fix:

if( i < index ) {
    // Any element previous to index is given the 'past' class
    slide.setAttribute('class', 'past');
    var vids = document.getElementsByClassName("past");
    for (var i = 0; i < vids.length; i++) {
        vids[i].pause();
    }
}
elseif( i > index ) {
    // Any element subsequent to index is given the 'future' class
    slide.setAttribute('class', 'future');
    var vids = document.getElementsByClassName("future");
    for (var i = 0; i < vids.length; i++) {
        vids[i].pause();
    }
}

See if that helps. If it doesn't, are you using a modern and standards-compliant browser? getElementsByClassName() is a relatively new feature. It works in the latest version of Chrome for me.

Solution 2:

I don't know if setTimeout would work here but you could try the following:

functionPauseVids() {
    var vids = document.getElementsByClassName("past");
    var vids2 = document.getElementsByClassName("future");
    for (var i = 0; i < vids.length; i++) {
        vids[i].pause();
    }
    for (var i = 0; i < vids2.length; i++) {
        vids2[i].pause();
    }
}

// Within onLoad or $(document).ready()setTimeout("PauseVids()", 1000);

Tell me if that works.

Solution 3:

@petschekr :guess this won't work, because classname past future is not only set to videoelements?!

i have no idea how reveals work and what kind of player you are using! but my way would be sth like:

there is only one file with the present class, right (current Slide)

a) define sth like a onChange function (for example on every button which changes pages + keypresses)

b) trigger that function before you switch pages

functiononChange(){
       var currentSlice = document.getElementByClassName('present')  //get current html elemenvar videoObjects = currentSlice.getElementsByTag('video')  //get videoelements here html5 videofor each videoObj      
            videoObj.pause()

edit: pseudocode to get you an idea!