当 div 在视口中时加载 Javascript

Question

Thats the Div in HTML file

<div class="inViewport">

And this script should be loading only when the div is in viewport

    <script type="text/javascript">
        document.addEventListener('DOMContentLoaded', function () {
            ToxProgress.create();
            ToxProgress.animate();
        });
    </script>

Answer 1

This is what you should look at: Check if element is visible after scrolling

Here is an example for you that demonstrates this technique: http://jsfiddle.net/XYS2G/ - just try to scroll the Result window.

HTML:

<div class="indicators">
    <span class="indicator" data-id="section1">section1</span>
    <span class="indicator" data-id="section2">section2</span>
    <span class="indicator" data-id="section3">section3</span>
    <span class="indicator" data-id="section4">section4</span>
    <span class="indicator" data-id="section5">section5</span>
    <span class="indicator" data-id="section6">section6</span>
</div>
<div class="sections">
    <div class="section" id="section1">section1</div>
    <div class="section" id="section2">section2</div>
    <div class="section" id="section3">section3</div>
    <div class="section" id="section4">section4</div>
    <div class="section" id="section5">section5</div>
    <div class="section" id="section6">section6</div>
</div>

CSS:

.indicators { position: fixed; }
.section { height: 150px; }

Javascript:

function isScrolledIntoView(elem)
{
    var docViewTop = $(window).scrollTop();
    var docViewBottom = docViewTop + $(window).height();

    var elemTop = $(elem).offset().top;
    var elemBottom = elemTop + $(elem).height();

    return ((elemBottom <= docViewBottom) && (elemTop >= docViewTop));
}

function refreshIndicators() {
    $('.indicator').each(function () {
        if (isScrolledIntoView($('#' + $(this).attr('data-id')))) {
            $(this).css('color', 'red');
        } else {
            $(this).css('color', 'black');
        }
    });
}

refreshIndicators();

$(window).bind('scroll', refreshIndicators);

Answer 2

Hello and thanks for the quick response. But I want to run the script when the div comes to viewport because there is an animation skill circle.

Thats my div with skill bar cirlce inlcuded

<div id="inViewport">

Thats the new script

<script type="text/javascript">
if (document.getElementById("inViewport")){
   ToxProgress.create();
   ToxProgress.animate();
}
</script>

Answer 3

Like this: But not working... sorry I am a noob

<script type="text/javascript">
    var rect = el.getBoundingClientRect();

    return (
        rect.top >= 0 &&
        rect.left >= 0 &&
        rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
        rect.right <= (window.innerWidth || document.documentElement.clientWidth)
    );

window.addEventListener("scroll resize", function() {
    if (isInViewport(document.getById("inViewport"))) {
       ToxProgress.create();
       ToxProgress.animate();
    }
});
</script>

Answer 4

I think this function will help you:

function isInViewport(el) {
    var rect = el.getBoundingClientRect();

    return (
        rect.top >= 0 &&
        rect.left >= 0 &&
        rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
        rect.right <= (window.innerWidth || document.documentElement.clientWidth)
    );
}

(taken from here ) Then, you need to listen to the scroll event, and every time the user scrolls, you check if the element is in the viewport by calling above function. Sample:

window.addEventListener("scroll resize", function() {
    if (isInViewport(document.getById("inViewport"))) {
       ToxProgress.create();
       ToxProgress.animate();
    }
});