Если вы хотите прокрутить до половины общего расстояния прокрутки, вам нужно будет вручную рассчитать значение пикселя. Высота элемента, на который можно заглянуть, - это просто разница между clientHeight
и scrollHeight
. Эти свойства доступны в самом элементе HTML, поэтому нам нужно сначала получить его, используя $('#sc')[0]
, который возвращает узел DOM:
$("button").on("click", function(){
var sc = $('#sc')[0];
var scrollableHeight = sc.scrollHeight - sc.clientHeight;
$('#sc').animate({ scrollTop: 0.5 * scrollableHeight }, 1);
});
См. Пример проверки концепции:
$("button").on("click", function(){
var sc = $('#sc')[0];
var scrollableHeight = sc.scrollHeight - sc.clientHeight;
$('#sc').animate({ scrollTop: 0.5 * scrollableHeight }, 1);
});
#sc {
background: khaki;
width: 400px;
height: 200px;
position: relative;
margin:20px;
padding:0px;
overflow:hidden;
overflow-y: auto;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<button>Scrool 50%</button>
<div id="sc">
<p>
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</p>
</div>