仅当在视口中时Javascript滚动IntoView-PHP中文网问答

我制作了一个模型（请注意，它使用间隔，因为它在视频播放时滚动到新文本行）。我正在使用带有块的scrollIntoView：'nearest'。

问题是，由于整个页面都有滚动，它仍然滚动页面。我只是希望它滚动到lines div 中的活动文本行（它不必在视图中）。因为如果我正在查看“video”div，它将继续向下滚动（这是不需要的行为）。

var text = document.querySelector('.text')


setInterval(function() {
  text.scrollIntoView({
    behavior: 'smooth',
    block: 'nearest'
  });

}, 3000)

.a {
  height: 200px;
}

.elem {
  position: relative;
}

.video {
  width: 200px;
  height: 400px;
  background: #ccc;
  margin-bottom: 100px;
}

.lines {
  overflow-y: auto;
  height:120px;
}

<div class="a"></div>


<div class="elem">
  <div class="video"></div>


  <div class="lines">
    <div>lorem ipsum dolir sit amet</div>
    <div>Vestibulum nulla justo</div>
    <div>Fusce egestas, est ut fringilla facilisis</div>
    <div>Maecenas eu erat condimentum </div>
    <div>Quisque risus</div>
    <div>fames ac turpis egestas</div>
    <div>lorem ipsum dolir sit amet</div>
    <div>Vestibulum nulla justo</div>
    <div class="text">Fusce egestas, est ut fringilla facilisis</div>
    <div>Maecenas eu erat condimentum </div>
    <div>Quisque risus</div>
    <div>fames ac turpis egestas</div>

  </div>


</div>

<div class="a"></div>

var text = document.querySelector('.text') setInterval(function() { const parent = text.parentElement; const parentHeight = parent.clientHeight; const textTop = text.offsetTop - parent.offsetTop; const textMiddle = textTop + text.offsetHeight / 2; parent.scrollTo({ top: textMiddle - parentHeight / 2, behavior: "smooth" }); }, 3000)

.a { height: 200px; } .elem { position: relative; } .video { width: 200px; height: 400px; background: #ccc; margin-bottom: 100px; } .lines { overflow-y: auto; height:120px; } .text { background: yellow; }

<div class="a"></div> <div class="elem"> <div class="video"></div> <div class="lines"> <div>lorem ipsum dolir sit amet</div> <div>Vestibulum nulla justo</div> <div>Fusce egestas, est ut fringilla facilisis</div> <div>Maecenas eu erat condimentum </div> <div>Quisque risus</div> <div>fames ac turpis egestas</div> <div>lorem ipsum dolir sit amet</div> <div>Vestibulum nulla justo</div> <div class="text">Fusce egestas, est ut fringilla facilisis</div> <div>Maecenas eu erat condimentum </div> <div>Quisque risus</div> <div>fames ac turpis egestas</div> </div> </div> <div class="a"></div>