如果父div是透明的，则将子div设置为白色

Question

使用一个稍微修改过的引导程序转盘，我需要能够将祖父母div（在本例中为.row类）检测到.row-light和.row-dark，它可以不同于默认的.row-default（具有透明背景）。我可以从各个类中获取浅色和深色，但我需要能够检测背景色是否设置为透明，并且如果祖父母设置为透明则将控件类设置为白色或#fff。这将允许控件位于转盘幻灯片的边缘。

HTML

<div class="row row-dark">
<div class="container">
<div class="carousel slide" id="myCarousel">
<div class="quote-carousel">
  <div class="carousel-inner">
    <h6>What customers say about us</h6>
    <div class="item active">
      <ul class="thumbnails">
        <li class="col-xs-12 col-sm-12 slide-content">
            <h3>"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do tempor incididunt ut labore et dolore magna aliqua, ipsum dolor amet."</h3>
              <span class="time">-Robyn Estroff</span>
          </li>
      </ul>
    </div>
    <div class="item">
      <ul class="thumbnails">
        <li class="col-xs-12 col-sm-12 slide-content">
            <h3>"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do tempor incididunt ut labore et dolore magna aliqua, ipsum dolor amet."</h3>
              <span class="time">-Robyn Estroff</span>
          </li>
      </ul>
    </div>
    <div class="item">
      <ul class="thumbnails">
        <li class="col-xs-12 col-sm-12 slide-content">
            <h3>"Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do tempor incididunt ut labore et dolore magna aliqua, ipsum dolor amet."</h3>
              <span class="time">-Robyn Estroff</span>
          </li>
      </ul>
    </div>
  </div>
    <a class="left carousel-control" href="#myCarousel" role="button" data-slide="prev">
      <i class="material-icons">&#xE314;</i>
    </a>
    <a class="right carousel-control" href="#myCarousel" role="button" data-slide="next">
      <i class="material-icons">&#xE315;</i>
    </a>
</div>
</div>
</div>
</div>

CSS

.row-dark{
  background-color: #ddd;
}
.quote-carousel{
  h6{
    color: $purple;
    font-weight: bold;
    text-align: center;
  }
  h3{
    color: $dark-navy-blue;
    font-weight: 100;
    padding: 30px 0px 30px 0px;
    margin: 0% 12% -1% 12%;
  }
  .carousel{
    position: relative;
    width: 60%;
    margin: 0 auto;
    min-height: 170px;
    padding-left: 5%;
    padding-right: 5%;
  }
  .carousel-control{
    padding-top: 4%;
    padding-bottom: 7%;
    width:7%;
  }
  .material-icons{
    color: $black;
    padding: 0px;
    border: 1px solid $darkest-grey;
    border-top-right-radius: 50px;
    border-top-left-radius: 50px;
    border-bottom-right-radius: 50px;
    border-bottom-left-radius: 50px;
  }
  .active{
    margin-top: -13px;
  }
  .thumbnails{
    padding: 0px 40px;
    li{
      margin-bottom: 5%;
    }
  }
  .slide-content{
    text-align: center;
  }
}
/***************** TABLET **************/
@media (min-device-width: $screen-sm-min) and (max-device-width: $screen-lg-min) {
  .quote-carousel h3{
    margin: 0 auto;
    padding: 30px 0px 15px;
  }
  .carousel-control{
    background-color: #ebebeb;
    padding-top: 4%;
    padding-bottom: 7%;
    width: 7%;
  }
}
/****************** MOBILE ***************/
@media (max-device-width: $screen-xs-max) {
  .quote-carousel h3{
    margin: 0 auto;
    font-size: 12px;
    padding: 30px 0px 15px;
  }
  .carousel-control{
    background-color: #ebebeb;
    padding-top: 4%;
    padding-bottom: 7%;
    width: 7%
  }
}

jQuery

$('.left').hide();
$('.carousel').carousel({
      wrap: false
    }).on('slid.bs.carousel', function () {
        curSlide = $('.active');
      if(curSlide.is( ':nth-child(2)' )) {
         $('.left').hide();
         return;
      } else {
         $('.left').show();
      }
      if (curSlide.is( ':last-child' )) {
         $('.right').hide();
         return;
      } else {
         $('.right').show();
      }
    });

这是获取祖父母类并从那里应用属性，但我不知道如果行背景是透明的，如何将控件背景设置为白色

jQuery.fn.inheritGrandparent = function( property ) {
  var $this = $(this),
      value = $this.parent().parent().parent().parent().css(property);
  if(property && value) $this.css(property, value);
};
$('.carousel-control').inheritGrandparent('background');

Fiddle：https://jsfiddle.net/ccajtj64/1/

Answer 1

我认为最简单的方法是将函数转换为条件函数，看看祖父母是否有.row-default类，并相应地应用。

jQuery.fn.inheritGrandparent = function( property ) {
      var $this = $(this),
          grandparent = $this.closest('.row'),
          value = grandparent.css(property);
      if (property && value) {
        if (grandparent.hasClass('row-default')) {
            $this.css(property, 'white');
        } else {
            $this.css(property, value);
        }
      }
        };
    $('.carousel-control').inheritGrandparent('background');

但是您也可以检查祖父母类的值并使用条件。不过，它返回的值可能不一致，并且因浏览器而异。

jQuery.fn.inheritGrandparent = function( property ) {
      var $this = $(this),
          value = $this.closest('.row').css(property);
      if (property && value) {
        if (value.indexOf('transparent') !== -1 || value.indexOf('rgba(0, 0, 0, 0)') !== -1 ) {
            $this.css(property, 'white');
        } else {
            $this.css(property, value);
        }
      }
        };
    $('.carousel-control').inheritGrandparent('background');