滚动时，视图中特定div的背景颜色变化的最佳方法是什么？

Question

我正在创建一个广告产品的布局，产品的功能位于占据浏览器全宽的div栏内。

我希望它在用户滚动时，屏幕中心的div将背景颜色从白色变为浅灰色，以便专注于该功能。然后当用户继续下一个功能时返回白色。示例：

我使用jquery scrollTop（）来查找滚动位置，然后根据滚动位置设置应突出显示哪个功能。 问题是当浏览器调整大小时，功能div改变高度并且我设置为最大宽度的滚动位置不起作用！下面是我用来生成转换的相关coffeescript。 无论屏幕或浏览器尺寸如何，我该如何才能完成这项工作？

$(document).ready ->
  scroll_pos = 0
  $(document).scroll ->
    scroll_pos = $(this).scrollTop()
    scrollBottom = $(window).scrollTop() + $(window).height()

    if scroll_pos < 300
      $("#featureOne").css "background-color", "white"
      $("#featureOne").css "-webkit-box-shadow", "none"
    else if scroll_pos > 300 and scroll_pos < 730
      $("#featureOne").css "background-color", "#eee"
      $("#featureOne").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"
      $("#featureTwo").css "background-color", "white"
      $("#featureTwo").css "-webkit-box-shadow", "none"
    else if scroll_pos > 730 and scroll_pos < 1150
      $("#featureOne").css "background-color", "white"
      $("#featureOne").css "-webkit-box-shadow", "none"
      $("#featureTwo").css "background-color", "#eee"
      $("#featureTwo").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"
      $("#featureThree").css "background-color", "white"
      $("#featureThree").css "-webkit-box-shadow", "none"
    else if scroll_pos > 1150 and scroll_pos < 1700
      $("#featureTwo").css "background-color", "white"
      $("#featureTwo").css "-webkit-box-shadow", "none"
      $("#featureThree").css "background-color", "#eee"
      $("#featureThree").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"
      $("#featureFour").css "background-color", "white"
      $("#featureFour").css "-webkit-box-shadow", "none"
    else if scroll_pos > 1700 and scroll_pos < 2050
      $("#featureThree").css "background-color", "white"
      $("#featureThree").css "-webkit-box-shadow", "none"
      $("#featureFour").css "background-color", "#eee"
      $("#featureFour").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"
      $("#featureFive").css "background-color", "white"
      $("#featureFive").css "-webkit-box-shadow", "none"
    else if scroll_pos > 2050 and scroll_pos < 2450
      $("#featureFour").css "background-color", "white"
      $("#featureFour").css "-webkit-box-shadow", "none"
      $("#featureFive").css "background-color", "#eee"
      $("#featureFive").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"
      $("#featureSix").css "background-color", "white"
      $("#featureSix").css "-webkit-box-shadow", "none"
    else if scroll_pos > 2450 and scroll_pos < 2810
      $("#featureFive").css "background-color", "white"
      $("#featureFive").css "-webkit-box-shadow", "none"
      $("#featureSix").css "background-color", "#eee"
      $("#featureSix").css "-webkit-box-shadow", "0px 5px 15px 5px #eee"

Answer 1

我明白了。所以我删除了@mu_is_too_short建议我的所有讨厌的.css调用，然后使用了这个例子中给出的函数：

Check if element is visible after scrolling

这是我的咖啡因解决方案：

isScrolledIntoView = (elem) ->
  console.log(elem)
  docViewTop = $(window).scrollTop()
  docViewBottom = docViewTop + $(window).height()
  elemTop = $(elem).offset().top
  elemBottom = elemTop + $(elem).height()
  console.log("elemBottom: " + elemBottom + " docViewBottom: " + docViewBottom + " elemTop: " + elemTop + " docViewTop: " + docViewTop)
  ((elemBottom <= (docViewBottom - 300)) && (elemTop >= (docViewTop)))


shouldHighlight = (elem) ->
  if isScrolledIntoView(elem)
      $(elem).addClass "addHighlight" 
      console.log('test')
    else 
      $(elem).removeClass "addHighlight"


$(document).ready ->
  scroll_pos = 0
  $(document).scroll ->
    scroll_pos = $(this).scrollTop()
    scrollBottom = $(window).scrollTop() + $(window).height()

    shouldHighlight("#featureOne")
    shouldHighlight("#featureTwo")
    shouldHighlight("#featureThree")
    shouldHighlight("#featureFour")
    shouldHighlight("#featureFive")
    shouldHighlight("#featureSix")
    shouldHighlight("#featureSeven")