纯HTML、CSS、JS实现树形列表结构

纯HTML、CSS、JS实现树形列表结构

 

效果查看：https://codepen.io/bisserof/pen/nrMveb

HTML:

<div id="fontSizeWrapper">
  <label for="fontSize">Font size</label>
  <input type="range" value="1" id="fontSize" step="0.5" min="0.5" max="5" />
</div>
<ul class="tree">
  <li>
    <input type="checkbox" checked="checked" id="c1" />
    <label class="tree_label" for="c1">Level 0</label>
    <ul>
      <li>
        <input type="checkbox" checked="checked" id="c2" />
        <label for="c2" class="tree_label">Level 1</label>
        <ul>
          <li><span class="tree_label">Level 2</span></li>
          <li><span class="tree_label">Level 2</span></li>
        </ul>
      </li>
      <li>
        <input type="checkbox" id="c3" />
        <label for="c3" class="tree_label">Looong level 1 <br/>label text <br/>with line-breaks</label>
        <ul>
          <li><span class="tree_label">Level 2</span></li>
          <li>
            <input type="checkbox" id="c4" />
            <label for="c4" class="tree_label"><span class="tree_custom">Specified tree item view</span></label>
            <ul>
              <li><span class="tree_label">Level 3</span></li>
            </ul>
          </li>
        </ul>
      </li>
    </ul>
  </li>
  
  
  <li>
    <input type="checkbox" id="c5" />
    <label class="tree_label" for="c5">Level 0</label>
    <ul>
      <li>
        <input type="checkbox" id="c6" />
        <label for="c6" class="tree_label">Level 1</label>
        <ul>
          <li><span class="tree_label">Level 2</span></li>
        </ul>
      </li>
      <li>
        <input type="checkbox" id="c7" />
        <label for="c7" class="tree_label">Level 1</label>
        <ul>
          <li><span class="tree_label">Level 2</span></li>
          <li>
            <input type="checkbox" id="c8" />
            <label for="c8" class="tree_label">Level 2</label>
            <ul>
              <li><span class="tree_label">Level 3</span></li>
            </ul>
          </li>
        </ul>
      </li>
    </ul>
  </li>
</ul>

CSS:

body {
  margin: 30px;
  font-family: sans-serif;
  }

#fontSizeWrapper { font-size: 16px; }

#fontSize {
  width: 100px;
  font-size: 1em;
  }

/* ————————————————————–
  Tree core styles
*/
.tree { margin: 1em; }

.tree input {
  position: absolute;
  clip: rect(0, 0, 0, 0);
  }

.tree input ~ ul { display: none; }

.tree input:checked ~ ul { display: block; }

/* ————————————————————–
  Tree rows
*/
.tree li {
  line-height: 1.2;
  position: relative;
  padding: 0 0 1em 1em;
  }

.tree ul li { padding: 1em 0 0 1em; }

.tree > li:last-child { padding-bottom: 0; }

/* ————————————————————–
  Tree labels
*/
.tree_label {
  position: relative;
  display: inline-block;
  background: #fff;
  }

label.tree_label { cursor: pointer; }

label.tree_label:hover { color: #666; }

/* ————————————————————–
  Tree expanded icon
*/
label.tree_label:before {
  background: #000;
  color: #fff;
  position: relative;
  z-index: 1;
  float: left;
  margin: 0 1em 0 -2em;
  width: 1em;
  height: 1em;
  border-radius: 1em;
  content: '+';
  text-align: center;
  line-height: .9em;
  }

:checked ~ label.tree_label:before { content: '–'; }

/* ————————————————————–
  Tree branches
*/
.tree li:before {
  position: absolute;
  top: 0;
  bottom: 0;
  left: -.5em;
  display: block;
  width: 0;
  border-left: 1px solid #777;
  content: "";
  }

.tree_label:after {
  position: absolute;
  top: 0;
  left: -1.5em;
  display: block;
  height: 0.5em;
  width: 1em;
  border-bottom: 1px solid #777;
  border-left: 1px solid #777;
  border-radius: 0 0 0 .3em;
  content: '';
  }

label.tree_label:after { border-bottom: 0; }

:checked ~ label.tree_label:after {
  border-radius: 0 .3em 0 0;
  border-top: 1px solid #777;
  border-right: 1px solid #777;
  border-bottom: 0;
  border-left: 0;
  bottom: 0;
  top: 0.5em;
  height: auto;
  }

.tree li:last-child:before {
  height: 1em;
  bottom: auto;
  }

.tree > li:last-child:before { display: none; }

.tree_custom {
  display: block;
  background: #eee;
  padding: 1em;
  border-radius: 0.3em;
}

JS:

function isNumber(n) {
  return !isNaN(parseFloat(n)) && isFinite(n);
}

function setFontSize(el) {
    var fontSize = el.val();
    
    if ( isNumber(fontSize) && fontSize >= 0.5 ) {
      $('body').css({ fontSize: fontSize + 'em' });
    } else if ( fontSize ) {
      el.val('1');
      $('body').css({ fontSize: '1em' });  
    }
}

$(function() {
  
  $('#fontSize')
    .bind('change', function(){ setFontSize($(this)); })
    .bind('keyup', function(e){
      if (e.keyCode == 27) {
        $(this).val('1');
        $('body').css({ fontSize: '1em' });  
      } else {
        setFontSize($(this));
      }
    });
  
  $(window)
    .bind('keyup', function(e){
      if (e.keyCode == 27) {
        $('#fontSize').val('1');
        $('body').css({ fontSize: '1em' });  
      }
    });
  
});