问检查ul中的任何文本是否被选中

EN

document.querySelector('#one').addEventListener('mousedown', function (event) {

  window.onmousemove = function (event) {
    console.log('the user is selecting text');
  }
  
  window.onmouseup = function (event) {
    console.log('the user mousedup');
    console.log(window.getSelection());
    autoScrollEnabled = 1;
    window.onmousemove = null;
    window.onmouseup = null;
  }
  
  console.log('user mouseddown in ' + event.target.nodeName);
  autoScrollEnabled = 0;
}, false);

<ul id="one" class="logbox">
   <li class="debug"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.learn how to make a website. We offer free tutorials in all web development technologies.</li>
   <li class="error"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
   <li class="warning"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
   <li>blabla</li>
</ul>

/*
This Snippet demonstrates that:
   A. It can detect the selection of text with or without form inputs.
   B. Will trigger on mouseup event and adequately handle false positives like text clicked but nothing highlighted.
*/

// Reference a selection object
var selection = window.getSelection();

/*
1. Delegate the whole document to listen for a mouseup event.

2. Next define the boolean state with:

  a. Condition 1 (needs to be true): That a selection object exists
  
     ＊ selection is true as soon as any text is the event.target (i.e. clicked, mouseup, farted on, etc.)
  b. Condition 2 (needs to be not collapsed): That the selection is not just a single click on text (i.e. nothing highlighted)
  
     ＊ By using the property .isCollapsed we know that if the starting point of a selection is the same as the ending point of a selection, then .isCollapsed is true and therefore no text was highlighted.
     
3. Since autoscroll was never explained, I have simplified it as an alert.

   a. If autoScroll is disabled, the alert will also contain the text that's selected. 
*/

$(document).on('mouseup', function(e) {
  var state = (selection && !selection.isCollapsed) ? alert('autoScroll is disabled {{' + selection + '}} is selected') : alert('autoScroll is still enabled');
  return state;
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

<ul id="list1" class="logbox">
  <li class="debug"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li class="error"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li class="warning"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li>blabla</li>
</ul>

- [window.getSelection()](https://developer.mozilla.org/en-US/docs/Web/API/Window/getSelection) 
- [.isCollapsed](https://developer.mozilla.org/en-US/docs/Web/API/Selection/isCollapsed)

var autoScrollOn = 1; //declare globally
var timeoutHandle = 0; //for additional service
$('#ul1').on('click', 'li', function() { //delegate click event
  clearTimeout(timeoutHandle); //clear timeout if any
  if ($(this).hasClass('selected')) { 
    //remove selection on the second click
    $('#ul1 li').removeClass('selected');
    autoScrollOn = 0;
  } else {
    //remove selection from siblings
    $('#ul1 li').removeClass('selected');
    //and add to the clicked element
    $(this).addClass('selected');
    autoScrollOn = 1;
    //restore autoscroll after 10s
    timeoutHandle = setTimeout(function() {
      $('#ul1 li').removeClass('selected');
      autoScrollOn = 0;
      console.log(autoScrollOn);
    }, 10000);
  }
  //do whatever you want with autoscroll
  console.log(autoScrollOn);
});

.debug {
  background: #aaf;
}
.error {
  background: #faa;
}
.warning {
  background: #ffa;
}
.selected {
  border: solid 1px #f00;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<ul id="ul1" class="logbox">
  <li class="debug"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li class="error"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li class="warning"><b>At</b> w3schools.com you will learn how to make a website. We offer free tutorials in all web development technologies.</li>
  <li>blabla</li>
</ul>