如何在两个 div 之间的 contenteditable div 中设置插入符号/光标位置

浏览器对此不一致.Firefox 将允许您将插入符号定位在比大多数浏览器更多的位置，但 WebKit 和 IE 都对有效插入符号位置有明确的想法，并将修改您添加到选择中的范围以符合最近的有效位置.这确实是有道理的:具有不同的文档位置，因此对于相同的视觉插入符号位置的行为会让用户感到困惑.然而，这是以开发人员的不灵活为代价的.

这在任何地方都没有记录.当前选择规范对此只字未提，主要是因为不存在规范当浏览器实现其选择 API 并且当前规范没有统一的行为记录时.

一种选择是按照您的建议拦截 keypress 事件，尽管当用户使用编辑或上下文菜单粘贴内容时这无济于事.另一种方法是使用鼠标和键事件来跟踪选择，创建具有例如零宽度空格字符的元素以放置插入符号，并在必要时将插入符号放置在这些元素中.正如你所说，丑陋.

Consider the following contenteditable div.

<div contenteditable="true">
<div>bold text</div><div>bold text</div>
</div>

If I position the cursor between the two divs and start typing the text comes out bold instead of inserting a new text node between the two divs. The same happens if you hit home and try to type something in front of the first div. It becomes part of the first div.

If I inspect the startContainer of the range that's returned from the selection, I get the content for one of the div's instead of an empty text node as I would expect.

$( '#EDITABLE' ).focus();

var selection = window.getSelection();

var range = document.createRange();

var div = $('#div2').get(0);

range.setStartBefore(div);
range.collapse(true);

selection.removeAllRanges();
selection.addRange(range);

// cursor should now be between div1 and div2

range = window.getSelection().getRangeAt(0);

console.log("range object returned is: ", range);

// type something into the content editable div. why is it coming
// up bold since the cursor should be between the divs? it's 
// positioning the cursor at the end of the previous div. I want to
// target the spot between the divs. how?

div.content {
  display: inline-block;
  font-weight: bold;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<div contenteditable="true" id="EDITABLE">
  <div class="content" id="div1">Content for div1</div>
  <div class="content" id="div2">content for div 2</div>
</div>

Original jsfiddle: http://jsfiddle.net/9ZZpX/3/

The question is why does this happen? How can I select the spot between the divs so that when I type something it does not bold? (Obviously I can add a space and that works around the problem but that's quite ugly.)

You can see this working correctly at Facebook if you enter an @mention in a status update box and press HOME. If you type the text will not get highlighted.

The only thing I've been able to think of is intercepting the keypress and inserting a text node programmatically but that seems ugly.

I searched like crazy and can't find any references that document how this is really supposed to work. There is obviously something that I do not understand and the documentation is really lacking in this area.

(What I want to be able to do as well is detect when the cursor is about to enter one of these divs and jump over it. If the two divs are right next to each other, the cursor jumps into one of the divs and it mucks up the works.)

More info on what I'm trying to do: http://a-software-guy.com/2012/12/the-horrors-of-cursor-positioning-in-contenteditable-divs/

Browsers are inconsistent on this. Firefox will let you position the caret in more positions than most browsers but WebKit and IE both have definite ideas about valid caret positions and will amend a range you add to the selection to conform to the nearest valid position. This does make sense: having different document positions and hence behaviours for the same visual caret location is confusing for the user. However, this comes at the cost of inflexibility for the developer.

This is not documented anywhere. The current Selection spec says nothing about it, principally because no spec existed when browsers implemented their selection APIs and there is no uniform behaviour for the current spec to document.

One option would be to intercept the keypress event as you suggest, although this will not help when the user pastes in content using the edit or context menus. Another would be to keep track of the selection using mouse and key events, create elements with, say, a zero-width space character for the caret to be placed in and place the caret in one those elements when necessary. As you say, ugly.