var editor = null;
var output = null;
const getTextSelection = function (editor) {
const selection = window.getSelection();
if (selection != null && selection.rangeCount > 0) {
const range = selection.getRangeAt(0);
return {
start: getTextLength(editor, range.startContainer, range.startOffset),
end: getTextLength(editor, range.endContainer, range.endOffset)
};
} else
return null;
}
const getTextLength = function (parent, node, offset) {
var textLength = 0;
if (node.nodeName == '#text')
textLength += offset;
else for (var i = 0; i < offset; i++)
textLength += getNodeTextLength(node.childNodes[i]);
if (node != parent)
textLength += getTextLength(parent, node.parentNode, getNodeOffset(node));
return textLength;
}
const getNodeTextLength = function (node) {
var textLength = 0;
if (node.nodeName == 'BR')
textLength = 1;
else if (node.nodeName == '#text')
textLength = node.nodeValue.length;
else if (node.childNodes != null)
for (var i = 0; i < node.childNodes.length; i++)
textLength += getNodeTextLength(node.childNodes[i]);
return textLength;
}
const getNodeOffset = function (node) {
return node == null ? -1 : 1 + getNodeOffset(node.previousSibling);
}
window.onload = function () {
editor = document.querySelector('.editor');
output = document.querySelector('#output');
document.addEventListener('selectionchange', handleSelectionChange);
}
const handleSelectionChange = function () {
if (isEditor(document.activeElement)) {
const textSelection = getTextSelection(document.activeElement);
if (textSelection != null) {
const text = document.activeElement.innerText;
const selection = text.slice(textSelection.start, textSelection.end);
print(`Selection: [${selection}] (Start: ${textSelection.start}, End: ${textSelection.end})`);
} else
print('Selection is null!');
} else
print('Select some text above');
}
const isEditor = function (element) {
return element != null && element.classList.contains('editor');
}
const print = function (message) {
if (output != null)
output.innerText = message;
else
console.log('output is null!');
}
* {
font-family: 'Georgia', sans-serif;
padding: 0;
margin: 0;
}
body {
margin: 16px;
}
.p {
font-size: 16px;
line-height: 24px;
padding: 0 2px;
}
.editor {
border: 1px solid #0000001e;
border-radius: 2px;
white-space: pre-wrap;
}
#output {
margin-top: 16px;
}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<script src="./script.js" async></script>
<link href="./stylesheet.css" rel="stylesheet">
<title>Caret Position</title>
</head>
<body>
<p class="editor" contenteditable="true"><em>Write<br></em><br>some <br>awesome <b><em>text </em></b>here...</p>
<p id="output">Select some text above</p>
</body>
</html>
#parent
中选择了所有内容,他的选择将包括一些HTML标签(<a>和<p>)。 - Tom Lehman