我有一个简单的HTML作为例子:
<div id="editable" contenteditable="true">
text text text<br>
text text text<br>
text text text<br>
</div>
<button id="button">focus</button>
我想要简单的东西-当我点击按钮时，我想在可编辑的div中放置插入符号(光标)到特定的地方。从网上搜索，我有这个JS附加到按钮点击，但它不起作用(FF, Chrome):
const range = document.createRange();
const myDiv = document.getElementById("editable");
range.setStart(myDiv, 5);
range.setEnd(myDiv, 5);
是否可以像这样手动设置插入符号的位置?
当前回答
您在可满足光标定位方面找到的大多数答案都相当简单，因为它们只满足带有普通文本的输入。一旦在容器中使用html元素，输入的文本就会被分割成节点，并在树结构中自由分布。
为了设置光标位置，我使用了这个函数，它在提供的节点内循环所有子文本节点，并设置从初始节点开始到字符的范围。数字符:
function createRange(node, chars, range) {
if (!range) {
range = document.createRange()
range.selectNode(node);
range.setStart(node, 0);
}
if (chars.count === 0) {
range.setEnd(node, chars.count);
} else if (node && chars.count >0) {
if (node.nodeType === Node.TEXT_NODE) {
if (node.textContent.length < chars.count) {
chars.count -= node.textContent.length;
} else {
range.setEnd(node, chars.count);
chars.count = 0;
}
} else {
for (var lp = 0; lp < node.childNodes.length; lp++) {
range = createRange(node.childNodes[lp], chars, range);
if (chars.count === 0) {
break;
}
}
}
}
return range;
};
然后我用这个函数调用这个例程:
function setCurrentCursorPosition(chars) {
if (chars >= 0) {
var selection = window.getSelection();
range = createRange(document.getElementById("test").parentNode, { count: chars });
if (range) {
range.collapse(false);
selection.removeAllRanges();
selection.addRange(range);
}
}
};
range.collapse(false)将光标设置到范围的末尾。我用最新版本的Chrome、IE、Mozilla和Opera对它进行了测试，它们都运行良好。
PS.如果有人感兴趣，我得到当前的光标位置使用这段代码:
function isChildOf(node, parentId) {
while (node !== null) {
if (node.id === parentId) {
return true;
}
node = node.parentNode;
}
return false;
};
function getCurrentCursorPosition(parentId) {
var selection = window.getSelection(),
charCount = -1,
node;
if (selection.focusNode) {
if (isChildOf(selection.focusNode, parentId)) {
node = selection.focusNode;
charCount = selection.focusOffset;
while (node) {
if (node.id === parentId) {
break;
}
if (node.previousSibling) {
node = node.previousSibling;
charCount += node.textContent.length;
} else {
node = node.parentNode;
if (node === null) {
break
}
}
}
}
}
return charCount;
};
代码的作用与set函数相反——它获取当前的window.getSelection()。focusNode和focusOffset，并向后计算遇到的所有文本字符，直到它到达id为containerId的父节点。isChildOf函数只是在运行之前检查所提供的节点实际上是所提供的parentId的子节点。
代码应该工作直接没有改变，但我刚刚从一个jQuery插件我已经开发了，所以已经黑出了一对这的一对-让我知道，如果有什么不工作!
其他回答
function set_mouse() { var as = document.getElementById("editable"); el = as.childNodes[1].childNodes[0]; //goal is to get ('we') id to write (object Text) because it work only in object text var range = document.createRange(); var sel = window.getSelection(); range.setStart(el, 1); range.collapse(true); sel.removeAllRanges(); sel.addRange(range); document.getElementById("we").innerHTML = el; // see out put of we id } <div id="editable" contenteditable="true">dddddddddddddddddddddddddddd <p>dd</p>psss <p>dd</p> <p>dd</p> <p>text text text</p> </div> <p id='we'></p> <button onclick="set_mouse()">focus</button>
当你有(p) (span)等高级元素时，将插入符号设置在合适的位置是非常困难的。目标是获取(对象文本):
<div id="editable" contenteditable="true">dddddddddddddddddddddddddddd<p>dd</p>psss<p>dd</p>
<p>dd</p>
<p>text text text</p>
</div>
<p id='we'></p>
<button onclick="set_mouse()">focus</button>
<script>
function set_mouse() {
var as = document.getElementById("editable");
el = as.childNodes[1].childNodes[0];//goal is to get ('we') id to write (object Text) because it work only in object text
var range = document.createRange();
var sel = window.getSelection();
range.setStart(el, 1);
range.collapse(true);
sel.removeAllRanges();
sel.addRange(range);
document.getElementById("we").innerHTML = el;// see out put of we id
}
</script>
我认为将插入符号设置到可满足元素中的某个位置并不简单。我为此写了自己的代码。它绕过了计算剩余字符数的节点树，并在所需元素中设置插入符号。我没有对这段代码进行太多测试。
//Set offset in current contenteditable field (for start by default or for with forEnd=true)
function setCurSelectionOffset(offset, forEnd = false) {
const sel = window.getSelection();
if (sel.rangeCount !== 1 || !document.activeElement) return;
const firstRange = sel.getRangeAt(0);
if (offset > 0) {
bypassChildNodes(document.activeElement, offset);
}else{
if (forEnd)
firstRange.setEnd(document.activeElement, 0);
else
firstRange.setStart(document.activeElement, 0);
}
//Bypass in depth
function bypassChildNodes(el, leftOffset) {
const childNodes = el.childNodes;
for (let i = 0; i < childNodes.length && leftOffset; i++) {
const childNode = childNodes[i];
if (childNode.nodeType === 3) {
const curLen = childNode.textContent.length;
if (curLen >= leftOffset) {
if (forEnd)
firstRange.setEnd(childNode, leftOffset);
else
firstRange.setStart(childNode, leftOffset);
return 0;
}else{
leftOffset -= curLen;
}
}else
if (childNode.nodeType === 1) {
leftOffset = bypassChildNodes(childNode, leftOffset);
}
}
return leftOffset;
}
}
我还写了代码来获取当前插入符号的位置(没有测试):
//Get offset in current contenteditable field (start offset by default or end offset with calcEnd=true)
function getCurSelectionOffset(calcEnd = false) {
const sel = window.getSelection();
if (sel.rangeCount !== 1 || !document.activeElement) return 0;
const firstRange = sel.getRangeAt(0),
startContainer = calcEnd ? firstRange.endContainer : firstRange.startContainer,
startOffset = calcEnd ? firstRange.endOffset : firstRange.startOffset;
let needStop = false;
return bypassChildNodes(document.activeElement);
//Bypass in depth
function bypassChildNodes(el) {
const childNodes = el.childNodes;
let ans = 0;
if (el === startContainer) {
if (startContainer.nodeType === 3) {
ans = startOffset;
}else
if (startContainer.nodeType === 1) {
for (let i = 0; i < startOffset; i++) {
const childNode = childNodes[i];
ans += childNode.nodeType === 3 ? childNode.textContent.length :
childNode.nodeType === 1 ? childNode.innerText.length :
0;
}
}
needStop = true;
}else{
for (let i = 0; i < childNodes.length && !needStop; i++) {
const childNode = childNodes[i];
ans += bypassChildNodes(childNode);
}
}
return ans;
}
}
你还需要注意范围。starttooffset和range。endOffset包含文本节点(nodeType === 3)的字符偏移量和元素节点(nodeType === 1)的子节点偏移量。startContainer和range。endContainer可以引用树中任何级别的任何元素节点(当然它们也可以引用文本节点)。
const el = document.getElementById("editable");
el.focus()
let char = 1, sel; // character at which to place caret
if (document.selection) {
sel = document.selection.createRange();
sel.moveStart('character', char);
sel.select();
}
else {
sel = window.getSelection();
sel.collapse(el.lastChild, char);
}
我为我的简单文本编辑器做了这个。
与其他方法的区别:
高性能 适用于所有空间
使用
// get current selection
const [start, end] = getSelectionOffset(container)
// change container html
container.innerHTML = newHtml
// restore selection
setSelectionOffset(container, start, end)
// use this instead innerText for get text with keep all spaces
const innerText = getInnerText(container)
const textBeforeCaret = innerText.substring(0, start)
const textAfterCaret = innerText.substring(start)
selection.ts
/** return true if node found */
function searchNode(
container: Node,
startNode: Node,
predicate: (node: Node) => boolean,
excludeSibling?: boolean,
): boolean {
if (predicate(startNode as Text)) {
return true
}
for (let i = 0, len = startNode.childNodes.length; i < len; i++) {
if (searchNode(startNode, startNode.childNodes[i], predicate, true)) {
return true
}
}
if (!excludeSibling) {
let parentNode = startNode
while (parentNode && parentNode !== container) {
let nextSibling = parentNode.nextSibling
while (nextSibling) {
if (searchNode(container, nextSibling, predicate, true)) {
return true
}
nextSibling = nextSibling.nextSibling
}
parentNode = parentNode.parentNode
}
}
return false
}
function createRange(container: Node, start: number, end: number): Range {
let startNode
searchNode(container, container, node => {
if (node.nodeType === Node.TEXT_NODE) {
const dataLength = (node as Text).data.length
if (start <= dataLength) {
startNode = node
return true
}
start -= dataLength
end -= dataLength
return false
}
})
let endNode
if (startNode) {
searchNode(container, startNode, node => {
if (node.nodeType === Node.TEXT_NODE) {
const dataLength = (node as Text).data.length
if (end <= dataLength) {
endNode = node
return true
}
end -= dataLength
return false
}
})
}
const range = document.createRange()
if (startNode) {
if (start < startNode.data.length) {
range.setStart(startNode, start)
} else {
range.setStartAfter(startNode)
}
} else {
if (start === 0) {
range.setStart(container, 0)
} else {
range.setStartAfter(container)
}
}
if (endNode) {
if (end < endNode.data.length) {
range.setEnd(endNode, end)
} else {
range.setEndAfter(endNode)
}
} else {
if (end === 0) {
range.setEnd(container, 0)
} else {
range.setEndAfter(container)
}
}
return range
}
export function setSelectionOffset(node: Node, start: number, end: number) {
const range = createRange(node, start, end)
const selection = window.getSelection()
selection.removeAllRanges()
selection.addRange(range)
}
function hasChild(container: Node, node: Node): boolean {
while (node) {
if (node === container) {
return true
}
node = node.parentNode
}
return false
}
function getAbsoluteOffset(container: Node, offset: number) {
if (container.nodeType === Node.TEXT_NODE) {
return offset
}
let absoluteOffset = 0
for (let i = 0, len = Math.min(container.childNodes.length, offset); i < len; i++) {
const childNode = container.childNodes[i]
searchNode(childNode, childNode, node => {
if (node.nodeType === Node.TEXT_NODE) {
absoluteOffset += (node as Text).data.length
}
return false
})
}
return absoluteOffset
}
export function getSelectionOffset(container: Node): [number, number] {
let start = 0
let end = 0
const selection = window.getSelection()
for (let i = 0, len = selection.rangeCount; i < len; i++) {
const range = selection.getRangeAt(i)
if (range.intersectsNode(container)) {
const startNode = range.startContainer
searchNode(container, container, node => {
if (startNode === node) {
start += getAbsoluteOffset(node, range.startOffset)
return true
}
const dataLength = node.nodeType === Node.TEXT_NODE
? (node as Text).data.length
: 0
start += dataLength
end += dataLength
return false
})
const endNode = range.endContainer
searchNode(container, startNode, node => {
if (endNode === node) {
end += getAbsoluteOffset(node, range.endOffset)
return true
}
const dataLength = node.nodeType === Node.TEXT_NODE
? (node as Text).data.length
: 0
end += dataLength
return false
})
break
}
}
return [start, end]
}
export function getInnerText(container: Node) {
const buffer = []
searchNode(container, container, node => {
if (node.nodeType === Node.TEXT_NODE) {
buffer.push((node as Text).data)
}
return false
})
return buffer.join('')
}
我重构了@Liam的答案。我把它放在一个带有静态方法的类中，我让它的函数接收一个元素而不是#id，还有其他一些小调整。
这段代码特别适用于在富文本框中固定光标，例如<div contenteditable="true">。在得到下面的代码之前，我被这个问题困了好几天。
编辑:他的答案和这个答案有一个bug，涉及到按回车键。由于enter不能算作一个字符，所以按下enter键后光标的位置就乱了。如果我能够修复代码，我将更新我的答案。
edit2:为自己省去很多麻烦，确保<div contenteditable=true>为display: inline-block。这修复了一些有关Chrome浏览器把<div>而不是<br>当你按下enter的错误。
如何使用
let richText = document.getElementById('rich-text');
let offset = Cursor.getCurrentCursorPosition(richText);
// insert code here that does stuff to the innerHTML, such as adding/removing <span> tags
Cursor.setCurrentCursorPosition(offset, richText);
richText.focus();
Code
// Credit to Liam (Stack Overflow)
// https://stackoverflow.com/a/41034697/3480193
class Cursor {
static getCurrentCursorPosition(parentElement) {
var selection = window.getSelection(),
charCount = -1,
node;
if (selection.focusNode) {
if (Cursor._isChildOf(selection.focusNode, parentElement)) {
node = selection.focusNode;
charCount = selection.focusOffset;
while (node) {
if (node === parentElement) {
break;
}
if (node.previousSibling) {
node = node.previousSibling;
charCount += node.textContent.length;
} else {
node = node.parentNode;
if (node === null) {
break;
}
}
}
}
}
return charCount;
}
static setCurrentCursorPosition(chars, element) {
if (chars >= 0) {
var selection = window.getSelection();
let range = Cursor._createRange(element, { count: chars });
if (range) {
range.collapse(false);
selection.removeAllRanges();
selection.addRange(range);
}
}
}
static _createRange(node, chars, range) {
if (!range) {
range = document.createRange()
range.selectNode(node);
range.setStart(node, 0);
}
if (chars.count === 0) {
range.setEnd(node, chars.count);
} else if (node && chars.count >0) {
if (node.nodeType === Node.TEXT_NODE) {
if (node.textContent.length < chars.count) {
chars.count -= node.textContent.length;
} else {
range.setEnd(node, chars.count);
chars.count = 0;
}
} else {
for (var lp = 0; lp < node.childNodes.length; lp++) {
range = Cursor._createRange(node.childNodes[lp], chars, range);
if (chars.count === 0) {
break;
}
}
}
}
return range;
}
static _isChildOf(node, parentElement) {
while (node !== null) {
if (node === parentElement) {
return true;
}
node = node.parentNode;
}
return false;
}
}
