js 编辑器 获取光标位置

let input = document.getElementById('myInput');
let cursorPosition = input.selectionStart;
console.log(cursorPosition); // 输出光标位置

function getCursorPosition() {
    let selection = window.getSelection();
    if (selection.rangeCount > 0) {
        let range = selection.getRangeAt(0);
        let preCaretRange = range.cloneRange();
        preCaretRange.selectNodeContents(range.startContainer);
        preCaretRange.setEnd(range.startContainer, range.startOffset);
        let cursorPosition = preCaretRange.toString().length;
        return cursorPosition;
    }
    return -1;
}

console.log(getCursorPosition()); // 输出光标位置

// 使用 rangy 库获取光标位置
let cursorPosition = rangy.getSelection().getRangeAt(0).startOffset;
console.log(cursorPosition);

function getCursorPositionInNode(node) {
    let range = window.getSelection().getRangeAt(0);
    if (range.startContainer === node) {
        return range.startOffset;
    }
    for (let child of node.childNodes) {
        let pos = getCursorPositionInNode(child);
        if (pos !== -1) {
            return pos;
        }
    }
    return -1;
}