小编典典

如何将光标移动到内容可编辑实体的末尾

javascript

我需要将插入符号移动到contenteditable节点的末端,例如在Gmail注释小部件上。

我在StackOverflow上阅读了线程,但是这些解决方案基于使用输入,并且不适用于contenteditable元素。


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2020-04-25

共1个答案

小编典典

还有另一个问题。

如果的解决方案工作contenteditableDIV不包含其他元素multilined。

例如,如果一个div包含其他div,而这些其他div里面包含其他内容,则可能会出现一些问题。

为了解决这些问题,我安排了以下解决方案,它是对Nico的解决方案的改进:

//Namespace management idea from http://enterprisejquery.com/2010/10/how-good-c-habits-can-encourage-bad-javascript-habits-part-1/
(function( cursorManager ) {

    //From: http://www.w3.org/TR/html-markup/syntax.html#syntax-elements
    var voidNodeTags = ['AREA', 'BASE', 'BR', 'COL', 'EMBED', 'HR', 'IMG', 'INPUT', 'KEYGEN', 'LINK', 'MENUITEM', 'META', 'PARAM', 'SOURCE', 'TRACK', 'WBR', 'BASEFONT', 'BGSOUND', 'FRAME', 'ISINDEX'];

    //From: https://stackoverflow.com/questions/237104/array-containsobj-in-javascript
    Array.prototype.contains = function(obj) {
        var i = this.length;
        while (i--) {
            if (this[i] === obj) {
                return true;
            }
        }
        return false;
    }

    //Basic idea from: https://stackoverflow.com/questions/19790442/test-if-an-element-can-contain-text
    function canContainText(node) {
        if(node.nodeType == 1) { //is an element node
            return !voidNodeTags.contains(node.nodeName);
        } else { //is not an element node
            return false;
        }
    };

    function getLastChildElement(el){
        var lc = el.lastChild;
        while(lc && lc.nodeType != 1) {
            if(lc.previousSibling)
                lc = lc.previousSibling;
            else
                break;
        }
        return lc;
    }

    //Based on Nico Burns's answer
    cursorManager.setEndOfContenteditable = function(contentEditableElement)
    {

        while(getLastChildElement(contentEditableElement) &&
              canContainText(getLastChildElement(contentEditableElement))) {
            contentEditableElement = getLastChildElement(contentEditableElement);
        }

        var range,selection;
        if(document.createRange)//Firefox, Chrome, Opera, Safari, IE 9+
        {    
            range = document.createRange();//Create a range (a range is a like the selection but invisible)
            range.selectNodeContents(contentEditableElement);//Select the entire contents of the element with the range
            range.collapse(false);//collapse the range to the end point. false means collapse to end rather than the start
            selection = window.getSelection();//get the selection object (allows you to change selection)
            selection.removeAllRanges();//remove any selections already made
            selection.addRange(range);//make the range you have just created the visible selection
        }
        else if(document.selection)//IE 8 and lower
        { 
            range = document.body.createTextRange();//Create a range (a range is a like the selection but invisible)
            range.moveToElementText(contentEditableElement);//Select the entire contents of the element with the range
            range.collapse(false);//collapse the range to the end point. false means collapse to end rather than the start
            range.select();//Select the range (make it the visible selection
        }
    }

}( window.cursorManager = window.cursorManager || {}));

用法:

var editableDiv = document.getElementById("my_contentEditableDiv");
cursorManager.setEndOfContenteditable(editableDiv);

这样,游标肯定会定位在最后一个元素的末尾,并最终嵌套。

编辑#1 :为了更通用,while语句还应该考虑所有其他不能包含文本的标记。这些元素被称为 void元素
,在这个问题上,有一些方法可以测试元素是否为void。因此,假设存在一个调用的函数canContainTexttrue如果参数不是void元素,则该函数返回以下代码行:

contentEditableElement.lastChild.tagName.toLowerCase() != 'br'

应替换为:

canContainText(getLastChildElement(contentEditableElement))

编辑#2 :上面的代码已完全更新,描述和讨论的每个更改

2020-04-25