javascript - 获取选定的文本位置并在其旁边放置一个元素

Question

tl;博士

这个想法是允许用户标记任何文本并查看所选内容旁边的弹出菜单，以及适用于所选文本的可能操作。

<小时/>

我需要在用户选择的文本旁边放置一个绝对定位按钮。

我将鼠标事件绑定(bind)到文档，并获取选定的文本，但我目前不知道如何知道实际选择的位置，而不将其包装在某些元素，因为文本的选择可以跨多个元素，如果我将其换行，则会弄乱结构。

Answer 1

您可以将标记范围放置在选择的末尾，使用 jQuery 获取其坐标，将按钮放置在这些坐标处并删除标记范围。

以下内容应该可以帮助您入门:

var markSelection = (function() {
    var markerTextChar = "\ufeff";
    var markerTextCharEntity = "";

    var markerEl, markerId = "sel_" + new Date().getTime() + "_" + Math.random().toString().substr(2);

    var selectionEl;

    return function(win) {
        win = win || window;
        var doc = win.document;
        var sel, range;
        // Branch for IE <= 8 
        if (doc.selection && doc.selection.createRange) {
            // Clone the TextRange and collapse
            range = doc.selection.createRange().duplicate();
            range.collapse(false);

            // Create the marker element containing a single invisible character by creating literal HTML and insert it
            range.pasteHTML('<span id="' + markerId + '" style="position: relative;">' + markerTextCharEntity + '</span>');
            markerEl = doc.getElementById(markerId);
        } else if (win.getSelection) {
            sel = win.getSelection();
            range = sel.getRangeAt(0).cloneRange();
            range.collapse(false);

            // Create the marker element containing a single invisible character using DOM methods and insert it
            markerEl = doc.createElement("span");
            markerEl.id = markerId;
            markerEl.appendChild( doc.createTextNode(markerTextChar) );
            range.insertNode(markerEl);
        }

        if (markerEl) {
            // Lazily create element to be placed next to the selection
            if (!selectionEl) {
                selectionEl = doc.createElement("div");
                selectionEl.style.border = "solid darkblue 1px";
                selectionEl.style.backgroundColor = "lightgoldenrodyellow";
                selectionEl.innerHTML = "&lt;- selection";
                selectionEl.style.position = "absolute";

                doc.body.appendChild(selectionEl);
            }

            // Find markerEl position http://www.quirksmode.org/js/findpos.html
        var obj = markerEl;
        var left = 0, top = 0;
        do {
            left += obj.offsetLeft;
            top += obj.offsetTop;
        } while (obj = obj.offsetParent);

            // Move the button into place.
            // Substitute your jQuery stuff in here
            selectionEl.style.left = left + "px";
            selectionEl.style.top = top + "px";

            markerEl.parentNode.removeChild(markerEl);
        }
    };
})();