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Get selected text position and place an element next to it

Tags:

javascript

dom

tl;dr

The idea is to allow a user to mark any text and see menu pop-up just next to the selection, with possible actions to apply to the selected text.


I need to position an absolute positioned button next to user's selected text.

I'm binding a mouseup event to the Document, and getting the selected text, but I'm currently out of ideas on how to know where the actual selection is positioned, without wrapping it in some element, because selection of text can be across several elements, and it would mess the structure if I would wrap it.

like image 766
vsync Avatar asked Oct 19 '09 16:10

vsync


3 Answers

You could position a marker span at the end of the selection, get its coordinates using jQuery, place your button at those coordinates and remove the marker span.

The following should get you started:

var markSelection = (function() {     var markerTextChar = "\ufeff";     var markerTextCharEntity = "&#xfeff;";      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);         }     }; })(); 
like image 170
Tim Down Avatar answered Sep 24 '22 02:09

Tim Down


I use getBoundingClientRect() when I need the content to remain undisturbed, while placing additional content near it.

    var r=window.getSelection().getRangeAt(0).getBoundingClientRect();     var relative=document.body.parentNode.getBoundingClientRect();     ele.style.top =(r.bottom -relative.top)+'px';//this will place ele below the selection     ele.style.right=-(r.right-relative.right)+'px';//this will align the right edges together 

this works in Chrome, but IE likes to give weird things, so here's a cross-browser solution: (Tested in Chrome and IE, probably works elsewhere)

https://jsfiddle.net/joktrpkz/7/

like image 26
Rick Avatar answered Sep 20 '22 02:09

Rick


You should probably insert an absolutely position element at the end of the 'range.' This works differently in different browsers, so your best bet might be to sniff.

And since you asked: this is how the new york times does it in their 'altClickToSearch.js' file:

function insertButton() {

selectionButton = new Element(
        'span', {
          'className':'nytd_selection_button',
          'id':'nytd_selection_button',
          'title':'Lookup Word',
          'style': 'margin:-20px 0 0 -20px; position:absolute; background:url(http://graphics8.nytimes.com/images/global/word_reference/ref_bubble.png);width:25px;height:29px;cursor:pointer;_background-image: none;filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src="http://graphics8.nytimes.com/images/global/word_reference/ref_bubble.png", sizingMethod="image");'
        }
    )

if (Prototype.Browser.IE) {
  var tmp = new Element('div');
  tmp.appendChild(selectionButton);
  newRange = selection.duplicate();
  newRange.setEndPoint( "StartToEnd", selection);
  newRange.pasteHTML(tmp.innerHTML);
  selectionButton = $('nytd_selection_button');
}
else {
  var range = selection.getRangeAt(0);
  newRange = document.createRange();
  newRange.setStart(selection.focusNode, range.endOffset);
  newRange.insertNode(selectionButton);
}
}
like image 34
Alex Sexton Avatar answered Sep 22 '22 02:09

Alex Sexton