Function onDragStart

src/codemirror.js:3920–3941

(cm, e)

  }

  function onDragStart(cm, e) {
    if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
    if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;

    e.dataTransfer.setData("Text", cm.getSelection());
    e.dataTransfer.effectAllowed = "copyMove"

    // Use dummy image instead of default browsers image.
    // Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
    if (e.dataTransfer.setDragImage && !safari) {
      var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
      img.src = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
      if (presto) {
        img.width = img.height = 1;
        cm.display.wrapper.appendChild(img);
        // Force a relayout, or Opera won't use our image for some obscure reason
        img._top = img.offsetTop;
      }
      e.dataTransfer.setDragImage(img, 0, 0);
      if (presto) img.parentNode.removeChild(img);
    }
  }

  function onDragOver(cm, e) {
    var pos = posFromMouse(cm, e);