touch_selection.html - Android社区 - https://www.androidos.net.cn/

<html>
<div id='textDiv'>Some text we can select</div>
<input id='textfield' type="text" value="Text in a textfield">
<script>

function select_all_text() {
  var div = document.getElementById("textDiv");
  var range = document.createRange();
  range.selectNodeContents(div);
  var sel = window.getSelection();
  sel.removeAllRanges();
  sel.addRange(range);
}

function get_selection() {
  return (window.getSelection() + "");
}

function focus_textfield() {
  document.getElementById("textfield").focus();
  // Focusing the textfiled selects its text. Collapse selection to a cursor.
  window.getSelection().collapseToStart();
}

function get_cursor_position() {
  var div = document.getElementById("textfield");
  var start = div.selectionStart;
  var end = div.selectionEnd;
  if (start == end)
    return start;
  else
    return -1;
}

</script>

</html>