function getSelection(el) {
  var start = 0, end = 0, normalizedValue, range,
    textInputRange, len, endRange;

  if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
    start = el.selectionStart;
    end = el.selectionEnd;
  } else {
    range = document.selection.createRange();

    if (range && range.parentElement() == el) {
      len = el.value.length;
      normalizedValue = el.value.replace(/\r\n/g, "\n");

      // Create a working TextRange that lives only in the input
      textInputRange = el.createTextRange();
      textInputRange.moveToBookmark(range.getBookmark());

      // Check if the start and end of the selection are at the very end
      // of the input, since moveStart/moveEnd doesn't return what we want
      // in those cases
      endRange = el.createTextRange();
      endRange.collapse(false);

      if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
        start = end = len;
      } else {
        start = -textInputRange.moveStart("character", -len);
        start += normalizedValue.slice(0, start).split("\n").length - 1;

        if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
            end = len;
        } else {
            end = -textInputRange.moveEnd("character", -len);
            end += normalizedValue.slice(0, end).split("\n").length - 1;
        }
      }
    }
  }
  return {
    start: start,
    end: end
  }
}
function getSelection(el) {
  var start = 0, end = 0, normalizedValue, range,
    textInputRange, len, endRange;

  if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
    start = el.selectionStart;
    end = el.selectionEnd;
  } else {
    range = document.selection.createRange();

    if (range && range.parentElement() == el) {
      len = el.value.length;
      normalizedValue = el.value.replace(/\r\n/g, "\n");

      
      textInputRange = el.createTextRange();
      textInputRange.moveToBookmark(range.getBookmark());

      
      
      
      endRange = el.createTextRange();
      endRange.collapse(false);

      if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
        start = end = len;
      } else {
        start = -textInputRange.moveStart("character", -len);
        start += normalizedValue.slice(0, start).split("\n").length - 1;

        if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
            end = len;
        } else {
            end = -textInputRange.moveEnd("character", -len);
            end += normalizedValue.slice(0, end).split("\n").length - 1;
        }
      }
    }
  }
  return {
    start: start,
    end: end
  }
}
function getSelection ( el ) { var start = 0 , end = 0 , normalizedValue , range , textInputRange , len , endRange ; if ( typeof el . selectionStart == "number" && typeof el . selectionEnd == "number" ) { start = el . selectionStart ; end = el . selectionEnd ; } else { range = document . selection . createRange ( ) ; if ( range && range . parentElement ( ) == el ) { len = el . value . length ; normalizedValue = el . value . replace ( / \r\n / g , "\n" ) ; // Create a working TextRange that lives only in the input textInputRange = el . createTextRange ( ) ; textInputRange . moveToBookmark ( range . getBookmark ( ) ) ; // Check if the start and end of the selection are at the very end // of the input, since moveStart/moveEnd doesn't return what we want // in those cases endRange = el . createTextRange ( ) ; endRange . collapse ( false ) ; if ( textInputRange . compareEndPoints ( "StartToEnd" , endRange ) > - 1 ) { start = end = len ; } else { start = - textInputRange . moveStart ( "character" , - len ) ; start += normalizedValue . slice ( 0 , start ) . split ( "\n" ) . length - 1 ; if ( textInputRange . compareEndPoints ( "EndToEnd" , endRange ) > - 1 ) { end = len ; } else { end = - textInputRange . moveEnd ( "character" , - len ) ; end += normalizedValue . slice ( 0 , end ) . split ( "\n" ) . length - 1 ; } } } } return { start : start , end : end } }
获取焦点起始坐标
获取焦点起始坐标