Function positiveSize

javascript/atoms/dom.js:519–559

(e)

  // Any element without positive size dimensions is not shown.
  function positiveSize(e) {
    var rect = bot.dom.getClientRect(e);
    if (rect.height > 0 && rect.width > 0) {
      return true;
    }
    // A vertical or horizontal SVG Path element will report zero width or
    // height but is "shown" if it has a positive stroke-width.
    if (bot.dom.isElement(e, 'PATH') && (rect.height > 0 || rect.width > 0)) {
      var strokeWidth = bot.dom.getEffectiveStyle(e, 'stroke-width');
      return !!strokeWidth && (parseInt(strokeWidth, 10) > 0);
    }

    // Any element with hidden/collapsed visibility is not shown.
    var visibility = bot.dom.getEffectiveStyle(e, 'visibility');
    if (visibility == 'collapse' || visibility == 'hidden') {
      return false;
    }

    if (!displayedFn(e)) {
      return false;
    }
    // Zero-sized elements should still be considered to have positive size
    // if they have a child element or text node with positive size, unless
    // the element has an 'overflow' style of 'hidden'.
    // Note: Text nodes containing only structural whitespace (with newlines
    // or tabs) are ignored as they are likely just HTML formatting, not
    // visible content.
    return bot.dom.getEffectiveStyle(e, 'overflow') != 'hidden' &&
      goog.array.some(e.childNodes, function (n) {
        if (n.nodeType == goog.dom.NodeType.TEXT) {
          var text = n.nodeValue;
          // Ignore text nodes that are purely structural whitespace
          // (contain newlines or tabs and nothing else besides spaces)
          if (/^[\s]*$/.test(text) && /[\n\r\t]/.test(text)) {
            return false;
          }
          return true;
        }
        return bot.dom.isElement(n) && positiveSize(n);
      });
  }
  if (!positiveSize(elem)) {
    return false;
  }