Function boxModelAdjustment

src/modules/jquery.js:6711–6802

(
    elem,
    dimension,
    box,
    isBorderBox,
    styles,
    computedVal
  )

  }

  function boxModelAdjustment(
    elem,
    dimension,
    box,
    isBorderBox,
    styles,
    computedVal
  ) {
    var i = dimension === 'width' ? 1 : 0,
      extra = 0,
      delta = 0,
      marginDelta = 0;

    // Adjustment may not be necessary
    if (box === (isBorderBox ? 'border' : 'content')) {
      return 0;
    }

    for (; i < 4; i += 2) {
      // Both box models exclude margin
      // Count margin delta separately to only add it after scroll gutter adjustment.
      // This is needed to make negative margins work with `outerHeight( true )` (gh-3982).
      if (box === 'margin') {
        marginDelta += jQuery.css(elem, box + cssExpand[i], true, styles);
      }

      // If we get here with a content-box, we're seeking "padding" or "border" or "margin"
      if (!isBorderBox) {
        // Add padding
        delta += jQuery.css(elem, 'padding' + cssExpand[i], true, styles);

        // For "border" or "margin", add border
        if (box !== 'padding') {
          delta += jQuery.css(
            elem,
            'border' + cssExpand[i] + 'Width',
            true,
            styles
          );

          // But still keep track of it otherwise
        } else {
          extra += jQuery.css(
            elem,
            'border' + cssExpand[i] + 'Width',
            true,
            styles
          );
        }

        // If we get here with a border-box (content + padding + border), we're seeking "content" or
        // "padding" or "margin"
      } else {
        // For "content", subtract padding
        if (box === 'content') {
          delta -= jQuery.css(elem, 'padding' + cssExpand[i], true, styles);
        }