code: public void setContentHeightPercent(double contentHeightPercent) {
          double oldVal = this.contentHeightPercent;
          this.contentHeightPercent = contentHeightPercent;
          if (oldVal != this.contentHeightPercent && content != null && content.isAttached()) {
              recalcContentHeightPercent();
              centerContent();
              initWindowResize();
          }
      }
docs: Defines content band's height as percent of available content area's height.