Bug 135284 [Viewers] API: need to add methods to StructuredViewer to support ViewerComparator
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
if(background != null) {
					control.setBackground(background);
				}
			
				if(foreground != null) {
					control.setForeground(foreground);
				}
		
				if(font != null) {
					control.setFont(font);
				}
			}
			clear();
		}
		
		/**
		 * Set the background color.
		 * @param background 
		 */
		public void setBackground(Color background) {
			this.background = background;
		}
		/**
		 * Set the font.
		 * @param font 
		 */
		public void setFont(Font font) {
			this.font = font;
		}