Bug 6700 Code assist should not just beep
suggest to show a status message: Could not complete due to syntax errors. This is also better for accessability reasons.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/CompilationUnitEditor.java
if (fBracketHighlighter != null)
						fBracketHighlighter.setHighlightColor(getColor(MATCHING_BRACKETS_COLOR));
					return;
				} 
				
				IContentAssistant c= isv.getContentAssistant();
				if (c instanceof ContentAssistant)
					ContentAssistPreference.changeConfiguration((ContentAssistant) c, getPreferenceStore(), event);
			}
				
		} finally {
			super.handlePreferenceStoreChanged(event);
		}
	}
	/**
	 * @see AbstractTextEditor#affectsTextPresentation(PropertyChangeEvent)
	 */
	protected boolean affectsTextPresentation(PropertyChangeEvent event) {
		String p= event.getProperty();
		boolean affects=MATCHING_BRACKETS_COLOR.equals(p);
		return affects ? affects : super.affectsTextPresentation(event);
	}
	
	/**
	 * @see AbstractTextEditor#createSourceViewer(Composite, IVerticalRuler, int)
	 */
	protected ISourceViewer createSourceViewer(Composite parent, IVerticalRuler ruler, int styles) {
		return new InternalSourceViewer(parent, ruler, styles);
	}
}