Bug 62896 [misc] Quick Outline should not show override indicators if decorator disabled
I20040519 The quick outline shows override indicators no matter whether the Override indicator decorator is enabled in the prefs or not. We should only install the decorator if the prefs says so since this is a performance saver.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaOutlineInformationControl.java
if (compilationUnit == null)
				return null;
			
			String name= compilationUnit.getElementName();
			int index= name.indexOf('.');
			if (index != -1)
				name= name.substring(0, index);
			IType type= compilationUnit.getType(name);
			return type.exists() ? type : null;
		}
		/**
		 * Returns the primary type of a class file.
		 * 
		 * @param classFile the class file
		 * @return returns the primary type of the class file, or <code>null</code>
		 * if is does not have one
		 */
		private IType getMainType(IClassFile classFile) {
			try {
				IType type= classFile.getType();
				return type != null && type.exists() ? type : null;
			} catch (JavaModelException e) {
				return null;	
			}
		}
	}
	
	
	private class ShowOnlyMainTypeAction extends Action {