Bug 62909 [performance] quick outline takes forever to show up
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 {