Bug 81983 [preferences] Disabling and enabling folding on small file takes forever
3.1 M4 Using enable/disable folding on a small CU takes forever. This is caused by the recent change to apply the preference to all Java editors. In another (hidden) window (Debug) I had StyledText open which (understandably) took long to react on the preference change. Non-visible editor's should not react to this change until they become visible.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
*/
		public void setValue(String name, long value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, String value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * {@inheritDoc}
		 */
		public void setValue(String name, boolean value) {
			throw new UnsupportedOperationException();
		}
		/**
		 * Returns the adapted options Map.
		 * 
		 * @return Returns the adapted options Map.
		 */
		public Map getOptions() {
			return fOptions;
		}
		/**
		 * Returns the mock-up preference store, events are received through this preference store.
		 * @return Returns the mock-up preference store.
		 */
		public IPreferenceStore getMockupPreferenceStore() {
			return fMockupPreferenceStore;