Bug 18266 Turning off lightbulb preference doesn't turn the lights off right away
When you turn off the lightbulb preference, editors with existing lightbulbs continue to show them. Closing and reopening the editors gets rid of them.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/JavaEditorPreferencePage.java
int value= Integer.parseInt(number);
				if (value < 0)
					status.setError(JavaUIMessages.getFormattedString("JavaEditorPreferencePage.invalid_input", number)); 
			} catch (NumberFormatException e) {
				status.setError(JavaUIMessages.getFormattedString("JavaEditorPreferencePage.invalid_input", number)); 
			}
		}
		return status;
	}
	
	private void updateStatus(IStatus status) {
		if (!status.matches(IStatus.ERROR)) {
			for (int i= 0; i < fNumberFields.size(); i++) {
				Text text= (Text) fNumberFields.get(i);
				IStatus s= validatePositiveNumber(text.getText());
				status= StatusUtil.getMoreSevere(s, status);
			}
		}	
		setValid(!status.matches(IStatus.ERROR));
		StatusUtil.applyToStatusLine(this, status);
	}
	public static boolean showTempProblems() {
		return JavaPlugin.getDefault().getPreferenceStore().getBoolean(JavaEditorPreferencePage.PREF_SHOW_TEMP_PROBLEMS);
	}
	
	static public boolean synchronizeOutlineOnCursorMove() {
		return JavaPlugin.getDefault().getPreferenceStore().getBoolean(PREF_SYNC_OUTLINE_ON_CURSOR_MOVE);
	}
}