001/* 002 * Copyright 2002-2012 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.ui.context; 018 019import org.springframework.lang.Nullable; 020 021/** 022 * Sub-interface of ThemeSource to be implemented by objects that 023 * can resolve theme messages hierarchically. 024 * 025 * @author Jean-Pierre Pawlak 026 * @author Juergen Hoeller 027 */ 028public interface HierarchicalThemeSource extends ThemeSource { 029 030 /** 031 * Set the parent that will be used to try to resolve theme messages 032 * that this object can't resolve. 033 * @param parent the parent ThemeSource that will be used to 034 * resolve messages that this object can't resolve. 035 * May be {@code null}, in which case no further resolution is possible. 036 */ 037 void setParentThemeSource(@Nullable ThemeSource parent); 038 039 /** 040 * Return the parent of this ThemeSource, or {@code null} if none. 041 */ 042 @Nullable 043 ThemeSource getParentThemeSource(); 044 045}