001 // Copyright 2005 The Apache Software Foundation 002 // 003 // Licensed under the Apache License, Version 2.0 (the "License"); 004 // you may not use this file except in compliance with the License. 005 // You may obtain a copy of the License at 006 // 007 // http://www.apache.org/licenses/LICENSE-2.0 008 // 009 // Unless required by applicable law or agreed to in writing, software 010 // distributed under the License is distributed on an "AS IS" BASIS, 011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012 // See the License for the specific language governing permissions and 013 // limitations under the License. 014 015 package org.apache.tapestry.describe; 016 017 import java.util.Collection; 018 019 /** 020 * An object that is provided with a description of another object. The receiver will format this 021 * information. 022 * 023 * @author Howard M. Lewis Ship 024 * @since 4.0 025 */ 026 public interface DescriptionReceiver 027 { 028 /** 029 * Invoke to describe another object instead of the current object. 030 */ 031 032 public void describeAlternate(Object alternate); 033 034 /** 035 * Provides a title for the object; usually the object's class name. 036 * 037 * @throws IllegalStateException 038 * if called more than once (for the same object) 039 */ 040 public void title(String title); 041 042 /** 043 * Starts a new sub-section within the description. A description may have any number of 044 * sections (but sections do not nest). A second title is only emitted when the firstproperty 045 * within the section is emitted. 046 * 047 * @throws IllegalStateException 048 * if called before invoking {@link #title(String)}. 049 */ 050 public void section(String section); 051 052 /** 053 * Emits a key/value pair, describing a property of the object. The value will itself be 054 * described. This method is overridden for scalar property types. 055 * 056 * @throws IllegalStateException 057 * if called before invoking {@link #title(String)} 058 */ 059 public void property(String key, Object value); 060 061 public void property(String key, boolean value); 062 063 public void property(String key, byte value); 064 065 public void property(String key, short value); 066 067 public void property(String key, int value); 068 069 public void property(String key, long value); 070 071 public void property(String key, float value); 072 073 public void property(String key, double value); 074 075 public void property(String key, char value); 076 077 /** 078 * Emits a list of values for the key. Each value will be described. Emits nothing if the array 079 * is null. 080 */ 081 public void array(String key, Object[] values); 082 083 /** 084 * As with {@link #array(String, Object[])}, but the values are in a collection (which may be 085 * null, to emit nothing). 086 */ 087 088 public void collection(String key, Collection values); 089 }