001// Copyright 2004, 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 015package org.apache.tapestry.contrib.palette; 016 017import java.util.ArrayList; 018import java.util.Collections; 019import java.util.Comparator; 020import java.util.List; 021 022import org.apache.tapestry.IMarkupWriter; 023import org.apache.tapestry.IRender; 024import org.apache.tapestry.IRequestCycle; 025 026/** 027 * One of the two columns in a Palette component: the left column lists available options, the right 028 * column lists the selected columns. 029 * 030 * @author Howard Lewis Ship 031 */ 032public class PaletteColumn implements IRender 033{ 034 private String _name; 035 036 private String _clientId; 037 038 private int _rows; 039 040 private List _options = new ArrayList(); 041 042 private static class ValueComparator implements Comparator 043 { 044 public int compare(Object o1, Object o2) 045 { 046 PaletteOption option1 = (PaletteOption) o1; 047 PaletteOption option2 = (PaletteOption) o2; 048 049 return option1.getValue().compareTo(option2.getValue()); 050 } 051 } 052 053 private static class LabelComparator implements Comparator 054 { 055 public int compare(Object o1, Object o2) 056 { 057 PaletteOption option1 = (PaletteOption) o1; 058 PaletteOption option2 = (PaletteOption) o2; 059 060 return option1.getLabel().compareTo(option2.getLabel()); 061 } 062 } 063 064 /** 065 * @param name 066 * the name of the column (the name attribute of the <select>) 067 * @param rows 068 * the number of visible rows (the size attribute of the <select>) 069 */ 070 public PaletteColumn(String name, String clientId, int rows) 071 { 072 _name = name; 073 _clientId = clientId; 074 _rows = rows; 075 } 076 077 public void addOption(PaletteOption option) 078 { 079 _options.add(option); 080 } 081 082 /** 083 * Sorts the options by value (the hidden value for the option that represents the object 084 * value). This should be invoked before rendering this PaletteColumn. 085 */ 086 public void sortByValue() 087 { 088 Collections.sort(_options, new ValueComparator()); 089 } 090 091 /** 092 * Sorts the options by the label visible to the user. This should be invoked before rendering 093 * this PaletteColumn. 094 */ 095 public void sortByLabel() 096 { 097 Collections.sort(_options, new LabelComparator()); 098 } 099 100 /** 101 * Renders the <select> and <option> tags for this column. 102 */ 103 public void render(IMarkupWriter writer, IRequestCycle cycle) 104 { 105 writer.begin("select"); 106 writer.attribute("multiple", "multiple"); 107 writer.attribute("name", _name); 108 109 if (_clientId != null) 110 writer.attribute("id", _clientId); 111 112 writer.attribute("size", _rows); 113 writer.println(); 114 115 int count = _options.size(); 116 for (int i = 0; i < count; i++) 117 { 118 PaletteOption o = (PaletteOption) _options.get(i); 119 120 o.render(writer, cycle); 121 } 122 123 writer.end(); 124 } 125 126}