source: trunk/gli/src/org/greenstone/gatherer/checklist/CheckList.java@ 4366

Last change on this file since 4366 was 4366, checked in by kjdon, 21 years ago

re-tabbed the code for java
  • Property svn:keywords set to Author Date Id Revision
File size: 8.8 KB
Line 
1/**
2 *#########################################################################
3 *
4 * A component of the Gatherer application, part of the Greenstone digital
5 * library suite from the New Zealand Digital Library Project at the
6 * University of Waikato, New Zealand.
7 *
8 * <BR><BR>
9 *
10 * Author: John Thompson, Greenstone Digital Library, University of Waikato
11 *
12 * <BR><BR>
13 *
14 * Copyright (C) 1999 New Zealand Digital Library Project
15 *
16 * <BR><BR>
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * <BR><BR>
24 *
25 * This program is distributed in the hope that it will be useful,
26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU General Public License for more details.
29 *
30 * <BR><BR>
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
35 *########################################################################
36 */
37
38
39
40
41
42
43/* GPL_HEADER */
44package org.greenstone.gatherer.checklist;
45/**************************************************************************************
46 * Title: Gatherer
47 * Description: The Gatherer: a tool for gathering and enriching a digital collection.
48 * Company: The University of Waikato
49 * Written: 14/08/02
50 * Revised:
51 **************************************************************************************/
52import java.awt.*;
53import java.awt.event.*;
54import java.util.*;
55import javax.swing.*;
56import javax.swing.border.*;
57import org.greenstone.gatherer.checklist.Entry;
58/** This class provides a visual component that has the form of a list, as provided by JList but uses JCheckBox for data selection. Thus several elements can be 'ticked' in the list, and this selection returned using the method getSelected().<BR>Parts of this code modified from Trevor Harmon's posting on www.dejanews.com.
59 * @author John Thompson
60 * @version 2.3
61 */
62// ####################################################################################
63// Optimization Saving
64// ####################################################################################
65// Vector -> ArrayList + Processor
66// ####################################################################################
67public class CheckList
68 extends JList {
69 /** The border used when a list row is not in focus. */
70 protected static Border noFocusBorder = new EmptyBorder(1, 1, 1, 1);
71 /** Constructor. */
72 public CheckList() {
73 super();
74 setCellRenderer(new CellRenderer());
75 setModel(new DefaultListModel());
76 setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
77 addMouseListener(new CheckListListener());
78 }
79 /** Constructor.
80 * @param list_data An <strong>ArrayList</strong> of entries for this checklist.
81 * @see org.greenstone.gatherer.checklist.CheckList.Entry
82 */
83 public CheckList(ArrayList list_data) {
84 super();
85 // Create a new model.
86 DefaultListModel model = new DefaultListModel();
87 for(int i = 0; i < list_data.size(); i++) {
88 Entry entry = new Entry(list_data.get(i));
89 String name = entry.toString();
90 int index = 0;
91 boolean found = false;
92 while(index < model.size() && !found) {
93 Object sibling = model.getElementAt(index);
94 if(name.compareTo(sibling.toString()) <= 0) {
95 model.add(index, entry);
96 found = true;
97 }
98 index++;
99 }
100 if(!found) {
101 model.addElement(entry);
102 }
103 }
104 setModel(model);
105 setCellRenderer(new CellRenderer());
106 addMouseListener(new CheckListListener());
107 setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
108 }
109
110 /** Constructor. */
111 public CheckList(ListModel data_model) {
112 super(data_model);
113 setCellRenderer(new CellRenderer());
114 addMouseListener(new CheckListListener());
115 setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
116 }
117
118 public void addEntry(Entry entry) {
119 DefaultListModel model = (DefaultListModel) getModel();
120 String name = entry.toString();
121 int index = 0;
122 boolean found = false;
123 while(index < model.size() && !found) {
124 Object sibling = model.getElementAt(index);
125 if(name.compareTo(sibling.toString()) <= 0) {
126 model.add(index, entry);
127 found = true;
128 }
129 index++;
130 sibling = null;
131 }
132 if(!found) {
133 model.addElement(entry);
134 }
135 name = null;
136 model = null;
137 }
138
139 public Entry get(int index) {
140 DefaultListModel model = (DefaultListModel) getModel();
141 return (Entry) model.get(index);
142 }
143
144 /** Retrieve the currently ticked entries from this list.
145 * @return An <strong>ArrayList</strong> containing only those entries from the initial list that are checked.
146 * @see org.greenstone.gatherer.checklist.CheckList.Entry
147 */
148 public ArrayList getSelected() {
149 ArrayList result = new ArrayList();
150 DefaultListModel model = (DefaultListModel) getModel();
151 int size = model.size();
152 for(int i = 0; i < size; i++) {
153 Entry entry = (Entry) model.get(i);
154 if(entry.isSelected()) {
155 result.add(entry.getObject());
156 }
157 }
158 return result;
159 }
160
161 public boolean isSelected(int index) {
162 DefaultListModel model = (DefaultListModel) getModel();
163 Entry entry = (Entry) model.get(index);
164 return entry.isSelected();
165 }
166
167 public int getEntryCount() {
168 return getModel().getSize();
169 }
170
171 /** Checks the entries in the list whose name appear in the given array.
172 * @param names The name of entries to be checked as a <strong>String[]</strong>.
173 * @see org.greenstone.gatherer.checklist.CheckList.Entry
174 */
175 public void setSelected(String names[]) {
176 DefaultListModel model = (DefaultListModel) getModel();
177 int size = model.size();
178 for(int i = 0; i < size; i++) {
179 Entry entry = (Entry) model.get(i);
180 for(int j = 0; names != null && j < names.length; j++) {
181 if(entry.toString().equals(names[j])) {
182 entry.setSelected(true);
183 }
184 }
185 }
186 }
187 /** A custom list cell renderer for producing rows which contain clickable check boxes. */
188 protected class CellRenderer
189 implements ListCellRenderer {
190 /** Return a component that has been configured to display the specified value. That component's paint method is then called to "render" the cell. If it is necessary to compute the dimensions of a list because the list cells do not have a fixed size, this method is called to generate a component on which getPreferredSize can be invoked.
191 * @param list The </strong>JList</strong> we're painting.
192 * @param value The value returned by list.getModel().getElementAt(index), as an <strong>Object</strong>.
193 * @param index The cells index as an <i>int</i>.
194 * @param is_selected <i>true</i> if the specified cell was selected, <i>false</i> otherwise.
195 * @param cell_has_focus <i>true</i> if and only if the specified cell has the focus.
196 * @return A <strong>Component</strong> whose paint() method will render the specified value.
197 */
198 public Component getListCellRendererComponent(JList list, Object value, int index, boolean is_selected, boolean cell_has_focus) {
199 JCheckBox checkbox = (JCheckBox) value;
200 checkbox.setBackground(is_selected ? list.getSelectionBackground() : list.getBackground());
201 checkbox.setForeground(is_selected ? list.getSelectionForeground() : list.getForeground());
202 checkbox.setEnabled(list.isEnabled());
203 checkbox.setFont(list.getFont());
204 checkbox.setFocusPainted(false);
205 checkbox.setBorderPainted(true);
206 checkbox.setBorder((is_selected) ? UIManager.getBorder("List.focusCellHighlightBorder") : noFocusBorder);
207 return checkbox;
208 }
209 }
210 /** Listens for clicks apon the checks within the list, and updates as necessary. */
211 private class CheckListListener
212 extends MouseAdapter {
213 private Entry previous_checkbox = null;
214 /** Called whenever the mouse is clicked over our list. We find the nearest checkbox and change its state.
215 * @param e A <strong>MouseEvent</strong> containing everything you ever wanted to know about the mouse event but were afraid to ask.
216 */
217 public void mousePressed(MouseEvent e) {
218 JList list = (JList) e.getSource();
219 int index = list.locationToIndex(e.getPoint());
220 Entry checkbox = (Entry)list.getModel().getElementAt(index);
221 // If this is the same checkbox as was recently selected, change the tick.
222 if(list.isSelectedIndex(index) && checkbox == previous_checkbox) {
223 if(!checkbox.isFixed()) {
224 checkbox.setSelected(!checkbox.isSelected());
225 }
226 checkbox.grabFocus();
227 }
228 // Otherwise the selection has just changed, so select the new checkbox
229 else if(list.isSelectedIndex(index)) {
230 previous_checkbox = checkbox;
231 }
232 else {
233 previous_checkbox = null;
234 }
235 }
236 }
237}
238
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