1 /* TreeUI.java -- 2 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. 3 4 This file is part of GNU Classpath. 5 6 GNU Classpath is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 2, or (at your option) 9 any later version. 10 11 GNU Classpath is distributed in the hope that it will be useful, but 12 WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with GNU Classpath; see the file COPYING. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19 02110-1301 USA. 20 21 Linking this library statically or dynamically with other modules is 22 making a combined work based on this library. Thus, the terms and 23 conditions of the GNU General Public License cover the whole 24 combination. 25 26 As a special exception, the copyright holders of this library give you 27 permission to link this library with independent modules to produce an 28 executable, regardless of the license terms of these independent 29 modules, and to copy and distribute the resulting executable under 30 terms of your choice, provided that you also meet, for each linked 31 independent module, the terms and conditions of the license of that 32 module. An independent module is a module which is not derived from 33 or based on this library. If you modify this library, you may extend 34 this exception to your version of the library, but you are not 35 obligated to do so. If you do not wish to do so, delete this 36 exception statement from your version. */ 37 38 39 package javax.swing.plaf; 40 41 import java.awt.Rectangle; 42 43 import javax.swing.JTree; 44 import javax.swing.tree.TreePath; 45 46 /** 47 * An abstract base class for delegates that provide the user 48 * interface for <code>JTree</code>. 49 * 50 * @see javax.swing.JTree 51 * 52 * @author Sascha Brawer (brawer@dandelis.ch) 53 */ 54 public abstract class TreeUI extends ComponentUI 55 { 56 /** 57 * Constructs a new <code>TreeUI</code>. 58 */ TreeUI()59 public TreeUI() 60 { 61 // Nothing to do here. 62 } 63 64 65 /** 66 * Determines the geometric extent of the label that is 67 * drawn for a path. 68 * 69 * @param tree the <code>JTree</code> for which this delegate 70 * object provides the user interface. 71 * 72 * @param path the path whose label extent is requested. 73 * 74 * @return a rectangle enclosing the label, or <code>null</code> 75 * if <code>path</code> contains invalid nodes. 76 */ getPathBounds(JTree tree, TreePath path)77 public abstract Rectangle getPathBounds(JTree tree, TreePath path); 78 79 80 /** 81 * Creates a <code>TreePath</code> for the specified row. 82 * 83 * @param tree the <code>JTree</code> for which this delegate 84 * object provides the user interface. 85 * 86 * @param row the index of the row, which should be a number 87 * in the range <code>[0, getRowCount(tree) - 1]</code>. 88 * 89 * @return a <code>TreePath</code> for the specified row, or 90 * <code>null</code> if <code>row</code> is outside 91 * the valid range. 92 */ getPathForRow(JTree tree, int row)93 public abstract TreePath getPathForRow(JTree tree, int row); 94 95 96 /** 97 * Determines in which row a <code>TreePath</code> is currently 98 * being displayed. 99 * 100 * @param tree the <code>JTree</code> for which this delegate 101 * object provides the user interface. 102 * 103 * @param path the path for which the caller wants to know 104 * in which row it is being displayed. 105 * 106 * @return a number in the range <code>[0, getRowCount(tree) 107 * - 1]</code> if the path is currently on display; 108 * <code>-1</code> if the path is not shown to the 109 * user. 110 */ getRowForPath(JTree tree, TreePath path)111 public abstract int getRowForPath(JTree tree, TreePath path); 112 113 114 /** 115 * Counts how many rows are currently displayed. 116 * 117 * @param tree the <code>JTree</code> for which this delegate 118 * object provides the user interface. 119 * 120 * @return the number of visible rows. 121 */ getRowCount(JTree tree)122 public abstract int getRowCount(JTree tree); 123 124 125 /** 126 * Finds the path that is closest to the specified position. 127 * 128 * <p><img src="doc-files/TreeUI-1.png" width="300" height="250" 129 * alt="[A screen shot of a JTree]" /> 130 * 131 * <p>As shown by the above illustration, the bounds of the 132 * closest path do not necessarily need to contain the passed 133 * location. 134 * 135 * @param tree the <code>JTree</code> for which this delegate 136 * object provides the user interface. 137 * 138 * @param x the horizontal location, relative to the origin 139 * of <code>tree</code>. 140 * 141 * @param y the vertical location, relative to the origin 142 * of <code>tree</code>. 143 * 144 * @return the closest path, or <code>null</code> if the 145 * tree is currenlty not displaying any paths at all. 146 */ getClosestPathForLocation(JTree tree, int x, int y)147 public abstract TreePath getClosestPathForLocation(JTree tree, 148 int x, int y); 149 150 151 /** 152 * Determines whether the user is currently editing a tree cell. 153 * 154 * @param tree the <code>JTree</code> for which this delegate 155 * object provides the user interface. 156 * 157 * @see #getEditingPath 158 */ isEditing(JTree tree)159 public abstract boolean isEditing(JTree tree); 160 161 162 /** 163 * Stops editing a tree cell, committing the entered value into the 164 * tree’s model. If no editing session is active, or if the 165 * active editor does not agree to stopping, nothing happens. In 166 * some look and feels, this action happens when the user has 167 * pressed the enter key. 168 * 169 * @param tree the <code>JTree</code> for which this delegate 170 * object provides the user interface. 171 * 172 * @return <code>false</code> if the editing still goes on because 173 * the cell editor has objected to stopping the session; 174 * <code>true</code> if editing has been stopped. 175 */ stopEditing(JTree tree)176 public abstract boolean stopEditing(JTree tree); 177 178 179 /** 180 * Cancels editing a tree cell, discarding any entered value. 181 * If no editing session is active, nothing happens. The cell 182 * editor is not given an opportunity to veto the canceling. 183 * In some look and feels, this action happens when the user has 184 * pressed the escape key. 185 * 186 * @param tree the <code>JTree</code> for which this delegate 187 * object provides the user interface. 188 */ cancelEditing(JTree tree)189 public abstract void cancelEditing(JTree tree); 190 191 192 /** 193 * Starts a session to edit a tree cell. If the cell editor 194 * rejects editing the cell, it will just be selected. 195 * 196 * @param tree the <code>JTree</code> for which this delegate 197 * object provides the user interface. 198 * 199 * @param path the cell to edit. 200 */ startEditingAtPath(JTree tree, TreePath path)201 public abstract void startEditingAtPath(JTree tree, TreePath path); 202 203 204 /** 205 * Retrieves the tree cell that is currently being edited. 206 * 207 * @return the currently edited path, or <code>null</code> 208 * if no editing session is currently active. 209 */ getEditingPath(JTree tree)210 public abstract TreePath getEditingPath(JTree tree); 211 } 212
