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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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 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: */ 210: public abstract TreePath getEditingPath(JTree tree); 211: }