1 /* 2 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 package javax.swing.tree; 26 27 import java.awt.Component; 28 import javax.swing.JTree; 29 30 /** 31 * Defines the requirements for an object that displays a tree node. 32 * See <a 33 href="http://java.sun.com/docs/books/tutorial/uiswing/components/tree.html">How to Use Trees</a> 34 * in <em>The Java Tutorial</em> 35 * for an example of implementing a tree cell renderer 36 * that displays custom icons. 37 * 38 * @author Rob Davis 39 * @author Ray Ryan 40 * @author Scott Violet 41 */ 42 public interface TreeCellRenderer { 43 44 /** 45 * Sets the value of the current tree cell to <code>value</code>. 46 * If <code>selected</code> is true, the cell will be drawn as if 47 * selected. If <code>expanded</code> is true the node is currently 48 * expanded and if <code>leaf</code> is true the node represents a 49 * leaf and if <code>hasFocus</code> is true the node currently has 50 * focus. <code>tree</code> is the <code>JTree</code> the receiver is being 51 * configured for. Returns the <code>Component</code> that the renderer 52 * uses to draw the value. 53 * <p> 54 * The <code>TreeCellRenderer</code> is also responsible for rendering the 55 * the cell representing the tree's current DnD drop location if 56 * it has one. If this renderer cares about rendering 57 * the DnD drop location, it should query the tree directly to 58 * see if the given row represents the drop location: 59 * <pre> 60 * JTree.DropLocation dropLocation = tree.getDropLocation(); 61 * if (dropLocation != null 62 * && dropLocation.getChildIndex() == -1 63 * && tree.getRowForPath(dropLocation.getPath()) == row) { 64 * 65 * // this row represents the current drop location 66 * // so render it specially, perhaps with a different color 67 * } 68 * </pre> 69 * 70 * @return the <code>Component</code> that the renderer uses to draw the value 71 */ 72 Component getTreeCellRendererComponent(JTree tree, Object value, 73 boolean selected, boolean expanded, 74 boolean leaf, int row, boolean hasFocus); 75 76 }