/* * Copyright (c) 1997, 1998, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing.plaf; import java.awt.Rectangle;import javax.swing.JTree;import javax.swing.tree.TreePath; /** * Pluggable look and feel interface for JTree. * * @author Rob Davis * @author Scott Violet */public abstract class TreeUI extends ComponentUI{    /**      * Returns the Rectangle enclosing the label portion that the      * last item in path will be drawn into.  Will return null if      * any component in path is currently valid.      */    public abstract Rectangle getPathBounds(JTree tree, TreePath path);     /**      * Returns the path for passed in row.  If row is not visible      * null is returned.      */    public abstract TreePath getPathForRow(JTree tree, int row);     /**      * Returns the row that the last item identified in path is visible      * at.  Will return -1 if any of the elements in path are not      * currently visible.      */    public abstract int getRowForPath(JTree tree, TreePath path);     /**      * Returns the number of rows that are being displayed.      */    public abstract int getRowCount(JTree tree);     /**      * Returns the path to the node that is closest to x,y.  If      * there is nothing currently visible this will return null, otherwise      * it'll always return a valid path.  If you need to test if the      * returned object is exactly at x, y you should get the bounds for      * the returned path and test x, y against that.      */    public abstract TreePath getClosestPathForLocation(JTree tree, int x,                                                       int y);     /**      * Returns true if the tree is being edited.  The item that is being      * edited can be returned by getEditingPath().      */    public abstract boolean isEditing(JTree tree);     /**      * Stops the current editing session.  This has no effect if the      * tree isn't being edited.  Returns true if the editor allows the      * editing session to stop.      */    public abstract boolean stopEditing(JTree tree);     /**      * Cancels the current editing session. This has no effect if the      * tree isn't being edited.  Returns true if the editor allows the      * editing session to stop.      */    public abstract void cancelEditing(JTree tree);     /**      * Selects the last item in path and tries to edit it.  Editing will      * fail if the CellEditor won't allow it for the selected item.      */    public abstract void startEditingAtPath(JTree tree, TreePath path);     /**     * Returns the path to the element that is being edited.     */    public abstract TreePath getEditingPath(JTree tree);}