/* TreeUI.java -- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package javax.swing.plaf; import java.awt.Rectangle; import javax.swing.JTree; import javax.swing.tree.TreePath; /** * An abstract base class for delegates that provide the user * interface for JTree. * * @see javax.swing.JTree * * @author Sascha Brawer (brawer@dandelis.ch) */ public abstract class TreeUI extends ComponentUI { /** * Constructs a new TreeUI. */ public TreeUI() { // Nothing to do here. } /** * Determines the geometric extent of the label that is * drawn for a path. * * @param tree the JTree for which this delegate * object provides the user interface. * * @param path the path whose label extent is requested. * * @return a rectangle enclosing the label, or null * if path contains invalid nodes. */ public abstract Rectangle getPathBounds(JTree tree, TreePath path); /** * Creates a TreePath for the specified row. * * @param tree the JTree for which this delegate * object provides the user interface. * * @param row the index of the row, which should be a number * in the range [0, getRowCount(tree) - 1]. * * @return a TreePath for the specified row, or * null if row is outside * the valid range. */ public abstract TreePath getPathForRow(JTree tree, int row); /** * Determines in which row a TreePath is currently * being displayed. * * @param tree the JTree for which this delegate * object provides the user interface. * * @param path the path for which the caller wants to know * in which row it is being displayed. * * @return a number in the range [0, getRowCount(tree) * - 1] if the path is currently on display; * -1 if the path is not shown to the * user. */ public abstract int getRowForPath(JTree tree, TreePath path); /** * Counts how many rows are currently displayed. * * @param tree the JTree for which this delegate * object provides the user interface. * * @return the number of visible rows. */ public abstract int getRowCount(JTree tree); /** * Finds the path that is closest to the specified position. * *

[A screen shot of a JTree] * *

As shown by the above illustration, the bounds of the * closest path do not necessarily need to contain the passed * location. * * @param tree the JTree for which this delegate * object provides the user interface. * * @param x the horizontal location, relative to the origin * of tree. * * @param y the vertical location, relative to the origin * of tree. * * @return the closest path, or null if the * tree is currenlty not displaying any paths at all. */ public abstract TreePath getClosestPathForLocation(JTree tree, int x, int y); /** * Determines whether the user is currently editing a tree cell. * * @param tree the JTree for which this delegate * object provides the user interface. * * @see #getEditingPath */ public abstract boolean isEditing(JTree tree); /** * Stops editing a tree cell, committing the entered value into the * tree’s model. If no editing session is active, or if the * active editor does not agree to stopping, nothing happens. In * some look and feels, this action happens when the user has * pressed the enter key. * * @param tree the JTree for which this delegate * object provides the user interface. * * @return false if the editing still goes on because * the cell editor has objected to stopping the session; * true if editing has been stopped. */ public abstract boolean stopEditing(JTree tree); /** * Cancels editing a tree cell, discarding any entered value. * If no editing session is active, nothing happens. The cell * editor is not given an opportunity to veto the canceling. * In some look and feels, this action happens when the user has * pressed the escape key. * * @param tree the JTree for which this delegate * object provides the user interface. */ public abstract void cancelEditing(JTree tree); /** * Starts a session to edit a tree cell. If the cell editor * rejects editing the cell, it will just be selected. * * @param tree the JTree for which this delegate * object provides the user interface. * * @param path the cell to edit. */ public abstract void startEditingAtPath(JTree tree, TreePath path); /** * Retrieves the tree cell that is currently being edited. * * @return the currently edited path, or null * if no editing session is currently active. */ public abstract TreePath getEditingPath(JTree tree); }