1 /* Scrollable.java -- 2 Copyright (C) 2002, 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 package javax.swing; 39 40 import java.awt.Dimension; 41 import java.awt.Rectangle; 42 43 /** 44 * Defines the method that a component should implement to behave nicely 45 * in {@link JScrollPane}s. Note that this is not required for a component 46 * to be used in a <code>JScrollPane</code>, but can highly improve the 47 * user experience when scrolling the component. 48 */ 49 public interface Scrollable 50 { getPreferredScrollableViewportSize()51 Dimension getPreferredScrollableViewportSize(); 52 53 /** 54 * Return the preferred scrolling amount (in pixels) for the given 55 * scrolling direction and orientation when scrolling in small amounts 56 * like table lines. 57 * 58 * @param visibleRect the currently visible part of the component. 59 * @param orientation the scrolling orientation 60 * @param direction the scrolling direction (negative - up, positive -down). 61 * The values greater than one means that more mouse wheel or similar 62 * events were generated, and hence it is better to scroll the longer 63 * distance. 64 * 65 * @return the preferred scrolling distance, negative if up or left. 66 */ getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction)67 int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, 68 int direction); 69 70 /** 71 * Return the preferred scrolling amount (in pixels) for the given 72 * scrolling direction and orientation when scrolling in large amounts 73 * (pages). 74 * 75 * @param visibleRect the currently visible part of the component. 76 * @param orientation the scrolling orientation 77 * @param direction the scrolling direction (negative - up, positive -down). 78 * The values greater than one means that more mouse wheel or similar 79 * events were generated, and hence it is better to scroll the longer 80 * distance. 81 * 82 * @return the preferred scrolling distance, negative if up or left. 83 */ getScrollableBlockIncrement(Rectangle visibleRect, int orientation, int direction)84 int getScrollableBlockIncrement(Rectangle visibleRect, int orientation, 85 int direction); 86 87 /** 88 * Return true if the width of the scrollable is always equal to the 89 * view, where it is displayed, width (for instance, the text area with 90 * the word wrap). In such case, the horizontal scrolling should not be 91 * performed. 92 * 93 * @return true is no horizontal scrolling is assumed, faster otherwise. 94 */ getScrollableTracksViewportWidth()95 boolean getScrollableTracksViewportWidth(); 96 97 /** 98 * Return true if the height of the scrollable is always equal to the view, 99 * where it is displayed, height.In such case, the vertical scrolling should 100 * not be performed. 101 * 102 * @return true is no horizontal scrolling is assumed, faster otherwise. 103 */ getScrollableTracksViewportHeight()104 boolean getScrollableTracksViewportHeight(); 105 106 } 107