1/* 2 * Copyright (c) 1998, 1999, 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 26package java.awt.dnd; 27 28import java.awt.Insets; 29import java.awt.Point; 30 31/** 32 * During DnD operations it is possible that a user may wish to drop the 33 * subject of the operation on a region of a scrollable GUI control that is 34 * not currently visible to the user. 35 * <p> 36 * In such situations it is desirable that the GUI control detect this 37 * and institute a scroll operation in order to make obscured region(s) 38 * visible to the user. This feature is known as autoscrolling. 39 * <p> 40 * If a GUI control is both an active {@code DropTarget} 41 * and is also scrollable, it 42 * can receive notifications of autoscrolling gestures by the user from 43 * the DnD system by implementing this interface. 44 * <p> 45 * An autoscrolling gesture is initiated by the user by keeping the drag 46 * cursor motionless with a border region of the {@code Component}, 47 * referred to as 48 * the "autoscrolling region", for a predefined period of time, this will 49 * result in repeated scroll requests to the {@code Component} 50 * until the drag {@code Cursor} resumes its motion. 51 * 52 * @since 1.2 53 */ 54 55public interface Autoscroll { 56 57 /** 58 * This method returns the {@code Insets} describing 59 * the autoscrolling region or border relative 60 * to the geometry of the implementing Component. 61 * <P> 62 * This value is read once by the {@code DropTarget} 63 * upon entry of the drag {@code Cursor} 64 * into the associated {@code Component}. 65 * 66 * @return the Insets 67 */ 68 69 public Insets getAutoscrollInsets(); 70 71 /** 72 * notify the {@code Component} to autoscroll 73 * 74 * @param cursorLocn A {@code Point} indicating the 75 * location of the cursor that triggered this operation. 76 */ 77 78 public void autoscroll(Point cursorLocn); 79 80} 81