Showing the changes to java/pkg/java/awt/dnd/Autoscroll.java (1 of 18352 files). Show all
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| 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 | + | |
| 26 | +package java.awt.dnd; | |
| 27 | + | |
| 28 | +import java.awt.Insets; | |
| 29 | +import 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</code> | |
| 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</code>, | |
| 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</code> | |
| 50 | + * until the drag <code>Cursor</code> resumes its motion. | |
| 51 | + * | |
| 52 | + * @since 1.2 | |
| 53 | + */ | |
| 54 | + | |
| 55 | +public interface Autoscroll { | |
| 56 | + | |
| 57 | + /** | |
| 58 | + * This method returns the <code>Insets</code> 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</code> | |
| 63 | + * upon entry of the drag <code>Cursor</code> | |
| 64 | + * into the associated <code>Component</code>. | |
| 65 | + * <P> | |
| 66 | + * @return the Insets | |
| 67 | + */ | |
| 68 | + | |
| 69 | + public Insets getAutoscrollInsets(); | |
| 70 | + | |
| 71 | + /** | |
| 72 | + * notify the <code>Component</code> to autoscroll | |
| 73 | + * <P> | |
| 74 | + * @param cursorLocn A <code>Point</code> indicating the | |
| 75 | + * location of the cursor that triggered this operation. | |
| 76 | + */ | |
| 77 | + | |
| 78 | + public void autoscroll(Point cursorLocn); | |
| 79 | + | |
| 80 | +} | |