| /* |
| * Copyright (c) 2012, 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. |
| * |
| * 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. |
| */ |
| |
| import javax.swing.*; |
| import java.awt.*; |
| import java.awt.dnd.Autoscroll; |
| |
| public class JListWithScroll<E> extends JList<E> implements Autoscroll { |
| private Insets scrollInsets; |
| |
| public JListWithScroll(E[] listData) { |
| super(listData); |
| scrollInsets = new Insets(50, 50, 50, 50); |
| } |
| |
| @Override |
| public Insets getAutoscrollInsets() { |
| return scrollInsets; |
| } |
| |
| @Override |
| public void autoscroll(Point cursorLoc) { |
| JViewport viewport = getViewport(); |
| |
| if (viewport == null) { |
| return; |
| } |
| |
| Point viewPos = viewport.getViewPosition(); |
| int viewHeight = viewport.getExtentSize().height; |
| int viewWidth = viewport.getExtentSize().width; |
| |
| if ((cursorLoc.y - viewPos.y) < scrollInsets.top) { |
| viewport.setViewPosition(new Point(viewPos.x, Math.max(viewPos.y - scrollInsets.top, 0))); |
| } else if (((viewPos.y + viewHeight) - cursorLoc.y) < scrollInsets.bottom) { |
| viewport.setViewPosition( |
| new Point(viewPos.x, Math.min(viewPos.y + scrollInsets.bottom, this.getHeight() - viewHeight)) |
| ); |
| } else if ((cursorLoc.x - viewPos.x) < scrollInsets.left) { |
| viewport.setViewPosition(new Point(Math.max(viewPos.x - scrollInsets.left, 0), viewPos.y)); |
| } else if (((viewPos.x + viewWidth) - cursorLoc.x) < scrollInsets.right) { |
| viewport.setViewPosition( |
| new Point(Math.min(viewPos.x + scrollInsets.right, this.getWidth() - viewWidth), viewPos.y) |
| ); |
| } |
| |
| } |
| |
| public JViewport getViewport() { |
| Component curComp = this; |
| |
| while (!(curComp instanceof JViewport) && (curComp != null)) { |
| curComp = curComp.getParent(); |
| } |
| if(curComp instanceof JViewport) { |
| return (JViewport) curComp; |
| } else { |
| return null; |
| } |
| } |
| } |