1 /*
   2  * Copyright (c) 2011, 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 com.apple.laf;
  27 
  28 import java.awt.event.*;
  29 
  30 import javax.swing.*;
  31 import javax.swing.plaf.ComponentUI;
  32 
  33 public class AquaScrollPaneUI extends javax.swing.plaf.basic.BasicScrollPaneUI {
  34     public static ComponentUI createUI(final JComponent x) {
  35         return new AquaScrollPaneUI();
  36     }
  37 
  38     protected MouseWheelListener createMouseWheelListener() {
  39         return new XYMouseWheelHandler();
  40     }
  41 
  42     // This is a grody hack to trick BasicScrollPaneUI into scrolling horizontally
  43     // when we notice that the shift key is down. This should be removed when AWT/Swing
  44     // becomes aware of of multi-axis scroll wheels.
  45     protected class XYMouseWheelHandler extends javax.swing.plaf.basic.BasicScrollPaneUI.MouseWheelHandler {
  46         public void mouseWheelMoved(final MouseWheelEvent e) {
  47             JScrollBar vScrollBar = null;
  48             boolean wasVisible = false;
  49 
  50             if (e.isShiftDown()) {
  51                 vScrollBar = scrollpane.getVerticalScrollBar();
  52                 if (vScrollBar != null) {
  53                     wasVisible = vScrollBar.isVisible();
  54                     vScrollBar.setVisible(false);
  55                 }
  56             }
  57 
  58             super.mouseWheelMoved(e);
  59 
  60             if (wasVisible) {
  61                 vScrollBar.setVisible(true);
  62             }
  63             // Consume the event even when the scrollBar is invisible
  64             // see #7124320
  65             e.consume();
  66         }
  67     }
  68 }