8191639: NPE from BasicListUI.Actions.getNextPageIndex
authorpsadhukhan
Fri, 08 Dec 2017 10:03:07 +0530
changeset 48276 34f0232538f6
parent 48275 b2190c70a1ac
child 48277 dbfd916af279
8191639: NPE from BasicListUI.Actions.getNextPageIndex Reviewed-by: serb, ssadetsky
src/java.desktop/share/classes/javax/swing/plaf/basic/BasicListUI.java
test/jdk/javax/swing/JList/BasicListTest.java
--- a/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicListUI.java	Thu Dec 07 13:23:18 2017 -0800
+++ b/src/java.desktop/share/classes/javax/swing/plaf/basic/BasicListUI.java	Fri Dec 08 10:03:07 2017 +0530
@@ -2134,8 +2134,11 @@
             Rectangle leadRect =
                 (lead==-1) ? new Rectangle() : list.getCellBounds(lead, lead);
 
+            if (leadRect == null) {
+                return index;
+            }
             if (list.getLayoutOrientation() == JList.VERTICAL_WRAP &&
-                list.getVisibleRowCount() <= 0) {
+                    list.getVisibleRowCount() <= 0) {
                 if (!list.getComponentOrientation().isLeftToRight()) {
                     direction = -direction;
                 }
@@ -2146,14 +2149,20 @@
                     visRect.x = leadRect.x + leadRect.width - visRect.width;
                     Point p = new Point(visRect.x - 1, leadRect.y);
                     index = list.locationToIndex(p);
+                    if (index == -1) {
+                        return index;
+                    }
                     Rectangle cellBounds = list.getCellBounds(index, index);
-                    if (visRect.intersects(cellBounds)) {
+                    if (cellBounds != null && visRect.intersects(cellBounds)) {
                         p.x = cellBounds.x - 1;
                         index = list.locationToIndex(p);
+                        if (index == -1) {
+                            return index;
+                        }
                         cellBounds = list.getCellBounds(index, index);
                     }
                     // this is necessary for right-to-left orientation only
-                    if (cellBounds.y != leadRect.y) {
+                    if (cellBounds != null && cellBounds.y != leadRect.y) {
                         p.x = cellBounds.x + cellBounds.width;
                         index = list.locationToIndex(p);
                     }
@@ -2163,13 +2172,19 @@
                     visRect.x = leadRect.x;
                     Point p = new Point(visRect.x + visRect.width, leadRect.y);
                     index = list.locationToIndex(p);
+                    if (index == -1) {
+                        return index;
+                    }
                     Rectangle cellBounds = list.getCellBounds(index, index);
-                    if (visRect.intersects(cellBounds)) {
+                    if (cellBounds != null && visRect.intersects(cellBounds)) {
                         p.x = cellBounds.x + cellBounds.width;
                         index = list.locationToIndex(p);
+                        if (index == -1) {
+                            return index;
+                        }
                         cellBounds = list.getCellBounds(index, index);
                     }
-                    if (cellBounds.y != leadRect.y) {
+                    if (cellBounds != null && cellBounds.y != leadRect.y) {
                         p.x = cellBounds.x - 1;
                         index = list.locationToIndex(p);
                     }
@@ -2187,17 +2202,23 @@
                         visRect.y = leadRect.y + leadRect.height - visRect.height;
                         p.y = visRect.y;
                         index = list.locationToIndex(p);
+                        if (index == -1) {
+                            return index;
+                        }
                         Rectangle cellBounds = list.getCellBounds(index, index);
                         // go one cell down if first visible cell doesn't fit
                         // into adjasted visible rectangle
-                        if (cellBounds.y < visRect.y) {
+                        if (cellBounds != null && cellBounds.y < visRect.y) {
                             p.y = cellBounds.y + cellBounds.height;
                             index = list.locationToIndex(p);
+                            if (index == -1) {
+                                return index;
+                            }
                             cellBounds = list.getCellBounds(index, index);
                         }
                         // if index isn't less then lead
                         // try to go to cell previous to lead
-                        if (cellBounds.y >= leadRect.y) {
+                        if (cellBounds != null && cellBounds.y >= leadRect.y) {
                             p.y = leadRect.y - 1;
                             index = list.locationToIndex(p);
                         }
@@ -2207,15 +2228,23 @@
                     // down
                     // go to the last completely visible cell
                     Point p = new Point(leadRect.x,
-                                        visRect.y + visRect.height - 1);
+                            visRect.y + visRect.height - 1);
                     index = list.locationToIndex(p);
+                    if (index == -1) {
+                        return index;
+                    }
                     Rectangle cellBounds = list.getCellBounds(index, index);
                     // go up one cell if last visible cell doesn't fit
                     // into visible rectangle
-                    if (cellBounds.y + cellBounds.height >
-                        visRect.y + visRect.height) {
+                    if (cellBounds != null &&
+                            cellBounds.y + cellBounds.height >
+                            visRect.y + visRect.height)
+                    {
                         p.y = cellBounds.y - 1;
                         index = list.locationToIndex(p);
+                        if (index == -1) {
+                            return index;
+                        }
                         cellBounds = list.getCellBounds(index, index);
                         index = Math.max(index, lead);
                     }
@@ -2226,24 +2255,33 @@
                         visRect.y = leadRect.y;
                         p.y = visRect.y + visRect.height - 1;
                         index = list.locationToIndex(p);
+                        if (index == -1) {
+                            return index;
+                        }
                         cellBounds = list.getCellBounds(index, index);
                         // go one cell up if last visible cell doesn't fit
                         // into adjasted visible rectangle
-                        if (cellBounds.y + cellBounds.height >
-                            visRect.y + visRect.height) {
+                        if (cellBounds != null &&
+                                cellBounds.y + cellBounds.height >
+                                visRect.y + visRect.height)
+                        {
                             p.y = cellBounds.y - 1;
                             index = list.locationToIndex(p);
+                            if (index == -1) {
+                                return index;
+                            }
                             cellBounds = list.getCellBounds(index, index);
                         }
                         // if index isn't greater then lead
                         // try to go to cell next after lead
-                        if (cellBounds.y <= leadRect.y) {
+                        if (cellBounds != null && cellBounds.y <= leadRect.y) {
                             p.y = leadRect.y + leadRect.height;
                             index = list.locationToIndex(p);
                         }
                     }
                 }
             }
+
             return index;
         }
 
@@ -2308,18 +2346,27 @@
                                 cellBounds.x + cellBounds.width - visRect.width);
                             int startIndex =
                                 list.locationToIndex(new Point(x, cellBounds.y));
+                            if (startIndex == -1) {
+                                return;
+                            }
                             Rectangle startRect = list.getCellBounds(startIndex,
                                                                      startIndex);
-                            if (startRect.x < x && startRect.x < cellBounds.x) {
+                            if (startRect != null &&
+                                startRect.x < x && startRect.x < cellBounds.x) {
                                 startRect.x += startRect.width;
                                 startIndex =
                                     list.locationToIndex(startRect.getLocation());
+                                if (startIndex == -1) {
+                                    return;
+                                }
                                 startRect = list.getCellBounds(startIndex,
                                                                startIndex);
                             }
                             cellBounds = startRect;
                         }
-                        cellBounds.width = visRect.width;
+                        if (cellBounds != null) {
+                            cellBounds.width = visRect.width;
+                        }
                     }
                     else {
                         if (direction > 0) {
@@ -2327,15 +2374,20 @@
                             int x = cellBounds.x + visRect.width;
                             int rightIndex =
                                 list.locationToIndex(new Point(x, cellBounds.y));
+                            if (rightIndex == -1) {
+                                return;
+                            }
                             Rectangle rightRect = list.getCellBounds(rightIndex,
                                                                      rightIndex);
-                            if (rightRect.x + rightRect.width > x &&
-                                rightRect.x > cellBounds.x) {
-                                rightRect.width = 0;
+                            if (rightRect != null) {
+                                if (rightRect.x + rightRect.width > x &&
+                                        rightRect.x > cellBounds.x) {
+                                    rightRect.width = 0;
+                                }
+                                cellBounds.x = Math.max(0,
+                                        rightRect.x + rightRect.width - visRect.width);
+                                cellBounds.width = visRect.width;
                             }
-                            cellBounds.x = Math.max(0,
-                                rightRect.x + rightRect.width - visRect.width);
-                            cellBounds.width = visRect.width;
                         }
                         else {
                             cellBounds.x += Math.max(0,
@@ -2357,24 +2409,35 @@
                             cellBounds.y + cellBounds.height - visRect.height);
                         int startIndex =
                             list.locationToIndex(new Point(cellBounds.x, y));
+                        if (startIndex == -1) {
+                            return;
+                        }
                         Rectangle startRect = list.getCellBounds(startIndex,
                                                                  startIndex);
-                        if (startRect.y < y && startRect.y < cellBounds.y) {
+                        if (startRect != null &&
+                                startRect.y < y && startRect.y < cellBounds.y) {
                             startRect.y += startRect.height;
                             startIndex =
                                 list.locationToIndex(startRect.getLocation());
+                            if (startIndex == -1) {
+                                return;
+                            }
                             startRect =
                                 list.getCellBounds(startIndex, startIndex);
                         }
                         cellBounds = startRect;
-                        cellBounds.height = visRect.height;
+                        if (cellBounds != null) {
+                            cellBounds.height = visRect.height;
+                        }
                     }
                     else {
                         // adjust height to fit into visible rectangle
                         cellBounds.height = Math.min(cellBounds.height, visRect.height);
                     }
                 }
-                list.scrollRectToVisible(cellBounds);
+                if (cellBounds != null) {
+                    list.scrollRectToVisible(cellBounds);
+                }
             }
         }
 
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/javax/swing/JList/BasicListTest.java	Fri Dec 08 10:03:07 2017 +0530
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2017, 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.
+ */
+/*
+ * @test
+ * @bug 8191639
+ * @headful
+ * @summary  Verifies no NPE is thrown wjen pageup/down is pressed in a JList
+ * @run main BasicListTest
+ */
+
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.Robot;
+import java.awt.event.InputEvent;
+import java.awt.event.KeyEvent;
+import javax.swing.JFrame;
+import javax.swing.JList;
+import javax.swing.JScrollPane;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.UnsupportedLookAndFeelException;
+
+class MyList extends JList {
+    // I need this to be able to unselect when clicking outside list content
+    @Override
+    public int locationToIndex(final Point location) {
+        final int n = super.locationToIndex(location);
+        //return n;
+        final Rectangle q = getCellBounds(n, n);
+        return q != null && q.contains(location)?n:-1;
+    }
+}
+
+public class BasicListTest {
+    private static void initComponents() {
+        f = new JFrame();
+        jScrollPane1 = new JScrollPane();
+        list1 = new MyList();
+
+        f.setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
+
+        list1.setModel(new javax.swing.AbstractListModel() {
+            String[] strings = { "Item 1", "Item 2", "Item 3", "Item 4", "Item 5" };
+            @Override
+            public int getSize() { return strings.length; }
+            @Override
+            public Object getElementAt(int i) { return strings[i]; }
+        });
+        jScrollPane1.setViewportView(list1);
+
+        f.getContentPane().add(jScrollPane1, java.awt.BorderLayout.CENTER);
+
+        f.pack();
+        f.setVisible(true);
+        p = list1.getLocationOnScreen();
+    }
+
+    private static void setLookAndFeel(final UIManager.LookAndFeelInfo laf) {
+        try {
+            UIManager.setLookAndFeel(laf.getClassName());
+        } catch (ClassNotFoundException | InstantiationException |
+                 UnsupportedLookAndFeelException | IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public static void main(String args[]) throws Exception {
+        for (UIManager.LookAndFeelInfo laf : UIManager.getInstalledLookAndFeels()) {
+            try {
+                SwingUtilities.invokeAndWait(() -> setLookAndFeel(laf));
+                System.out.println("Test for LookAndFeel " + laf.getClassName());
+                SwingUtilities.invokeAndWait(() -> {
+                    initComponents();
+                });
+                System.out.println("Test passed for LookAndFeel " + laf.getClassName());
+            }  catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+
+            Robot robot = new Robot();
+            robot.setAutoDelay(200);
+            robot.mouseMove(p.x, p.y);
+            robot.waitForIdle();
+            robot.mousePress(InputEvent.BUTTON1_DOWN_MASK);
+            robot.mouseRelease(InputEvent.BUTTON1_DOWN_MASK);
+            robot.waitForIdle();
+            robot.keyPress(KeyEvent.VK_PAGE_DOWN);
+            robot.keyRelease(KeyEvent.VK_PAGE_DOWN);
+
+            try {
+                Thread.sleep(1000);
+            } catch (InterruptedException ex) {
+            }
+            SwingUtilities.invokeAndWait(() -> {
+                f.dispose();
+            });
+        }
+    }
+
+    private static JScrollPane jScrollPane1;
+    private static MyList list1;
+    private static Point p;
+    private static JFrame f;
+
+}