8016833: Underlines and strikethrough not rendering correctly

Reviewed-by: alexsch, serb
Contributed-by: anton.nashatyrev@oracle.com

src/share/classes/javax/swing/text/GlyphView.java

 /*
- * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2013, 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
@@ -514,7 +514,7 @@ public class GlyphView extends View implements TabableView, Cloneable {
             int x1 = x0 + (int) painter.getSpan(this, p0, p1, getTabExpander(), x0);
 
             // calculate y coordinate
-            int y = alloc.y + alloc.height - (int) painter.getDescent(this);
+            int y = alloc.y + (int)(painter.getHeight(this) - painter.getDescent(this));
             if (underline) {
                 int yTmp = y + 1;
                 g.drawLine(x0, yTmp, x1, yTmp);

test/javax/swing/text/StyledEditorKit/8016833/bug8016833.java

+/*
+ * Copyright (c) 2013, 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 8016833
+   @summary underlines and strikethroughs should be  painted at the correct
+            positions for different kind of text styles: normal, superscript and subscript
+   @author Anton Nashatyrev
+   @run main bug8016833
+*/
+import javax.swing.*;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Style;
+import javax.swing.text.StyleConstants;
+import javax.swing.text.StyledDocument;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.lang.reflect.InvocationTargetException;
+
+public class bug8016833 {
+
+    void drawText(final Graphics g, final boolean underline, final boolean strikethrough, final boolean background) {
+        drawText(g, "mama", underline, strikethrough, background);
+    }
+
+    void drawText(final Graphics g, final String text, final boolean underline, final boolean strikethrough, final boolean background) {
+        try {
+            SwingUtilities.invokeAndWait(new Runnable() {
+                @Override
+                public void run() {
+                    final JTextPane comp = new JTextPane();
+                    final StyledDocument doc = comp.getStyledDocument();
+
+                    Style style = comp.addStyle("superscript", null);
+                    setNormalStyle(style);
+
+                    if (underline) {
+                        StyleConstants.setUnderline(style, true);
+                    }
+                    if (strikethrough) {
+                        StyleConstants.setStrikeThrough(style, true);
+                    }
+                    if (background) {
+                        StyleConstants.setBackground(style, Color.BLUE);
+                    }
+                    try {
+                        doc.insertString(doc.getLength(), "mama", style);
+                    } catch (BadLocationException e) {
+                        throw new RuntimeException(e);
+                    }
+
+                    comp.setSize(200, 100);
+                    comp.paint(g);
+                }
+            });
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        } catch (InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    void setNormalStyle(Style style) {
+        StyleConstants.setSuperscript(style, true);
+    }
+
+    int getEmptyPixel() {
+        return 0xFFFFFFFF;
+    }
+
+    boolean isPixelEmpty(int argb) {
+        return (argb & 0x00FFFFFF) == (getEmptyPixel() & 0x00FFFFFF);
+    }
+
+    boolean isLineEmpty(BufferedImage img, int coord, boolean isHorizontal) {
+        int len = isHorizontal ? img.getWidth() : img.getHeight();
+        for (int i = 0; i < len; i++) {
+            int pixel = isHorizontal ? img.getRGB(i, coord) : img.getRGB(coord, i);
+            if (!isPixelEmpty(pixel)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    Rectangle getPixelsOutline(BufferedImage img) {
+        int x1 = 0;
+        while (x1 < img.getWidth() && isLineEmpty(img, x1, false)) {
+            x1++;
+        }
+        int x2 = img.getWidth() - 1;
+        while (x2 >= 0 && isLineEmpty(img, x2, false)) {
+            x2--;
+        }
+        int y1 = 0;
+        while (y1 < img.getHeight() && isLineEmpty(img, y1, true)) {
+            y1++;
+        }
+        int y2 = img.getHeight() - 1;
+        while (y2 >= 0 && isLineEmpty(img, y2, true)) {
+            y2--;
+        }
+
+        return new Rectangle(x1, y1, x2 - x1 + 1, y2 - y1 + 1);
+    }
+
+    BufferedImage createImage() {
+        final BufferedImage img = new BufferedImage(200, 100, BufferedImage.TYPE_INT_ARGB);
+        try {
+            SwingUtilities.invokeAndWait(new Runnable() {
+                @Override
+                public void run() {
+                    Graphics g = img.getGraphics();
+                    g.setColor(new Color(getEmptyPixel()));
+                    g.fillRect(0, 0, 10000, 10000);
+                }
+            });
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        } catch (InvocationTargetException e) {
+            throw new RuntimeException(e);
+        }
+        return img;
+    }
+
+    int subPixels(int pix1, int pix2) {
+        if (pix1 == pix2) {
+            return getEmptyPixel();
+        }
+        return pix1;
+    }
+
+    /**
+     * Subtracts img2 from img1
+     */
+    BufferedImage subImages(BufferedImage img1, BufferedImage img2) {
+        if (img1.getHeight() != img2.getHeight() ||
+                img1.getWidth() != img2.getWidth()) {
+            throw new RuntimeException("Different sizes");
+        }
+        BufferedImage ret = new BufferedImage(img1.getWidth(), img1.getHeight(), img1.getType());
+
+        for (int x = 0; x < ret.getWidth(); x++) {
+            for (int y = 0; y < ret.getHeight(); y++) {
+                ret.setRGB(x, y, subPixels(img1.getRGB(x, y), img2.getRGB(x, y)));
+            }
+        }
+        return ret;
+    }
+
+    void testUnderline() {
+        System.out.println("  testUnderline()");
+
+        final BufferedImage img1 = createImage();
+        drawText(img1.getGraphics(), true, false, false);
+        final Rectangle out1 = getPixelsOutline(img1);
+        System.out.println("   Underlined: " + out1);
+
+        final BufferedImage img2 = createImage();
+        drawText(img2.getGraphics(), false, false, false);
+        final Rectangle out2 = getPixelsOutline(img2);
+        System.out.println("   Normal: " + out2);
+
+        final BufferedImage img3 = subImages(img1, img2);
+        final Rectangle out3 = getPixelsOutline(img3);
+        System.out.println("   Sub: " + out3);
+
+        // underline is not too thick
+        assertTrue(out3.getHeight() <= 2);
+        // not too wide
+        assertTrue(out3.getWidth() * 0.8 < out2.getWidth());
+        // not too low
+        assertTrue(out3.getY() - (out1.getY() + out2.getHeight()) < 3);
+        // not too high
+        assertTrue(out3.getY() - (out1.getY() + out2.getHeight()) > 0);
+    }
+
+    void testStrikthrough() {
+        System.out.println("  testStrikthrough()");
+
+        final BufferedImage img1 = createImage();
+        drawText(img1.getGraphics(), false, true, false);
+        final Rectangle out1 = getPixelsOutline(img1);
+        System.out.println("   Striked: " + out1);
+
+        final BufferedImage img2 = createImage();
+        drawText(img2.getGraphics(), false, false, false);
+        final Rectangle out2 = getPixelsOutline(img2);
+        System.out.println("   Normal: " + out2);
+
+        final BufferedImage img3 = subImages(img1, img2);
+        final Rectangle out3 = getPixelsOutline(img3);
+        System.out.println("   Sub: " + out3);
+
+        // strikethrough is not too thick
+        assertTrue(out3.getHeight() <= 2);
+        // not too wide
+        assertTrue(out3.getWidth() * 0.8 < out2.getWidth());
+        // not too low
+        assertTrue(out3.getY() - (out1.getY() + out2.getHeight()) < 0);
+        // not too high
+        assertTrue(out3.getY() - out1.getY() > 1);
+    }
+    void assertTrue(boolean b) {
+        if (!b) {
+            throw new RuntimeException("Assertion failed");
+        }
+    }
+
+    static void testSuperScript() {
+        System.out.println("testSuperScript()");
+        bug8016833 b = new bug8016833() {
+            @Override
+            void setNormalStyle(Style style) {
+                StyleConstants.setSuperscript(style, true);
+            }
+        };
+        b.testUnderline();
+        b.testStrikthrough();
+    }
+
+    static void testSubScript() {
+        System.out.println("testSubScript()");
+        bug8016833 b = new bug8016833() {
+            @Override
+            void setNormalStyle(Style style) {
+                StyleConstants.setSubscript(style, true);
+            }
+        };
+        b.testUnderline();
+        b.testStrikthrough();
+    }
+
+    static void testNormalScript() {
+        System.out.println("testNormalScript()");
+        bug8016833 b = new bug8016833() {
+            @Override
+            void setNormalStyle(Style style) {
+            }
+        };
+        b.testUnderline();
+        b.testStrikthrough();
+    }
+
+    public static void main(String[] args) {
+        testSubScript();
+        testSuperScript();
+        testNormalScript();
+    }
+}