8165943: LineBreakMeasurer does not measure correctly if TextAttribute.TRACKING is set.

Co-authored-by: Jason Fordham <jclf@azul.com>
Reviewed-by: prr

Author: 2 people

src/java.desktop/share/classes/sun/font/AttributeValues.java

@@ -846,6 +846,23 @@ public static AffineTransform getCharTransform(Map<?, ?> map) {
         return null;
     }
 
+    @SuppressWarnings("unchecked")
+    public static float getTracking(Map<?, ?> map) {
+        if (map != null) {
+            AttributeValues av = null;
+            if (map instanceof AttributeMap &&
+                    ((AttributeMap) map).getValues() != null) {
+                av = ((AttributeMap)map).getValues();
+            } else if (map.get(TextAttribute.TRACKING) != null) {
+                av = AttributeValues.fromMap((Map<Attribute, ?>)map);
+            }
+            if (av != null) {
+                return av.tracking;
+            }
+        }
+        return 0;
+    }
+
     public void updateDerivedTransforms() {
         // this also updates the mask for the baseline transform
         if (transform == null) {

src/java.desktop/share/classes/sun/font/ExtendedTextSourceLabel.java

@@ -71,6 +71,8 @@ class ExtendedTextSourceLabel extends ExtendedTextLabel implements Decoration.La
   StandardGlyphVector gv;
   float[] charinfo;
 
+  float advTracking;
+
   /**
    * Create from a TextSource.
    */
@@ -110,6 +112,8 @@ private void finishInit() {
           source.getStart() + source.getLength(), source.getFRC());
       cm = CoreMetrics.get(lm);
     }
+
+    advTracking = font.getSize() * AttributeValues.getTracking(atts);
   }
 
 
@@ -378,10 +382,10 @@ public float getCharAdvance(int index) {
     validate(index);
     float[] charinfo = getCharinfo();
     int idx = l2v(index) * numvals + advx;
-    if (charinfo == null || idx >= charinfo.length) {
+    if (charinfo == null || idx >= charinfo.length || charinfo[idx] == 0) {
         return 0f;
     } else {
-        return charinfo[idx];
+        return charinfo[idx] + advTracking;
     }
   }
 
@@ -477,16 +481,25 @@ public int visualToLogical(int visualIndex) {
   }
 
   public int getLineBreakIndex(int start, float width) {
+    final float epsilon = 0.005f;
+
     float[] charinfo = getCharinfo();
     int length = source.getLength();
+
+    if (advTracking > 0) {
+      width += advTracking;
+    }
+
     --start;
-    while (width >= 0 && ++start < length) {
+    while (width >= -epsilon && ++start < length) {
       int cidx = l2v(start) * numvals + advx;
       if (cidx >= charinfo.length) {
           break; // layout bailed for some reason
       }
       float adv = charinfo[cidx];
-      width -= adv;
+      if (adv != 0) {
+          width -= adv + advTracking;
+      }
     }
 
     return start;
@@ -502,7 +515,10 @@ public float getAdvanceBetween(int start, int limit) {
       if (cidx >= charinfo.length) {
           break; // layout bailed for some reason
       }
-      a += charinfo[cidx];
+      float adv = charinfo[cidx];
+      if (adv != 0) {
+          a += adv + advTracking;
+      }
     }
 
     return a;

src/java.desktop/share/classes/sun/font/StandardGlyphVector.java

@@ -197,21 +197,22 @@ public StandardGlyphVector(Font font, FontRenderContext frc, int[] glyphs, float
 
             // how do we know its a base glyph
             // for now, it is if the natural advance of the glyph is non-zero
-            Font2D f2d = FontUtilities.getFont2D(font);
-            FontStrike strike = f2d.getStrike(font, frc);
 
             float[] deltas = { trackPt.x, trackPt.y };
             for (int j = 0; j < deltas.length; ++j) {
                 float inc = deltas[j];
+                float prevPos = 0;
                 if (inc != 0) {
                     float delta = 0;
-                    for (int i = j, n = 0; n < glyphs.length; i += 2) {
-                        if (strike.getGlyphAdvance(glyphs[n++]) != 0) { // might be an inadequate test
+                    for (int i = j; i < positions.length; i += 2) {
+                        if (i == j || prevPos != positions[i]) {
+                            prevPos = positions[i];
                             positions[i] += delta;
                             delta += inc;
+                        } else if (prevPos == positions[i]) {
+                            positions[i] = positions[i - 2];
                         }
                     }
-                    positions[positions.length-2+j] += delta;
                 }
             }
         }

test/jdk/java/awt/font/LineBreakMeasurer/LineBreakWithTracking.java

@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2022, 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 8165943
+ * @summary LineBreakMeasurer does not measure correctly if TextAttribute.TRACKING is set
+ * @library ../../regtesthelpers
+ * @build PassFailJFrame
+ * @run main/manual LineBreakWithTracking
+ */
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.awt.event.WindowAdapter;
+import java.awt.event.WindowEvent;
+import java.awt.font.FontRenderContext;
+import java.awt.font.LineBreakMeasurer;
+import java.awt.font.TextAttribute;
+import java.awt.font.TextLayout;
+import java.text.AttributedString;
+import java.util.Hashtable;
+import java.lang.reflect.InvocationTargetException;
+
+class LineBreakPanel extends JPanel implements ActionListener {
+
+  private float textTracking = 0.0f;
+  private static String fontName = "Dialog";
+  private static String text = "This is a long line of text that should be broken across multiple lines. "
+          + "Please set the different tracking values to test via menu! This test should pass if "
+          + "these lines are broken to fit the width, and fail otherwise.  It should "
+          + "also format the hebrew (\u05d0\u05d1\u05d2 \u05d3\u05d4\u05d5) and arabic "
+          + "(\u0627\u0628\u062a\u062c \u062e\u0644\u0627\u062e) and CJK "
+          + "(\u4e00\u4e01\u4e02\uac00\uac01\uc4fa\u67b1\u67b2\u67b3\u67b4\u67b5\u67b6\u67b7"
+          + "\u67b8\u67b9) text correctly.";
+
+  private LineBreakMeasurer lineMeasurer;
+
+  public void actionPerformed(ActionEvent e) {
+    textTracking = (float)((JRadioButtonMenuItem)e.getSource()).getClientProperty( "tracking" );
+    lineMeasurer = null;
+    invalidate();
+    repaint();
+  }
+
+  public void paintComponent(Graphics g) {
+    super.paintComponent(g);
+    setBackground(Color.white);
+
+    Graphics2D g2d = (Graphics2D)g;
+
+    if (lineMeasurer == null) {
+      Float regular = Float.valueOf(16.0f);
+      Float big = Float.valueOf(24.0f);
+
+      Hashtable map = new Hashtable();
+      map.put(TextAttribute.SIZE, (float)18.0);
+      map.put(TextAttribute.TRACKING, (float)textTracking);
+
+      AttributedString astr = new AttributedString(text, map);
+      astr.addAttribute(TextAttribute.SIZE, regular, 0, text.length());
+      astr.addAttribute(TextAttribute.FAMILY, fontName, 0, text.length());
+
+      int ix = text.indexOf("broken");
+      astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
+      ix = text.indexOf("hebrew");
+      astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
+      ix = text.indexOf("arabic");
+      astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 6);
+      ix = text.indexOf("CJK");
+      astr.addAttribute(TextAttribute.SIZE, big, ix, ix + 3);
+
+      FontRenderContext frc = g2d.getFontRenderContext();
+      lineMeasurer = new LineBreakMeasurer(astr.getIterator(), frc);
+    }
+
+    lineMeasurer.setPosition(0);
+
+    float w = (float)getSize().width;
+    float x = 0, y = 0;
+    TextLayout layout;
+    while ((layout = lineMeasurer.nextLayout(w)) != null) {
+      x = layout.isLeftToRight() ? 0 : w - layout.getAdvance();
+      y += layout.getAscent();
+      layout.draw(g2d, x, y);
+      y += layout.getDescent() + layout.getLeading();
+    }
+  }
+}
+
+public class LineBreakWithTracking {
+
+  private static final String INSTRUCTIONS = """
+     This manual test verifies that LineBreakMeasurer measures the lines'
+     breaks correctly taking into account the TextAttribute.TRACKING value.
+     The test string includes Latin, Arabic, CJK and Hebrew.
+
+     You should choose a tracking value from the menu and resize the window.
+     If the text lines break exactly to the wrapping width:
+     no room for one more word exists and
+     the text lines are not too long for given wrapping width, -
+     then press PASS, otherwise - FAIL.
+     """;
+
+  public void createGUI(JFrame frame) {
+
+    LineBreakPanel panel = new LineBreakPanel();
+    frame.getContentPane().add(panel, BorderLayout.CENTER);
+
+    JMenuBar menuBar = new JMenuBar();
+
+    JMenu menu = new JMenu("Tracking");
+    ButtonGroup btnGroup = new ButtonGroup();
+    String btnLabels[] = {"-0.1", "0", "0.1", "0.2", "0.3"};
+    float val = -0.1f;
+    for (String label : btnLabels) {
+      JRadioButtonMenuItem btn = new JRadioButtonMenuItem(label);
+      btn.putClientProperty( "tracking", val );
+      btn.addActionListener(panel);
+      btnGroup.add(btn);
+      menu.add(btn);
+      val += 0.1f;
+    }
+    menuBar.add(menu);
+
+    frame.setJMenuBar(menuBar);
+  }
+
+  public static void main(String[] args) throws InterruptedException, InvocationTargetException {
+
+    JFrame frame = new JFrame("LineBreakMeasurer with Tracking");
+    frame.setSize(new Dimension(640, 480));
+
+    LineBreakWithTracking controller = new LineBreakWithTracking();
+    controller.createGUI(frame);
+
+    PassFailJFrame passFailJFrame = new PassFailJFrame(INSTRUCTIONS);
+    PassFailJFrame.addTestWindow(frame);
+    PassFailJFrame.positionTestWindow(frame, PassFailJFrame.Position.HORIZONTAL);
+    frame.setVisible(true);
+    passFailJFrame.awaitAndCheck();
+  }
+}