Add minimal javadoc to all classes (and enforce with checkstyle); minor refactoring to of array sum code

android/src/com/google/zxing/client/android/Contents.java

@@ -28,6 +28,9 @@ public final class Contents {
   private Contents() {
   }
 
+  /**
+   * Contains type constants used when sending Intents.
+   */
   public static final class Type {
     /**
      * Plain text. Use Intent.putExtra(DATA, string). This can be used for URLs too, but string

android/src/com/google/zxing/client/android/HttpHelper.java

@@ -46,6 +46,9 @@ public final class HttpHelper {
   private HttpHelper() {
   }
 
+  /**
+   * Enumeration of supported HTTP content types
+   */
   public enum ContentType {
     /** HTML-like content type, including HTML, XHTML, etc. */
     HTML,

android/src/com/google/zxing/client/android/Intents.java

@@ -26,6 +26,9 @@ public final class Intents {
   private Intents() {
   }
 
+  /**
+   * Constants related to the {@link Scan#ACTION} Intent.
+   */
   public static final class Scan {
     /**
      * Send this intent to open the Barcodes app in scanning mode, find a barcode, and return
@@ -174,6 +177,9 @@ public final class Intents {
     }
   }
 
+  /**
+   * Constants related to the scan history and retrieving history items.
+   */
   public static final class History {
 
     public static final String ITEM_NUMBER = "ITEM_NUMBER";
@@ -182,6 +188,9 @@ public final class Intents {
     }
   }
 
+  /**
+   * Constants related to the {@link Encode#ACTION} Intent.
+   */
   public static final class Encode {
     /**
      * Send this intent to encode a piece of data as a QR code and display it full screen, so
@@ -220,6 +229,9 @@ public final class Intents {
     }
   }
 
+  /**
+   * Constants related to the {@link SearchBookContents#ACTION} Intent.
+   */
   public static final class SearchBookContents {
     /**
      * Use Google Book Search to search the contents of the book provided.
@@ -240,6 +252,9 @@ public final class Intents {
     }
   }
 
+  /**
+   * Constants related to the {@link WifiConnect#ACTION} Intent.
+   */
   public static final class WifiConnect {
     /**
      * Internal intent used to trigger connection to a wi-fi network.
@@ -265,6 +280,9 @@ public final class Intents {
     }
   }
 
+  /**
+   * Constants related to the {@link Share#ACTION} Intent.
+   */
   public static final class Share {
     /**
      * Give the user a choice of items to encode as a barcode, then render it as a QR Code and

android/src/com/google/zxing/client/android/PreferencesFragment.java

@@ -30,6 +30,11 @@ import android.preference.Preference;
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceScreen;
 
+/**
+ * Implements support for barcode scanning preferences.
+ *
+ * @see PreferencesActivity
+ */
 public final class PreferencesFragment 
     extends PreferenceFragment 
     implements SharedPreferences.OnSharedPreferenceChangeListener {

android/src/com/google/zxing/client/android/camera/open/CameraFacing.java

@@ -16,6 +16,9 @@
 
 package com.google.zxing.client.android.camera.open;
 
+/**
+ * Enumeration of directions a camera may face: front or back.
+ */
 public enum CameraFacing {
 
   BACK,  // must be value 0!

android/src/com/google/zxing/client/android/camera/open/OpenCamera.java

@@ -18,6 +18,9 @@ package com.google.zxing.client.android.camera.open;
 
 import android.hardware.Camera;
 
+/**
+ * Represents an open {@link Camera} and its metadata, like facing direction and orientation.
+ */
 public final class OpenCamera {
   
   private final int index;

android/src/com/google/zxing/client/android/camera/open/OpenCameraInterface.java

@@ -19,6 +19,9 @@ package com.google.zxing.client.android.camera.open;
 import android.hardware.Camera;
 import android.util.Log;
 
+/**
+ * Abstraction over the {@link Camera} API that helps open them and return their metadata.
+ */
 public final class OpenCameraInterface {
 
   private static final String TAG = OpenCameraInterface.class.getName();

android/src/com/google/zxing/client/android/clipboard/ClipboardInterface.java

@@ -21,6 +21,9 @@ import android.content.ClipboardManager;
 import android.content.Context;
 import android.util.Log;
 
+/**
+ * Abstraction over the {@link ClipboardManager} API that manages copying and pasting.
+ */
 public final class ClipboardInterface {
   
   private static final String TAG = ClipboardInterface.class.getSimpleName();

android/src/com/google/zxing/client/android/history/HistoryActivity.java

@@ -38,6 +38,9 @@ import com.google.zxing.client.android.CaptureActivity;
 import com.google.zxing.client.android.Intents;
 import com.google.zxing.client.android.R;
 
+/**
+ * The activity for interacting with the scan history.
+ */
 public final class HistoryActivity extends ListActivity {
 
   private static final String TAG = HistoryActivity.class.getSimpleName();

android/src/com/google/zxing/client/android/history/HistoryItem.java

@@ -18,6 +18,9 @@ package com.google.zxing.client.android.history;
 
 import com.google.zxing.Result;
 
+/**
+ * Represents one item in the scan history.
+ */
 public final class HistoryItem {
 
   private final Result result;

android/src/com/google/zxing/client/android/result/supplement/SupplementalInfoRetriever.java

@@ -38,6 +38,10 @@ import com.google.zxing.client.result.ParsedResult;
 import com.google.zxing.client.result.ProductParsedResult;
 import com.google.zxing.client.result.URIParsedResult;
 
+/**
+ * Superclass of implementations which can asynchronously retrieve more information
+ * about a barcode scan.
+ */
 public abstract class SupplementalInfoRetriever extends AsyncTask<Object,Object,Object> {
 
   private static final String TAG = "SupplementalInfo";

android/src/com/google/zxing/client/android/share/AppPickerActivity.java

@@ -25,6 +25,9 @@ import android.widget.ListView;
 
 import java.util.List;
 
+/**
+ * Activity for picking an installed application to share via Intent.
+ */
 public final class AppPickerActivity extends ListActivity {
 
   private AsyncTask<Object,Object,List<AppInfo>> backgroundTask;

androidtest/src/com/google/zxing/client/androidtest/BenchmarkActivity.java

@@ -23,6 +23,9 @@ import android.os.Environment;
 import android.view.View;
 import android.widget.TextView;
 
+/**
+ * Activity that runs barcode scanning benchmarks.
+ */
 public final class BenchmarkActivity extends Activity {
 
   private View runBenchmarkButton;

androidtest/src/com/google/zxing/client/androidtest/BenchmarkAsyncTask.java

@@ -33,6 +33,9 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
+/**
+ * Asynchronous task which actually runs benchmarks and collects timing.z
+ */
 public final class BenchmarkAsyncTask extends AsyncTask<Object,Object,String> {
 
   private static final String TAG = BenchmarkAsyncTask.class.getSimpleName();

androidtest/src/com/google/zxing/client/androidtest/ZXingTestActivity.java

@@ -42,6 +42,9 @@ import java.io.OutputStreamWriter;
 import java.io.Writer;
 import java.nio.charset.Charset;
 
+/**
+ * Main test app activity.
+ */
 public final class ZXingTestActivity extends Activity {
 
   private static final String TAG = ZXingTestActivity.class.getSimpleName();

core/src/main/java/com/google/zxing/aztec/AztecDetectorResult.java

@@ -20,6 +20,12 @@ import com.google.zxing.ResultPoint;
 import com.google.zxing.common.BitMatrix;
 import com.google.zxing.common.DetectorResult;
 
+/**
+ * <p>Extends {@link DetectorResult} with more information specific to the Aztec format,
+ * like the number of layers and whether it's compact.</p>
+ *
+ * @author Sean Owen
+ */
 public final class AztecDetectorResult extends DetectorResult {
 
   private final boolean compact;

core/src/main/java/com/google/zxing/aztec/AztecWriter.java

@@ -26,6 +26,9 @@ import com.google.zxing.common.BitMatrix;
 import java.nio.charset.Charset;
 import java.util.Map;
 
+/**
+ * Renders an Aztec code as a {@link BitMatrix}.
+ */
 public final class AztecWriter implements Writer {
   
   private static final Charset DEFAULT_CHARSET = Charset.forName("ISO-8859-1");

core/src/main/java/com/google/zxing/client/result/AddressBookParsedResult.java

@@ -17,6 +17,9 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes contact information, like that in an address book
+ * entry.
+ *
  * @author Sean Owen
  */
 public final class AddressBookParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/CalendarParsedResult.java

@@ -28,6 +28,9 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 /**
+ * Represents a parsed result that encodes a calendar event at a certain time, optionally
+ * with attendees and a location.
+ *
  * @author Sean Owen
  */
 public final class CalendarParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/EmailAddressParsedResult.java

@@ -17,6 +17,9 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes an email message including recipients, subject
+ * and body text.
+ *
  * @author Sean Owen
  */
 public final class EmailAddressParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/ExpandedProductParsedResult.java

@@ -29,6 +29,9 @@ package com.google.zxing.client.result;
 import java.util.Map;
 
 /**
+ * Represents a parsed result that encodes extended product information as encoded
+ * by the RSS format, like weight, price, dates, etc.
+ *
  * @author Antonio Manuel Benjumea Conde, Servinform, S.A.
  * @author Agustín Delgado, Servinform, S.A.
  */

core/src/main/java/com/google/zxing/client/result/GeoParsedResult.java

@@ -17,6 +17,9 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes a geographic coordinate, with latitude,
+ * longitude and altitude.
+ *
  * @author Sean Owen
  */
 public final class GeoParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/ISBNParsedResult.java

@@ -17,6 +17,8 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes a product ISBN number.
+ *
  * @author jbreiden@google.com (Jeff Breidenbach)
  */
 public final class ISBNParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/ProductParsedResult.java

@@ -17,6 +17,8 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes a product by an identifier of some kind.
+ *
  * @author dswitkin@google.com (Daniel Switkin)
  */
 public final class ProductParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/SMSParsedResult.java

@@ -17,6 +17,9 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes an SMS message, including recipients, subject
+ * and body text.
+ *
  * @author Sean Owen
  */
 public final class SMSParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/TelParsedResult.java

@@ -17,6 +17,8 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes a telephone number.
+ *
  * @author Sean Owen
  */
 public final class TelParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/URIParsedResult.java

@@ -19,6 +19,8 @@ package com.google.zxing.client.result;
 import java.util.regex.Pattern;
 
 /**
+ * A simple result type encapsulating a URI that has no further interpretation.
+ *
  * @author Sean Owen
  */
 public final class URIParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/client/result/VINParsedResult.java

@@ -17,7 +17,9 @@
 
 package com.google.zxing.client.result;
 
-
+/**
+ * Represents a parsed result that encodes a Vehicle Identification Number (VIN).
+ */
 public final class VINParsedResult extends ParsedResult {
 
   private final String vin;

core/src/main/java/com/google/zxing/client/result/WifiParsedResult.java

@@ -17,6 +17,8 @@
 package com.google.zxing.client.result;
 
 /**
+ * Represents a parsed result that encodes wifi network information, like SSID and password.
+ *
  * @author Vikram Aggarwal
  */
 public final class WifiParsedResult extends ParsedResult {

core/src/main/java/com/google/zxing/common/detector/MathUtils.java

@@ -16,6 +16,9 @@
 
 package com.google.zxing.common.detector;
 
+/**
+ * General math-related and numeric utility functions.
+ */
 public final class MathUtils {
 
   private MathUtils() {
@@ -34,16 +37,42 @@ public final class MathUtils {
     return (int) (d + (d < 0.0f ? -0.5f : 0.5f));
   }
 
+  /**
+   * @param aX point A x coordinate
+   * @param aY point A y coordinate
+   * @param bX point B x coordinate
+   * @param bY point B y coordinate
+   * @return Euclidean distance between points A and B
+   */
   public static float distance(float aX, float aY, float bX, float bY) {
     float xDiff = aX - bX;
     float yDiff = aY - bY;
     return (float) Math.sqrt(xDiff * xDiff + yDiff * yDiff);
   }
 
+  /**
+   * @param aX point A x coordinate
+   * @param aY point A y coordinate
+   * @param bX point B x coordinate
+   * @param bY point B y coordinate
+   * @return Euclidean distance between points A and B
+   */
   public static float distance(int aX, int aY, int bX, int bY) {
     int xDiff = aX - bX;
     int yDiff = aY - bY;
     return (float) Math.sqrt(xDiff * xDiff + yDiff * yDiff);
   }
 
+  /**
+   * @param array values to sum
+   * @return sum of values in array
+   */
+  public static int sum(int[] array) {
+    int count = 0;
+    for (int a : array) {
+      count += a;
+    }
+    return count;
+  }
+
 }

core/src/main/java/com/google/zxing/oned/rss/AbstractRSSReader.java

@@ -17,8 +17,13 @@
 package com.google.zxing.oned.rss;
 
 import com.google.zxing.NotFoundException;
+import com.google.zxing.common.detector.MathUtils;
 import com.google.zxing.oned.OneDReader;
 
+/**
+ * Superclass of {@link OneDReader} implementations that read barcodes in the RSS family
+ * of formats.
+ */
 public abstract class AbstractRSSReader extends OneDReader {
 
   private static final float MAX_AVG_VARIANCE = 0.2f;
@@ -34,7 +39,7 @@ public abstract class AbstractRSSReader extends OneDReader {
   private final int[] oddCounts;
   private final int[] evenCounts;
 
-  protected AbstractRSSReader(){
+  protected AbstractRSSReader() {
     decodeFinderCounters = new int[4];
     dataCharacterCounters = new int[8];
     oddRoundingErrors = new float[4];
@@ -78,12 +83,9 @@ public abstract class AbstractRSSReader extends OneDReader {
     throw NotFoundException.getNotFoundInstance();
   }
 
+  @Deprecated
   protected static int count(int[] array) {
-    int count = 0;
-    for (int a : array) {
-      count += a;
-    }
-    return count;
+    return MathUtils.sum(array);
   }
 
   protected static void increment(int[] array, float[] errors) {

core/src/main/java/com/google/zxing/oned/rss/DataCharacter.java

@@ -16,6 +16,9 @@
 
 package com.google.zxing.oned.rss;
 
+/**
+ * Encapsulates a since character value in an RSS barcode, including its checksum information.
+ */
 public class DataCharacter {
 
   private final int value;

core/src/main/java/com/google/zxing/oned/rss/FinderPattern.java

@@ -18,6 +18,9 @@ package com.google.zxing.oned.rss;
 
 import com.google.zxing.ResultPoint;
 
+/**
+ * Encapsulates an RSS barcode finder pattern, including its start/end position and row.
+ */
 public final class FinderPattern {
 
   private final int value;

core/src/main/java/com/google/zxing/oned/rss/RSS14Reader.java

@@ -23,6 +23,7 @@ import com.google.zxing.Result;
 import com.google.zxing.ResultPoint;
 import com.google.zxing.ResultPointCallback;
 import com.google.zxing.common.BitArray;
+import com.google.zxing.common.detector.MathUtils;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -209,7 +210,7 @@ public final class RSS14Reader extends AbstractRSSReader {
     }
 
     int numModules = outsideChar ? 16 : 15;
-    float elementWidth = (float) count(counters) / (float) numModules;
+    float elementWidth = (float) MathUtils.sum(counters) / (float) numModules;
 
     int[] oddCounts = this.getOddCounts();
     int[] evenCounts = this.getEvenCounts();
@@ -355,8 +356,8 @@ public final class RSS14Reader extends AbstractRSSReader {
 
   private void adjustOddEvenCounts(boolean outsideChar, int numModules) throws NotFoundException {
 
-    int oddSum = count(getOddCounts());
-    int evenSum = count(getEvenCounts());
+    int oddSum = MathUtils.sum(getOddCounts());
+    int evenSum = MathUtils.sum(getEvenCounts());
     int mismatch = oddSum + evenSum - numModules;
     boolean oddParityBad = (oddSum & 0x01) == (outsideChar ? 1 : 0);
     boolean evenParityBad = (evenSum & 0x01) == 1;

core/src/main/java/com/google/zxing/oned/rss/expanded/RSSExpandedReader.java

@@ -33,6 +33,7 @@ import com.google.zxing.NotFoundException;
 import com.google.zxing.Result;
 import com.google.zxing.ResultPoint;
 import com.google.zxing.common.BitArray;
+import com.google.zxing.common.detector.MathUtils;
 import com.google.zxing.oned.rss.AbstractRSSReader;
 import com.google.zxing.oned.rss.DataCharacter;
 import com.google.zxing.oned.rss.FinderPattern;
@@ -607,7 +608,7 @@ public final class RSSExpandedReader extends AbstractRSSReader {
     }//counters[] has the pixels of the module
 
     int numModules = 17; //left and right data characters have all the same length
-    float elementWidth = (float) count(counters) / (float) numModules;
+    float elementWidth = (float) MathUtils.sum(counters) / (float) numModules;
 
     // Sanity check: element width for pattern and the character should match
     float expectedElementWidth = (pattern.getStartEnd()[1] - pattern.getStartEnd()[0]) / 15.0f;
@@ -691,8 +692,8 @@ public final class RSSExpandedReader extends AbstractRSSReader {
 
   private void adjustOddEvenCounts(int numModules) throws NotFoundException {
 
-    int oddSum = count(this.getOddCounts());
-    int evenSum = count(this.getEvenCounts());
+    int oddSum = MathUtils.sum(this.getOddCounts());
+    int evenSum = MathUtils.sum(this.getEvenCounts());
     int mismatch = oddSum + evenSum - numModules;
     boolean oddParityBad = (oddSum & 0x01) == 1;
     boolean evenParityBad = (evenSum & 0x01) == 0;

core/src/main/java/com/google/zxing/pdf417/PDF417Common.java

@@ -18,6 +18,8 @@ package com.google.zxing.pdf417;
 import java.util.Arrays;
 import java.util.Collection;
 
+import com.google.zxing.common.detector.MathUtils;
+
 /**
  * @author SITA Lab (kevin.osullivan@sita.aero)
  * @author Guenther Grau
@@ -40,12 +42,9 @@ public final class PDF417Common {
   private PDF417Common() {
   }
 
+  @Deprecated
   public static int getBitCountSum(int[] moduleBitCount) {
-    int bitCountSum = 0;
-    for (int count : moduleBitCount) {
-      bitCountSum += count;
-    }
-    return bitCountSum;
+    return MathUtils.sum(moduleBitCount);
   }
 
   public static int[] toIntArray(Collection<Integer> list) {

core/src/main/java/com/google/zxing/pdf417/decoder/PDF417CodewordDecoder.java

@@ -16,6 +16,7 @@
 
 package com.google.zxing.pdf417.decoder;
 
+import com.google.zxing.common.detector.MathUtils;
 import com.google.zxing.pdf417.PDF417Common;
 
 /**
@@ -56,7 +57,7 @@ final class PDF417CodewordDecoder {
   }
 
   private static int[] sampleBitCounts(int[] moduleBitCount) {
-    float bitCountSum = PDF417Common.getBitCountSum(moduleBitCount);
+    float bitCountSum = MathUtils.sum(moduleBitCount);
     int[] result = new int[PDF417Common.BARS_IN_MODULE];
     int bitCountIndex = 0;
     int sumPreviousBits = 0;
@@ -89,7 +90,7 @@ final class PDF417CodewordDecoder {
   }
 
   private static int getClosestDecodedValue(int[] moduleBitCount) {
-    int bitCountSum = PDF417Common.getBitCountSum(moduleBitCount);
+    int bitCountSum = MathUtils.sum(moduleBitCount);
     float[] bitCountRatios = new float[PDF417Common.BARS_IN_MODULE];
     for (int i = 0; i < bitCountRatios.length; i++) {
       bitCountRatios[i] = moduleBitCount[i] / (float) bitCountSum;

core/src/main/java/com/google/zxing/pdf417/decoder/PDF417ScanningDecoder.java

@@ -22,6 +22,7 @@ import com.google.zxing.NotFoundException;
 import com.google.zxing.ResultPoint;
 import com.google.zxing.common.BitMatrix;
 import com.google.zxing.common.DecoderResult;
+import com.google.zxing.common.detector.MathUtils;
 import com.google.zxing.pdf417.PDF417Common;
 import com.google.zxing.pdf417.decoder.ec.ErrorCorrection;
 
@@ -326,7 +327,7 @@ public final class PDF417ScanningDecoder {
     throw ChecksumException.getChecksumInstance();
   }
 
-  private static BarcodeValue[][] createBarcodeMatrix(DetectionResult detectionResult) throws FormatException {
+  private static BarcodeValue[][] createBarcodeMatrix(DetectionResult detectionResult) {
     BarcodeValue[][] barcodeMatrix =
         new BarcodeValue[detectionResult.getBarcodeRowCount()][detectionResult.getBarcodeColumnCount() + 2];
     for (int row = 0; row < barcodeMatrix.length; row++) {
@@ -417,7 +418,7 @@ public final class PDF417ScanningDecoder {
       return null;
     }
     int endColumn;
-    int codewordBitCount = PDF417Common.getBitCountSum(moduleBitCount);
+    int codewordBitCount = MathUtils.sum(moduleBitCount);
     if (leftToRight) {
       endColumn = startColumn + codewordBitCount;
     } else {

core/src/main/java/com/google/zxing/pdf417/encoder/Compaction.java

@@ -16,6 +16,9 @@
 
 package com.google.zxing.pdf417.encoder;
 
+/**
+ * Represents possible PDF417 barcode compaction types.
+ */
 public enum Compaction {
   
   AUTO,

core/src/test/java/com/google/zxing/client/result/CalendarParsedResultTestCase.java

@@ -34,7 +34,7 @@ import java.util.TimeZone;
  */
 public final class CalendarParsedResultTestCase extends Assert {
 
-  private static final double EPSILON = 0.0000000001;
+  private static final double EPSILON = 1.0E-10;
 
   private static DateFormat makeGMTFormat() {
     DateFormat format = new SimpleDateFormat("yyyyMMdd'T'HHmmss'Z'", Locale.ENGLISH);

core/src/test/java/com/google/zxing/client/result/GeoParsedResultTestCase.java

@@ -28,7 +28,7 @@ import org.junit.Test;
  */
 public final class GeoParsedResultTestCase extends Assert {
 
-  private static final double EPSILON = 0.0000000001;
+  private static final double EPSILON = 1.0E-10;
 
   @Test
   public void testGeo() {

core/src/test/java/com/google/zxing/common/PerspectiveTransformTestCase.java

@@ -24,7 +24,7 @@ import org.junit.Test;
  */
 public final class PerspectiveTransformTestCase extends Assert {
 
-  private static final float EPSILON = 0.0001f;
+  private static final float EPSILON = 1.0E-4f;
 
   @Test
   public void testSquareToQuadrilateral() {

core/src/test/java/com/google/zxing/common/detector/MathUtilsTestCase.java

@@ -21,6 +21,8 @@ import org.junit.Test;
 
 public final class MathUtilsTestCase extends Assert {
 
+  private static final float EPSILON = 1.0E-8f;
+
   @Test
   public void testRound() {
     assertEquals(-1, MathUtils.round(-1.0f));
@@ -46,4 +48,21 @@ public final class MathUtilsTestCase extends Assert {
     assertEquals(0, MathUtils.round(Float.NaN));
   }
 
+  @Test
+  public void testDistance() {
+    assertEquals((float) Math.sqrt(8.0), MathUtils.distance(1.0f, 2.0f, 3.0f, 4.0f), EPSILON);
+    assertEquals(0.0f, MathUtils.distance(1.0f, 2.0f, 1.0f, 2.0f), EPSILON);
+
+    assertEquals((float) Math.sqrt(8.0), MathUtils.distance(1, 2, 3, 4), EPSILON);
+    assertEquals(0.0f, MathUtils.distance(1, 2, 1, 2), EPSILON);
+  }
+
+  @Test
+  public void testSum() {
+    assertEquals(0, MathUtils.sum(new int[] {}));
+    assertEquals(1, MathUtils.sum(new int[] {1}));
+    assertEquals(4, MathUtils.sum(new int[] {1, 3}));
+    assertEquals(0, MathUtils.sum(new int[] {-1, 1}));
+  }
+
 }

src/checkstyle/checkstyle.xml

@@ -72,11 +72,9 @@
       <property name="scope" value="protected"/>
     </module>
     -->
-    <!--
     <module name="JavadocType">
       <property name="scope" value="protected"/>
     </module>
-     -->
     <!--<module name="JavadocVariable"/>-->
     <module name="JavadocStyle">
       <property name="checkFirstSentence" value="false"/>

zxing.appspot.com/src/main/java/com/google/zxing/web/generator/client/Generator.java

@@ -43,6 +43,9 @@ import com.google.gwt.user.client.ui.Widget;
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * Main generator for the encoder web interface.
+ */
 public final class Generator implements EntryPoint {
 
   private final List<GeneratorSource> generators = new ArrayList<>();

zxingorg/src/main/java/com/google/zxing/web/RedirectFilter.java

@@ -28,11 +28,24 @@ import javax.servlet.annotation.WebFilter;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import java.util.Collection;
+import java.util.HashSet;
 
+/**
+ * A {@link Filter} which handles a few web app redirects, like redirecting {@code /} to the
+ * main page.
+ */
 @WebFilter("/*")
 public final class RedirectFilter implements Filter {
 
   private static final String OLD_JAVADOC_PREFIX = "/w/docs/javadoc";
+  private static final Collection<String> REDIRECT_WELCOME_PATHS = new HashSet<>();
+  static {
+    REDIRECT_WELCOME_PATHS.add("/");
+    REDIRECT_WELCOME_PATHS.add("/index.jspx");
+    REDIRECT_WELCOME_PATHS.add("/w/");
+    REDIRECT_WELCOME_PATHS.add("/w/index.jspx");
+  }
 
   @Override
   public void init(FilterConfig filterConfig) {
@@ -45,8 +58,7 @@ public final class RedirectFilter implements Filter {
                        FilterChain filterChain) throws IOException, ServletException {
     HttpServletRequest request = (HttpServletRequest) servletRequest;
     String requestURI = request.getRequestURI();
-    if ("/".equals(requestURI) || "/index.jspx".equals(requestURI) ||
-        "/w/".equals(requestURI) || "/w/index.jspx".equals(requestURI)) {
+    if (REDIRECT_WELCOME_PATHS.contains(requestURI)) {
       redirect(servletResponse, "/w/decode.jspx");
     } else if (requestURI.startsWith(OLD_JAVADOC_PREFIX)) {
       String withoutPrefix = requestURI.substring(OLD_JAVADOC_PREFIX.length());