1 files changed, 40 insertions, 18 deletions

diff --git a/gallerycommon/src/com/android/gallery3d/exif/Rational.java b/gallerycommon/src/com/android/gallery3d/exif/Rational.java
index 3f8c18a88..591d63faf 100644
--- a/gallerycommon/src/com/android/gallery3d/exif/Rational.java
+++ b/gallerycommon/src/com/android/gallery3d/exif/Rational.java
@@ -17,50 +17,72 @@
 package com.android.gallery3d.exif;
 
 /**
- * The rational data type of EXIF tag.
+ * The rational data type of EXIF tag. Contains a pair of longs representing the
+ * numerator and denominator of a Rational number.
  */
 public class Rational {
 
-    private final long mNominator;
+    private final long mNumerator;
     private final long mDenominator;
 
+    /**
+     * Create a Rational with a given numerator and denominator.
+     *
+     * @param nominator
+     * @param denominator
+     */
     public Rational(long nominator, long denominator) {
-        mNominator = nominator;
+        mNumerator = nominator;
         mDenominator = denominator;
     }
 
-    /*
-     * Gets the nominator of the rational.
+    /**
+     * Create a copy of a Rational.
+     */
+    public Rational(Rational r) {
+        mNumerator = r.mNumerator;
+        mDenominator = r.mDenominator;
+    }
+
+    /**
+     * Gets the numerator of the rational.
      */
-    public long getNominator() {
-        return mNominator;
+    public long getNumerator() {
+        return mNumerator;
     }
 
-    /*
+    /**
      * Gets the denominator of the rational
      */
     public long getDenominator() {
         return mDenominator;
     }
 
+    /**
+     * Gets the rational value as type double. Will cause a divide-by-zero error
+     * if the denominator is 0.
+     */
+    public double toDouble() {
+        return mNumerator / (double) mDenominator;
+    }
+
     @Override
     public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (this == obj) {
+            return true;
+        }
         if (obj instanceof Rational) {
             Rational data = (Rational) obj;
-            return mNominator == data.mNominator && mDenominator == data.mDenominator;
+            return mNumerator == data.mNumerator && mDenominator == data.mDenominator;
         }
         return false;
     }
 
     @Override
     public String toString() {
-        return mNominator + "/" + mDenominator;
-    }
-
-    /*
-     * Gets the rational value as type double.
-     */
-    public double toDouble() {
-        return mNominator / (double) mDenominator;
+        return mNumerator + "/" + mDenominator;
     }
-}
\ No newline at end of file
+}