Fix in BreakIterator.

An index equal to the length of text is indeed a valid position,
representing a cursor located after the last character.

Also changed iterator to comply to the documentation.

Change-Id: I7b9e427e4e37df20ab7e66d99053a9d8a6af6eb3

2 files changed, 20 insertions, 15 deletions

diff --git a/core/java/android/text/CharSequenceIterator.java b/core/java/android/text/CharSequenceIterator.java
index 4946406..4b8ac10 100644
--- a/core/java/android/text/CharSequenceIterator.java
+++ b/core/java/android/text/CharSequenceIterator.java
@@ -16,22 +16,18 @@
 
 package android.text;
 
-import android.util.MathUtils;
-
 import java.text.CharacterIterator;
 
 /** {@hide} */
 public class CharSequenceIterator implements CharacterIterator {
     private final CharSequence mValue;
 
-    private final int mStart;
-    private final int mEnd;
+    private final int mLength;
     private int mIndex;
 
     public CharSequenceIterator(CharSequence value) {
         mValue = value;
-        mStart = 0;
-        mEnd = value.length();
+        mLength = value.length();
         mIndex = 0;
     }
 
@@ -46,7 +42,7 @@ public class CharSequenceIterator implements CharacterIterator {
 
     /** {@inheritDoc} */
     public char current() {
-        if (mIndex == mEnd) {
+        if (mIndex == mLength) {
             return DONE;
         }
         return mValue.charAt(mIndex);
@@ -54,12 +50,12 @@ public class CharSequenceIterator implements CharacterIterator {
 
     /** {@inheritDoc} */
     public int getBeginIndex() {
-        return mStart;
+        return 0;
     }
 
     /** {@inheritDoc} */
     public int getEndIndex() {
-        return mEnd;
+        return mLength;
     }
 
     /** {@inheritDoc} */
@@ -69,27 +65,36 @@ public class CharSequenceIterator implements CharacterIterator {
 
     /** {@inheritDoc} */
     public char first() {
-        return setIndex(mStart);
+        return setIndex(0);
     }
 
     /** {@inheritDoc} */
     public char last() {
-        return setIndex(mEnd - 1);
+        return setIndex(mLength - 1);
     }
 
     /** {@inheritDoc} */
     public char next() {
+        if (mIndex == mLength) {
+            return DONE;
+        }
         return setIndex(mIndex + 1);
     }
 
     /** {@inheritDoc} */
     public char previous() {
+        if (mIndex == 0) {
+            return DONE;
+        }
         return setIndex(mIndex - 1);
     }
 
     /** {@inheritDoc} */
     public char setIndex(int index) {
-        mIndex = MathUtils.constrain(index, mStart, mEnd);
+        if ((index < 0) || (index > mLength)) {
+            throw new IllegalArgumentException("Valid range is [" + 0 + "..." + mLength + "]");
+        }
+        mIndex = index;
         return current();
     }
 }
diff --git a/core/java/android/text/method/ArrowKeyMovementMethod.java b/core/java/android/text/method/ArrowKeyMovementMethod.java
index 80c0106..b25ba8d 100644
--- a/core/java/android/text/method/ArrowKeyMovementMethod.java
+++ b/core/java/android/text/method/ArrowKeyMovementMethod.java
@@ -390,7 +390,7 @@ public class ArrowKeyMovementMethod extends BaseMovementMethod implements Moveme
         }
 
         private boolean isValidOffset(int offset) {
-            return offset >= 0 && offset < mCurrent.length();
+            return offset >= 0 && offset <= mCurrent.length();
         }
 
         private boolean isLetterOrDigit(int offset) {
@@ -404,7 +404,7 @@ public class ArrowKeyMovementMethod extends BaseMovementMethod implements Moveme
         /** {@inheritDoc} */
         public int preceding(int offset) {
             // always round cursor index into valid string index
-            offset = MathUtils.constrain(offset, 0, mCurrent.length() - 1);
+            offset = MathUtils.constrain(offset, 0, mCurrent.length());
 
             do {
                 offset = mIterator.preceding(offset);
@@ -417,7 +417,7 @@ public class ArrowKeyMovementMethod extends BaseMovementMethod implements Moveme
         /** {@inheritDoc} */
         public int following(int offset) {
             // always round cursor index into valid string index
-            offset = MathUtils.constrain(offset, 0, mCurrent.length() - 1);
+            offset = MathUtils.constrain(offset, 0, mCurrent.length());
 
             do {
                 offset = mIterator.following(offset);