Messaging: Further code improvements

* Remove redundant casts
* getParcelable(ArrayList|Exra) without class argument is deprecated
* ViewPager.setOnPageChangeListener -> addOnPageChangeListener
* RecyclerView.setOnScrollListener -> addOnScrollListener
* Remove unused initializations
* Remove unused code

Change-Id: I21beb6c90c675a4f2cfd7e3d5ebbd18b745f5911

src/com/android/messaging/mmslib/pdu/PduComposer.java

@@ -96,22 +96,22 @@ public class PduComposer {
     /**
      * The output message.
      */
-    protected ByteArrayOutputStream mMessage = null;
+    protected ByteArrayOutputStream mMessage;
 
     /**
      * The PDU.
      */
-    private GenericPdu mPdu = null;
+    private GenericPdu mPdu;
 
     /**
      * Current visiting position of the mMessage.
      */
-    protected int mPosition = 0;
+    protected int mPosition;
 
     /**
      * Message compose buffer stack.
      */
-    private BufferStack mStack = null;
+    private BufferStack mStack;
 
     /**
      * Content resolver.
@@ -121,12 +121,12 @@ public class PduComposer {
     /**
      * Header of this pdu.
      */
-    private PduHeaders mPduHeader = null;
+    private PduHeaders mPduHeader;
 
     /**
      * Map of all content type
      */
-    private static SimpleArrayMap<String, Integer> mContentTypeMap = null;
+    private static SimpleArrayMap<String, Integer> mContentTypeMap;
 
     static {
         mContentTypeMap = new SimpleArrayMap<>();
@@ -469,7 +469,7 @@ public class PduComposer {
     }
 
     private EncodedStringValue appendAddressType(final EncodedStringValue address) {
-        EncodedStringValue temp = null;
+        EncodedStringValue temp;
 
         try {
             final int addressType = checkAddressType(address.getString());
@@ -1065,7 +1065,7 @@ public class PduComposer {
                 try {
                     final byte[] buffer = new byte[PDU_COMPOSER_BLOCK_SIZE];
                     cr = mResolver.openInputStream(part.getDataUri());
-                    int len = 0;
+                    int len;
                     while ((len = cr.read(buffer)) != -1) {
                         mMessage.write(buffer, 0, len);
                         mPosition += len;

src/com/android/messaging/mmslib/pdu/PduPersister.java

@@ -373,7 +373,7 @@ public class PduPersister {
                 Uri.parse("content://mms/" + msgId + "/part"),
                 PART_PROJECTION, null, null, null);
 
-        PduPart[] parts = null;
+        PduPart[] parts;
 
         try {
             if ((c == null) || (c.getCount() == 0)) {
@@ -560,7 +560,7 @@ public class PduPersister {
      */
     public GenericPdu load(final Uri uri) throws MmsException {
         GenericPdu pdu = null;
-        PduCacheEntry cacheEntry = null;
+        PduCacheEntry cacheEntry;
         int msgBox = 0;
         final long threadId = -1;
         try {
@@ -859,7 +859,7 @@ public class PduPersister {
         OutputStream os = null;
         InputStream is = null;
         DrmConvertSession drmConvertSession = null;
-        Uri dataUri = null;
+        Uri dataUri;
         String path = null;
 
         try {
@@ -936,7 +936,7 @@ public class PduPersister {
                     }
 
                     final byte[] buffer = new byte[8192];
-                    for (int len = 0; (len = is.read(buffer)) != -1; ) {
+                    for (int len; (len = is.read(buffer)) != -1; ) {
                         if (!isDrm) {
                             os.write(buffer, 0, len);
                         } else {
@@ -955,7 +955,6 @@ public class PduPersister {
                     if (!isDrm) {
                         os.write(data);
                     } else {
-                        dataUri = uri;
                         final byte[] convertedData = drmConvertSession.convert(data, data.length);
                         if (convertedData != null) {
                             os.write(convertedData, 0, convertedData.length);
@@ -1093,7 +1092,7 @@ public class PduPersister {
         PDU_CACHE_INSTANCE.purge(uri);
 
         final PduHeaders header = pdu.getPduHeaders();
-        PduBody body = null;
+        PduBody body;
         ContentValues values = new ContentValues();
 
         // Mark new messages as seen in the telephony database so that we don't have to

src/com/android/messaging/mmslib/util/DrmConvertSession.java

@@ -86,7 +86,7 @@ public class DrmConvertSession {
     public byte[] convert(byte[] inBuffer, int size) {
         byte[] result = null;
         if (inBuffer != null) {
-            DrmConvertedStatus convertedStatus = null;
+            DrmConvertedStatus convertedStatus;
             try {
                 if (size != inBuffer.length) {
                     byte[] buf = new byte[size];
@@ -125,7 +125,7 @@ public class DrmConvertSession {
      *         Downloads.Impl.STATUS_UNKNOWN_ERROR if a general error occurred.
      */
     public int close(String filename) {
-        DrmConvertedStatus convertedStatus = null;
+        DrmConvertedStatus convertedStatus;
         int result = Downloads.Impl.STATUS_UNKNOWN_ERROR;
         if (mDrmClient != null && mConvertSessionId >= 0) {
             try {

src/com/android/messaging/mmslib/util/PduCache.java

@@ -188,7 +188,7 @@ public final class PduCache extends AbstractCache<Uri, PduCacheEntry> {
      */
     private Uri normalizeKey(Uri uri) {
         int match = URI_MATCHER.match(uri);
-        Uri normalizedKey = null;
+        Uri normalizedKey;
 
         switch (match) {
             case MMS_ALL_ID: