Refactor group messaging protocol.

// FREEBIE

library/protobuf/IncomingPushMessageSignal.proto

@@ -30,11 +30,9 @@ message PushMessageContent {
   message GroupContext {
     enum Type {
       UNKNOWN = 0;
-      CREATE  = 1;
+      UPDATE  = 1;
-      MODIFY  = 2;
+      DELIVER = 2;
-      DELIVER = 3;
+      QUIT    = 3;
-      ADD     = 4;
-      QUIT    = 5;
     }
     optional bytes             id      = 1;
     optional Type              type    = 2;

library/src/org/whispersystems/textsecure/push/PushMessageProtos.java

@@ -1463,19 +1463,15 @@ public final class PushMessageProtos {
       public enum Type
           implements com.google.protobuf.ProtocolMessageEnum {
         UNKNOWN(0, 0),
-        CREATE(1, 1),
+        UPDATE(1, 1),
-        MODIFY(2, 2),
+        DELIVER(2, 2),
-        DELIVER(3, 3),
+        QUIT(3, 3),
-        ADD(4, 4),
-        QUIT(5, 5),
         ;
         
         public static final int UNKNOWN_VALUE = 0;
-        public static final int CREATE_VALUE = 1;
+        public static final int UPDATE_VALUE = 1;
-        public static final int MODIFY_VALUE = 2;
+        public static final int DELIVER_VALUE = 2;
-        public static final int DELIVER_VALUE = 3;
+        public static final int QUIT_VALUE = 3;
-        public static final int ADD_VALUE = 4;
-        public static final int QUIT_VALUE = 5;
         
         
         public final int getNumber() { return value; }
@@ -1483,11 +1479,9 @@ public final class PushMessageProtos {
         public static Type valueOf(int value) {
           switch (value) {
             case 0: return UNKNOWN;
-            case 1: return CREATE;
+            case 1: return UPDATE;
-            case 2: return MODIFY;
+            case 2: return DELIVER;
-            case 3: return DELIVER;
+            case 3: return QUIT;
-            case 4: return ADD;
-            case 5: return QUIT;
             default: return null;
           }
         }
@@ -1518,7 +1512,7 @@ public final class PushMessageProtos {
         }
         
         private static final Type[] VALUES = {
-          UNKNOWN, CREATE, MODIFY, DELIVER, ADD, QUIT, 
+          UNKNOWN, UPDATE, DELIVER, QUIT, 
         };
         
         public static Type valueOf(
@@ -3073,22 +3067,22 @@ public final class PushMessageProtos {
       "evice\030\007 \001(\r\022\r\n\005relay\030\003 \001(\t\022\021\n\ttimestamp\030" +
       "\005 \001(\004\022\017\n\007message\030\006 \001(\014\"W\n\004Type\022\013\n\007UNKNOW" +
       "N\020\000\022\016\n\nCIPHERTEXT\020\001\022\020\n\014KEY_EXCHANGE\020\002\022\021\n" +
-      "\rPREKEY_BUNDLE\020\003\022\r\n\tPLAINTEXT\020\004\"\234\004\n\022Push" +
+      "\rPREKEY_BUNDLE\020\003\022\r\n\tPLAINTEXT\020\004\"\207\004\n\022Push" +
       "MessageContent\022\014\n\004body\030\001 \001(\t\022E\n\013attachme" +
       "nts\030\002 \003(\01320.textsecure.PushMessageConten",
       "t.AttachmentPointer\022:\n\005group\030\003 \001(\0132+.tex" +
       "tsecure.PushMessageContent.GroupContext\022" +
       "\r\n\005flags\030\004 \001(\r\032A\n\021AttachmentPointer\022\n\n\002i" +
       "d\030\001 \001(\006\022\023\n\013contentType\030\002 \001(\t\022\013\n\003key\030\003 \001(" +
-      "\014\032\210\002\n\014GroupContext\022\n\n\002id\030\001 \001(\014\022>\n\004type\030\002" +
+      "\014\032\363\001\n\014GroupContext\022\n\n\002id\030\001 \001(\014\022>\n\004type\030\002" +
       " \001(\01620.textsecure.PushMessageContent.Gro" +
       "upContext.Type\022\014\n\004name\030\003 \001(\t\022\017\n\007members\030" +
       "\004 \003(\t\022@\n\006avatar\030\005 \001(\01320.textsecure.PushM" +
-      "essageContent.AttachmentPointer\"K\n\004Type\022" +
+      "essageContent.AttachmentPointer\"6\n\004Type\022" +
-      "\013\n\007UNKNOWN\020\000\022\n\n\006CREATE\020\001\022\n\n\006MODIFY\020\002\022\013\n\007",
+      "\013\n\007UNKNOWN\020\000\022\n\n\006UPDATE\020\001\022\013\n\007DELIVER\020\002\022\010\n",
-      "DELIVER\020\003\022\007\n\003ADD\020\004\022\010\n\004QUIT\020\005\"\030\n\005Flags\022\017\n" +
+      "\004QUIT\020\003\"\030\n\005Flags\022\017\n\013END_SESSION\020\001B7\n\"org" +
-      "\013END_SESSION\020\001B7\n\"org.whispersystems.tex" +
+      ".whispersystems.textsecure.pushB\021PushMes" +
-      "tsecure.pushB\021PushMessageProtos"
+      "sageProtos"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {

src/org/thoughtcrime/securesms/GroupCreateActivity.java

@@ -337,6 +337,11 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
     }
   }
 
+  private void handleGroupUpdate() {
+    Log.w("GroupCreateActivity", "Creating...");
+    new UpdateWhisperGroupAsyncTask().execute();
+  }
+
   private static List<String> recipientsToNormalizedStrings(Collection<Recipient> recipients, String localNumber) {
     final List<String> e164numbers = new ArrayList<String>(recipients.size());
     for (Recipient contact : recipients) {
@@ -349,63 +354,6 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
     return e164numbers;
   }
 
-  private void handleGroupUpdate() {
-    Log.i(TAG, "Updating group info.");
-    GroupDatabase db = DatabaseFactory.getGroupDatabase(this);
-    final String localNumber = TextSecurePreferences.getLocalNumber(this);
-    List<String> e164numbers = recipientsToNormalizedStrings(selectedContacts, localNumber);
-    if (selectedContacts.size() > 0) {
-      db.add(groupId, localNumber, e164numbers);
-      GroupContext context = GroupContext.newBuilder()
-                                         .setId(ByteString.copyFrom(groupId))
-                                         .setType(GroupContext.Type.ADD)
-                                         .addAllMembers(e164numbers)
-                                         .build();
-      OutgoingGroupMediaMessage outgoingMessage = new OutgoingGroupMediaMessage(this, groupRecipient, context, null);
-      try {
-        MessageSender.send(this, masterSecret, outgoingMessage, groupThread);
-      } catch (MmsException me) {
-        Log.w(TAG, "MmsException encountered when trying to add members to group.", me);
-      }
-    }
-
-    GroupContext.Builder builder = GroupContext.newBuilder()
-                                       .setId(ByteString.copyFrom(groupId))
-                                       .setType(GroupContext.Type.MODIFY);
-    boolean shouldSendUpdate = false;
-    final String title = groupName.getText().toString();
-    if (existingTitle == null || (groupName.getText() != null && !existingTitle.equals(title))) {
-      builder.setName(title);
-      db.updateTitle(groupId, title);
-      shouldSendUpdate = true;
-    }
-    byte[] avatarBytes = null;
-    if (existingAvatarBmp == null || !existingAvatarBmp.equals(avatarBmp)) {
-      if (avatarBmp != null) {
-        ByteArrayOutputStream stream = new ByteArrayOutputStream();
-        avatarBmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
-        avatarBytes = stream.toByteArray();
-      }
-      db.updateAvatar(groupId, avatarBytes);
-      shouldSendUpdate = true;
-    }
-
-    if (shouldSendUpdate) {
-      GroupContext context = builder.build();
-      OutgoingGroupMediaMessage outgoingMessage = new OutgoingGroupMediaMessage(this, groupRecipient, context, avatarBytes);
-      try {
-        MessageSender.send(this, masterSecret, outgoingMessage, groupThread);
-      } catch (MmsException me) {
-        Log.w(TAG, "MmsException encountered when trying to add members to group.", me);
-      }
-    }
-
-    RecipientFactory.clearCache(groupRecipient.getPrimaryRecipient());
-
-    setResult(RESULT_OK, getIntent());
-    finish();
-  }
-
   private void enableWhisperGroupCreatingUi() {
     findViewById(R.id.group_details_layout).setVisibility(View.GONE);
     findViewById(R.id.creating_group_layout).setVisibility(View.VISIBLE);
@@ -475,29 +423,56 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
     }
   }
 
-  private Pair<Long, Recipients> handleCreatePushGroup(String groupName,
+  private Pair<Long, Recipients> handleCreatePushGroup(String groupName, byte[] avatar,
-                                                       byte[] avatar,
                                                        Set<Recipient> members)
       throws InvalidNumberException, MmsException
   {
-    GroupDatabase groupDatabase = DatabaseFactory.getGroupDatabase(this);
+    GroupDatabase groupDatabase     = DatabaseFactory.getGroupDatabase(this);
-    byte[]        groupId       = groupDatabase.allocateGroupId();
+    byte[]        groupId           = groupDatabase.allocateGroupId();
+    List<String>  memberE164Numbers = getE164Numbers(members);
+
+    groupDatabase.create(groupId, TextSecurePreferences.getLocalNumber(this), groupName,
+                         memberE164Numbers, null, null);
+    groupDatabase.updateAvatar(groupId, avatar);
+
+    return handlePushOperation(groupId, groupName, avatar, memberE164Numbers);
+  }
+
+  private Pair<Long, Recipients> handleUpdatePushGroup(byte[] groupId, String groupName,
+                                                       byte[] avatar, Set<Recipient> members)
+      throws InvalidNumberException, MmsException
+  {
+    GroupDatabase groupDatabase     = DatabaseFactory.getGroupDatabase(this);
+    List<String>  memberE164Numbers = getE164Numbers(members);
+
+    GroupDatabase.GroupRecord record     = groupDatabase.getGroup(groupId);
+    Set<String>               newMembers = new HashSet<String>(memberE164Numbers);
+    newMembers.removeAll(record.getMembers());
+
+    groupDatabase.add(groupId, TextSecurePreferences.getLocalNumber(this),
+                      new LinkedList<String>(newMembers));
+
+    groupDatabase.updateTitle(groupId, groupName);
+    groupDatabase.updateAvatar(groupId, avatar);
+
+
+    return handlePushOperation(groupId, groupName, avatar, memberE164Numbers);
+  }
+
+  private Pair<Long, Recipients> handlePushOperation(byte[] groupId, String groupName, byte[] avatar,
+                                                     List<String> e164numbers)
+      throws MmsException, InvalidNumberException
+  {
 
     try {
-      List<String> memberE164Numbers = getE164Numbers(members);
+      String     groupRecipientId = GroupUtil.getEncodedId(groupId);
-      String       groupRecipientId  = GroupUtil.getEncodedId(groupId);
+      Recipients groupRecipient   = RecipientFactory.getRecipientsFromString(this, groupRecipientId, false);
-
-      groupDatabase.create(groupId, TextSecurePreferences.getLocalNumber(this), groupName,
-                           memberE164Numbers, null, null);
-      groupDatabase.updateAvatar(groupId, avatar);
-
-      Recipients groupRecipient = RecipientFactory.getRecipientsFromString(this, groupRecipientId, false);
 
       GroupContext context = GroupContext.newBuilder()
                                          .setId(ByteString.copyFrom(groupId))
-                                         .setType(GroupContext.Type.CREATE)
+                                         .setType(GroupContext.Type.UPDATE)
                                          .setName(groupName)
-                                         .addAllMembers(memberE164Numbers)
+                                         .addAllMembers(e164numbers)
                                          .build();
 
       OutgoingGroupMediaMessage outgoingMessage = new OutgoingGroupMediaMessage(this, groupRecipient, context, avatar);
@@ -508,7 +483,6 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
       throw new AssertionError(e);
     } catch (MmsException e) {
       Log.w(TAG, e);
-      groupDatabase.remove(groupId, TextSecurePreferences.getLocalNumber(this));
       throw new MmsException(e);
     }
   }
@@ -588,6 +562,30 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
     }
   }
 
+  private class UpdateWhisperGroupAsyncTask extends AsyncTask<Void,Void,Pair<Long,Recipients>> {
+    private long RES_BAD_NUMBER = -2;
+    private long RES_MMS_EXCEPTION = -3;
+    @Override
+    protected Pair<Long, Recipients> doInBackground(Void... params) {
+      byte[] avatarBytes = null;
+      if (avatarBmp != null) {
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        avatarBmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
+        avatarBytes = stream.toByteArray();
+      }
+      final String name = (groupName.getText() != null) ? groupName.getText().toString() : null;
+      try {
+        return handleUpdatePushGroup(groupId, name, avatarBytes, selectedContacts);
+      } catch (MmsException e) {
+        Log.w(TAG, e);
+        return new Pair<Long,Recipients>(RES_MMS_EXCEPTION, null);
+      } catch (InvalidNumberException e) {
+        Log.w(TAG, e);
+        return new Pair<Long,Recipients>(RES_BAD_NUMBER, null);
+      }
+    }
+  }
+
   private class CreateWhisperGroupAsyncTask extends AsyncTask<Void,Void,Pair<Long,Recipients>> {
     private long RES_BAD_NUMBER = -2;
     private long RES_MMS_EXCEPTION = -3;
@@ -664,8 +662,7 @@ public class GroupCreateActivity extends PassphraseRequiredSherlockFragmentActiv
           existingContacts.addAll(recipientList);
         }
       }
-      final GroupDatabase.Reader groupReader = db.getGroup(groupId);
+      GroupDatabase.GroupRecord group = db.getGroup(groupId);
-      GroupDatabase.GroupRecord group = groupReader.getNext();
       if (group != null) {
         existingTitle = group.getTitle();
         final byte[] existingAvatar = group.getAvatar();

src/org/thoughtcrime/securesms/database/GroupDatabase.java

@@ -66,12 +66,16 @@ public class GroupDatabase extends Database {
     super(context, databaseHelper);
   }
 
-  public Reader getGroup(byte[] groupId) {
+  public GroupRecord getGroup(byte[] groupId) {
     Cursor cursor = databaseHelper.getReadableDatabase().query(TABLE_NAME, null, GROUP_ID + " = ?",
                                                                new String[] {GroupUtil.getEncodedId(groupId)},
                                                                null, null, null);
 
-    return new Reader(cursor);
+    Reader      reader = new Reader(cursor);
+    GroupRecord record = reader.getNext();
+
+    reader.close();
+    return record;
   }
 
   public Recipients getGroupMembers(byte[] groupId) {
@@ -107,7 +111,6 @@ public class GroupDatabase extends Database {
       }
     }
 
-
     ContentValues contentValues = new ContentValues();
     contentValues.put(GROUP_ID, GroupUtil.getEncodedId(groupId));
     contentValues.put(OWNER, owner);

src/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -532,9 +532,8 @@ public class MmsDatabase extends Database implements MmsSmsColumns {
     }
 
     if (message.isGroup()) {
-      if      (((OutgoingGroupMediaMessage)message).isGroupAdd())    type |= Types.GROUP_ADD_MEMBERS_BIT;
+      if      (((OutgoingGroupMediaMessage)message).isGroupUpdate()) type |= Types.GROUP_UPDATE_BIT;
       else if (((OutgoingGroupMediaMessage)message).isGroupQuit())   type |= Types.GROUP_QUIT_BIT;
-      else if (((OutgoingGroupMediaMessage)message).isGroupModify()) type |= Types.GROUP_MODIFY_BIT;
     }
 
     SendReq sendRequest = new SendReq();

src/org/thoughtcrime/securesms/database/MmsSmsColumns.java

@@ -41,9 +41,8 @@ public interface MmsSmsColumns {
     protected static final long PUSH_MESSAGE_BIT   = 0x200000;
 
     // Group Message Information
-    protected static final long GROUP_ADD_MEMBERS_BIT = 0x10000;
+    protected static final long GROUP_UPDATE_BIT = 0x10000;
-    protected static final long GROUP_QUIT_BIT        = 0x20000;
+    protected static final long GROUP_QUIT_BIT   = 0x20000;
-    protected static final long GROUP_MODIFY_BIT      = 0x40000;
 
     // Encrypted Storage Information
     protected static final long ENCRYPTION_MASK                  = 0xFF000000;
@@ -116,12 +115,8 @@ public interface MmsSmsColumns {
       return (type & KEY_EXCHANGE_IDENTITY_UPDATE_BIT) != 0;
     }
 
-    public static boolean isGroupAdd(long type) {
+    public static boolean isGroupUpdate(long type) {
-      return (type & GROUP_ADD_MEMBERS_BIT) != 0;
+      return (type & GROUP_UPDATE_BIT) != 0;
-    }
-
-    public static boolean isGroupModify(long type) {
-      return (type & GROUP_MODIFY_BIT) != 0;
     }
 
     public static boolean isGroupQuit(long type) {

src/org/thoughtcrime/securesms/database/SmsDatabase.java

@@ -262,9 +262,8 @@ public class SmsDatabase extends Database implements MmsSmsColumns {
       type |= Types.ENCRYPTION_REMOTE_BIT;
     } else if (message.isGroup()) {
       type |= Types.SECURE_MESSAGE_BIT;
-      if      (((IncomingGroupMessage)message).isAdd())    type |= Types.GROUP_ADD_MEMBERS_BIT;
+      if      (((IncomingGroupMessage)message).isUpdate()) type |= Types.GROUP_UPDATE_BIT;
       else if (((IncomingGroupMessage)message).isQuit())   type |= Types.GROUP_QUIT_BIT;
-      else if (((IncomingGroupMessage)message).isModify()) type |= Types.GROUP_MODIFY_BIT;
     } else if (message.isEndSession()) {
       type |= Types.SECURE_MESSAGE_BIT;
       type |= Types.END_SESSION_BIT;

src/org/thoughtcrime/securesms/database/model/DisplayRecord.java

@@ -83,12 +83,8 @@ public abstract class DisplayRecord {
     return SmsDatabase.Types.isEndSessionType(type);
   }
 
-  public boolean isGroupAdd() {
+  public boolean isGroupUpdate() {
-    return SmsDatabase.Types.isGroupAdd(type);
+    return SmsDatabase.Types.isGroupUpdate(type);
-  }
-
-  public boolean isGroupModify() {
-    return SmsDatabase.Types.isGroupModify(type);
   }
 
   public boolean isGroupQuit() {
@@ -96,7 +92,7 @@ public abstract class DisplayRecord {
   }
 
   public boolean isGroupAction() {
-    return isGroupAdd() || isGroupModify() || isGroupQuit();
+    return isGroupUpdate() || isGroupQuit();
   }
 
   public static class Body {

src/org/thoughtcrime/securesms/database/model/MessageRecord.java

@@ -84,12 +84,10 @@ public abstract class MessageRecord extends DisplayRecord {
 
   @Override
   public SpannableString getDisplayBody() {
-    if (isGroupAdd()) {
+    if (isGroupUpdate()) {
-      return emphasisAdded(context.getString(R.string.ConversationItem_group_action_joined, Util.join(GroupUtil.getSerializedArgumentMembers(getBody().getBody()), ", ")));
+      return emphasisAdded(GroupUtil.getDescription(getBody().getBody()));
     } else if (isGroupQuit()) {
       return emphasisAdded(context.getString(R.string.ConversationItem_group_action_left, getIndividualRecipient().toShortString()));
-    } else if (isGroupModify()) {
-      return emphasisAdded(context.getString(R.string.ConversationItem_group_action_modify, getIndividualRecipient().toShortString()));
     }
 
     return new SpannableString(getBody().getBody());

src/org/thoughtcrime/securesms/database/model/ThreadRecord.java

@@ -56,12 +56,10 @@ public class ThreadRecord extends DisplayRecord {
     // TODO jake is going to fill these in
     if (SmsDatabase.Types.isDecryptInProgressType(type)) {
       return emphasisAdded(context.getString(R.string.MessageDisplayHelper_decrypting_please_wait));
-    } else if (isGroupAdd()) {
+    } else if (isGroupUpdate()) {
-      return emphasisAdded(Util.join(GroupUtil.getSerializedArgumentMembers(getBody().getBody()), ", ") + " have joined the group");
+      return emphasisAdded(GroupUtil.getDescription(getBody().getBody()));
     } else if (isGroupQuit()) {
       return emphasisAdded(getRecipients().toShortString() + " left the group.");
-    } else if (isGroupModify()) {
-      return emphasisAdded(getRecipients().toShortString() + " modified the group.");
     } else if (isKeyExchange()) {
       return emphasisAdded(context.getString(R.string.ConversationListItem_key_exchange_message));
     } else if (SmsDatabase.Types.isFailedDecryptType(type)) {

src/org/thoughtcrime/securesms/mms/OutgoingGroupMediaMessage.java

@@ -37,17 +37,11 @@ public class OutgoingGroupMediaMessage extends OutgoingSecureMediaMessage {
     return true;
   }
 
-  public boolean isGroupAdd() {
+  public boolean isGroupUpdate() {
-    return
+    return group.getType().getNumber() == GroupContext.Type.UPDATE_VALUE;
-        group.getType().getNumber() == GroupContext.Type.ADD_VALUE ||
-        group.getType().getNumber() == GroupContext.Type.CREATE_VALUE;
   }
 
   public boolean isGroupQuit() {
     return group.getType().getNumber() == GroupContext.Type.QUIT_VALUE;
   }
-
-  public boolean isGroupModify() {
-    return group.getType().getNumber() == GroupContext.Type.MODIFY_VALUE;
-  }
 }

src/org/thoughtcrime/securesms/recipients/RecipientProvider.java

@@ -144,23 +144,17 @@ public class RecipientProvider {
 
   private RecipientDetails getGroupRecipientDetails(Context context, String groupId) {
     try {
-      GroupDatabase.Reader reader = DatabaseFactory.getGroupDatabase(context)
+      GroupDatabase.GroupRecord record  = DatabaseFactory.getGroupDatabase(context)
-                                                   .getGroup(GroupUtil.getDecodedId(groupId));
+                                                         .getGroup(GroupUtil.getDecodedId(groupId));
 
-      GroupDatabase.GroupRecord record;
+      if (record != null) {
+        byte[] avatarBytes = record.getAvatar();
+        Bitmap avatar;
 
-      try {
+        if (avatarBytes == null) avatar = ContactPhotoFactory.getDefaultContactPhoto(context);
-        if ((record = reader.getNext()) != null) {
+        else                     avatar = BitmapFactory.decodeByteArray(avatarBytes, 0, avatarBytes.length);
-          byte[] avatarBytes = record.getAvatar();
-          Bitmap avatar;
 
-          if (avatarBytes == null) avatar = ContactPhotoFactory.getDefaultContactPhoto(context);
+        return new RecipientDetails(record.getTitle(), null, avatar);
-          else                     avatar = BitmapFactory.decodeByteArray(avatarBytes, 0, avatarBytes.length);
-
-          return new RecipientDetails(record.getTitle(), null, avatar);
-        }
-      } finally {
-        reader.close();
       }
 
       return null;

src/org/thoughtcrime/securesms/service/AvatarDownloader.java

@@ -37,19 +37,17 @@ public class AvatarDownloader {
       if (!SendReceiveService.DOWNLOAD_AVATAR_ACTION.equals(intent.getAction()))
         return;
 
-      byte[]               groupId  = intent.getByteArrayExtra("group_id");
+      byte[]                    groupId  = intent.getByteArrayExtra("group_id");
-      GroupDatabase        database = DatabaseFactory.getGroupDatabase(context);
+      GroupDatabase             database = DatabaseFactory.getGroupDatabase(context);
-      GroupDatabase.Reader reader   = database.getGroup(groupId);
+      GroupDatabase.GroupRecord record   = database.getGroup(groupId);
 
-      GroupDatabase.GroupRecord record;
+      if (record != null) {
-
-      while ((record = reader.getNext()) != null) {
         long        avatarId           = record.getAvatarId();
         byte[]      key                = record.getAvatarKey();
         String      relay              = record.getRelay();
 
         if (avatarId == -1 || key == null) {
-          continue;
+          return;
         }
 
         File        attachment         = downloadAttachment(relay, avatarId);

src/org/thoughtcrime/securesms/service/GroupReceiver.java

@@ -0,0 +1,159 @@
+package org.thoughtcrime.securesms.service;
+
+import android.content.Context;
+import android.content.Intent;
+import android.util.Log;
+import android.util.Pair;
+
+import org.thoughtcrime.securesms.database.DatabaseFactory;
+import org.thoughtcrime.securesms.database.EncryptingSmsDatabase;
+import org.thoughtcrime.securesms.database.GroupDatabase;
+import org.thoughtcrime.securesms.notifications.MessageNotifier;
+import org.thoughtcrime.securesms.sms.IncomingGroupMessage;
+import org.thoughtcrime.securesms.sms.IncomingTextMessage;
+import org.whispersystems.textsecure.crypto.MasterSecret;
+import org.whispersystems.textsecure.push.IncomingPushMessage;
+import org.whispersystems.textsecure.util.Base64;
+
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+
+import static org.thoughtcrime.securesms.database.GroupDatabase.GroupRecord;
+import static org.whispersystems.textsecure.push.PushMessageProtos.PushMessageContent;
+import static org.whispersystems.textsecure.push.PushMessageProtos.PushMessageContent.GroupContext;
+
+public class GroupReceiver {
+
+  private final Context context;
+
+  public GroupReceiver(Context context) {
+    this.context = context.getApplicationContext();
+  }
+
+  public void process(MasterSecret masterSecret,
+                      IncomingPushMessage message,
+                      PushMessageContent messageContent,
+                      boolean secure)
+  {
+    if (!messageContent.getGroup().hasId()) {
+      Log.w("GroupReceiver", "Received group message with no id! Ignoring...");
+      return;
+    }
+
+    if (!secure) {
+      Log.w("GroupReceiver", "Received insecure group push action! Ignoring...");
+      return;
+    }
+
+    GroupDatabase database = DatabaseFactory.getGroupDatabase(context);
+    GroupContext  group    = messageContent.getGroup();
+    byte[]        id       = group.getId().toByteArray();
+    int           type     = group.getType().getNumber();
+    GroupRecord   record   = database.getGroup(id);
+
+    if (record != null && type == GroupContext.Type.UPDATE_VALUE) {
+      handleGroupUpdate(masterSecret, message, group, record);
+    } else if (record == null && type == GroupContext.Type.UPDATE_VALUE) {
+      handleGroupCreate(masterSecret, message, group);
+    } else if (type == GroupContext.Type.QUIT_VALUE) {
+      handleGroupLeave(masterSecret, message, group, record);
+    } else if (type == GroupContext.Type.UNKNOWN_VALUE) {
+      Log.w("GroupReceiver", "Received unknown type, ignoring...");
+    }
+  }
+
+  private void handleGroupCreate(MasterSecret masterSecret,
+                                 IncomingPushMessage message,
+                                 GroupContext group)
+  {
+    GroupDatabase database = DatabaseFactory.getGroupDatabase(context);
+    byte[]        id       = group.getId().toByteArray();
+
+    database.create(id, message.getSource(), group.getName(), group.getMembersList(),
+                    group.getAvatar(), message.getRelay());
+
+    storeMessage(masterSecret, message, group);
+  }
+
+  private void handleGroupUpdate(MasterSecret masterSecret,
+                                 IncomingPushMessage message,
+                                 GroupContext group,
+                                 GroupRecord groupRecord)
+  {
+
+    GroupDatabase database = DatabaseFactory.getGroupDatabase(context);
+    byte[]        id       = group.getId().toByteArray();
+
+    Set<String> recordMembers = new HashSet<String>(groupRecord.getMembers());
+    Set<String> messageMembers = new HashSet<String>(group.getMembersList());
+
+    Set<String> addedMembers = new HashSet<String>(messageMembers);
+    addedMembers.removeAll(recordMembers);
+
+    Set<String> missingMembers = new HashSet<String>(recordMembers);
+    missingMembers.removeAll(messageMembers);
+
+    if (addedMembers.size() > 0) {
+      Set<String> unionMembers = new HashSet<String>(recordMembers);
+      unionMembers.addAll(messageMembers);
+      database.add(id, message.getSource(), new LinkedList<String>(unionMembers));
+
+      group = group.toBuilder().clearMembers().addAllMembers(addedMembers).build();
+    } else {
+      group = group.toBuilder().clearMembers().build();
+    }
+
+    if (missingMembers.size() > 0) {
+      // TODO We should tell added and missing about each-other.
+    }
+
+    if (group.hasName() || group.hasAvatar()) {
+      database.update(id, message.getSource(), group.getName(), group.getAvatar());
+    }
+
+    if (group.hasName() && group.getName() != null && group.getName().equals(groupRecord.getTitle())) {
+      group = group.toBuilder().clearName().build();
+    }
+
+    storeMessage(masterSecret, message, group);
+  }
+
+  private void handleGroupLeave(MasterSecret        masterSecret,
+                                IncomingPushMessage message,
+                                GroupContext        group,
+                                GroupRecord         record)
+  {
+    GroupDatabase database = DatabaseFactory.getGroupDatabase(context);
+    byte[]        id       = group.getId().toByteArray();
+    List<String>  members  = record.getMembers();
+
+    if (members.contains(message.getSource())) {
+      database.remove(id, message.getSource());
+
+      storeMessage(masterSecret, message, group);
+    }
+  }
+
+
+  private void storeMessage(MasterSecret masterSecret, IncomingPushMessage message, GroupContext group) {
+    if (group.hasAvatar()) {
+      Intent intent = new Intent(context, SendReceiveService.class);
+      intent.setAction(SendReceiveService.DOWNLOAD_AVATAR_ACTION);
+      intent.putExtra("group_id", group.getId().toByteArray());
+      context.startService(intent);
+    }
+
+    EncryptingSmsDatabase smsDatabase  = DatabaseFactory.getEncryptingSmsDatabase(context);
+    String                body         = Base64.encodeBytes(group.toByteArray());
+    IncomingTextMessage   incoming     = new IncomingTextMessage(message, body, group);
+    IncomingGroupMessage  groupMessage = new IncomingGroupMessage(incoming, group, body);
+
+    Pair<Long, Long> messageAndThreadId = smsDatabase.insertMessageInbox(masterSecret, groupMessage);
+    smsDatabase.updateMessageBody(masterSecret, messageAndThreadId.first, body);
+
+    MessageNotifier.updateNotification(context, masterSecret, messageAndThreadId.second);
+  }
+
+}

src/org/thoughtcrime/securesms/service/PushReceiver.java

@@ -12,7 +12,6 @@ import org.thoughtcrime.securesms.crypto.KeyExchangeProcessor;
 import org.thoughtcrime.securesms.crypto.KeyExchangeProcessorV2;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.EncryptingSmsDatabase;
-import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
 import org.thoughtcrime.securesms.mms.IncomingMediaMessage;
 import org.thoughtcrime.securesms.notifications.MessageNotifier;
@@ -22,7 +21,6 @@ import org.thoughtcrime.securesms.recipients.RecipientFormattingException;
 import org.thoughtcrime.securesms.recipients.Recipients;
 import org.thoughtcrime.securesms.sms.IncomingEncryptedMessage;
 import org.thoughtcrime.securesms.sms.IncomingEndSessionMessage;
-import org.thoughtcrime.securesms.sms.IncomingGroupMessage;
 import org.thoughtcrime.securesms.sms.IncomingKeyExchangeMessage;
 import org.thoughtcrime.securesms.sms.IncomingPreKeyBundleMessage;
 import org.thoughtcrime.securesms.sms.IncomingTextMessage;
@@ -38,11 +36,9 @@ import org.whispersystems.textsecure.push.PushMessageProtos.PushMessageContent;
 import org.whispersystems.textsecure.storage.InvalidKeyIdException;
 import org.whispersystems.textsecure.storage.RecipientDevice;
 import org.whispersystems.textsecure.storage.Session;
-import org.whispersystems.textsecure.util.Base64;
 
 import ws.com.google.android.mms.MmsException;
 
-import static org.whispersystems.textsecure.push.PushMessageProtos.PushMessageContent.GroupContext;
 import static org.whispersystems.textsecure.push.PushMessageProtos.PushMessageContent.GroupContext.Type;
 
 public class PushReceiver {
@@ -51,10 +47,12 @@ public class PushReceiver {
   public static final int RESULT_NO_SESSION     = 1;
   public static final int RESULT_DECRYPT_FAILED = 2;
 
-  private final Context context;
+  private final Context       context;
+  private final GroupReceiver groupReceiver;
 
   public PushReceiver(Context context) {
-    this.context = context.getApplicationContext();
+    this.context       = context.getApplicationContext();
+    this.groupReceiver = new GroupReceiver(context);
   }
 
   public void process(MasterSecret masterSecret, Intent intent) {
@@ -160,7 +158,7 @@ public class PushReceiver {
         handleEndSessionMessage(masterSecret, message, messageContent);
       } else if (messageContent.hasGroup() && messageContent.getGroup().getType().getNumber() != Type.DELIVER_VALUE) {
         Log.w("PushReceiver", "Received push group message...");
-        handleReceivedGroupMessage(masterSecret, message, messageContent, secure);
+        groupReceiver.process(masterSecret, message, messageContent, secure);
       } else if (messageContent.getAttachmentsCount() > 0) {
         Log.w("PushReceiver", "Received push media message...");
         handleReceivedMediaMessage(masterSecret, message, messageContent, secure);
@@ -174,57 +172,6 @@ public class PushReceiver {
     }
   }
 
-  private void handleReceivedGroupMessage(MasterSecret masterSecret,
-                                          IncomingPushMessage message,
-                                          PushMessageContent messageContent,
-                                          boolean secure)
-  {
-    if (!messageContent.getGroup().hasId()) {
-      Log.w("PushReceiver", "Received group message with no id!");
-      return;
-    }
-
-    if (!secure) {
-      Log.w("PushReceiver", "Received insecure group push action!");
-      return;
-    }
-
-    GroupDatabase database = DatabaseFactory.getGroupDatabase(context);
-    GroupContext  group    = messageContent.getGroup();
-    byte[]        id       = group.getId().toByteArray();
-    int           type     = group.getType().getNumber();
-
-    if (type == Type.CREATE_VALUE) {
-      database.create(id, message.getSource(), group.getName(), group.getMembersList(), group.getAvatar(), message.getRelay());
-    } else if (type == Type.ADD_VALUE) {
-      database.add(id, message.getSource(), group.getMembersList());
-    } else if (type == Type.QUIT_VALUE) {
-      database.remove(id, message.getSource());
-    } else if (type == Type.MODIFY_VALUE) {
-      database.update(id, message.getSource(), group.getName(), group.getAvatar());
-    } else if (type == Type.UNKNOWN_VALUE) {
-      Log.w("PushReceiver", "Receied group message from unknown type: " + type);
-      return;
-    }
-
-    if (group.hasAvatar()) {
-      Intent intent = new Intent(context, SendReceiveService.class);
-      intent.setAction(SendReceiveService.DOWNLOAD_AVATAR_ACTION);
-      intent.putExtra("group_id", group.getId().toByteArray());
-      context.startService(intent);
-    }
-
-    EncryptingSmsDatabase smsDatabase  = DatabaseFactory.getEncryptingSmsDatabase(context);
-    String                body         = Base64.encodeBytes(group.toByteArray());
-    IncomingTextMessage   incoming     = new IncomingTextMessage(message, body, group);
-    IncomingGroupMessage  groupMessage = new IncomingGroupMessage(incoming, group, body);
-
-    Pair<Long, Long> messageAndThreadId = smsDatabase.insertMessageInbox(masterSecret, groupMessage);
-    smsDatabase.updateMessageBody(masterSecret, messageAndThreadId.first, body);
-
-    MessageNotifier.updateNotification(context, masterSecret, messageAndThreadId.second);
-  }
-
   private void handleEndSessionMessage(MasterSecret masterSecret,
                                        IncomingPushMessage message,
                                        PushMessageContent messageContent)

src/org/thoughtcrime/securesms/sms/IncomingGroupMessage.java

@@ -3,7 +3,6 @@ package org.thoughtcrime.securesms.sms;
 import com.google.protobuf.ByteString;
 
 import org.thoughtcrime.securesms.util.GroupUtil;
-import org.whispersystems.textsecure.push.PushMessageProtos;
 
 import java.io.IOException;
 
@@ -28,20 +27,14 @@ public class IncomingGroupMessage extends IncomingTextMessage {
     return true;
   }
 
-  public boolean isAdd() {
+  public boolean isUpdate() {
-    return
+    return groupContext.getType().getNumber() == GroupContext.Type.UPDATE_VALUE;
-        groupContext.getType().getNumber() == GroupContext.Type.ADD_VALUE ||
-        groupContext.getType().getNumber() == GroupContext.Type.CREATE_VALUE;
   }
 
   public boolean isQuit() {
     return groupContext.getType().getNumber() == GroupContext.Type.QUIT_VALUE;
   }
 
-  public boolean isModify() {
-    return groupContext.getType().getNumber() == GroupContext.Type.MODIFY_VALUE;
-  }
-
   public static IncomingGroupMessage createForQuit(String groupId, String user) throws IOException {
     IncomingTextMessage base    = new IncomingTextMessage(user, groupId);
     GroupContext        context = GroupContext.newBuilder()

src/org/thoughtcrime/securesms/transport/PushTransport.java

@@ -250,8 +250,7 @@ public class PushTransport extends BaseTransport {
       groupBuilder.setId(ByteString.copyFrom(groupId));
       groupBuilder.setType(GroupContext.Type.DELIVER);
 
-      if (MmsSmsColumns.Types.isGroupAdd(message.getDatabaseMessageBox()) ||
+      if (MmsSmsColumns.Types.isGroupUpdate(message.getDatabaseMessageBox()) ||
-          MmsSmsColumns.Types.isGroupModify(message.getDatabaseMessageBox()) ||
           MmsSmsColumns.Types.isGroupQuit(message.getDatabaseMessageBox()))
       {
         if (messageBody != null && messageBody.trim().length() > 0) {

src/org/thoughtcrime/securesms/util/GroupUtil.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.util;
 import android.util.Log;
 
 import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
 
 import org.whispersystems.textsecure.util.Base64;
 import org.whispersystems.textsecure.util.Hex;
@@ -33,34 +34,32 @@ public class GroupUtil {
     return groupId.startsWith(ENCODED_GROUP_PREFIX);
   }
 
-  public static boolean isMetaGroupAction(int groupAction) {
+  public static String getDescription(String encodedGroup) {
-    return groupAction > 0
+    if (encodedGroup == null) {
-        && groupAction != GroupContext.Type.DELIVER_VALUE;
+      return "Group updated.";
-  }
-
-  public static String serializeArguments(byte[] id, String name, List<String> members) {
-    return Base64.encodeBytes(GroupContext.newBuilder()
-                                          .setId(ByteString.copyFrom(id))
-                                          .setName(name)
-                                          .addAllMembers(members)
-                                          .build().toByteArray());
-  }
-
-  public static String serializeArguments(GroupContext context) {
-    return Base64.encodeBytes(context.toByteArray());
-  }
-
-  public static List<String> getSerializedArgumentMembers(String serialized) {
-    if (serialized == null) {
-      return new LinkedList<String>();
     }
 
     try {
-      GroupContext context = GroupContext.parseFrom(Base64.decode(serialized));
+      String       description = "";
-      return context.getMembersList();
+      GroupContext context = GroupContext.parseFrom(Base64.decode(encodedGroup));
+      List<String> members = context.getMembersList();
+      String       title   = context.getName();
+
+      if (!members.isEmpty()) {
+        description += org.whispersystems.textsecure.util.Util.join(members, ", ") + " joined the group.";
+      }
+
+      if (title != null && !title.trim().isEmpty()) {
+        description += " Updated title to '" + title + "'.";
+      }
+
+      return description;
+    } catch (InvalidProtocolBufferException e) {
+      Log.w("GroupUtil", e);
+      return "Group updated.";
     } catch (IOException e) {
       Log.w("GroupUtil", e);
-      return new LinkedList<String>();
+      return "Group updated.";
     }
   }
 }