push notification, chat message

private ArrayList<Conversation> mConversationArrayList;
private ChatAdapter mChatAdapter;
private EditText mChatEditText;
private String mBuddy;
private ListView mChatMessageList;
private Button mSendChatMessageButton;
private Date mLastMessageDate;
private boolean isRunning;
private static Handler mHandler;
private String chatMessage;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_chat);

    // ConvertList
    mConversationArrayList = new ArrayList<Conversation>();
    mChatMessageList = (ListView) findViewById(R.id.chatMessageList);

    // Adapter into ListView
    mChatAdapter = new ChatAdapter(this, mConversationArrayList);
    mChatMessageList.setAdapter(mChatAdapter);
    mChatMessageList.setTranscriptMode(AbsListView.TRANSCRIPT_MODE_ALWAYS_SCROLL);
    mChatMessageList.setStackFromBottom(true);

    // UserName
    TextView ChatUserName = (TextView) findViewById(R.id.chatUserName);
    mBuddy = getIntent().getStringExtra(ParseConstants.EXTRA_DATA);
    ChatUserName.setText(mBuddy);

    mChatEditText = (EditText) findViewById(R.id.chatMessageText);
    mChatEditText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_FLAG_MULTI_LINE);

    mHandler = new Handler();

    mSendChatMessageButton = (Button) findViewById(R.id.sendChatMessageButton);
    mSendChatMessageButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            sendMessage();
        }
    });
}

@Override
protected void onResume() {
    super.onResume();
    isRunning = true;
    loadConversationList();
}

@Override
protected void onPause() {
    super.onPause();
    isRunning = false;
}

protected void sendMessage() {
    // Toast.makeText(this, "Send Message OK", Toast.LENGTH_LONG).show();
    if (mChatEditText.length() == 0) {
        return;
    }

    InputMethodManager inputMethodManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    inputMethodManager.hideSoftInputFromWindow(mChatEditText.getWindowToken(), 0);

    chatMessage = mChatEditText.getText().toString();
    final Conversation conversation = new Conversation(chatMessage, new Date(),
            FriendsFragment.mCurrentUser.getUsername());
    conversation.setStatus(Conversation.STATUS_SENDING);
    mConversationArrayList.add(conversation);
    mChatAdapter.notifyDataSetChanged();
    mChatEditText.setText(null);

    ParseObject parseObject = new ParseObject(ParseConstants.CLASS_CHAT);
    parseObject.put(ParseConstants.KEY_SENDER, FriendsFragment.mCurrentUser.getUsername());
    parseObject.put(ParseConstants.KEY_RECEIVER, mBuddy);
    parseObject.put(ParseConstants.KEY_MESSAGE_BODY, chatMessage);
    parseObject.saveEventually(new SaveCallback() {
        @Override
        public void done(ParseException e) {
            if(e == null) {
                conversation.setStatus(Conversation.STATUS_SENT);
                Toast.makeText(ChatActivity.this, com.oikostudio.famchat.R.string.success_message, Toast.LENGTH_LONG).show();
                sendPushNotification();
            } else {
                conversation.setStatus(Conversation.STATUS_FAILED);
            }
            mChatAdapter.notifyDataSetChanged();
        }
    });
}

public void sendPushNotification() {
    ParseQuery<ParseInstallation> query = ParseInstallation.getQuery();
    // query.whereContainedIn(ParseConstants.KEY_USER_ID, getRecipientIds());

    // send push notification
    ParsePush push = new ParsePush();
    push.setQuery(query);
    push.setMessage(getString(R.string.push_message, ParseUser.getCurrentUser().getUsername()));
    push.sendInBackground();
}


protected void loadConversationList() {
    ParseQuery<ParseObject> query = ParseQuery.getQuery(ParseConstants.CLASS_CHAT);
    if (mConversationArrayList.size() == 0) {
        // load all Messages
        ArrayList<String> messageAll = new ArrayList<String>();
        messageAll.add(mBuddy);
        messageAll.add(FriendsFragment.mCurrentUser.getUsername());
        query.whereContainedIn(ParseConstants.KEY_SENDER, messageAll);
        query.whereContainedIn(ParseConstants.KEY_RECEIVER, messageAll);

    } else {
        // load only newly received msg
        if(mLastMessageDate != null)
            query.whereGreaterThan(ParseConstants.KEY_CREATED_AT, mLastMessageDate);
        query.whereEqualTo(ParseConstants.KEY_SENDER, mBuddy);
        query.whereEqualTo(ParseConstants.KEY_RECEIVER, FriendsFragment.mCurrentUser.getUsername());
    }
    query.orderByDescending(ParseConstants.KEY_CREATED_AT);
    query.setLimit(30);
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> chatMessageBody, ParseException e) {
            if(chatMessageBody != null && chatMessageBody.size() > 0) {
                for (int i = chatMessageBody.size() - 1; i >= 0; i--) {
                    ParseObject messageBody = chatMessageBody.get(i);
                    Conversation conversation = new Conversation(
                            messageBody.getString(ParseConstants.KEY_MESSAGE_BODY),
                            messageBody.getCreatedAt(), messageBody.getString(ParseConstants.KEY_SENDER));
                    mConversationArrayList.add(conversation);
                    if(mLastMessageDate == null || mLastMessageDate.before(conversation.getDate()))
                        mLastMessageDate = conversation.getDate();
                    mChatAdapter.notifyDataSetChanged();
                }
            }
            mHandler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    if(isRunning) {
                        loadConversationList();
                    }
                }
            }, 1000);
        }
    });
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_chat, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    if (item.getItemId() == android.R.id.home)
    {
        finish();
    }
    return super.onOptionsItemSelected(item);
}

    // send push notification
    ParsePush push = new ParsePush();
    push.setQuery(query);
    push.setMessage(getString(R.string.push_message, ParseUser.getCurrentUser().getUsername()));
    push.sendInBackground();
}