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Android Studio - Chat not displaying

Main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="16dp"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:paddingTop="16dp"
android:id="#+id/activity_main"
tools:context="com.example.syafiq.mychatapp.MainActivity">
<android.support.design.widget.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:clickable="true"
android:src="#drawable/ic_send"
android:id="#+id/fab"
android:tint="#android:color/white"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
app:fabSize="mini"
/>
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_toLeftOf="#+id/fab"
android:layout_alignParentBottom="true"
android:layout_alignParentEnd="true"
>
<EditText
android:id="#+id/messageinput"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/fab"
android:layout_centerHorizontal="true"
android:hint="Message..." />
</android.support.design.widget.TextInputLayout>
<ListView
android:id="#+id/list_of_message"
android:layout_alignParentTop="true"
android:layout_alignParentStart="true"
android:layout_above="#+id/fab"
android:dividerHeight="16dp"
android:divider="#android:color/transparent"
android:layout_marginBottom="16dp"
android:layout_width="match_parent"
android:layout_height="match_parent">
</ListView>
Maincode
private static int SIGN_IN_REQUEST_CODE =1;
//private List<ChatMessage> list = new ArrayList<ChatMessage>();
FirebaseListAdapter<ChatMessage> adapter;
RelativeLayout activity_main;
FloatingActionButton fab;
FirebaseDatabase db = FirebaseDatabase.getInstance();
DatabaseReference myRef = db.getReference("message");
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
if (item.getItemId() == R.id.menu_signout)
{
AuthUI
.getInstance()
.signOut(this)
.addOnCompleteListener(
new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task)
{
Snackbar
.make(
activity_main,
"You have been signed out.",
Snackbar.LENGTH_SHORT
).show()
;
finish();
}
}
)
;
}
return true;
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
super.onActivityResult(requestCode, resultCode, data);
if (resultCode==SIGN_IN_REQUEST_CODE)
{
if (resultCode==RESULT_OK)
{
Snackbar
.make(
activity_main,
"Successfully signed in!",
Snackbar.LENGTH_SHORT
).show()
;
displayChatMessage();
}
else
{
Snackbar
.make(
activity_main,
"We couldn't sign you in. Please try again lter!",
Snackbar.LENGTH_SHORT
).show()
;
finish();
}
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
getMenuInflater().inflate(R.menu.main_menu,menu);
return true;
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
activity_main = (RelativeLayout) findViewById(R.id.activity_main);
fab = (FloatingActionButton) findViewById(R.id.fab);
fab
.setOnClickListener(
new View.OnClickListener()
{
#Override
public void onClick(View v)
{
EditText input = (EditText) findViewById(R.id.messageinput);
FirebaseDatabase
.getInstance()
.getReference()
.push()
.setValue(
new ChatMessage(
input.getText().toString(),
FirebaseAuth.getInstance().getCurrentUser().getEmail()
)
)
;
input.setText("");
displayChatMessage();
}
}
)
;
if (FirebaseAuth.getInstance().getCurrentUser()== null)
{
startActivityForResult(
AuthUI
.getInstance()
.createSignInIntentBuilder()
.build(),
SIGN_IN_REQUEST_CODE
);
}
else
{
Snackbar
.make(
activity_main,
"Welcome " + FirebaseAuth
.getInstance()
.getCurrentUser()
.getEmail(),
Snackbar.LENGTH_SHORT
).show()
;
//displayChatMessage();
}
}
DisplaychatMessage() function to display my chat message
private void displayChatMessage() {
Query query = FirebaseDatabase.getInstance().getReference().child("Chats");
ListView listofmsgs = (ListView) findViewById(R.id.list_of_message);
FirebaseListOptions<ChatMessage> options = new FirebaseListOptions
.Builder<ChatMessage>()
.setQuery(query, ChatMessage.class)
.setLayout(R.layout.list_item)
.build()
;
//adapter.startListening();
Log.d("ErrorCheck", "1");
adapter = new FirebaseListAdapter<ChatMessage>(options) {
#Override protected void populateView(View v, ChatMessage model, int position) {
//ChatMessage cm = (ChatMessage) model;
TextView messageText, messageUser, messageTime;
messageText = (TextView) v.findViewById(R.id.messageinput);
messageUser = (TextView) v.findViewById(R.id.message_user);
messageTime = (TextView) v.findViewById(R.id.message_time);
messageText.setText(model.getMessageText().toString());
messageUser.setText(model.getMessageUser());
messageTime
.setText(
android.text.format.DateFormat.format(
"dd-mm-yyyy (HH:mm:ss)",
model.getMessageTime()
)
)
;
Log.d("ErrorCheck", "2");
}
};
listofmsgs.setAdapter(adapter);
adapter.startListening();
}
Hi guys, i did this but it doesn't seem like anything appear on my APP. But the then, when i press send, in my database, my chat appears there but again it doesn't appear on my Chat app. I did a debug log. Errorcheck 1, and 2 to see where the code ends. When i checked, looks like the debug log only display up till ErrorCheck 1 and does not display display 2. How do i solve this?

You've put ErrorCheck 2 in something called an anonymous class. That's why calling your displayChatMessage() will only log ErrorCheck 1. The code in the anonymous FirebaseListAdapter class you defined will only run when it's populateView() method is called. You don't call that method. You call adapter.startListening(); Something, somewhere, needs to call adapter.populateView() before you'll see ErrorCheck 2 logged.
You likely don't want to call it here. You can call it here just for a test but you should track down what is supposed to be calling it.
According to the docs about FirebaseListAdapter
This class is a generic way of backing an Android ListView with a Firebase location. It handles all of the child events at the given Firebase location. It marshals received data into the given class type. Extend this class and provide an implementation of populateView, which will be given an instance of your list item mLayout and an instance your class that holds your data. Simply populate the view however you like and this class will handle updating the list as the data changes.
So trying changing the data and see if that makes you log ErrorCheck 2

NullPointerException when try change text in textView from other class

Can u help me understand why when I want set text in TextView, I got NullPointerException? I know, because my TextView is null but how I can get TextView again?
What is my logic:
Start Application
Click button
Go to nullPoint and get data from firebase, when the proccessing is finished back to MainActivity and update text in TextView.
This is my example code:
MainActivity
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnAddNewWord = findViewById(R.id.button);
btnAddNewWord.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
nullPoint np = new nullPoint();
np.takeCount();
}
});
}
public void setTextView(int count){
TextView tv = findViewById(R.id.textView);
tv.setText("count = " + count);
}
}
nullPoint
public class nullPoint {
//the class gets asynchronous data from the Firebase database and does not know when the process will end
public void takeCount(){
//det data
//.
//.
// finish
//send data to MainActivity and update textView text
MainActivity ma = new MainActivity();
ma.setTextView(5);
}
}
XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"
android:layout_gravity="center">
<TextView
android:id="#+id/textView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!"
android:layout_gravity="center"/>
<Button
android:id="#+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
android:layout_gravity="center"/>
</LinearLayout>

I guess the nullPoint class is not inside the MainActivity. As a result, inside your nullPoint class there is no reference for the TextView in which you are trying to set a data.
In your case I would like to suggest you to implement a listener like the following.
public interface FirebaseResponseListener {
void onFirebaseResponseReceived(int count);
}
Now from your MainActivity, you need to implement the listener as follows.
public class MainActivity extends AppCompatActivity implements FirebaseResponseListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnAddNewWord = findViewById(R.id.button);
btnAddNewWord.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
nullPoint np = new nullPoint();
np.listener = this; // Initialize the listener here
np.takeCount();
}
});
}
public void setTextView(int count){
TextView tv = findViewById(R.id.textView);
tv.setText("count = " + count);
}
#Override
void onFirebaseResponseReceived(int count) {
setTextView(count);
}
}
And you have to add a listener in your nullPoint class as well.
public class nullPoint {
public FirebaseResponseListener listener;
//the class gets asynchronous data from the Firebase database and does not know when the process will end
public void takeCount(){
//det data
//.
//.
// finish
//send data to MainActivity and update textView text
listener.onFirebaseResponseReceived(5);
}
}
Hope that solves your problem.

How to animate view to slide down and push down everything below it?

So I have looked into how to animate fade and drop down/slide up animations of Views using this thread, however it didn't quite work as expected. To begin with, here is the code I use for the animating:
public void toggleAdvancedVisibility(View text) { //text is a clickable textview thats acts as a toggle
int dur = 1000;
final View advView = findViewById(R.id.enc_advanced);
if(advView.getVisibility() == View.GONE && animationDone) {
advView.setVisibility(View.VISIBLE);
advView.setAlpha(0.0f);
//animate fade + drop down
advView.animate()
.setDuration(dur)
.translationY(advView.getHeight())
.alpha(1.0f)
.setListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
animationDone = true;
}
});
animationDone=false;
}
else if(advView.getVisibility() == View.VISIBLE && animationDone) {
//animate fade + slide up
advView.animate()
.setDuration(dur)
.translationY(0)
.alpha(0.0f)
.setListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animation) {
super.onAnimationEnd(animation);
advView.setVisibility(View.GONE);
animationDone = true;
}
});
animationDone = false;
}
}
As I said, while there was animation, it didn't act anywhere near as expected.
Problem #1
The view is almost pushed out of visibility. I believe that this is due to the line .translationY(advView.getHeight()) as if I set the location of the view before the animation to advView.setTranslationY(-advView.getHeight()) and then animate .translationY(0) it goes to where it is supposed to.
The obvious problem with this is that while the view is animating, the view "collides" with the view above it before it is done. So how do I properly get this to slide down/up without running into the view above it?
Problem #2
The animation doesn't exactly "push" the view down, which is what I expected. What I mean by this is that the view being animated also has a view below it. I expected the view below it to be pushed down with the animated view. While I haven't tried it yet, I assume this can be simulated by setting the same animation to the view below it, but is there another way of doing it?
I am very new to this animation stuff and manipulating Views like this so any help is appreciated.

I made you a short example and I see it pushes down the rest of the view.
xml:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.teststuff.MainActivity"
android:orientation="vertical">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/b1"
android:text="show"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/tv1"
android:text="Hello World!"
android:visibility="gone"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hello World!!!!"/>
and here is the .java:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv1 = (TextView) findViewById(R.id.tv1);
tv2 = (TextView) findViewById(R.id.tv2);
b1 = (Button) findViewById(R.id.b1);
b1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (tv1.isShown()){
tv1.startAnimation(slideInAnimation(view));
tv1.setVisibility(View.GONE);
}
else {
tv1.startAnimation(slideOutAnimation(view));
tv1.setVisibility(View.VISIBLE);
}
}
});
}
private TranslateAnimation slideOutAnimation(View view){
TranslateAnimation animate = new TranslateAnimation(0,0,-view.getHeight(),0);
animate.setDuration(500);
animate.setFillAfter(false);
return animate;
}
private TranslateAnimation slideInAnimation(View view){
TranslateAnimation animate = new TranslateAnimation(0,0,0,-view.getHeight());
animate.setDuration(500);
animate.setFillAfter(true);
return animate;
}
It works fine for me.

Trying to set OnTouchListener to multiple ImageViews using ArrayLists

I'm trying for quite a long time to set OnTouchListener to multiple ImageViews using ArrayLists but my Application keeps on crushing down. This is my code:
MainActivity:
public class MainActivity extends AppCompatActivity {
private DragAndDrop dragAndDrop;
private InstantiateImages instantiateImages;
private ArrayList<ImageView> faces = new ArrayList<ImageView>();
private int i;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dragAndDrop = new DragAndDrop();
InstantiateImages instantiateImages = new InstantiateImages(this);
//Add elements to ArrayLists:
instantiateImages.Add();
//Get elements into ArrayLists:
faces = instantiateImages.getFaces();
for (i = 0; i< faces.size(); i++) {
faces.get(i).setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
//Follow the touch on the ImageView and move the
//ImageView accordingly:
dragAndDrop.action(v, event, faces.get(i));
return true;
}
});
}
}
}
InstantiateImages Class:
public class InstantiateImages {
this.activity = activity;
private ArrayList<ImageView> faces = new ArrayList<ImageView>();
//Faces declarations:
private ImageView FacesNoFace;
InstantiateEmojis() {
//Faces instantiations:
FacesNoFace = (ImageView)this.activity.findViewById(R.id.faces_no_face);
}
public void Add() {
//Add faces to ArrayList faces:
faces.add(FacesNoFace);
}
//Getters:
//Get Faces:
public ArrayList<ImageView> getFaces() {
return faces;
}
}
XML of layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="myproject.myproject.MainActivity"
tools:layout_editor_absoluteY="81dp"
tools:layout_editor_absoluteX="0dp"
tools:background="#ffffff">
<ImageView
android:id="#+id/faces_no_face"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:contentDescription=""
app:srcCompat="#drawable/faces_no_face"
tools:ignore="ContentDescription"
tools:layout_editor_absoluteX="16dp"
tools:layout_editor_absoluteY="16dp" />
</android.support.constraint.ConstraintLayout>
The DragAndDrop Class is a class that only has a method which follows the ImageView drag and drop (the inside/heart of the OnTouchListener) and before I tried to put the ImageView inside of the ArrayList "faces" which I created in the "InstantiateImages" Class I instentiate the OnTouchListener only on one ImageView (the one I added to the ArrayList now) and it worked totaly fine (I could drag and drop the ImageView arround the app screen). Now the Application is crushing after I Run it and it says: "MyProject keep stopping close app" or "MyProject Has stoped reopen app".
Any Help would be appreciated!!

I think you are overcomplicating parts of this. I think this will do what you're trying to do.
public class MainActivity extends AppCompatActivity {
private DragAndDrop dragAndDrop;
private final ArrayList<ImageView> faces = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
dragAndDrop = new DragAndDrop();
faces.add((ImageView) findViewById(R.id.faces_no_face));
for (ImageView face : faces) {
face.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
//Follow the touch on the ImageView and move the
//ImageView accordingly:
dragAndDrop.action(v, event, (ImageView) v);
return false;
}
});
}
}
}
If you are planning on having a variable number of ImageViews that you want to listen to clicks on, you might want to look into RecyclerView and Lists.

How can I transfer some value between activities in Android

I tried to send a int value from current activity to the new one, here is the parts in current activity.
dialog.setPositiveButton("4 players", new OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "Start a new game!", Toast.LENGTH_SHORT).show();
// need send extra value to PlayerBoardActivity to decide how many buttons I should have
Intent intent = new Intent(MainActivity.this,
PlayBoardActivity.class);
intent.putExtra(PLAYER_NO, 4);
startActivity(intent);
}
});
dialog.setNegativeButton("2 players", new OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this, "Start a new game!", Toast.LENGTH_SHORT).show();
// need send extra value to PlayerBoardActivity to decide how many buttons I should have
Intent intent = new Intent(MainActivity.this,
PlayBoardActivity.class);
intent.putExtra(PLAYER_NO, 2);
startActivity(intent);
}
});
The problem is, I create 2 layout files for the new activity. When I press the negative button in the dialog for example, what I want is let the new activity (PlayerBoardActivity in my case) load the layout file corresponding to the value I have sent by "intent.putExtra(PLAYER_NO, 2); "
The code in the new activity is
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final String PLAYER_NO = "the number of players";
Bundle b = getIntent().getExtras();
int a = b.getInt(PLAYER_NO);
if (b != null) {
if (a == 2) {
setContentView(R.layout.two_player);
}
if(a == 4){
setContentView(R.layout.four_player);
}
}
}
I do want to know whether I can load different layout file in this way? Or is there any better solution for my problem.
Thank you all in advance.

If you use
intent.putExtra(PLAYER_NO, 2);
you should call following code to get values (without using "Bundle"):
getIntent().getIntExtra(PLAYER_NO, -1)

In your code, the problem is in your second activity to which you are calling.
You are trying to fetching the values from intent in incorrect way.
Try this in your second activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Intent intent = getIntent();
int b = intent.getIntExtra(PLAYER_NO, 0);
if (b == 2) {
setContentView(R.layout.two_player);
}
if(b == 4){
setContentView(R.layout.four_player);
}
}

Ji Yang... it is fine..if both the layout content the same kind of structure and dealing with different resources of any layout in the same activity is not so difficult..
suppose layout two_player.xml is
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="6dp"
android:paddingLeft="12dp"
android:paddingRight="12dp"
android:orientation="vertical">
<TextView
android:id="#+id/textview1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#777370"
android:textSize="16sp"
android:paddingLeft="5dp"
android:text="Dummy Text"
android:visibility="gone"
android:textStyle="bold"/>
</RelativeLayout>
and layout four_player.xml is something like that
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="6dp"
android:paddingLeft="12dp"
android:paddingRight="12dp"
android:orientation="vertical">
<ImageView
android:id="#+id/iv1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/order_content"
android:src="#drawable/order_next_sap"
android:layout_alignLeft="#+id/order_content"/>
<ImageView
android:id="#+id/iv2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/order_content"
android:src="#drawable/order_next_sap"
android:layout_alignLeft="#+id/order_content"/>
</RelativeLayout>
means ...both layout of different defination.. than its difficult to use resource of both layout in same activity and its not good too..
The better solution in this case is to create fragment of both layout
class TwoPlayerFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.two_player, container, false);
return v;
}
}
class FourPlayerFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v=inflater.inflate(R.layout.four_player, container, false);
return v;
}
}
and use the fragment according to the intent value pass from dialog..

try this,
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final String PLAYER_NO = "the number of players";
Intent b = getIntent();
int a = b.getExtras().getInt(PLAYER_NO);
if (b != null) {
if (a == 2) {
setContentView(R.layout.two_player);
}
if(a == 4){
setContentView(R.layout.four_player);
}
}
}

You are doing very wrong way. You should use fragment for this. You should create two fragment in which you can inflate different different layout. But this is your call.
From PlayBoardActivity you are sending data like :
intent.putExtra(PLAYER_NO, 4);
So in new activity you need to retreive like:
int b=getIntent.getIntExtra(PLAYER_NO,defaulValue);
you are trying to get value from bundle which is wrong.