Zero to App: Develop with Firebase (for Android - Google I/O 2016)

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.google.firebase.zerotoapp.MainActivity">

    <RelativeLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/header"
        android:gravity="end">

        <ImageView
            android:layout_width="36dp"
            android:layout_height="36dp"
            android:background="@drawable/ic_account_box_black_24dp"
            android:id="@+id/userIcon"
            android:foregroundGravity="center"
            android:layout_alignParentStart="true"
            android:layout_alignParentLeft="true" />

        <TextView
            android:layout_width="141dp"
            android:layout_height="wrap_content"
            android:id="@+id/usernameTxt"
            android:layout_toRightOf="@+id/userIcon"
            android:layout_alignTop="@+id/userIcon"
            android:layout_alignBottom="@+id/userIcon"
            android:gravity="center_vertical"
            tools:text="Username"
            android:layout_weight="0" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Sign in"
            android:id="@+id/loginBtn"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true" />
        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Sign out"
            android:id="@+id/logoutBtn"
            android:layout_alignParentEnd="true"
            android:layout_alignParentRight="true" />
    </RelativeLayout>

    <android.support.v7.widget.RecyclerView
        android:id="@+id/messagesList"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        tools:listitem="@android:layout/two_line_list_item"
        android:layout_above="@+id/footer"
        android:layout_below="@+id/header" />

    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:id="@+id/footer">

        <ImageButton
            android:layout_width="36dp"
            android:layout_height="36dp"
            android:id="@+id/imageBtn"
            android:background="@android:drawable/ic_menu_gallery" />

        <EditText
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/messageTxt"
            android:layout_gravity="bottom"
            android:layout_weight="1"
            android:inputType="textShortMessage|textAutoCorrect" />

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Send"
            android:id="@+id/sendBtn"
            android:layout_gravity="bottom" />
    </LinearLayout>
</RelativeLayout>

build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 24
    buildToolsVersion '24'

    defaultConfig {
        applicationId "com.google.firebase.zerotoapp"
        minSdkVersion 16
        targetSdkVersion 23
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.0.0'
    compile 'com.android.support:design:24.0.0'
    compile 'com.android.support:recyclerview-v7:24.0.0'
    compile 'com.google.firebase:firebase-database:9.2.1'
    compile 'com.google.firebase:firebase-auth:9.2.1'
    compile 'com.google.firebase:firebase-storage:9.2.1'
    compile 'com.github.bumptech.glide:glide:3.7.0'
    compile 'com.firebaseui:firebase-ui-auth:0.4.3'
}
apply plugin: 'com.google.gms.google-services'

ChatMessage.java

package com.google.firebase.zerotoapp;

public class ChatMessage {
    public String name;
    public String message;

    public ChatMessage() {
    }

    public ChatMessage(String name, String message) {
        this.name = name;
        this.message = message;
    }
}

ChatMessageAdapter.java

package com.google.firebase.zerotoapp;

import android.app.Activity;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.ViewGroup;

import java.util.ArrayList;
import java.util.List;

public class ChatMessageAdapter extends RecyclerView.Adapter<ChatMessageViewHolder> {
    private static final String TAG = "ChatMessageAdapter";
    private final Activity activity;
    List<ChatMessage> messages = new ArrayList<>();

    public ChatMessageAdapter(Activity activity) {
        this.activity = activity;
    }

    public void addMessage(ChatMessage chat) {
        messages.add(chat);
        notifyItemInserted(messages.size());
    }


    @Override
    public ChatMessageViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        return new ChatMessageViewHolder(activity, activity.getLayoutInflater().inflate(android.R.layout.two_line_list_item, parent, false));
    }

    @Override
    public void onBindViewHolder(ChatMessageViewHolder holder, int position) {
        holder.bind(messages.get(position));
    }

    @Override
    public int getItemCount() {
        return messages.size();
    }
}

ChatMessageViewHolder.java

package com.google.firebase.zerotoapp;

import android.app.Activity;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import com.bumptech.glide.Glide;

public class ChatMessageViewHolder extends RecyclerView.ViewHolder {
    private static final String TAG = "ChatMessageViewHolder";
    private final Activity activity;

    TextView name, message;
    ImageView image;

    public ChatMessageViewHolder(Activity activity, View itemView) {
        super(itemView);
        this.activity = activity;
        name = (TextView) itemView.findViewById(android.R.id.text1);
        message = (TextView) itemView.findViewById(android.R.id.text2);
        image= new ImageView(activity);
        ((ViewGroup)itemView).addView(image);

    }

    public void bind(ChatMessage chat) {
        name.setText(chat.name);
        if (chat.message.startsWith("https://firebasestorage.googleapis.com/") || chat.message.startsWith("content://")) {
            message.setVisibility(View.INVISIBLE);
            image.setVisibility(View.VISIBLE);
            Glide.with(activity)
                    .load(chat.message)
                    .into(image);
        }
        else {
            message.setVisibility(View.VISIBLE);
            image.setVisibility(View.GONE);
            message.setText(chat.message);
        }
    }
}

LoginDialog.java

package com.google.firebase.zerotoapp;

import android.app.Activity;
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.text.InputType;
import android.widget.EditText;
import android.widget.LinearLayout;

import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.FirebaseApp;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;

import java.util.ArrayList;
import java.util.List;

public class LoginDialog {
    private static final String TAG = "LoginDialog";

    static List<OnSuccessListener<EmailPasswordResult>> callbacks = new ArrayList<>();

    public static void onCredentials(final OnSuccessListener<EmailPasswordResult> callback) {
        callbacks.add(callback);
    }

    public static class EmailPasswordResult {
        public String email;
        public String password;

        public EmailPasswordResult() {
        }

        public EmailPasswordResult(String email, String password) {
            this.email = email;
            this.password = password;
        }
    }

    public static void showLoginPrompt(final Activity activity, final FirebaseApp app) {
        showLoginPrompt(activity, app, null);
    }
    public static void showLoginPrompt(final Activity activity, final FirebaseApp app, final OnSuccessListener<EmailPasswordResult> callback) {
        AlertDialog.Builder builder = new AlertDialog.Builder(activity);
        builder.setTitle("What's your username");

        LinearLayout parent = new LinearLayout(activity);
        parent.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
        parent.setOrientation(LinearLayout.VERTICAL);

        final EditText email = new EditText(activity);
        email.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS);
        email.setHint("User name");
        parent.addView(email);

        final EditText password = new EditText(activity);
        password.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
        password.setHint("Password");
        parent.addView(password);

        builder.setView(parent);

        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                FirebaseAuth.getInstance(app).createUserWithEmailAndPassword(email.getText().toString(), password.getText().toString())
                        .addOnCompleteListener(activity, new OnCompleteListener<AuthResult>() {
                            public void onComplete(Task<AuthResult> task) {
                                EmailPasswordResult result = new EmailPasswordResult(email.getText().toString(), password.getText().toString());
                                if (callback != null) {
                                    callback.onSuccess(result);
                                }
                                else {
                                    for (OnSuccessListener<EmailPasswordResult> callback: callbacks){
                                        callback.onSuccess(result);
                                    }
                                }
                            }
                        });
                dialog.dismiss();
            }
        });
        builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.cancel();
            }
        });

        builder.show();
    }
}

MainActivity.java

package com.google.firebase.zerotoapp;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.FirebaseApp;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";

    static final int RC_PHOTO_PICKER = 1;

    private Button sendBtn;
    private EditText messageTxt;
    private RecyclerView messagesList;
    private ChatMessageAdapter adapter;
    private ImageButton imageBtn;
    private TextView usernameTxt;
    private View loginBtn;
    private View logoutBtn;

    private FirebaseApp app;
    private FirebaseDatabase database;
    private FirebaseAuth auth;
    private FirebaseStorage storage;

    private DatabaseReference databaseRef;
    private StorageReference storageRef;

    private String username;

    private void setUsername(String username) {
        Log.d(TAG, "setUsername("+String.valueOf(username)+")");
        if (username == null) {
            username = "Android";
        }
        boolean isLoggedIn = !username.equals("Android");
        this.username = username;
        this.usernameTxt.setText(username);
        this.logoutBtn.setVisibility(isLoggedIn ? View.VISIBLE : View.GONE);
        this.loginBtn .setVisibility(isLoggedIn ? View.GONE    : View.VISIBLE);
    }

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

        sendBtn = (Button) findViewById(R.id.sendBtn);
        messageTxt = (EditText) findViewById(R.id.messageTxt);
        messagesList = (RecyclerView) findViewById(R.id.messagesList);
        imageBtn = (ImageButton) findViewById(R.id.imageBtn);
        loginBtn = findViewById(R.id.loginBtn);
        logoutBtn = findViewById(R.id.logoutBtn);
        usernameTxt = (TextView) findViewById(R.id.usernameTxt);
        setUsername("Android");

        LinearLayoutManager layoutManager = new LinearLayoutManager(this);
        messagesList.setHasFixedSize(false);
        messagesList.setLayoutManager(layoutManager);

        // Show an image picker when the user wants to upload an imasge
        imageBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                intent.setType("image/jpeg");
                intent.putExtra(Intent.EXTRA_LOCAL_ONLY, true);
                startActivityForResult(Intent.createChooser(intent, "Complete action using"), RC_PHOTO_PICKER);
            }
        });
        // Show a popup when the user asks to sign in
        loginBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                LoginDialog.showLoginPrompt(MainActivity.this, app);
            }
        });
        // Allow the user to sign out
        logoutBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                auth.signOut();
            }
        });

        adapter = new ChatMessageAdapter(this);
        messagesList.setAdapter(adapter);
        adapter.registerAdapterDataObserver(new RecyclerView.AdapterDataObserver() {
            public void onItemRangeInserted(int positionStart, int itemCount) {
                messagesList.smoothScrollToPosition(adapter.getItemCount());
            }
        });
        
        // Get the Firebase app and all primitives we'll use
        app = FirebaseApp.getInstance();
        database = FirebaseDatabase.getInstance(app);
        auth = FirebaseAuth.getInstance(app);
        storage = FirebaseStorage.getInstance(app);
        
        // Get a reference to our chat "room" in the database
        databaseRef = database.getReference("chat");

        sendBtn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                ChatMessage chat = new ChatMessage(username, messageTxt.getText().toString());
                // Push the chat message to the database
                databaseRef.push().setValue(chat);
                messageTxt.setText("");
            }
        });
        // Listen for when child nodes get added to the collection
        databaseRef.addChildEventListener(new ChildEventListener() {
            public void onChildAdded(DataSnapshot snapshot, String s) {
                // Get the chat message from the snapshot and add it to the UI
                ChatMessage chat = snapshot.getValue(ChatMessage.class);
                adapter.addMessage(chat);
            }

            public void onChildChanged(DataSnapshot dataSnapshot, String s) { }
            public void onChildRemoved(DataSnapshot dataSnapshot) { }
            public void onChildMoved(DataSnapshot dataSnapshot, String s) { }
            public void onCancelled(DatabaseError databaseError) { }
        });
        
        // When the user has entered credentials in the login dialog
        LoginDialog.onCredentials(new OnSuccessListener<LoginDialog.EmailPasswordResult>() {
            public void onSuccess(LoginDialog.EmailPasswordResult result) {
                // Sign the user in with the email address and password they entered
                auth.signInWithEmailAndPassword(result.email, result.password);
            }
        });

        // When the user signs in or out, update the username we keep for them
        auth.addAuthStateListener(new FirebaseAuth.AuthStateListener() {
            public void onAuthStateChanged(FirebaseAuth firebaseAuth) {
                if (firebaseAuth.getCurrentUser() != null) {
                    // User signed in, set their email address as the user name
                    setUsername(firebaseAuth.getCurrentUser().getEmail());
                }
                else {
                    // User signed out, set a default username
                    setUsername("Android");
                }
            }
        });
    }

    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == RC_PHOTO_PICKER && resultCode == RESULT_OK) {
            Uri selectedImageUri = data.getData();

            // Get a reference to the location where we'll store our photos
            storageRef = storage.getReference("chat_photos");
            // Get a reference to store file at chat_photos/<FILENAME>
            final StorageReference photoRef = storageRef.child(selectedImageUri.getLastPathSegment());

            // Upload file to Firebase Storage
            photoRef.putFile(selectedImageUri)
                    .addOnSuccessListener(this, new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                            // When the image has successfully uploaded, we get its download URL
                            Uri downloadUrl = taskSnapshot.getDownloadUrl();
                            // Set the download URL to the message box, so that the user can send it to the database
                            messageTxt.setText(downloadUrl.toString());
                        }
                    });
        }
    }
}

i'm trying to do the same but facing a problem here: http://stackoverflow.com/questions/37941203/viewholder-not-setting-the-string-as-text-of-a-textview-please-see-details

best example of firebase till date.thank you very much

Really cool !

good one but facing an error on line 176 MainActivity.java You also need to update the dependencies.. Also realized the bintray.com is taking too long to respond to the sync issues.

Any tips on resolving the error? Has the firebase-ui-auth been updated to 0.6.0???

Fixed.. some imports
import com.google.firebase.storage.UploadTask was missing

Hi, do you mind helping me with the implementation that I did. I have been trying to solve it for a while now with no luck and no one seems to know where I went wrong...
http://stackoverflow.com/questions/41616312/nosuchmethodexception-while-using-firebaseui-recycleradapter/