MyChat

//////////// Java classes /////////////
// ----------- MainActivity.java ------

package com.sgl.mychat;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;

import com.backendless.Backendless;

import static com.sgl.mychat.Defaults.*;

public class MainActivity extends AppCompatActivity {

    private EditText userNameEditText;

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

        Backendless.setUrl(SERVER_URL);
        Backendless.initApp(this, MY_APPLICATION_ID, MY_API_KEY);

        userNameEditText = findViewById(R.id.user_name);

        findViewById(R.id.start_chat_button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                startChat();
            }
        });
    }

    private void startChat() {
        Intent intent = new Intent(this, ChatRoomActivity.class);
        String name = userNameEditText.getText().toString();
        intent.putExtra("name", name);
        startActivity(intent);
    }
}

// ------------- ChatRoomActivity.java --------------------

package com.sgl.mychatroom;

import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.media.MediaPlayer;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.Html;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;

import com.backendless.Backendless;
import com.backendless.async.callback.AsyncCallback;
import com.backendless.exceptions.BackendlessFault;
import com.backendless.messaging.MessageStatus;
import com.backendless.rt.messaging.Channel;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;

public class ChatRoomActivity extends AppCompatActivity {

    public static final String TAG = "RTChat";
    private EditText message;
    private TextView messages;
    private Channel channel;
    private String color = ColorPickerUtility.next();
    protected Spinner spinner;
    private static final String BACKENDLESS_URL = "https://api.backendless.com/644E29B8-6584-ADE2-FF90-B401C64BFC00/2231FF77-0AE4-4DDD-98EB-63D17FE98AC6/services/VoiceTranslator/VoiceTranslator";
    private static final String BACKENDLESS_TRANS = "https://api.backendless.com/644E29B8-6584-ADE2-FF90-B401C64BFC00/2231FF77-0AE4-4DDD-98EB-63D17FE98AC6/services/VoiceTranslator/Translate";
    private String transText;
    String lang;
    private MediaPlayer mediaPlayer;


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

    private void setPointer() {
        message = findViewById(R.id.message);
        messages = findViewById(R.id.messages);
        transText = "";
        lang = "en"; // Default language set to english
        spinner = (Spinner)findViewById(R.id.languages);
        // Create an array adapter using the string array and a default spinner layout
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this, R.array.languages, android.R.layout.simple_spinner_item);
        // Specify the layout to use when the list of choices appears
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // Apply the adapter to the spinner
        spinner.setAdapter(adapter);
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                // Retrieving the language from the selected item
                lang = parent.getItemAtPosition(position).toString();
                Log.e(TAG, "onItemSelected: " + lang );
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
        final String name = getIntent().getStringExtra("name");

        // Subscribe to a room
        channel = Backendless.Messaging.subscribe(Defaults.DEFAULT_CHANNEL);
        // Join to a room
        channel.addJoinListener(new AsyncCallback<Void>() {
            @Override
            public void handleResponse(Void response) {
                Backendless.Messaging.publish(Defaults.DEFAULT_CHANNEL, wrapToColor(name) + " joined", new AsyncCallback<MessageStatus>() {
                    @Override
                    public void handleResponse(MessageStatus response) {
                        Log.d(TAG, "handleResponse: sent joined " + response );
                    }

                    @Override
                    public void handleFault(BackendlessFault fault) {
                        ChatRoomActivity.this.handleFault(fault);
                    }
                });

                channel.addMessageListener(new AsyncCallback<String>() {
                    @Override
                    public void handleResponse(String response) {
                        messages.append(Html.fromHtml("<br/>" + response));
                    }

                    @Override
                    public void handleFault(BackendlessFault fault) {
                        ChatRoomActivity.this.handleFault(fault);
                    }
                });

                message.setOnEditorActionListener(new TextView.OnEditorActionListener() {
                    @SuppressLint("StaticFieldLeak")
                    @Override
                    public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                        final boolean[] handled = {false};
                        if(actionId == EditorInfo.IME_ACTION_SEND || event.getKeyCode() == KeyEvent.KEYCODE_ENTER) {
                            // Don't allow the user to enter messages
                            message.setEnabled(false);

                            final String transUrl = buildUrl(BACKENDLESS_TRANS, message.getText().toString(), getPreferredLanguage(lang));
                            new AsyncTask<String, Void, String>() {

                                @Override
                                protected String doInBackground(String... strings) {
                                    HttpURLConnection urlConnection = null;
                                    StringBuilder result = new StringBuilder();
                                    try {
                                        URL url = new URL(transUrl);
                                        urlConnection = (HttpURLConnection)url.openConnection();
                                        int statusCode = urlConnection.getResponseCode();
                                        if(statusCode == 200) {
                                            InputStream inputStream = new BufferedInputStream(urlConnection.getInputStream());
                                            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                                            String line;
                                            while((line = bufferedReader.readLine()) != null) result.append(line);
                                            inputStream.close();
                                            return result.toString();
                                        } else {
                                            Log.e("Network Error", "doInBackground: The request responded with code " + statusCode + "; " + urlConnection.getResponseMessage());
                                        }
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    } finally {
                                        assert urlConnection != null;
                                        urlConnection.disconnect();
                                    }
                                    return result.toString();
                                }

                                @Override
                                protected void onPostExecute(final String be_response) {
                                    Backendless.Messaging.publish(Defaults.DEFAULT_CHANNEL, wrapToColor("[" + name + "]") + ": "
                                            + be_response, new AsyncCallback<MessageStatus>() {
                                        @Override
                                        public void handleResponse(MessageStatus response) {
                                            Log.d(TAG, "sent message: " + response );
                                            message.setText("", TextView.BufferType.EDITABLE);
                                            message.setEnabled(true);
                                            Log.e(TAG, "FINAL RESOURCES: " + transText + "; " + lang + "; " + getPreferredLanguage(lang));
                                            getSoundUrl(be_response, getPreferredLanguage(lang), "FEMALE");
                                        }

                                        @Override
                                        public void handleFault(BackendlessFault fault) {
                                            ChatRoomActivity.this.handleFault(fault);
                                            message.setEnabled(true);
                                        }
                                    });
                                    handled[0] = true;
                                }
                            }.execute();
                        }
                        return handled[0];
                    }
                });
            }

            @Override
            public void handleFault(BackendlessFault fault) {
                ChatRoomActivity.this.handleFault(fault);
            }
        });
    }

    private void getSoundUrl(String textToSpeech, String language, String isFemale) {
        String transVoiceUrl = buildUrl(BACKENDLESS_URL, textToSpeech, language, isFemale);
        getUrl(transVoiceUrl, true);
    }

    @SuppressLint("StaticFieldLeak")
    private void getUrl(final String requestUrl, final boolean b) {
        transText = "";
        new AsyncTask<String, Void, String>() {

            @Override
            protected String doInBackground(String... strings) {
                HttpURLConnection urlConnection = null;
                StringBuilder result = new StringBuilder();
                try {
                    URL url = new URL(requestUrl);
                    urlConnection = (HttpURLConnection)url.openConnection();
                    int statusCode = urlConnection.getResponseCode();
                    if(statusCode == 200) {
                        InputStream inputStream = new BufferedInputStream(urlConnection.getInputStream());
                        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                        String line;
                        while((line = bufferedReader.readLine()) != null) result.append(line);
                        inputStream.close();
                        return result.toString();
                    } else {
                        Log.e("Network Error", "doInBackground: The request responded with code " + statusCode + "; " + urlConnection.getResponseMessage());
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                } finally {
                    assert urlConnection != null;
                    urlConnection.disconnect();
                }
                return result.toString();
            }

            @Override
            protected void onPostExecute(String be_response) {
                playSound(be_response);
            }
        }.execute();
    }

    private String buildUrl(String backUrl, String textToSpeech, String language, String isFemale) {
        String resUrl;
        try {
            textToSpeech = URLEncoder.encode(textToSpeech.trim(), "UTF-8");
            language = URLEncoder.encode(language.trim(), "UTF-8");
            if(isFemale != null) {
                isFemale = URLEncoder.encode(isFemale.trim(), "UTF-8");
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        resUrl = backUrl + "?text=" + textToSpeech + "&lang=" + language;
        if(isFemale != null) resUrl.concat("&isFemale=" + isFemale);
        Log.i("FULL_URL", "buildUrl: " + resUrl);
        return resUrl;
    }

    private String buildUrl(String backUrl, String textToSpeech, String language) {
        return buildUrl(backUrl, textToSpeech, language, null);
    }

    private void playSound(String myUrl) {
        final MediaPlayer mediaPlayer = new MediaPlayer();
        try {
            Log.e("myUrl", "playSound: " + myUrl.replace("\"", ""));
            mediaPlayer.setDataSource(myUrl.replace("\"", ""));
            mediaPlayer.prepareAsync();
            mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

                @Override
                public void onPrepared(MediaPlayer mp) {
                    mp.start();
                }

            });
            mediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mp) {
                    mp.reset();
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private String wrapToColor(String value) {
        return "<font color='" + color + "'>" + value + "</font>";
    }

    private void handleFault(BackendlessFault fault) {
        Log.e(TAG, fault.toString());
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if(channel != null) {
            channel.leave();
        }
        if(mediaPlayer != null) {
            mediaPlayer.release();
        }
    }

    private String getPreferredLanguage(String str) {
        String lng = "";
        switch(str) {
            case "Russian":
                lng = "ru";
                break;
            case "Spanish":
                lng = "es";
                break;
            case "French":
                lng = "fr";
                break;
            case "German":
                lng = "de";
                break;
            case "Italian":
                lng = "it";
                break;
            case "Hebrew":
                lng = "iw";
                break;
            default:
                lng = "en";
                break;
        }
        return lng;
    }
}

// ---------------- Defaults.java --------------------

package com.sgl.mychat;

public class Defaults {

    public static final String SERVER_URL = "https://api.backendless.com";

    public static final String MY_APPLICATION_ID = "APP_ID";
    public static final String MY_API_KEY = "API_KEY";

    public static final String DEFAULT_CHANNEL = "EranAndDaniel";
}

// ---------- ColorPickerUtility --------------

package com.sgl.mychat;

import java.util.Random;

public class ColorPickerUtility {

    //private static final String[] colors = new String[]{"#b1ffb0", "#660002", "#191970", "#f38630", "#057e95", "#7bb020"};
    private static final Random random = new Random();
    public static String next() {
        String acceptableChars = "0123456789ABCDEF";
        String color = "#";
        for(int i = 0; i < 6; i++) {
            color += Character.toString(acceptableChars.charAt(random.nextInt(acceptableChars.length()-1)));
        }
        return color;
    }
}

/////////////// XML files ////////////////
// ----------- activity_main.xml ----------

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:gravity="center_horizontal"
        android:padding="16dp">
        <!-- Login progress -->
        <ProgressBar
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginBottom="8dp"
            style="?android:attr/progressBarStyleLarge"
            android:visibility="gone"/>
        <ScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/login_form">
            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="vertical"
                android:id="@+id/email_login_form">
                <EditText
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:id="@+id/user_name"
                    android:hint="user name"
                    android:inputType="text"
                    android:maxLines="1"
                    android:singleLine="true"/>
                <Button
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:id="@+id/start_chat_button"
                    style="?android:textAppearanceSmall"
                    android:layout_marginTop="16dp"
                    android:text="Start chat"
                    android:textStyle="bold"
                    android:background="#9C27B0"
                    android:textColor="#FFFFFF"/>
            </LinearLayout>
        </ScrollView>

    </LinearLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

// ----------- activity_chat_room.xml -------------

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".ChatRoomActivity">
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center_horizontal"
        android:padding="16dp">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentTop="true"
            android:orientation="horizontal">
            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:id="@+id/title"
                android:text="Welcome to the chat room"
                android:layout_marginEnd="20dp"
                android:textSize="20sp"/>
            <Spinner
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:gravity="right"
                android:id="@+id/languages"/>
        </LinearLayout>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:id="@+id/messages"
            android:text=""
            android:layout_marginTop="50dp"
            android:layout_marginBottom="50dp"/>
        <EditText
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:id="@+id/message"
            android:hint="message"
            android:imeOptions="actionSend"
            android:inputType="text"
            android:maxLines="1"
            android:singleLine="true"
            android:layout_alignParentBottom="true"/>
    </RelativeLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

///////////////// values ////////////
// ------------- strings.xml -------------

<resources>
    <string name="app_name">MyChat</string>
    <string-array name="languages">
        <item>English</item>
        <item>Russian</item>
        <item>Spanish</item>
        <item>French</item>
        <item>Italian</item>
        <item>German</item>
    </string-array>
</resources>