new GUI for App

gui/src/androidTest/java/com/example/gui/ExampleInstrumentedTest.java

+package com.example.gui;
+
+import android.content.Context;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.*;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+public class ExampleInstrumentedTest {
+    @Test
+    public void useAppContext() {
+        // Context of the app under test.
+        Context appContext = InstrumentationRegistry.getTargetContext();
+
+        assertEquals("com.example.gui", appContext.getPackageName());
+    }
+}

gui/src/main/AndroidManifest.xml

+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.example.gui">
+    <!-- To auto-complete the email text field in the login form with the user's emails -->
+    <uses-permission android:name="android.permission.GET_ACCOUNTS" />
+    <uses-permission android:name="android.permission.READ_PROFILE" />
+    <uses-permission android:name="android.permission.READ_CONTACTS" />
+    <uses-permission android:name="android.permission.INTERNET" />
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/AppTheme">
+        <activity
+            android:name=".LoginActivity"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>
\ No newline at end of file

gui/src/main/java/com/example/gui/LoginActivity.java

+package com.example.gui;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.annotation.TargetApi;
+import android.content.pm.PackageManager;
+import android.support.annotation.NonNull;
+import android.support.design.widget.Snackbar;
+import android.support.v7.app.AppCompatActivity;
+import android.app.LoaderManager.LoaderCallbacks;
+
+import android.content.CursorLoader;
+import android.content.Loader;
+import android.database.Cursor;
+import android.net.Uri;
+import android.os.AsyncTask;
+
+import android.os.Build;
+import android.os.Bundle;
+import android.provider.ContactsContract;
+import android.text.TextUtils;
+import android.view.KeyEvent;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.inputmethod.EditorInfo;
+import android.widget.ArrayAdapter;
+import android.widget.AutoCompleteTextView;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.TextView;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.java_websocket.client.WebSocketClient;
+import org.java_websocket.handshake.ServerHandshake;
+import org.java_websocket.drafts.Draft_10;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import static android.Manifest.permission.READ_CONTACTS;
+
+/**
+ * A login screen that offers login via email/password.
+ */
+public class LoginActivity extends AppCompatActivity implements LoaderCallbacks<Cursor> {
+
+    /**
+     * Id to identity READ_CONTACTS permission request.
+     */
+    private static final int REQUEST_READ_CONTACTS = 0;
+
+    /**
+     * A dummy authentication store containing known user names and passwords.
+     * TODO: remove after connecting to a real authentication system.
+     */
+    private static final String[] DUMMY_CREDENTIALS = new String[]{
+            "foo@example.com:hello", "bar@example.com:world"
+    };
+    /**
+     * Keep track of the login task to ensure we can cancel it if requested.
+     */
+    private UserLoginTask mAuthTask = null;
+
+    // UI references.
+    private AutoCompleteTextView mEmailView;
+    private EditText mPasswordView;
+    private View mProgressView;
+    private View mLoginFormView;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_login);
+        // Set up the login form.
+        mEmailView = (AutoCompleteTextView) findViewById(R.id.email);
+        populateAutoComplete();
+
+        mPasswordView = (EditText) findViewById(R.id.password);
+        mPasswordView.setOnEditorActionListener(new TextView.OnEditorActionListener() {
+            @Override
+            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
+                if (id == EditorInfo.IME_ACTION_DONE || id == EditorInfo.IME_NULL) {
+                    attemptLogin();
+                    return true;
+                }
+                return false;
+            }
+        });
+
+        Button mEmailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
+        mEmailSignInButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                attemptLogin();
+            }
+        });
+
+        mLoginFormView = findViewById(R.id.login_form);
+        mProgressView = findViewById(R.id.login_progress);
+
+
+        WebSocketClient mWs = new WebSocketClient( new URI( "ws://192.168.3.7:9999" ), new Draft_10() )
+        {
+            @Override
+            public void onMessage( String message ) {
+                JSONObject obj = new JSONObject(message)
+                String channel = obj.getString("channel");
+            }
+
+            @Override
+            public void onOpen( ServerHandshake handshake ) {
+                System.out.println( "opened connection" );
+            }
+
+            @Override
+            public void onClose( int code, String reason, boolean remote ) {
+                System.out.println( "closed connection" );
+            }
+
+            @Override
+            public void onError( Exception ex ) {
+                ex.printStackTrace();
+            }
+
+        };
+        //open websocket
+        mWs.connect();
+        JSONObject obj = new JSONObject();
+        obj.put("event", "addChannel");
+        obj.put("channel", "ok_btccny_ticker");
+        String message = obj.toString();
+        //send message
+        mWs.send(message);
+    }
+
+    private void populateAutoComplete() {
+        if (!mayRequestContacts()) {
+            return;
+        }
+
+        getLoaderManager().initLoader(0, null, this);
+    }
+
+    private boolean mayRequestContacts() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            return true;
+        }
+        if (checkSelfPermission(READ_CONTACTS) == PackageManager.PERMISSION_GRANTED) {
+            return true;
+        }
+        if (shouldShowRequestPermissionRationale(READ_CONTACTS)) {
+            Snackbar.make(mEmailView, R.string.permission_rationale, Snackbar.LENGTH_INDEFINITE)
+                    .setAction(android.R.string.ok, new View.OnClickListener() {
+                        @Override
+                        @TargetApi(Build.VERSION_CODES.M)
+                        public void onClick(View v) {
+                            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+                        }
+                    });
+        } else {
+            requestPermissions(new String[]{READ_CONTACTS}, REQUEST_READ_CONTACTS);
+        }
+        return false;
+    }
+
+    /**
+     * Callback received when a permissions request has been completed.
+     */
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
+                                           @NonNull int[] grantResults) {
+        if (requestCode == REQUEST_READ_CONTACTS) {
+            if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                populateAutoComplete();
+            }
+        }
+    }
+
+
+    /**
+     * Attempts to sign in or register the account specified by the login form.
+     * If there are form errors (invalid email, missing fields, etc.), the
+     * errors are presented and no actual login attempt is made.
+     */
+    private void attemptLogin() {
+        if (mAuthTask != null) {
+            return;
+        }
+
+        // Reset errors.
+        mEmailView.setError(null);
+        mPasswordView.setError(null);
+
+        // Store values at the time of the login attempt.
+        String email = mEmailView.getText().toString();
+        String password = mPasswordView.getText().toString();
+
+        boolean cancel = false;
+        View focusView = null;
+
+        // Check for a valid password, if the user entered one.
+        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
+            mPasswordView.setError(getString(R.string.error_invalid_password));
+            focusView = mPasswordView;
+            cancel = true;
+        }
+
+        // Check for a valid email address.
+        if (TextUtils.isEmpty(email)) {
+            mEmailView.setError(getString(R.string.error_field_required));
+            focusView = mEmailView;
+            cancel = true;
+        } else if (!isEmailValid(email)) {
+            mEmailView.setError(getString(R.string.error_invalid_email));
+            focusView = mEmailView;
+            cancel = true;
+        }
+
+        if (cancel) {
+            // There was an error; don't attempt login and focus the first
+            // form field with an error.
+            focusView.requestFocus();
+        } else {
+            // Show a progress spinner, and kick off a background task to
+            // perform the user login attempt.
+            showProgress(true);
+            mAuthTask = new UserLoginTask(email, password);
+            mAuthTask.execute((Void) null);
+        }
+    }
+
+    private boolean isEmailValid(String email) {
+        //TODO: Replace this with your own logic
+        return email.contains("@");
+    }
+
+    private boolean isPasswordValid(String password) {
+        //TODO: Replace this with your own logic
+        return password.length() > 4;
+    }
+
+    /**
+     * Shows the progress UI and hides the login form.
+     */
+    @TargetApi(Build.VERSION_CODES.HONEYCOMB_MR2)
+    private void showProgress(final boolean show) {
+        // On Honeycomb MR2 we have the ViewPropertyAnimator APIs, which allow
+        // for very easy animations. If available, use these APIs to fade-in
+        // the progress spinner.
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR2) {
+            int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);
+
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+            mLoginFormView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+                }
+            });
+
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mProgressView.animate().setDuration(shortAnimTime).alpha(
+                    show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+                }
+            });
+        } else {
+            // The ViewPropertyAnimator APIs are not available, so simply show
+            // and hide the relevant UI components.
+            mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
+            mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
+        }
+    }
+
+    @Override
+    public Loader<Cursor> onCreateLoader(int i, Bundle bundle) {
+        return new CursorLoader(this,
+                // Retrieve data rows for the device user's 'profile' contact.
+                Uri.withAppendedPath(ContactsContract.Profile.CONTENT_URI,
+                        ContactsContract.Contacts.Data.CONTENT_DIRECTORY), ProfileQuery.PROJECTION,
+
+                // Select only email addresses.
+                ContactsContract.Contacts.Data.MIMETYPE +
+                        " = ?", new String[]{ContactsContract.CommonDataKinds.Email
+                .CONTENT_ITEM_TYPE},
+
+                // Show primary email addresses first. Note that there won't be
+                // a primary email address if the user hasn't specified one.
+                ContactsContract.Contacts.Data.IS_PRIMARY + " DESC");
+    }
+
+    @Override
+    public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) {
+        List<String> emails = new ArrayList<>();
+        cursor.moveToFirst();
+        while (!cursor.isAfterLast()) {
+            emails.add(cursor.getString(ProfileQuery.ADDRESS));
+            cursor.moveToNext();
+        }
+
+        addEmailsToAutoComplete(emails);
+    }
+
+    @Override
+    public void onLoaderReset(Loader<Cursor> cursorLoader) {
+
+    }
+
+    private void addEmailsToAutoComplete(List<String> emailAddressCollection) {
+        //Create adapter to tell the AutoCompleteTextView what to show in its dropdown list.
+        ArrayAdapter<String> adapter =
+                new ArrayAdapter<>(LoginActivity.this,
+                        android.R.layout.simple_dropdown_item_1line, emailAddressCollection);
+
+        mEmailView.setAdapter(adapter);
+    }
+
+
+    private interface ProfileQuery {
+        String[] PROJECTION = {
+                ContactsContract.CommonDataKinds.Email.ADDRESS,
+                ContactsContract.CommonDataKinds.Email.IS_PRIMARY,
+        };
+
+        int ADDRESS = 0;
+        int IS_PRIMARY = 1;
+    }
+
+    /**
+     * Represents an asynchronous login/registration task used to authenticate
+     * the user.
+     */
+    public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {
+
+        private final String mEmail;
+        private final String mPassword;
+
+        UserLoginTask(String email, String password) {
+            mEmail = email;
+            mPassword = password;
+        }
+
+        @Override
+        protected Boolean doInBackground(Void... params) {
+            // TODO: attempt authentication against a network service.
+
+            try {
+                // Simulate network access.
+                Thread.sleep(2000);
+            } catch (InterruptedException e) {
+                return false;
+            }
+
+            for (String credential : DUMMY_CREDENTIALS) {
+                String[] pieces = credential.split(":");
+                if (pieces[0].equals(mEmail)) {
+                    // Account exists, return true if the password matches.
+                    return pieces[1].equals(mPassword);
+                }
+            }
+
+            // TODO: register the new account here.
+            return true;
+        }
+
+        @Override
+        protected void onPostExecute(final Boolean success) {
+            mAuthTask = null;
+            showProgress(false);
+
+            if (success) {
+                finish();
+            } else {
+                mPasswordView.setError(getString(R.string.error_incorrect_password));
+                mPasswordView.requestFocus();
+            }
+        }
+
+        @Override
+        protected void onCancelled() {
+            mAuthTask = null;
+            showProgress(false);
+        }
+    }
+}
+

gui/src/main/res/drawable-v24/ic_launcher_foreground.xml

+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:aapt="http://schemas.android.com/aapt"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillType="evenOdd"
+        android:pathData="M32,64C32,64 38.39,52.99 44.13,50.95C51.37,48.37 70.14,49.57 70.14,49.57L108.26,87.69L108,109.01L75.97,107.97L32,64Z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000">
+        <aapt:attr name="android:fillColor">
+            <gradient
+                android:endX="78.5885"
+                android:endY="90.9159"
+                android:startX="48.7653"
+                android:startY="61.0927"
+                android:type="linear">
+                <item
+                    android:color="#44000000"
+                    android:offset="0.0" />
+                <item
+                    android:color="#00000000"
+                    android:offset="1.0" />
+            </gradient>
+        </aapt:attr>
+    </path>
+    <path
+        android:fillColor="#FFFFFF"
+        android:fillType="nonZero"
+        android:pathData="M66.94,46.02L66.94,46.02C72.44,50.07 76,56.61 76,64L32,64C32,56.61 35.56,50.11 40.98,46.06L36.18,41.19C35.45,40.45 35.45,39.3 36.18,38.56C36.91,37.81 38.05,37.81 38.78,38.56L44.25,44.05C47.18,42.57 50.48,41.71 54,41.71C57.48,41.71 60.78,42.57 63.68,44.05L69.11,38.56C69.84,37.81 70.98,37.81 71.71,38.56C72.44,39.3 72.44,40.45 71.71,41.19L66.94,46.02ZM62.94,56.92C64.08,56.92 65,56.01 65,54.88C65,53.76 64.08,52.85 62.94,52.85C61.8,52.85 60.88,53.76 60.88,54.88C60.88,56.01 61.8,56.92 62.94,56.92ZM45.06,56.92C46.2,56.92 47.13,56.01 47.13,54.88C47.13,53.76 46.2,52.85 45.06,52.85C43.92,52.85 43,53.76 43,54.88C43,56.01 43.92,56.92 45.06,56.92Z"
+        android:strokeWidth="1"
+        android:strokeColor="#00000000" />
+</vector>

gui/src/main/res/drawable/ic_launcher_background.xml

+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#008577"
+        android:pathData="M0,0h108v108h-108z" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M9,0L9,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,0L19,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,0L29,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,0L39,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,0L49,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,0L59,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,0L69,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,0L79,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M89,0L89,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M99,0L99,108"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,9L108,9"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,19L108,19"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,29L108,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,39L108,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,49L108,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,59L108,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,69L108,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,79L108,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,89L108,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M0,99L108,99"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,29L89,29"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,39L89,39"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,49L89,49"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,59L89,59"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,69L89,69"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M19,79L89,79"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M29,19L29,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M39,19L39,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M49,19L49,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M59,19L59,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M69,19L69,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+    <path
+        android:fillColor="#00000000"
+        android:pathData="M79,19L79,89"
+        android:strokeWidth="0.8"
+        android:strokeColor="#33FFFFFF" />
+</vector>

gui/src/main/res/layout/activity_login.xml

+<?xml version="1.0" encoding="utf-8"?>
+<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"
+    android:gravity="center_horizontal"
+    android:orientation="vertical"
+    android:paddingLeft="@dimen/activity_horizontal_margin"
+    android:paddingTop="@dimen/activity_vertical_margin"
+    android:paddingRight="@dimen/activity_horizontal_margin"
+    android:paddingBottom="@dimen/activity_vertical_margin"
+    tools:context=".LoginActivity">
+
+    <!-- Login progress -->
+    <ProgressBar
+        android:id="@+id/login_progress"
+        style="?android:attr/progressBarStyleLarge"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:visibility="gone" />
+
+    <ScrollView
+        android:id="@+id/login_form"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+
+        <LinearLayout
+            android:id="@+id/email_login_form"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical">
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <AutoCompleteTextView
+                    android:id="@+id/email"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_email"
+                    android:inputType="textEmailAddress"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <android.support.design.widget.TextInputLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content">
+
+                <EditText
+                    android:id="@+id/password"
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:hint="@string/prompt_password"
+                    android:imeActionId="6"
+                    android:imeActionLabel="@string/action_sign_in_short"
+                    android:imeOptions="actionUnspecified"
+                    android:inputType="textPassword"
+                    android:maxLines="1"
+                    android:singleLine="true" />
+
+            </android.support.design.widget.TextInputLayout>
+
+            <Button
+                android:id="@+id/email_sign_in_button"
+                style="?android:textAppearanceSmall"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:text="@string/action_sign_in"
+                android:textStyle="bold" />
+
+        </LinearLayout>
+    </ScrollView>
+</LinearLayout>
\ No newline at end of file

gui/src/main/res/values/colors.xml

+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="colorPrimary">#008577</color>
+    <color name="colorPrimaryDark">#00574B</color>
+    <color name="colorAccent">#D81B60</color>
+</resources>

gui/src/main/res/values/dimens.xml

+<resources>
+    <!-- Default screen margins, per the Android Design guidelines. -->
+    <dimen name="activity_horizontal_margin">16dp</dimen>
+    <dimen name="activity_vertical_margin">16dp</dimen>
+</resources>