chat+meto el validator en la clase

app/src/main/java/com/example/david/myapplication/EmailValidator.java

@@ -1,12 +0,0 @@
-package com.example.david.myapplication;
-import java.util.regex.Pattern;
-public class EmailValidator {
-    private static final String EMAIL_PATTERN =
-            "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
-          + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
-
-    private static Pattern pattern = Pattern.compile(EMAIL_PATTERN);
-    public static boolean validate(final String hex) {
-        return pattern.matcher(hex).matches();
-    }
-}

app/src/main/java/com/example/david/myapplication/LoginActivity.java

@@ -36,13 +36,16 @@ import org.json.JSONObject;
 import java.security.MessageDigest;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Pattern;
 
 
 /**
  * A login screen that offers login via email/password.
  */
 public class LoginActivity extends Activity implements LoaderCallbacks<Cursor> {
-
+    private static final String EMAIL_PATTERN =
+            "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
+                    + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
 
     /**
      * Keep track of the login task to ensure we can cancel it if requested.
@@ -144,7 +147,7 @@ public class LoginActivity extends Activity implements LoaderCallbacks<Cursor> {
     }
 
     private boolean isEmailValid(String email) {
-        return EmailValidator.validate(email);
+        return Pattern.compile(EMAIL_PATTERN).matcher(email).matches();
     }
 
     private boolean isPasswordValid(String password) {

app/src/main/res/layout/fragment_chat.xml

@@ -20,6 +20,9 @@
             android:layout_height="match_parent"
             android:layout_weight="4"
             android:layout_width="0dp"
+            android:maxLines="1"
+            android:singleLine="true"
+            android:imeOptions="flagNoExtractUi"
             android:id="@+id/send_text"/>
         <Button
             style="?android:attr/buttonStyleSmall"