adds error messages to sign up dialog edit texts

app/src/main/java/chat/rocket/android/fragment/server_config/UserRegistrationDialogFragment.java

@@ -4,14 +4,17 @@ import android.app.Dialog;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.design.widget.TextInputEditText;
+import android.support.design.widget.TextInputLayout;
 import android.support.v4.app.DialogFragment;
 import android.support.v7.app.AlertDialog;
 import android.util.Patterns;
 import android.view.LayoutInflater;
 import android.view.View;
-import android.widget.TextView;
 import android.widget.Toast;
 
+import com.jakewharton.rxbinding2.widget.RxTextView;
+
 import chat.rocket.android.R;
 import chat.rocket.android.api.MethodCallHelper;
 import chat.rocket.android.helper.TextUtils;
@@ -24,7 +27,13 @@ public class UserRegistrationDialogFragment extends DialogFragment {
     private String username;
     private String email;
     private String password;
-
+    private TextInputEditText txtUsername;
+    private TextInputEditText txtEmail;
+    private TextInputEditText txtPasswd;
+    private TextInputLayout textInputUsername;
+    private TextInputLayout textInputEmail;
+    private TextInputLayout textInputPassword;
+    private View waitingView;
     public UserRegistrationDialogFragment() {
         super();
     }
@@ -88,9 +97,8 @@ public class UserRegistrationDialogFragment extends DialogFragment {
         View dialog = LayoutInflater.from(getContext())
                 .inflate(R.layout.dialog_user_registration, null, false);
 
-    final TextView txtUsername = (TextView) dialog.findViewById(R.id.editor_username);
-    final TextView txtEmail = (TextView) dialog.findViewById(R.id.editor_email);
-    final TextView txtPasswd = (TextView) dialog.findViewById(R.id.editor_passwd);
+        initViews(dialog);
+        setUpRxBinders();
 
         if (!TextUtils.isEmpty(username)) {
             txtUsername.setText(username);
@@ -102,17 +110,19 @@ public class UserRegistrationDialogFragment extends DialogFragment {
             txtPasswd.setText(password);
         }
 
-    final View waitingView = dialog.findViewById(R.id.waiting);
         waitingView.setVisibility(View.GONE);
 
-    dialog.findViewById(R.id.btn_register_user).setOnClickListener(view -> {
-      view.setEnabled(false);
+        dialog.findViewById(R.id.btn_register_user).setOnClickListener(registerButton -> {
+            if (checkIfEditTextsEmpty())
+                return;
+
+            registerButton.setEnabled(false);
+            registerButton.setAlpha(0.5f);
             waitingView.setVisibility(View.VISIBLE);
 
             username = txtUsername.getText().toString();
             email = txtEmail.getText().toString();
             password = txtPasswd.getText().toString();
-
             MethodCallHelper methodCallHelper = new MethodCallHelper(getContext(), hostname);
             methodCallHelper.registerUser(username, email, password, password)
                     .onSuccessTask(task -> methodCallHelper.loginWithEmail(email, password))
@@ -126,7 +136,7 @@ public class UserRegistrationDialogFragment extends DialogFragment {
                         if (task.isFaulted()) {
                             Exception exception = task.getError();
                             showError(exception.getMessage());
-              view.setEnabled(true);
+                            registerButton.setEnabled(true);
                             waitingView.setVisibility(View.GONE);
                         }
                         return null;
@@ -135,6 +145,51 @@ public class UserRegistrationDialogFragment extends DialogFragment {
         return dialog;
     }
 
+    private void initViews(View dialog) {
+        txtUsername = dialog.findViewById(R.id.editor_username);
+        txtEmail = dialog.findViewById(R.id.editor_email);
+        txtPasswd = dialog.findViewById(R.id.editor_passwd);
+        textInputEmail = dialog.findViewById(R.id.text_input_email);
+        textInputUsername = dialog.findViewById(R.id.text_input_username);
+        textInputPassword = dialog.findViewById(R.id.text_input_passwd);
+        waitingView = dialog.findViewById(R.id.waiting);
+    }
+
+    private boolean checkIfEditTextsEmpty() {
+        boolean check = false;
+        if (TextUtils.isEmpty(txtEmail.getText().toString())) {
+            textInputEmail.setError("Enter an email address");
+            textInputEmail.setErrorEnabled(true);
+            check = true;
+        }
+        if (TextUtils.isEmpty(txtUsername.getText().toString())) {
+            textInputUsername.setError("Enter a username");
+            textInputUsername.setErrorEnabled(true);
+            check = true;
+        }
+        if (TextUtils.isEmpty(txtPasswd.getText().toString())) {
+            textInputPassword.setError("Enter a password");
+            textInputPassword.setErrorEnabled(true);
+            check = true;
+        }
+        return check;
+    }
+
+    private void setUpRxBinders() {
+        RxTextView.textChanges(txtUsername).subscribe(text -> {
+            if (!TextUtils.isEmpty(text) && textInputUsername.isErrorEnabled())
+                textInputUsername.setErrorEnabled(false);
+        });
+        RxTextView.textChanges(txtEmail).subscribe(text -> {
+            if (!TextUtils.isEmpty(text) && textInputEmail.isErrorEnabled())
+                textInputEmail.setErrorEnabled(false);
+        });
+        RxTextView.textChanges(txtPasswd).subscribe(text -> {
+            if (!TextUtils.isEmpty(text) && textInputPassword.isErrorEnabled())
+                textInputPassword.setErrorEnabled(false);
+        });
+    }
+
     private void showError(String errMessage) {
         Toast.makeText(getContext(), errMessage, Toast.LENGTH_SHORT).show();
     }