feat: Hide email sign up button if specified

Author: adangil97

auth/src/main/java/com/firebase/ui/auth/AuthUI.java

@@ -533,6 +533,17 @@ public EmailBuilder setAllowNewAccounts(boolean allow) {
                 return this;
             }
 
+            /**
+             * Hide the email sign-up button in the authentication flow.
+             * <p>
+             * Email sign-in is enabled by default.
+             */
+            @NonNull
+            public EmailBuilder hideEmailSignUp() {
+                getParams().putBoolean(ExtraConstants.HIDE_EMAIL_SIGN_UP, true);
+                return this;
+            }
+
             /**
              * Configures the requirement for the user to enter first and last name in the email
              * sign up flow.

auth/src/main/java/com/firebase/ui/auth/ui/email/CheckEmailFragment.java

@@ -21,7 +21,6 @@
 import com.firebase.ui.auth.util.data.PrivacyDisclosureUtils;
 import com.firebase.ui.auth.util.ui.ImeHelper;
 import com.firebase.ui.auth.util.ui.fieldvalidators.EmailFieldValidator;
-import com.google.android.material.snackbar.Snackbar;
 import com.google.android.material.textfield.TextInputLayout;
 import com.google.firebase.auth.EmailAuthProvider;
 
@@ -31,8 +30,6 @@
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProvider;
 
-import static com.firebase.ui.auth.AuthUI.EMAIL_LINK_PROVIDER;
-
 /**
  * Fragment that shows a form with an email field and checks for existing accounts with that email.
  * <p>
@@ -95,8 +92,8 @@ public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceStat
         mSignInButton.setOnClickListener(this);
         mSignUpButton.setOnClickListener(this);
 
-        // Hide sign up button for email link authentication
-        if (getEmailProvider().equals(EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD)) {
+        // Hide sign up button for email link authentication or if explicitly disabled.
+        if (getEmailProvider().equals(EmailAuthProvider.EMAIL_LINK_SIGN_IN_METHOD) || hideSignUpButton()) {
             mSignUpButton.setVisibility(View.GONE);
         }
 
@@ -165,6 +162,15 @@ public void onDonePressed() {
         signIn();
     }
 
+    private Boolean hideSignUpButton() {
+        for (AuthUI.IdpConfig config : getFlowParams().providers) {
+            if (EmailAuthProvider.EMAIL_PASSWORD_SIGN_IN_METHOD.equals(config.getProviderId())) {
+                return config.getParams().containsKey(ExtraConstants.HIDE_EMAIL_SIGN_UP);
+            }
+        }
+        return false;
+    }
+
     private String getEmailProvider() {
         // Iterate through all IdpConfig entries
         for (AuthUI.IdpConfig config : getFlowParams().providers) {

auth/src/main/java/com/firebase/ui/auth/util/ExtraConstants.java

@@ -30,6 +30,7 @@ public final class ExtraConstants {
     public static final String PASSWORD = "extra_password";
     public static final String DEFAULT_EMAIL = "extra_default_email";
     public static final String ALLOW_NEW_EMAILS = "extra_allow_new_emails";
+    public static final String HIDE_EMAIL_SIGN_UP = "extra_hide_email_sign_up";
     public static final String REQUIRE_NAME = "extra_require_name";
     public static final String GOOGLE_SIGN_IN_OPTIONS = "extra_google_sign_in_options";
     public static final String FACEBOOK_PERMISSIONS = "extra_facebook_permissions";