initial impl

android/app/src/main/AndroidManifest.xml

@@ -78,6 +78,16 @@
             android:exported="true"
             android:launchMode="singleTop"
             android:theme="@style/NdefActivityTheme">
+        </activity>
+
+        <activity-alias
+            android:name=".AliasNdefActivity"
+            android:exported="true"
+            android:enabled="true"
+            android:launchMode="singleTop"
+            android:theme="@style/NdefActivityTheme"
+            android:targetActivity=".NdefActivity">
+
             <intent-filter
                 android:autoVerify="true"
                 tools:ignore="UnusedAttribute">
@@ -89,7 +99,7 @@
 
             </intent-filter>
 
-        </activity>
+        </activity-alias>
 
         <!-- Don't delete the meta-data below.
              This is used by the Flutter tool to generate GeneratedPluginRegistrant.java -->

android/app/src/main/kotlin/com/yubico/authenticator/MainActivity.kt

@@ -97,16 +97,59 @@ class MainActivity : FlutterFragmentActivity() {
      *
      * @param enable if true, alias activity will be enabled
      */
-    private fun enableAliasMainActivityComponent(enable: Boolean) {
+    private fun enableActivityAlias(aliasName: String, enabledState: Int) {
-        val componentName = ComponentName(packageName, "com.yubico.authenticator.AliasMainActivity")
+        val componentName = ComponentName(packageName, "com.yubico.authenticator.$aliasName")
         applicationContext.packageManager.setComponentEnabledSetting(
             componentName,
-            if (enable)
+            enabledState,
-                PackageManager.COMPONENT_ENABLED_STATE_ENABLED
-            else
-                PackageManager.COMPONENT_ENABLED_STATE_DEFAULT,
             PackageManager.DONT_KILL_APP
         )
+        logger.trace("Activity alias '$aliasName' is enabled: $enabledState")
+    }
+
+    /**
+     * Sets state of AliasMainActivity to enabled. This will enable USB discovery.
+     */
+    private fun enableAppUsbDiscovery() {
+        enableActivityAlias(
+            "AliasMainActivity",
+            PackageManager.COMPONENT_ENABLED_STATE_ENABLED
+        )
+    }
+
+    /**
+     * Sets state of AliasMainActivity to default. This will deactivate the USB discovery.
+     *
+     * The default for AliasMainActivity is disabled.
+     */
+    private fun disableAppUsbDiscovery() {
+        enableActivityAlias(
+            "AliasMainActivity",
+            PackageManager.COMPONENT_ENABLED_STATE_DEFAULT
+        )
+    }
+
+    /**
+     * Sets state of AliasNdefActivity to defaut. This will activate NFC intent filters.
+     *
+     * The default for AliasNdefActivity is enabled.
+     */
+    private fun enableAppNfcDiscovery() {
+        enableActivityAlias(
+            "AliasNdefActivity",
+            PackageManager.COMPONENT_ENABLED_STATE_DEFAULT
+        )
+    }
+
+    /**
+     * Sets state of AliasNdefActivity to disabled. This will deactivate NFC intent filters.
+     */
+    private fun disableAppNfcDiscovery() {
+        // enable NFC discovery based on user preferences
+        enableActivityAlias(
+            "AliasNdefActivity",
+            PackageManager.COMPONENT_ENABLED_STATE_DISABLED
+        )
     }
 
     override fun onNewIntent(intent: Intent) {
@@ -180,16 +223,24 @@ class MainActivity : FlutterFragmentActivity() {
 
         stopUsbDiscovery()
         stopNfcDiscovery()
+
         if (!appPreferences.openAppOnUsb) {
-            enableAliasMainActivityComponent(false)
+            disableAppUsbDiscovery()
         }
+
+        if (appPreferences.openAppOnNfcTap || appPreferences.copyOtpOnNfcTap) {
+            enableAppNfcDiscovery()
+        } else {
+            disableAppNfcDiscovery()
+        }
+
         super.onPause()
     }
 
     override fun onResume() {
         super.onResume()
 
-        enableAliasMainActivityComponent(true)
+        enableAppUsbDiscovery()
 
         // Handle opening through otpauth:// link
         val intentData = intent.data

lib/android/models.dart

@@ -17,13 +17,15 @@
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 
 enum NfcTapAction {
+  noAction,
   launch,
   copy,
-  both;
+  launchAndCopy;
 
   String getDescription(AppLocalizations l10n) => switch (this) {
+        NfcTapAction.noAction => l10n.l_do_nothing,
         NfcTapAction.launch => l10n.l_launch_ya,
         NfcTapAction.copy => l10n.l_copy_otp_clipboard,
-        NfcTapAction.both => l10n.l_launch_and_copy_otp
+        NfcTapAction.launchAndCopy => l10n.l_launch_and_copy_otp
       };
 }

lib/android/state.dart

@@ -142,12 +142,13 @@ class NfcTapActionNotifier extends StateNotifier<NfcTapAction> {
     final copyOtp = prefs.getBool(_prefNfcCopyOtp) ?? false;
     final NfcTapAction action;
     if (launchApp && copyOtp) {
-      action = NfcTapAction.both;
+      action = NfcTapAction.launchAndCopy;
     } else if (copyOtp) {
       action = NfcTapAction.copy;
-    } else {
+    } else if (launchApp) {
-      // This is the default value if both are false.
       action = NfcTapAction.launch;
+    } else {
+      action = NfcTapAction.noAction;
     }
     return NfcTapActionNotifier._(prefs, action);
   }
@@ -155,8 +156,10 @@ class NfcTapActionNotifier extends StateNotifier<NfcTapAction> {
   Future<void> setTapAction(NfcTapAction value) async {
     if (state != value) {
       state = value;
-      await _prefs.setBool(_prefNfcOpenApp, value != NfcTapAction.copy);
+      await _prefs.setBool(_prefNfcOpenApp,
-      await _prefs.setBool(_prefNfcCopyOtp, value != NfcTapAction.launch);
+          value == NfcTapAction.launch || value == NfcTapAction.launchAndCopy);
+      await _prefs.setBool(_prefNfcCopyOtp,
+          value == NfcTapAction.copy || value == NfcTapAction.launchAndCopy);
     }
   }
 }

lib/l10n/app_en.arb

@@ -579,6 +579,7 @@
     "@_android_settings": {},
     "s_nfc_options": "NFC options",
     "l_on_yk_nfc_tap": "On YubiKey NFC tap",
+    "l_do_nothing": "Do nothing",
     "l_launch_ya": "Launch Yubico Authenticator",
     "l_copy_otp_clipboard": "Copy OTP to clipboard",
     "l_launch_and_copy_otp": "Launch app and copy OTP",

test/android_settings_page_test.dart

@@ -66,7 +66,7 @@ extension _WidgetTesterHelper on WidgetTester {
 
   Future<void> selectBothOption() async {
     await openNfcTapOptionSelection();
-    await tap(find.byKey(android_keys.nfcTapOption(NfcTapAction.both)));
+    await tap(find.byKey(android_keys.nfcTapOption(NfcTapAction.launchAndCopy)));
     await pumpAndSettle();
   }