tap-to-pay part 3: default wallet and shortcut

app/src/main/AndroidManifest.xml

@@ -62,6 +62,12 @@
             android:exported="false"
             android:screenOrientation="portrait" />
 
+        <activity
+            android:name=".nfc.BmlTapToPayActivity"
+            android:exported="false"
+            android:launchMode="singleTop"
+            android:theme="@style/Theme.BasedBank" />
+
         <service
             android:name=".nfc.BmlHostCardEmulatorService"
             android:exported="true"

app/src/main/java/sh/sar/basedbank/MainActivity.kt

@@ -9,6 +9,7 @@ import sh.sar.basedbank.ui.onboarding.OnboardingActivity
 import sh.sar.basedbank.util.CredentialStore
 import sh.sar.basedbank.BasedBankApp
 import sh.sar.basedbank.R
+import sh.sar.basedbank.nfc.BmlTapToPayActivity
 
 class MainActivity : AppCompatActivity() {
 
@@ -21,6 +22,13 @@ class MainActivity : AppCompatActivity() {
         val store = CredentialStore(this)
         val hasCredentials = store.hasMibCredentials() || store.hasBmlCredentials() || store.hasFahipayCredentials()
 
+        // Tap to Pay shortcut: go straight to the standalone payment activity
+        if (intent?.action == "sh.sar.basedbank.TAP_TO_PAY") {
+            startActivity(Intent(this, BmlTapToPayActivity::class.java))
+            finish()
+            return
+        }
+
         val navDestination = when (intent?.action) {
             "sh.sar.basedbank.OPEN_TRANSFER"      -> R.id.nav_transfer
             "sh.sar.basedbank.OPEN_SCAN_QR"       -> R.id.nav_transfer

app/src/main/java/sh/sar/basedbank/nfc/BmlHostCardEmulatorService.kt

@@ -1,5 +1,6 @@
 package sh.sar.basedbank.nfc
 
+import android.content.Intent
 import android.nfc.cardemulation.HostApduService
 import android.os.Bundle
 import android.util.Log
@@ -40,21 +41,25 @@ class BmlHostCardEmulatorService : HostApduService() {
 
     private fun handleSelect(apdu: Apdu): ByteArray {
         val data = apdu.data ?: return SW_UNKNOWN_ERROR
-        val token = activeToken ?: return SW_UNKNOWN_ERROR
 
-        return when {
-            data.contentEquals(PPSE_BYTES) -> {
-                // SELECT PPSE
-                val resp = buildSelectPpseResponse(token.appCode, applicationLabel(token.appCode), "01")
-                hexToBytes(resp)
-            }
-            data.contentEquals(hexToBytes(token.appCode)) -> {
-                // SELECT AID
-                val resp = buildSelectAidResponse(token.appCode, applicationLabel(token.appCode))
-                hexToBytes(resp)
-            }
-            else -> SW_UNKNOWN_ERROR
+        if (data.contentEquals(PPSE_BYTES)) {
+            val token = activeToken ?: run { launchPromptActivity(); return SW_UNKNOWN_ERROR }
+            return hexToBytes(buildSelectPpseResponse(token.appCode, applicationLabel(token.appCode), "01"))
         }
+
+        val token = activeToken ?: return SW_UNKNOWN_ERROR
+        return if (data.contentEquals(hexToBytes(token.appCode))) {
+            hexToBytes(buildSelectAidResponse(token.appCode, applicationLabel(token.appCode)))
+        } else {
+            SW_UNKNOWN_ERROR
+        }
+    }
+
+    private fun launchPromptActivity() {
+        val intent = Intent(applicationContext, BmlTapToPayActivity::class.java).apply {
+            flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_SINGLE_TOP
+        }
+        startActivity(intent)
     }
 
     private fun handleGpo(): ByteArray {

app/src/main/java/sh/sar/basedbank/nfc/BmlTapToPayActivity.kt

@@ -0,0 +1,167 @@
+package sh.sar.basedbank.nfc
+
+import android.content.Intent
+import android.os.Bundle
+import android.view.Gravity
+import android.widget.ImageView
+import android.widget.LinearLayout
+import android.widget.TextView
+import android.widget.Toast
+import androidx.appcompat.app.AppCompatActivity
+import androidx.biometric.BiometricManager
+import androidx.biometric.BiometricPrompt
+import androidx.core.content.ContextCompat
+import com.google.android.material.button.MaterialButton
+import com.google.android.material.color.MaterialColors
+import sh.sar.basedbank.R
+
+/**
+ * Launched by [BmlHostCardEmulatorService] when the phone is tapped against a POS terminal
+ * but no payment token is armed. Handles biometric auth and token loading from the local store,
+ * then arms the service so the user can tap again to complete the payment.
+ */
+class BmlTapToPayActivity : AppCompatActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        prepare()
+    }
+
+    // singleTop: if already showing, just ignore the re-launch
+    override fun onNewIntent(intent: Intent) {
+        super.onNewIntent(intent)
+    }
+
+    private fun prepare() {
+        val store = HceTokenStore(this)
+        if (!store.hasTokens()) {
+            Toast.makeText(this,
+                "Open the app and tap Tap to Pay first to load payment tokens",
+                Toast.LENGTH_LONG).show()
+            finish()
+            return
+        }
+
+        val prefs = getSharedPreferences("prefs", MODE_PRIVATE)
+        val biometricEnabled = prefs.getBoolean("biometrics_transfer_confirm", false)
+
+        if (biometricEnabled) {
+            val bmgr = BiometricManager.from(this)
+            if (bmgr.canAuthenticate(BiometricManager.Authenticators.BIOMETRIC_STRONG) == BiometricManager.BIOMETRIC_SUCCESS) {
+                showBiometricPrompt(store)
+                return
+            }
+        }
+        armAndShowReady(store)
+    }
+
+    private fun showBiometricPrompt(store: HceTokenStore) {
+        val prompt = BiometricPrompt(this, ContextCompat.getMainExecutor(this),
+            object : BiometricPrompt.AuthenticationCallback() {
+                override fun onAuthenticationSucceeded(result: BiometricPrompt.AuthenticationResult) {
+                    armAndShowReady(store)
+                }
+                override fun onAuthenticationError(errorCode: Int, errString: CharSequence) {
+                    finish()
+                }
+            })
+        prompt.authenticate(
+            BiometricPrompt.PromptInfo.Builder()
+                .setTitle(getString(R.string.card_pay_nfc))
+                .setSubtitle(getString(R.string.app_name))
+                .setNegativeButtonText(getString(R.string.cancel))
+                .build()
+        )
+    }
+
+    private fun armAndShowReady(store: HceTokenStore) {
+        val token = store.popToken() ?: run {
+            Toast.makeText(this,
+                "No valid payment tokens — please open the app",
+                Toast.LENGTH_LONG).show()
+            finish()
+            return
+        }
+
+        BmlHostCardEmulatorService.setToken(token)
+        BmlHostCardEmulatorService.onTransactionComplete = { success ->
+            runOnUiThread {
+                BmlHostCardEmulatorService.clearToken()
+                BmlHostCardEmulatorService.onTransactionComplete = null
+                if (success) Toast.makeText(this, "Payment complete", Toast.LENGTH_SHORT).show()
+                finish()
+            }
+        }
+        showReadyLayout()
+    }
+
+    private fun showReadyLayout() {
+        val dp = resources.displayMetrics.density
+        val colorSurface = MaterialColors.getColor(window.decorView,
+            com.google.android.material.R.attr.colorSurface, 0xFF1C1B1F.toInt())
+        val colorOnSurface = MaterialColors.getColor(window.decorView,
+            com.google.android.material.R.attr.colorOnSurface, 0xFFFFFFFF.toInt())
+        val colorOnSurfaceVariant = MaterialColors.getColor(window.decorView,
+            com.google.android.material.R.attr.colorOnSurfaceVariant, 0xFFCAC4D0.toInt())
+
+        val root = LinearLayout(this).apply {
+            orientation = LinearLayout.VERTICAL
+            gravity = Gravity.CENTER
+            setBackgroundColor(colorSurface)
+            setPadding((32 * dp).toInt(), (64 * dp).toInt(), (32 * dp).toInt(), (64 * dp).toInt())
+        }
+
+        root.addView(ImageView(this).apply {
+            setImageResource(R.drawable.ic_nfc)
+            setColorFilter(colorOnSurface)
+            layoutParams = LinearLayout.LayoutParams((72 * dp).toInt(), (72 * dp).toInt()).apply {
+                gravity = Gravity.CENTER_HORIZONTAL
+                bottomMargin = (32 * dp).toInt()
+            }
+        })
+
+        root.addView(TextView(this).apply {
+            text = getString(R.string.card_pay_nfc)
+            textSize = 22f
+            gravity = Gravity.CENTER
+            setTextColor(colorOnSurface)
+            layoutParams = LinearLayout.LayoutParams(
+                LinearLayout.LayoutParams.MATCH_PARENT,
+                LinearLayout.LayoutParams.WRAP_CONTENT
+            ).apply { bottomMargin = (8 * dp).toInt() }
+        })
+
+        root.addView(TextView(this).apply {
+            text = "Hold your phone near the payment terminal"
+            textSize = 14f
+            gravity = Gravity.CENTER
+            setTextColor(colorOnSurfaceVariant)
+            layoutParams = LinearLayout.LayoutParams(
+                LinearLayout.LayoutParams.MATCH_PARENT,
+                LinearLayout.LayoutParams.WRAP_CONTENT
+            ).apply { bottomMargin = (48 * dp).toInt() }
+        })
+
+        root.addView(MaterialButton(this, null,
+            com.google.android.material.R.attr.materialButtonOutlinedStyle
+        ).apply {
+            text = getString(R.string.cancel)
+            setOnClickListener {
+                BmlHostCardEmulatorService.clearToken()
+                BmlHostCardEmulatorService.onTransactionComplete = null
+                finish()
+            }
+        })
+
+        setContentView(root)
+    }
+
+    override fun onDestroy() {
+        super.onDestroy()
+        // If the activity is killed without completing, clean up the armed token
+        if (isFinishing && BmlHostCardEmulatorService.activeToken != null) {
+            BmlHostCardEmulatorService.clearToken()
+            BmlHostCardEmulatorService.onTransactionComplete = null
+        }
+    }
+}

app/src/main/res/xml/bml_aid_list.xml

@@ -1,8 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
-<aid-filter xmlns:android="http://schemas.android.com/apk/res/android">
+<host-apdu-service xmlns:android="http://schemas.android.com/apk/res/android"
+    android:description="@string/app_name"
+    android:requireDeviceUnlock="false">
 
-    <!-- Contactless PPSE directory -->
-    <aid-group android:description="@string/app_name"
+    <aid-group
+        android:description="@string/app_name"
         android:category="payment">
 
         <!-- PPSE: 2PAY.SYS.DDF01 -->
@@ -19,4 +21,4 @@
 
     </aid-group>
 
-</aid-filter>
+</host-apdu-service>

app/src/main/res/xml/shortcuts.xml

@@ -28,13 +28,13 @@
     </shortcut>
 
     <shortcut
-        android:shortcutId="pay_with_card"
+        android:shortcutId="tap_to_pay"
         android:enabled="true"
-        android:icon="@drawable/ic_shortcut_pay_card"
-        android:shortcutShortLabel="@string/nav_pay_with_card"
-        android:shortcutLongLabel="@string/nav_pay_with_card">
+        android:icon="@drawable/ic_nfc"
+        android:shortcutShortLabel="@string/card_pay_nfc"
+        android:shortcutLongLabel="@string/card_pay_nfc">
         <intent
-            android:action="sh.sar.basedbank.OPEN_PAY_WITH_CARD"
+            android:action="sh.sar.basedbank.TAP_TO_PAY"
             android:targetPackage="sh.sar.basedbank"
             android:targetClass="sh.sar.basedbank.MainActivity" />
         <categories android:name="android.shortcut.conversation" />