Replace corner-tap admin gesture with volume-key hold and admin barcode

The 7-tap top-left corner gesture passed every tap through to the page,
triggering site UI underneath it. Remove it entirely and open the admin
dialog (exit / toggle soft keyboard) by either:

- holding Volume Up + Volume Down together for 5 seconds; volume keys
  are consumed so they never reach the page, or
- scanning AppConfig.ADMIN_BARCODE in Intent output mode, which opens
  the dialog instead of being injected into the page.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -20,7 +20,7 @@ The real `InputConnection` from `super.onCreateInputConnection()` **must be retu
 
 ```
 app/src/main/java/mx/joykoo/scanner/
-  AppConfig.kt              — URL, allowed hosts, gesture thresholds (single config point)
+  AppConfig.kt              — URL, allowed hosts, admin triggers, scanner broadcasts (single config point)
   MainActivity.kt           — Fullscreen kiosk activity, WebView setup, navigation, lifecycle
   NoSoftKeyboardWebView.kt  — IME suppression via null InputConnection
   ScannerIntegration.kt     — Scanner lifecycle interface
@@ -62,14 +62,15 @@ All configurable values are in `AppConfig.kt`:
 - `HOME_URL` — the webpage to load
 - `ALLOWED_HOSTS` — domains that stay inside the WebView
 - `BACK_PRESS_EXIT_COUNT` / `BACK_PRESS_WINDOW_MS` — back-button exit guard
-- `ADMIN_TAP_COUNT` / `ADMIN_TAP_WINDOW_MS` — hidden admin exit gesture (7 taps top-left corner)
+- `ADMIN_VOLUME_HOLD_MS` — hold Volume Up + Volume Down this long to open the admin dialog
+- `ADMIN_BARCODE` — scanning this value (Intent mode) opens the admin dialog
 
 ## Navigation Rules
 
 - URLs on `joykoo.mx` or `smart.joykoo.mx` (and subdomains) load inside the WebView
 - All other URLs are silently blocked
 - Back button goes back in WebView history; 3 rapid presses exits when no history
-- Admin exit: 7 rapid taps in top-left 60dp corner → confirmation dialog (PIN-ready stub)
+- Admin dialog (exit / toggle soft keyboard): hold both volume keys 5 s, or scan `ADMIN_BARCODE`. Volume keys are consumed and never reach the page. No touch gestures — corner taps leaked through to site UI
 
 ## Security
 

README.md

@@ -9,7 +9,7 @@ Aplicación nativa de Android que funciona como navegador dedicado de pantalla c
 - **Modo kiosco** — Pantalla siempre encendida, modo inmersivo, navegación restringida al dominio de la empresa
 - **Persistencia de sesión** — Cookies y almacenamiento local persisten entre reinicios de la aplicación
 - **Manejo de errores de red** — Pantalla de reintento cuando no hay conexión Wi-Fi
-- **Salida protegida** — Se requieren 3 pulsaciones rápidas del botón Atrás para salir; gesto oculto de administrador (7 toques en esquina superior izquierda) con diálogo de confirmación
+- **Salida protegida** — Se requieren 3 pulsaciones rápidas del botón Atrás para salir; menú de administrador (salir / mostrar u ocultar teclado) al mantener presionados Subir y Bajar volumen 5 segundos, o al escanear el código de administrador
 
 ## Requisitos
 
@@ -54,7 +54,8 @@ Todos los valores configurables están en un solo archivo:
 | `HOME_URL` | URL que se carga al iniciar | `https://smart.joykoo.mx/` |
 | `ALLOWED_HOSTS` | Dominios permitidos dentro del WebView | `smart.joykoo.mx`, `joykoo.mx` |
 | `BACK_PRESS_EXIT_COUNT` | Pulsaciones rápidas de Atrás para salir | 3 |
-| `ADMIN_TAP_COUNT` | Toques en esquina superior izquierda para menú de administrador | 7 |
+| `ADMIN_VOLUME_HOLD_MS` | Tiempo (ms) con ambos botones de volumen presionados para abrir el menú de administrador | 5000 |
+| `ADMIN_BARCODE` | Código que, al escanearse (modo Intent), abre el menú de administrador | `JOYKOO-ADMIN-…` |
 
 ## Uso del escáner
 

app/src/main/java/mx/joykoo/scanner/AppConfig.kt

@@ -12,20 +12,18 @@ object AppConfig {
         "joykoo.mx",
     )
 
-    /** Size in dp of the corner regions used for hidden tap gestures. */
-    const val GESTURE_CORNER_DP = 60
-
     /** Number of rapid Back presses required to exit the app when there is no WebView history. */
     const val BACK_PRESS_EXIT_COUNT = 3
 
     /** Time window (ms) in which BACK_PRESS_EXIT_COUNT presses must occur to exit. */
     const val BACK_PRESS_WINDOW_MS = 2000L
 
-    /** Number of taps on the hidden admin area required to trigger the admin exit. */
-    const val ADMIN_TAP_COUNT = 7
+    /** How long (ms) Volume Up + Volume Down must be held together to open the admin dialog. */
+    const val ADMIN_VOLUME_HOLD_MS = 5000L
 
-    /** Time window (ms) for admin tap sequence. */
-    const val ADMIN_TAP_WINDOW_MS = 3000L
+    /** Scanning a barcode with exactly this value opens the admin dialog instead of
+     *  being typed into the page (Intent output mode only). Print it as a QR/Code128. */
+    const val ADMIN_BARCODE = "JOYKOO-ADMIN-O4306IFH9AUJ"
 
     /** Broadcast actions sent by scanners in "Intent output" mode (Urovo first, then
      *  other common Chinese vendors). Add the device's action here if it differs. */

app/src/main/java/mx/joykoo/scanner/MainActivity.kt

@@ -11,7 +11,6 @@ import android.os.Build
 import android.os.Bundle
 import android.util.Log
 import android.view.KeyEvent
-import android.view.MotionEvent
 import android.view.View
 import android.view.WindowInsets
 import android.view.WindowInsetsController
@@ -41,8 +40,9 @@ class MainActivity : AppCompatActivity() {
     private var fileUploadCallback: ValueCallback<Array<Uri>>? = null
     private var isShowingError = false
 
-    // Admin exit: rapid taps in the top-left corner
-    private var adminTapTimestamps = mutableListOf<Long>()
+    // Admin dialog: hold Volume Up + Volume Down, or scan AppConfig.ADMIN_BARCODE
+    private val volumeKeysDown = mutableSetOf<Int>()
+    private val adminHoldRunnable = Runnable { showAdminDialog() }
     private var isKeyboardSuppressed = true
 
     // Back-press exit: rapid presses when no WebView history
@@ -57,7 +57,7 @@ class MainActivity : AppCompatActivity() {
         setupWebView()
         setupErrorOverlay()
         setupBackNavigation()
-        scanner = BroadcastScannerIntegration(this, ::injectScannedText)
+        scanner = BroadcastScannerIntegration(this, ::onBarcodeScanned)
 
         if (savedInstanceState == null) {
             webView.loadUrl(AppConfig.HOME_URL)
@@ -214,30 +214,29 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
-    // ── Admin Exit (hidden tap gesture) ─────────────────────────────────
+    // ── Admin Dialog ────────────────────────────────────────────────────
+    // Opened by holding both volume keys (see dispatchKeyEvent) or by scanning
+    // AppConfig.ADMIN_BARCODE. Neither touches the page, unlike a tap gesture.
 
-    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
-        if (ev.actionMasked == MotionEvent.ACTION_DOWN) {
-            val threshold = (AppConfig.GESTURE_CORNER_DP * resources.displayMetrics.density).toInt()
-            if (ev.x < threshold && ev.y < threshold) {
-                handleAdminTap()
+    private fun handleVolumeKey(event: KeyEvent) {
+        when (event.action) {
+            KeyEvent.ACTION_DOWN -> if (event.repeatCount == 0) {
+                volumeKeysDown.add(event.keyCode)
+                if (volumeKeysDown.size == 2) {
+                    webView.postDelayed(adminHoldRunnable, AppConfig.ADMIN_VOLUME_HOLD_MS)
+                }
+            }
+            KeyEvent.ACTION_UP -> {
+                volumeKeysDown.remove(event.keyCode)
+                webView.removeCallbacks(adminHoldRunnable)
             }
-        }
-        return super.dispatchTouchEvent(ev)
-    }
-
-    private fun handleAdminTap() {
-        val now = System.currentTimeMillis()
-        adminTapTimestamps.add(now)
-        adminTapTimestamps.removeAll { now - it > AppConfig.ADMIN_TAP_WINDOW_MS }
-
-        if (adminTapTimestamps.size >= AppConfig.ADMIN_TAP_COUNT) {
-            adminTapTimestamps.clear()
-            showAdminDialog()
         }
     }
 
     private fun showAdminDialog() {
+        // The dialog takes focus, so the volume key-ups never reach us.
+        volumeKeysDown.clear()
+        webView.removeCallbacks(adminHoldRunnable)
         val keyboardLabel = if (isKeyboardSuppressed)
             getString(R.string.keyboard_show) else getString(R.string.keyboard_hide)
         AlertDialog.Builder(this)
@@ -311,6 +310,11 @@ class MainActivity : AppCompatActivity() {
     override fun dispatchKeyEvent(event: KeyEvent): Boolean {
         Log.d(TAG, "Key ${event.action} code=${event.keyCode} char=${event.unicodeChar} " +
                 "chars=${event.characters} dev=${event.deviceId} focus=${currentFocus?.javaClass?.simpleName}")
+        // Volume keys are reserved for the admin combo and never reach the page.
+        if (event.keyCode == KeyEvent.KEYCODE_VOLUME_UP || event.keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
+            handleVolumeKey(event)
+            return true
+        }
         return super.dispatchKeyEvent(event)
     }
 
@@ -320,6 +324,10 @@ class MainActivity : AppCompatActivity() {
     // which is what React-controlled inputs need to pick up the change —
     // assigning el.value directly is silently discarded by React.
 
+    private fun onBarcodeScanned(text: String) {
+        if (text == AppConfig.ADMIN_BARCODE) showAdminDialog() else injectScannedText(text)
+    }
+
     private fun injectScannedText(text: String) {
         if (!::webView.isInitialized) return
         ensureWebViewFocus()