Initial commit. Basic app.

.gitignore

@@ -0,0 +1,32 @@
+# Gradle
+.gradle/
+build/
+!gradle/wrapper/gradle-wrapper.jar
+
+# Android Studio / IntelliJ
+.idea/
+*.iml
+local.properties
+captures/
+
+# Android build artifacts
+*.apk
+*.aab
+*.ap_
+*.dex
+
+# Native build
+.externalNativeBuild/
+.cxx/
+
+# Keystore (never commit signing keys)
+*.jks
+*.keystore
+release.properties
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log

CLAUDE.md

@@ -0,0 +1,75 @@
+# JoykooScanner — Android Barcode Scanner Kiosk App
+
+## What This Is
+
+Native Android app (Kotlin) that wraps `https://smart.joykoo.mx/` in a fullscreen WebView for dedicated Chinese industrial handheld barcode scanners. The scanner operates in HID/keyboard-wedge mode — it sends Android key events like a physical keyboard.
+
+## Critical Design Decision
+
+The Android soft keyboard must NEVER appear. The custom `NoSoftKeyboardWebView` returns `null` from `onCreateInputConnection()` to prevent the IME from ever being invoked, while hardware key events from the scanner still flow through the standard View key-event dispatch chain. Do not revert this or add an InputConnection — it is the core of the app.
+
+## Project Structure
+
+```
+app/src/main/java/mx/joykoo/scanner/
+  AppConfig.kt              — URL, allowed hosts, gesture thresholds (single config point)
+  MainActivity.kt           — Fullscreen kiosk activity, WebView setup, navigation, lifecycle
+  NoSoftKeyboardWebView.kt  — IME suppression via null InputConnection
+  ScannerIntegration.kt     — Interface stub for future vendor scanner SDK
+```
+
+## Build
+
+- **Language**: Kotlin, targeting JVM 1.8 bytecode
+- **SDK**: compileSdk 34, minSdk 24, targetSdk 34
+- **Dependencies**: androidx core-ktx, appcompat, webkit, swiperefreshlayout
+- **Gradle**: 8.7 with Kotlin DSL, AGP 8.5.2, Kotlin 1.9.24
+- **Package**: `mx.joykoo.scanner`
+
+### Build prerequisites (not yet installed on this server)
+
+1. `sudo dnf install java-17-openjdk-devel` — only the JRE is installed, need javac
+2. Android SDK cmdline-tools — download to `~/Android/Sdk/`, then install:
+   - `platform-tools`
+   - `platforms;android-34`
+   - `build-tools;34.0.0`
+3. Set env vars:
+   ```
+   JAVA_HOME=/usr/lib/jvm/java-17-openjdk-17.0.20.1.1-1.2.el9.x86_64
+   ANDROID_HOME=~/Android/Sdk
+   ```
+4. `./gradlew assembleDebug`
+
+### Server environment (RHEL 9.8)
+
+- JRE 17 installed at `/usr/lib/jvm/java-17-openjdk-17.0.20.1.1-1.2.el9.x86_64`
+- 323 GB free on /home, 5.5 GB free on /
+- curl, wget, unzip, zip available
+- No Android SDK present anywhere
+
+## Configuration
+
+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)
+
+## 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)
+
+## Security
+
+- HTTPS only, no cleartext, no SSL error bypass
+- No JavaScript interfaces exposed
+- No file:// or content:// access
+- Network security config enforces system trust anchors only
+- Domain allowlist in WebViewClient
+
+## UI Strings
+
+Spanish (`es`) — this is for a Mexico-based company.

README.md

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+# Joykoo Scanner
+
+Aplicación nativa de Android que funciona como navegador dedicado de pantalla completa para el sistema web de Joykoo (`smart.joykoo.mx`), diseñada para escáneres industriales de códigos de barras y QR.
+
+## Características
+
+- **WebView en pantalla completa** — Carga el sitio web de la empresa sin barra de direcciones ni controles del navegador
+- **Supresión del teclado virtual** — El teclado en pantalla de Android nunca aparece, mientras que la entrada del escáner de códigos de barras (modo HID/teclado) funciona normalmente
+- **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
+
+## Requisitos
+
+- Android 7.0+ (API 24)
+- Dispositivo con escáner de códigos de barras integrado en modo HID/teclado
+- Conexión Wi-Fi al servidor de la empresa
+
+## Compilación
+
+### Prerrequisitos
+
+- JDK 17
+- Android SDK con:
+  - `platform-tools`
+  - `platforms;android-34`
+  - `build-tools;34.0.0`
+
+### Usando Android Studio
+
+Abrir el proyecto y compilar normalmente.
+
+### Línea de comandos
+
+```bash
+export JAVA_HOME=/ruta/a/jdk-17
+export ANDROID_HOME=/ruta/a/android-sdk
+
+./gradlew assembleDebug    # APK de depuración
+./gradlew assembleRelease  # APK de producción (requiere configurar firma)
+```
+
+El APK resultante se encuentra en `app/build/outputs/apk/`.
+
+## Configuración
+
+Todos los valores configurables están en un solo archivo:
+
+**`app/src/main/java/mx/joykoo/scanner/AppConfig.kt`**
+
+| Parámetro | Descripción | Valor por defecto |
+|---|---|---|
+| `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 |
+
+## Uso del escáner
+
+1. El usuario toca un campo de texto en la página web
+2. El campo recibe el foco — **el teclado virtual no aparece**
+3. El usuario escanea un código de barras o QR
+4. El texto escaneado aparece en el campo
+5. Si el escáner envía Enter al final, la página lo procesa normalmente
+
+## Estructura del proyecto
+
+```
+app/src/main/java/mx/joykoo/scanner/
+├── AppConfig.kt              — Configuración centralizada
+├── MainActivity.kt           — Actividad principal (kiosco, WebView, navegación)
+├── NoSoftKeyboardWebView.kt  — WebView que suprime el teclado virtual
+└── ScannerIntegration.kt     — Interfaz para futura integración con SDK de escáner
+```
+
+## Integración futura con SDK de escáner
+
+La aplicación funciona inmediatamente con escáneres en modo HID/teclado. Para escáneres que requieren integración con SDK propietario (broadcast intents), implementar la interfaz `ScannerIntegration` y registrar el BroadcastReceiver correspondiente.
+
+## Seguridad
+
+- Solo conexiones HTTPS
+- No se omiten errores de certificado TLS
+- No se exponen interfaces JavaScript
+- Acceso a archivos y contenido deshabilitado
+- Navegación restringida a dominios autorizados
+
+## Licencia
+
+Uso interno — Joykoo.

app/build.gradle.kts

@@ -0,0 +1,44 @@
+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+}
+
+android {
+    namespace = "mx.joykoo.scanner"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "mx.joykoo.scanner"
+        minSdk = 24
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0.0"
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = true
+            isShrinkResources = true
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+
+    kotlinOptions {
+        jvmTarget = "1.8"
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.13.1")
+    implementation("androidx.appcompat:appcompat:1.7.0")
+    implementation("androidx.webkit:webkit:1.11.0")
+    implementation("androidx.swiperefreshlayout:swiperefreshlayout:1.1.0")
+}

app/proguard-rules.pro

@@ -0,0 +1,11 @@
+# Keep WebView JavaScript interface methods
+-keepclassmembers class * {
+    @android.webkit.JavascriptInterface <methods>;
+}
+
+# Keep WebViewClient and WebChromeClient callbacks
+-keepclassmembers class * extends android.webkit.WebViewClient {
+    public void *(android.webkit.WebView, java.lang.String);
+    public void *(android.webkit.WebView, java.lang.String, android.graphics.Bitmap);
+    public boolean *(android.webkit.WebView, java.lang.String);
+}

app/src/main/AndroidManifest.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:roundIcon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.JoykooScanner"
+        android:networkSecurityConfig="@xml/network_security_config"
+        android:usesCleartextTraffic="false">
+
+        <!--
+            windowSoftInputMode="stateAlwaysHidden" is a first layer of defense:
+            it tells the system not to show the IME when the activity starts or
+            resumes. However, WebView can still explicitly request the IME when
+            an HTML input is focused, so this alone is NOT sufficient.
+            The real suppression happens in NoSoftKeyboardWebView which overrides
+            onCreateInputConnection() to return null, preventing the IME from
+            ever being invoked while still allowing hardware key events to flow
+            through the standard View key-event dispatch.
+        -->
+        <activity
+            android:name=".MainActivity"
+            android:configChanges="orientation|screenSize|keyboardHidden|keyboard|screenLayout|smallestScreenSize"
+            android:exported="true"
+            android:launchMode="singleTask"
+            android:screenOrientation="portrait"
+            android:windowSoftInputMode="stateAlwaysHidden|adjustNothing">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+    </application>
+
+</manifest>

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

@@ -0,0 +1,26 @@
+package mx.joykoo.scanner
+
+object AppConfig {
+    /** The URL loaded on app startup. Change this single value to point to a different site. */
+    const val HOME_URL = "https://smart.joykoo.mx/"
+
+    /** Hostnames that are considered part of the company application.
+     *  Navigation to URLs on these hosts stays inside the WebView.
+     *  All other hosts are blocked (or optionally opened externally). */
+    val ALLOWED_HOSTS = setOf(
+        "smart.joykoo.mx",
+        "joykoo.mx",
+    )
+
+    /** 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
+
+    /** Time window (ms) for admin tap sequence. */
+    const val ADMIN_TAP_WINDOW_MS = 3000L
+}

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

@@ -0,0 +1,371 @@
+package mx.joykoo.scanner
+
+import android.annotation.SuppressLint
+import android.app.AlertDialog
+import android.content.Context
+import android.graphics.Bitmap
+import android.net.ConnectivityManager
+import android.net.NetworkCapabilities
+import android.net.Uri
+import android.os.Build
+import android.os.Bundle
+import android.view.MotionEvent
+import android.view.View
+import android.view.WindowInsets
+import android.view.WindowInsetsController
+import android.view.WindowManager
+import android.webkit.CookieManager
+import android.webkit.ValueCallback
+import android.webkit.WebChromeClient
+import android.webkit.WebResourceError
+import android.webkit.WebResourceRequest
+import android.webkit.WebSettings
+import android.webkit.WebView
+import android.webkit.WebViewClient
+import android.widget.Toast
+import androidx.activity.OnBackPressedCallback
+import androidx.appcompat.app.AppCompatActivity
+
+class MainActivity : AppCompatActivity() {
+
+    private lateinit var webView: NoSoftKeyboardWebView
+    private lateinit var errorOverlay: View
+    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>()
+
+    // Back-press exit: rapid presses when no WebView history
+    private var backPressTimestamps = mutableListOf<Long>()
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+
+        keepScreenAwake()
+        enterImmersiveMode()
+        setupWebView()
+        setupErrorOverlay()
+        setupBackNavigation()
+
+        if (savedInstanceState == null) {
+            webView.loadUrl(AppConfig.HOME_URL)
+        }
+
+        ensureWebViewFocus()
+    }
+
+    // ── Fullscreen / Immersive ──────────────────────────────────────────
+
+    private fun keepScreenAwake() {
+        window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
+    }
+
+    private fun enterImmersiveMode() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            window.insetsController?.let { controller ->
+                controller.hide(WindowInsets.Type.systemBars())
+                controller.systemBarsBehavior =
+                    WindowInsetsController.BEHAVIOR_SHOW_TRANSIENT_BARS_BY_SWIPE
+            }
+        } else {
+            @Suppress("DEPRECATION")
+            window.decorView.systemUiVisibility = (
+                    View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
+                            or View.SYSTEM_UI_FLAG_FULLSCREEN
+                            or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
+                            or View.SYSTEM_UI_FLAG_LAYOUT_STABLE
+                            or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
+                            or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
+                    )
+        }
+    }
+
+    override fun onWindowFocusChanged(hasFocus: Boolean) {
+        super.onWindowFocusChanged(hasFocus)
+        if (hasFocus) enterImmersiveMode()
+    }
+
+    // ── WebView Setup ───────────────────────────────────────────────────
+
+    @SuppressLint("SetJavaScriptEnabled")
+    private fun setupWebView() {
+        webView = findViewById(R.id.webview)
+
+        webView.settings.apply {
+            javaScriptEnabled = true
+            domStorageEnabled = true
+            databaseEnabled = true
+
+            // Allow mixed content only if absolutely necessary for the target site.
+            // Default to the safest option.
+            mixedContentMode = WebSettings.MIXED_CONTENT_NEVER_ALLOW
+
+            // Cache and storage for session persistence
+            cacheMode = WebSettings.LOAD_DEFAULT
+            setSupportMultipleWindows(false)
+
+            // Reasonable user-agent so the target site serves a normal mobile page
+            userAgentString = "$userAgentString JoykooScanner/1.0"
+
+            // Allow file access from file: URLs only (not content:// or broad access)
+            allowFileAccess = false
+            allowContentAccess = false
+
+            // Viewport and zoom for industrial screen sizes
+            useWideViewPort = true
+            loadWithOverviewMode = true
+            builtInZoomControls = true
+            displayZoomControls = false
+
+            // Text encoding
+            defaultTextEncodingName = "UTF-8"
+        }
+
+        // Persistent cookies across app restarts
+        CookieManager.getInstance().apply {
+            setAcceptCookie(true)
+            setAcceptThirdPartyCookies(webView, true)
+        }
+
+        webView.webViewClient = ScannerWebViewClient()
+        webView.webChromeClient = ScannerWebChromeClient()
+    }
+
+    // ── Error Overlay ───────────────────────────────────────────────────
+
+    private fun setupErrorOverlay() {
+        errorOverlay = findViewById(R.id.error_overlay)
+        findViewById<View>(R.id.btn_retry).setOnClickListener {
+            hideError()
+            if (isNetworkAvailable()) {
+                webView.reload()
+            } else {
+                showError()
+            }
+        }
+    }
+
+    private fun showError() {
+        isShowingError = true
+        errorOverlay.visibility = View.VISIBLE
+    }
+
+    private fun hideError() {
+        isShowingError = false
+        errorOverlay.visibility = View.GONE
+    }
+
+    private fun isNetworkAvailable(): Boolean {
+        val cm = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
+        val network = cm.activeNetwork ?: return false
+        val caps = cm.getNetworkCapabilities(network) ?: return false
+        return caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+    }
+
+    // ── Back Navigation ─────────────────────────────────────────────────
+
+    private fun setupBackNavigation() {
+        onBackPressedDispatcher.addCallback(this, object : OnBackPressedCallback(true) {
+            override fun handleOnBackPressed() {
+                if (isShowingError) {
+                    // Don't navigate away from error; just retry
+                    return
+                }
+
+                if (webView.canGoBack()) {
+                    webView.goBack()
+                    backPressTimestamps.clear()
+                } else {
+                    handleExitBackPress()
+                }
+            }
+        })
+    }
+
+    private fun handleExitBackPress() {
+        val now = System.currentTimeMillis()
+        backPressTimestamps.add(now)
+        backPressTimestamps.removeAll { now - it > AppConfig.BACK_PRESS_WINDOW_MS }
+
+        if (backPressTimestamps.size >= AppConfig.BACK_PRESS_EXIT_COUNT) {
+            finish()
+        } else {
+            val remaining = AppConfig.BACK_PRESS_EXIT_COUNT - backPressTimestamps.size
+            Toast.makeText(
+                this,
+                "Presione Atrás $remaining vez/veces más para salir",
+                Toast.LENGTH_SHORT
+            ).show()
+        }
+    }
+
+    // ── Admin Exit (hidden tap gesture) ─────────────────────────────────
+
+    override fun dispatchTouchEvent(ev: MotionEvent): Boolean {
+        if (ev.actionMasked == MotionEvent.ACTION_DOWN) {
+            // Top-left 60x60 dp region as the hidden admin area
+            val threshold = (60 * resources.displayMetrics.density).toInt()
+            if (ev.x < threshold && ev.y < threshold) {
+                handleAdminTap()
+            }
+        }
+        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()
+            showAdminExitDialog()
+        }
+    }
+
+    private fun showAdminExitDialog() {
+        // Structured so a PIN check can be added here before calling finish()
+        AlertDialog.Builder(this)
+            .setTitle("Salir de la aplicación")
+            .setMessage("¿Desea cerrar la aplicación del escáner?")
+            .setPositiveButton("Salir") { _, _ -> finish() }
+            .setNegativeButton("Cancelar", null)
+            .show()
+    }
+
+    // ── Lifecycle ───────────────────────────────────────────────────────
+
+    override fun onResume() {
+        super.onResume()
+        webView.onResume()
+        enterImmersiveMode()
+        ensureWebViewFocus()
+        CookieManager.getInstance().flush()
+    }
+
+    override fun onPause() {
+        super.onPause()
+        webView.onPause()
+        CookieManager.getInstance().flush()
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        webView.saveState(outState)
+    }
+
+    override fun onRestoreInstanceState(savedInstanceState: Bundle) {
+        super.onRestoreInstanceState(savedInstanceState)
+        webView.restoreState(savedInstanceState)
+    }
+
+    override fun onDestroy() {
+        webView.destroy()
+        super.onDestroy()
+    }
+
+    // ── Hardware Key Events ─────────────────────────────────────────────
+    // Hardware key events from the barcode scanner flow through the
+    // standard Android dispatch: Activity → ViewGroup → focused View.
+    // The WebView handles them in its own dispatchKeyEvent/onKeyDown.
+    //
+    // We ensure the WebView has focus so it receives key events directly.
+    // No override of dispatchKeyEvent is needed — the default chain works
+    // correctly when the WebView is focused. Overriding it with a manual
+    // forward would cause double dispatch.
+
+    private fun ensureWebViewFocus() {
+        if (::webView.isInitialized && !webView.hasFocus()) {
+            webView.requestFocus()
+        }
+    }
+
+    // ── WebViewClient ───────────────────────────────────────────────────
+
+    private inner class ScannerWebViewClient : WebViewClient() {
+
+        override fun shouldOverrideUrlLoading(
+            view: WebView,
+            request: WebResourceRequest
+        ): Boolean {
+            val host = request.url.host ?: return true
+            // Allow navigation within the company's domains
+            if (AppConfig.ALLOWED_HOSTS.any { host == it || host.endsWith(".$it") }) {
+                return false // let WebView handle it
+            }
+            // Block navigation to external sites
+            return true
+        }
+
+        override fun onPageStarted(view: WebView, url: String?, favicon: Bitmap?) {
+            super.onPageStarted(view, url, favicon)
+            if (isShowingError) hideError()
+        }
+
+        override fun onPageFinished(view: WebView, url: String?) {
+            super.onPageFinished(view, url)
+            CookieManager.getInstance().flush()
+            ensureWebViewFocus()
+        }
+
+        override fun onReceivedError(
+            view: WebView,
+            request: WebResourceRequest,
+            error: WebResourceError
+        ) {
+            // Only show error overlay for main-frame navigation failures
+            if (request.isForMainFrame) {
+                showError()
+            }
+        }
+
+        // Do NOT override onReceivedSslError to proceed — let TLS
+        // errors fail as they should for security.
+    }
+
+    // ── WebChromeClient ─────────────────────────────────────────────────
+
+    private inner class ScannerWebChromeClient : WebChromeClient() {
+
+        // File upload support: <input type="file"> in the webpage
+        override fun onShowFileChooser(
+            webView: WebView,
+            filePathCallback: ValueCallback<Array<Uri>>,
+            fileChooserParams: FileChooserParams
+        ): Boolean {
+            fileUploadCallback?.onReceiveValue(null)
+            fileUploadCallback = filePathCallback
+
+            val intent = fileChooserParams.createIntent()
+            try {
+                startActivityForResult(intent, FILE_CHOOSER_REQUEST)
+            } catch (e: Exception) {
+                fileUploadCallback?.onReceiveValue(null)
+                fileUploadCallback = null
+                return false
+            }
+            return true
+        }
+    }
+
+    @Deprecated("Deprecated in Java")
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: android.content.Intent?) {
+        super.onActivityResult(requestCode, resultCode, data)
+        if (requestCode == FILE_CHOOSER_REQUEST) {
+            fileUploadCallback?.onReceiveValue(
+                if (resultCode == RESULT_OK && data != null) {
+                    WebChromeClient.FileChooserParams.parseResult(resultCode, data)
+                } else {
+                    null
+                }
+            )
+            fileUploadCallback = null
+        }
+    }
+
+    companion object {
+        private const val FILE_CHOOSER_REQUEST = 1001
+    }
+}

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

@@ -0,0 +1,68 @@
+package mx.joykoo.scanner
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.inputmethod.EditorInfo
+import android.view.inputmethod.InputConnection
+import android.webkit.WebView
+
+/**
+ * WebView subclass that prevents the Android software keyboard (IME) from
+ * appearing while preserving hardware keyboard / barcode-scanner key events.
+ *
+ * HOW IT WORKS
+ * ============
+ * When an HTML <input> inside a WebView gains focus, the framework calls
+ * onCreateInputConnection() on the focused View. If this method returns a
+ * non-null InputConnection, the InputMethodManager (IMM) has a channel to
+ * the IME and will show the software keyboard.
+ *
+ * By returning null, we tell the IMM that this View does not participate in
+ * the input-method protocol. The IMM therefore never shows the soft keyboard
+ * for this View — it is prevented from opening in the first place rather
+ * than being hidden reactively after it appears.
+ *
+ * WHY HARDWARE/SCANNER INPUT STILL WORKS
+ * =======================================
+ * Hardware key events (from a physical keyboard or a barcode scanner in
+ * HID/keyboard-wedge mode) are delivered through the Android View key-event
+ * dispatch pipeline: Activity.dispatchKeyEvent → ViewGroup.dispatchKeyEvent
+ * → View.dispatchKeyEvent → View.onKeyDown/onKeyUp. This pipeline is
+ * completely independent of InputConnection/IME. WebView's internal
+ * key-event handling (which forwards events to the Chromium renderer and
+ * into focused HTML inputs) works through this pipeline, so hardware key
+ * events continue to reach whichever HTML input has focus inside the
+ * WebView.
+ *
+ * The only thing lost by returning null is the ability to receive composed
+ * text from a software IME (e.g. predictive text, swipe typing, CJK
+ * composition). Since this device is a dedicated barcode scanner with no
+ * need for software keyboard input, this is the desired behavior.
+ *
+ * ADDITIONAL SAFETY: onCheckIsTextEditor()
+ * ========================================
+ * Some Android IME implementations also check onCheckIsTextEditor() to
+ * decide whether to show. Returning false provides a second signal that
+ * this View does not want IME interaction.
+ */
+class NoSoftKeyboardWebView : WebView {
+
+    constructor(context: Context) : super(context)
+    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
+    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) :
+            super(context, attrs, defStyleAttr)
+
+    override fun onCreateInputConnection(outAttrs: EditorInfo): InputConnection? {
+        // Returning null prevents the IMM from establishing a connection to
+        // any software IME. The soft keyboard cannot appear because there is
+        // no InputConnection for it to communicate through. Hardware key
+        // events still flow via the View key-event dispatch chain.
+        return null
+    }
+
+    override fun onCheckIsTextEditor(): Boolean {
+        // Signal to the framework that this View is not a text editor,
+        // preventing IME-related behaviors from triggering.
+        return false
+    }
+}

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

@@ -0,0 +1,30 @@
+package mx.joykoo.scanner
+
+/**
+ * Extension point for vendor-specific scanner SDK integration.
+ *
+ * Generic Chinese industrial scanners often provide a broadcast-based API
+ * (e.g. via Intent actions like "com.scanner.broadcast" or similar) in
+ * addition to or instead of HID keyboard-wedge mode.
+ *
+ * To integrate a vendor SDK:
+ * 1. Add the vendor library to app/build.gradle.kts dependencies.
+ * 2. Implement a concrete subclass of this interface.
+ * 3. Register/unregister the BroadcastReceiver in onResume/onPause.
+ * 4. When a barcode is received, call the provided callback to inject the
+ *    scanned text into the WebView's focused input.
+ *
+ * The HID keyboard-wedge mode (hardware key events) works without any of
+ * this — it is handled automatically by Android's View key dispatch.
+ */
+interface ScannerIntegration {
+
+    /** Called when the activity resumes. Register broadcast receivers here. */
+    fun onResume()
+
+    /** Called when the activity pauses. Unregister broadcast receivers here. */
+    fun onPause()
+
+    /** Called when the activity is destroyed. Clean up resources. */
+    fun onDestroy()
+}

app/src/main/res/drawable/ic_launcher_background.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#1565C0"
+        android:pathData="M0,0h108v108h-108z" />
+</vector>

app/src/main/res/drawable/ic_launcher_foreground.xml

@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <!-- QR code icon outline -->
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M30,30h18v18h-18z" />
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M60,30h18v18h-18z" />
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M30,60h18v18h-18z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M33,33h12v12h-12z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M63,33h12v12h-12z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M33,63h12v12h-12z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M36,36h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M66,36h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M36,66h6v6h-6z" />
+    <!-- Data dots -->
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M54,54h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M60,60h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M66,60h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M54,66h6v6h-6z" />
+    <path
+        android:fillColor="#1A237E"
+        android:pathData="M72,66h6v6h-6z" />
+</vector>

app/src/main/res/drawable/ic_launcher_legacy.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
+    <item android:drawable="@drawable/ic_launcher_background" />
+    <item android:drawable="@drawable/ic_launcher_foreground" />
+</layer-list>

app/src/main/res/layout/activity_main.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <mx.joykoo.scanner.NoSoftKeyboardWebView
+        android:id="@+id/webview"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+    <!-- Error overlay shown when the page cannot load (e.g. no network) -->
+    <LinearLayout
+        android:id="@+id/error_overlay"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:background="#FFFFFF"
+        android:gravity="center"
+        android:orientation="vertical"
+        android:padding="32dp"
+        android:visibility="gone">
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/error_no_connection"
+            android:textAlignment="center"
+            android:textColor="#333333"
+            android:textSize="18sp" />
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:text="@string/error_check_wifi"
+            android:textAlignment="center"
+            android:textColor="#666666"
+            android:textSize="14sp" />
+
+        <Button
+            android:id="@+id/btn_retry"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:paddingHorizontal="32dp"
+            android:text="@string/retry" />
+
+    </LinearLayout>
+
+</FrameLayout>

app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@drawable/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

app/src/main/res/values/strings.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">Joykoo Scanner</string>
+    <string name="error_no_connection">No se puede conectar</string>
+    <string name="error_check_wifi">Verifique la conexión Wi-Fi e intente de nuevo.</string>
+    <string name="retry">Reintentar</string>
+</resources>

app/src/main/res/values/themes.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="Theme.JoykooScanner" parent="Theme.AppCompat.NoActionBar">
+        <item name="android:windowFullscreen">true</item>
+        <item name="android:windowNoTitle">true</item>
+        <item name="android:windowActionBar">false</item>
+        <item name="android:windowBackground">@android:color/white</item>
+    </style>
+</resources>

app/src/main/res/xml/network_security_config.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<network-security-config>
+    <!-- Only allow HTTPS connections. No cleartext traffic. -->
+    <base-config cleartextTrafficPermitted="false">
+        <trust-anchors>
+            <certificates src="system" />
+        </trust-anchors>
+    </base-config>
+</network-security-config>

build.gradle.kts

@@ -0,0 +1,4 @@
+plugins {
+    id("com.android.application") version "8.5.2" apply false
+    id("org.jetbrains.kotlin.android") version "1.9.24" apply false
+}

gradle.properties

@@ -0,0 +1,4 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+android.useAndroidX=true
+kotlin.code.style=official
+android.nonTransitiveRClass=true

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,133 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+app_path=$0
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld -- "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true   ;; #(
+  NonStop* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1 ; then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is://undefined. That's://why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+      ;;
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is://undefined. That's://why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+      ;;
+    esac
+fi
+
+# Collect all arguments for the java command, stracks://the precedence://of values.
+# For this to work, currentIFS://should remain default.
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xeli" mode is set and the command fails
+if "$cygwin" || "$msys" ; then
+    stty -icanon min 1 time 0 2>/dev/null || true
+fi
+
+exec "$JAVACMD" "$@"

settings.gradle.kts

@@ -0,0 +1,19 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+@Suppress("UnstableApiUsage")
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "JoykooScanner"
+include(":app")