use engine caching

app/android/app/src/main/AndroidManifest.xml

@@ -6,6 +6,7 @@
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_SPECIAL_USE" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_REMOTE_MESSAGING" />
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />
 
     <uses-permission android:name="android.permission.RECORD_AUDIO" />
     <uses-permission android:name="android.permission.CAMERA" />
@@ -50,7 +51,7 @@
     
     <application
         android:label="Lensai"
-        android:name="${applicationName}"
+        android:name=".MyApplication"
         android:icon="@mipmap/launcher_icon"
         android:usesCleartextTraffic="true"
         android:enableOnBackInvokedCallback="true">

app/android/app/src/main/kotlin/me/movenext/bang_navigator/MainActivity.kt

@@ -1,7 +1,10 @@
 package me.movenext.bang_navigator
 
+import android.content.Context
+import android.os.Bundle
 import io.flutter.embedding.android.FlutterFragmentActivity
 import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.embedding.engine.FlutterEngineCache
 import io.flutter.plugin.common.MethodChannel
 
 class MainActivity: FlutterFragmentActivity() {
@@ -10,6 +13,7 @@ class MainActivity: FlutterFragmentActivity() {
 
     override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
         super.configureFlutterEngine(flutterEngine)
+
         channel = MethodChannel(flutterEngine.dartExecutor.binaryMessenger, CHANNEL)
     }
 
@@ -17,4 +21,12 @@ class MainActivity: FlutterFragmentActivity() {
         super.onTrimMemory(level)
         channel.invokeMethod("onTrimMemory", level)
     }
+
+    override fun getCachedEngineId(): String {
+        return "engine_id"
+    }
+
+    override fun shouldDestroyEngineWithHost(): Boolean {
+        return false // Keep engine alive when activity is destroyed
+    }
 }

app/android/app/src/main/kotlin/me/movenext/bang_navigator/MyApplication.kt

@@ -0,0 +1,46 @@
+package me.movenext.bang_navigator
+
+import android.app.ActivityManager
+import android.app.Application
+import android.content.Context
+import android.util.Log
+import io.flutter.embedding.engine.FlutterEngine
+import io.flutter.embedding.engine.FlutterEngineCache
+import io.flutter.embedding.engine.dart.DartExecutor
+
+class MyApplication : Application() {
+    private fun getProcessNameCompat(): String {
+        // Try to get process name from ActivityManager
+        val pid = android.os.Process.myPid()
+        val manager = getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
+
+        for (processInfo in manager.runningAppProcesses) {
+            if (processInfo.pid == pid) {
+                return processInfo.processName
+            }
+        }
+
+        // Fallback to package name if process name cannot be determined
+        return packageName
+    }
+
+    override fun onCreate() {
+        super.onCreate()
+
+        val processName = getProcessNameCompat()
+        // Only initialize Flutter engine in the main process
+        if (processName == packageName) {
+            // Initialize the Flutter engine
+            val flutterEngine = FlutterEngine(this)
+
+            // Pre-warm the Flutter engine with your initial route
+            flutterEngine.navigationChannel.setInitialRoute("/")
+            flutterEngine.dartExecutor.executeDartEntrypoint(
+                DartExecutor.DartEntrypoint.createDefault()
+            )
+
+            // Cache the Flutter engine
+            FlutterEngineCache.getInstance().put("engine_id", flutterEngine)
+        }
+    }
+}