InternetPreferenceController V2 (2/n)

Add ConnectivityRepository, when no validated connection,
show "Airplane mode is on" or "Networks available".

Bug: 339884322
Flag: com.android.settings.flags.internet_preference_controller_v2
Test: manual - on Internet
Test: unit test
Change-Id: I227d896fd52c099fb6d58a7ab60e98983fdab8cf

src/com/android/settings/network/ConnectivityRepository.kt

@@ -0,0 +1,63 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+package com.android.settings.network
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.ConnectivityManager.NetworkCallback
+import android.net.Network
+import android.net.NetworkCapabilities
+import android.util.Log
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.conflate
+import kotlinx.coroutines.flow.flowOn
+
+class ConnectivityRepository(context: Context) {
+    private val connectivityManager = context.getSystemService(ConnectivityManager::class.java)!!
+
+    fun networkCapabilitiesFlow(): Flow<NetworkCapabilities> = callbackFlow {
+        val callback = object : NetworkCallback() {
+            override fun onCapabilitiesChanged(
+                network: Network,
+                networkCapabilities: NetworkCapabilities,
+            ) {
+                trySend(networkCapabilities)
+                Log.d(TAG, "onCapabilitiesChanged: $networkCapabilities")
+            }
+
+            override fun onLost(network: Network) {
+                trySend(NetworkCapabilities())
+                Log.d(TAG, "onLost")
+            }
+        }
+        trySend(getNetworkCapabilities())
+        connectivityManager.registerDefaultNetworkCallback(callback)
+
+        awaitClose { connectivityManager.unregisterNetworkCallback(callback) }
+    }.conflate().flowOn(Dispatchers.Default)
+
+    private fun getNetworkCapabilities(): NetworkCapabilities =
+        connectivityManager.getNetworkCapabilities(connectivityManager.activeNetwork)
+            ?: NetworkCapabilities()
+
+    private companion object {
+        private const val TAG = "ConnectivityRepository"
+    }
+}