Refactor app. Update obsolete APIs, make jetpack friendly, update files

BluetoothLeChat/app/build.gradle

@@ -1,11 +1,11 @@
 /*
- * Copyright 2020 Google LLC
+ * Copyright (C) 2021 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
  *
- *     https://www.apache.org/licenses/LICENSE-2.0
+ *      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,
@@ -54,13 +54,14 @@ android {
 dependencies {
     implementation fileTree(dir: "libs", include: ["*.jar"])
     implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
-    implementation 'androidx.core:core-ktx:1.3.1'
-    implementation 'androidx.fragment:fragment-ktx:1.3.0-alpha08'
-    implementation 'androidx.activity:activity-ktx:1.2.0-alpha08'
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.1'
+    implementation 'androidx.core:core-ktx:1.3.2'
+    implementation 'androidx.fragment:fragment-ktx:1.3.4'
+    implementation 'androidx.activity:activity-ktx:1.3.0-alpha08'
     implementation 'androidx.appcompat:appcompat:1.2.0'
-    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0'
-    implementation 'androidx.constraintlayout:constraintlayout:2.0.1'
-    implementation 'androidx.recyclerview:recyclerview:1.1.0'
-    implementation "androidx.navigation:navigation-fragment-ktx:2.3.0"
-    implementation "androidx.navigation:navigation-ui-ktx:2.3.0"
+    implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1'
+    implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
+    implementation 'androidx.recyclerview:recyclerview:1.2.0'
+    implementation "androidx.navigation:navigation-fragment-ktx:2.3.5"
+    implementation "androidx.navigation:navigation-ui-ktx:2.3.5"
 }

BluetoothLeChat/app/src/main/AndroidManifest.xml

@@ -8,7 +8,7 @@
     <uses-feature android:name="android.hardware.bluetooth_le" android:required="true"/>
 
     <application
-        android:allowBackup="true"
+        android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/MainActivity.kt

@@ -15,8 +15,8 @@
  */
 package com.example.bluetoothlechat
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
 import com.example.bluetoothlechat.bluetooth.ChatServer
 
 class MainActivity : AppCompatActivity() {

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/bluetooth/ChatServer.kt

@@ -13,6 +13,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+/**
+ * Allows such property names as '_messages'
+ */
+@file:Suppress("ObjectPropertyName")
+
 package com.example.bluetoothlechat.bluetooth
 
 import android.app.Application
@@ -36,6 +42,7 @@ object ChatServer {
     // hold reference to app context to run the chat server
     private var app: Application? = null
     private lateinit var bluetoothManager: BluetoothManager
+
     // BluetoothAdapter should never be null if the app is installed from the Play store
     // since BLE is required per the <uses-feature> tag in the AndroidManifest.xml.
     // If the app is installed on an emulator without bluetooth then the app will crash
@@ -258,7 +265,15 @@ object ChatServer {
             offset: Int,
             value: ByteArray?
         ) {
-            super.onCharacteristicWriteRequest(device, requestId, characteristic, preparedWrite, responseNeeded, offset, value)
+            super.onCharacteristicWriteRequest(
+                device,
+                requestId,
+                characteristic,
+                preparedWrite,
+                responseNeeded,
+                offset,
+                value
+            )
             if (characteristic.uuid == MESSAGE_UUID) {
                 gattServer?.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, 0, null)
                 val message = value?.toString(Charsets.UTF_8)
@@ -275,7 +290,10 @@ object ChatServer {
             super.onConnectionStateChange(gatt, status, newState)
             val isSuccess = status == BluetoothGatt.GATT_SUCCESS
             val isConnected = newState == BluetoothProfile.STATE_CONNECTED
-            Log.d(TAG, "onConnectionStateChange: Client $gatt  success: $isSuccess connected: $isConnected")
+            Log.d(
+                TAG,
+                "onConnectionStateChange: Client $gatt  success: $isSuccess connected: $isConnected"
+            )
             // try to send a message to the other device as a test
             if (isSuccess && isConnected) {
                 // discover services
@@ -303,7 +321,7 @@ object ChatServer {
             super.onStartFailure(errorCode)
             // Send error state to display
             val errorMessage = "Advertise failed with error: $errorCode"
-            Log.d(TAG, "Advertising failed")
+            Log.d(TAG, errorMessage)
             //_viewState.value = DeviceScanViewState.Error(errorMessage)
         }
 

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/bluetooth/Constants.kt

@@ -15,6 +15,7 @@
  */
 
 package com.example.bluetoothlechat.bluetooth
+
 import java.util.*
 
 /**
@@ -25,7 +26,7 @@ import java.util.*
  *
  * Bluetooth requires a certain format for UUIDs associated with Services.
  * The official specification can be found here:
- * [://www.bluetooth.org/en-us/specification/assigned-numbers/service-discovery][https]
+ * [https://www.bluetooth.org/en-us/specification/assigned-numbers/service-discovery]
  */
 val SERVICE_UUID: UUID = UUID.fromString("0000b81d-0000-1000-8000-00805f9b34fb")
 
@@ -38,5 +39,3 @@ val MESSAGE_UUID: UUID = UUID.fromString("7db3e235-3608-41f3-a03c-955fcbd2ea4b")
  * UUID to confirm device connection
  */
 val CONFIRM_UUID: UUID = UUID.fromString("36d4dc5c-814b-4097-a5a6-b93b39085928")
-
-const val REQUEST_ENABLE_BT = 1

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/bluetooth/EnableBluetoothFragment.kt

@@ -22,6 +22,7 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.navigation.fragment.findNavController
@@ -31,6 +32,7 @@ import com.example.bluetoothlechat.databinding.FragmentEnableBluetoothBinding
 class EnableBluetoothFragment : Fragment() {
 
     private var _binding: FragmentEnableBluetoothBinding? = null
+
     // This property is only valid between onCreateView and onDestroyView.
     private val binding
         get() = _binding!!
@@ -42,6 +44,13 @@ class EnableBluetoothFragment : Fragment() {
         }
     }
 
+    private val startForResultEnableBluetooth =
+        registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
+            if (it.resultCode == Activity.RESULT_OK) {
+                ChatServer.startServer(requireActivity().application)
+            }
+        }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         ChatServer.requestEnableBluetooth.observe(this, bluetoothEnableObserver)
@@ -51,32 +60,16 @@ class EnableBluetoothFragment : Fragment() {
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
-    ): View? {
+    ): View {
         _binding = FragmentEnableBluetoothBinding.inflate(inflater, container, false)
 
         binding.errorAction.setOnClickListener {
-            // Prompt user to turn on Bluetooth (logic continues in onActivityResult()).
+            // Prompt user to turn on Bluetooth (logic continues in registerForActivityResult()).
             val enableBtIntent = Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE)
-            startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT)
+            startForResultEnableBluetooth.launch(enableBtIntent)
         }
 
         return binding.root
     }
 
-    override fun onActivityResult(
-        requestCode: Int,
-        resultCode: Int,
-        data: Intent?
-    ) {
-        super.onActivityResult(requestCode, resultCode, data)
-        when (requestCode) {
-            REQUEST_ENABLE_BT -> {
-                if (resultCode == Activity.RESULT_OK) {
-                    ChatServer.startServer(requireActivity().application)
-                }
-                super.onActivityResult(requestCode, resultCode, data)
-            }
-            else -> super.onActivityResult(requestCode, resultCode, data)
-        }
-    }
 }

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/bluetooth/LocationRequiredFragment.kt

@@ -18,19 +18,16 @@ package com.example.bluetoothlechat.bluetooth
 import android.Manifest
 import android.content.pm.PackageManager
 import android.os.Bundle
-import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.core.content.ContextCompat
 import androidx.fragment.app.Fragment
 import androidx.navigation.fragment.findNavController
 import com.example.bluetoothlechat.R
 import com.example.bluetoothlechat.databinding.FragmentLocationRequiredBinding
 
-private const val TAG = "LocationRequiredFrag"
-private const val LOCATION_REQUEST_CODE = 0
-
 // Fragment responsible for checking if the app has the ACCESS_FINE_LOCATION permission.
 // This permission is required when using the BLE APIs so the user must grant permission
 // to the app before viewing the BluetoothChatFragment or DeviceListFragment
@@ -44,7 +41,7 @@ class LocationRequiredFragment : Fragment() {
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
-    ): View? {
+    ): View {
         _binding = FragmentLocationRequiredBinding.inflate(inflater, container, false)
 
         // hide the error messages while checking the permissions
@@ -64,25 +61,14 @@ class LocationRequiredFragment : Fragment() {
         checkLocationPermission()
     }
 
-    override fun onRequestPermissionsResult(
-        requestCode: Int,
-        permissions: Array<out String>,
-        grantResults: IntArray
-    ) {
-        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
-        Log.d(TAG, "onRequestPermissionsResult: ")
-        when(requestCode) {
-            LOCATION_REQUEST_CODE -> {
-                if (grantResults.isNotEmpty() &&
-                    grantResults[0] == PackageManager.PERMISSION_GRANTED) {
-                    // Navigate to the chat fragment
-                    findNavController().navigate(R.id.action_start_chat)
-                } else {
-                    showError()
-                }
+    private val startForResultRequestPermission =
+        registerForActivityResult(ActivityResultContracts.RequestPermission()) {
+            if (it) {
+                findNavController().navigate(R.id.action_start_chat)
+            } else {
+                showError()
             }
         }
-    }
 
     private fun showError() {
         binding.locationErrorMessage.visibility = View.VISIBLE
@@ -99,10 +85,7 @@ class LocationRequiredFragment : Fragment() {
             // Navigate to the chat fragment
             findNavController().navigate(R.id.action_start_chat)
         } else {
-            requestPermissions(
-                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
-                LOCATION_REQUEST_CODE
-            )
+            startForResultRequestPermission.launch(Manifest.permission.ACCESS_FINE_LOCATION)
         }
     }
 }

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/chat/BluetoothChatFragment.kt

@@ -27,9 +27,9 @@ import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.navigation.fragment.findNavController
 import androidx.recyclerview.widget.LinearLayoutManager
-import com.example.bluetoothlechat.bluetooth.Message
 import com.example.bluetoothlechat.R
 import com.example.bluetoothlechat.bluetooth.ChatServer
+import com.example.bluetoothlechat.bluetooth.Message
 import com.example.bluetoothlechat.databinding.FragmentBluetoothChatBinding
 import com.example.bluetoothlechat.gone
 import com.example.bluetoothlechat.visible
@@ -39,12 +39,13 @@ private const val TAG = "BluetoothChatFragment"
 class BluetoothChatFragment : Fragment() {
 
     private var _binding: FragmentBluetoothChatBinding? = null
+
     // this property is valid between onCreateView and onDestroyView.
     private val binding: FragmentBluetoothChatBinding
         get() = _binding!!
 
     private val deviceConnectionObserver = Observer<DeviceConnectionState> { state ->
-        when(state) {
+        when (state) {
             is DeviceConnectionState.Connected -> {
                 val device = state.device
                 Log.d(TAG, "Gatt connection observer: have device $device")
@@ -54,7 +55,6 @@ class BluetoothChatFragment : Fragment() {
                 showDisconnected()
             }
         }
-
     }
 
     private val connectionRequestObserver = Observer<BluetoothDevice> { device ->
@@ -77,7 +77,7 @@ class BluetoothChatFragment : Fragment() {
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
-    ): View? {
+    ): View {
         _binding = FragmentBluetoothChatBinding.inflate(inflater, container, false)
 
         Log.d(TAG, "chatWith: set adapter $adapter")

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/chat/LocalMessageViewHolder.kt

@@ -18,8 +18,8 @@ package com.example.bluetoothlechat.chat
 import android.view.View
 import android.widget.TextView
 import androidx.recyclerview.widget.RecyclerView
-import com.example.bluetoothlechat.bluetooth.Message
 import com.example.bluetoothlechat.R
+import com.example.bluetoothlechat.bluetooth.Message
 
 class LocalMessageViewHolder(view: View) : RecyclerView.ViewHolder(view) {
 

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/chat/MessageAdapter.kt

@@ -19,9 +19,8 @@ import android.util.Log
 import android.view.LayoutInflater
 import android.view.ViewGroup
 import androidx.recyclerview.widget.RecyclerView
-import com.example.bluetoothlechat.bluetooth.Message
 import com.example.bluetoothlechat.R
-import java.lang.IllegalArgumentException
+import com.example.bluetoothlechat.bluetooth.Message
 
 private const val TAG = "MessageAdapter"
 private const val REMOTE_MESSAGE = 0
@@ -33,7 +32,7 @@ class MessageAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
         Log.d(TAG, "onCreateViewHolder: ")
         val inflater = LayoutInflater.from(parent.context)
-        return when(viewType) {
+        return when (viewType) {
             REMOTE_MESSAGE -> {
                 val view = inflater.inflate(R.layout.item_remote_message, parent, false)
                 RemoteMessageViewHolder(view)
@@ -50,8 +49,7 @@ class MessageAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
 
     override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
         Log.d(TAG, "onBindViewHolder: ")
-        val message = messages[position]
-        when(message) {
+        when (val message = messages[position]) {
             is Message.RemoteMessage -> {
                 (holder as RemoteMessageViewHolder).bind(message)
             }
@@ -68,7 +66,7 @@ class MessageAdapter : RecyclerView.Adapter<RecyclerView.ViewHolder>() {
 
     override fun getItemViewType(position: Int): Int {
         Log.d(TAG, "getItemViewType: ")
-        return when(messages[position]) {
+        return when (messages[position]) {
             is Message.RemoteMessage -> REMOTE_MESSAGE
             is Message.LocalMessage -> LOCAL_MESSAGE
         }

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/chat/RemoteMessageViewHolder.kt

@@ -18,8 +18,8 @@ package com.example.bluetoothlechat.chat
 import android.view.View
 import android.widget.TextView
 import androidx.recyclerview.widget.RecyclerView
-import com.example.bluetoothlechat.bluetooth.Message
 import com.example.bluetoothlechat.R
+import com.example.bluetoothlechat.bluetooth.Message
 
 class RemoteMessageViewHolder(view: View) : RecyclerView.ViewHolder(view) {
 

BluetoothLeChat/app/src/main/java/com/example/bluetoothlechat/scan/DeviceScanFragment.kt

@@ -35,7 +35,6 @@ import com.example.bluetoothlechat.scan.DeviceScanViewState.*
 import com.example.bluetoothlechat.visible
 
 private const val TAG = "DeviceScanFragment"
-const val GATT_KEY = "gatt_bundle_key"
 
 class DeviceScanFragment : Fragment() {
 
@@ -70,7 +69,7 @@ class DeviceScanFragment : Fragment() {
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
-    ): View? {
+    ): View {
         _binding = FragmentDeviceScanBinding.inflate(inflater, container, false)
         val devAddr = getString(R.string.your_device_address) + ChatServer.getYourDeviceAddress()
         binding.yourDeviceAddr.text = devAddr