Use latest protobuf compiler (pauldemarco#676)

* checkPermission fixes

* remove appcompat

* remove static instance which overrides a activity field

* Switch to new protobuf compiler

Author: ened

android/build.gradle

@@ -22,7 +22,7 @@ buildscript {
 
     dependencies {
         classpath 'com.android.tools.build:gradle:3.5.2'
-        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.10'
+        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.13'
     }
 }
 
@@ -59,25 +59,20 @@ protobuf {
     // Configure the protoc executable
     protoc {
         // Download from repositories
-        artifact = 'com.google.protobuf:protoc:3.9.1'
-    }
-    plugins {
-        javalite {
-            // The codegen for lite comes as a separate artifact
-            artifact = 'com.google.protobuf:protoc-gen-javalite:3.0.0'
-        }
+        artifact = 'com.google.protobuf:protoc:3.13.0'
     }
     generateProtoTasks {
         all().each { task ->
-            task.plugins {
-                javalite { }
+            task.builtins {
+                java {
+                    option "lite"
+                }
             }
         }
     }
 }
 
 dependencies {
-    implementation 'com.google.protobuf:protobuf-lite:3.0.1'
-    implementation 'androidx.appcompat:appcompat:1.0.0'
-    api 'androidx.core:core:1.0.1'
+    implementation 'com.google.protobuf:protobuf-javalite:3.11.0'
+    implementation 'androidx.core:core:1.2.0'
 }

android/src/main/java/com/pauldemarco/flutter_blue/FlutterBluePlugin.java

@@ -63,7 +63,6 @@
 /** FlutterBluePlugin */
 public class FlutterBluePlugin implements FlutterPlugin, ActivityAware, MethodCallHandler, RequestPermissionsResultListener  {
     private static final String TAG = "FlutterBluePlugin";
-    private static FlutterBluePlugin instance;
     private Object initializationLock = new Object();
     private Context context;
     private MethodChannel channel;
@@ -91,9 +90,7 @@ public class FlutterBluePlugin implements FlutterPlugin, ActivityAware, MethodCa
 
     /** Plugin registration. */
     public static void registerWith(Registrar registrar) {
-        if (instance == null) {
-            instance = new FlutterBluePlugin();
-        }
+        FlutterBluePlugin instance = new FlutterBluePlugin();
         Activity activity = registrar.activity();
         Application application = null;
         if (registrar.context() != null) {
@@ -151,6 +148,7 @@ private void setup(
             Log.i(TAG, "setup");
             this.activity = activity;
             this.application = application;
+            this.context = application;
             channel = new MethodChannel(messenger, NAMESPACE + "/methods");
             channel.setMethodCallHandler(this);
             stateChannel = new EventChannel(messenger, NAMESPACE + "/state");
@@ -240,10 +238,10 @@ public void onMethodCall(MethodCall call, Result result) {
 
             case "startScan":
             {
-                if (ContextCompat.checkSelfPermission(activity, Manifest.permission.ACCESS_FINE_LOCATION)
+                if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION)
                         != PackageManager.PERMISSION_GRANTED) {
                     ActivityCompat.requestPermissions(
-                            activity,
+                            activityBinding.getActivity(),
                             new String[] {
                                     Manifest.permission.ACCESS_FINE_LOCATION
                             },
@@ -308,9 +306,9 @@ public void onMethodCall(MethodCall call, Result result) {
                 // New request, connect and add gattServer to Map
                 BluetoothGatt gattServer;
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
-                    gattServer = device.connectGatt(activity, options.getAndroidAutoConnect(), mGattCallback, BluetoothDevice.TRANSPORT_LE);
+                    gattServer = device.connectGatt(context, options.getAndroidAutoConnect(), mGattCallback, BluetoothDevice.TRANSPORT_LE);
                 } else {
-                    gattServer = device.connectGatt(activity, options.getAndroidAutoConnect(), mGattCallback);
+                    gattServer = device.connectGatt(context, options.getAndroidAutoConnect(), mGattCallback);
                 }
                 mDevices.put(deviceId, new BluetoothDeviceCache(gattServer));
                 result.success(null);
@@ -728,13 +726,13 @@ public void onReceive(Context context, Intent intent) {
         public void onListen(Object o, EventChannel.EventSink eventSink) {
             sink = eventSink;
             IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
-            activity.registerReceiver(mReceiver, filter);
+            context.registerReceiver(mReceiver, filter);
         }
 
         @Override
         public void onCancel(Object o) {
             sink = null;
-            activity.unregisterReceiver(mReceiver);
+            context.unregisterReceiver(mReceiver);
         }
     };