Added runtime permission ACCESS_COARSE_LOCATION for Android when scan…

…ning. Fixes #28
ozxcorp · Apr 2, 2018 · 83b127a · 83b127a
1 parent a7698f2
commit 83b127a
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Showing 6 changed files with 61 additions and 15 deletions.
diff --git a/README.md b/README.md
@@ -111,3 +111,9 @@ device.onValueChanged(characteristic).listen((value) {
 | onValueChanged              |  :white_check_mark:  |  :white_check_mark:  | Notifies when the characteristic's value has changed. |
 | state                       |  :white_check_mark:  |  :white_check_mark:  | Gets the current state of the Bluetooth Device. |
 | onStateChanged              |  :white_check_mark:  |  :white_check_mark:  | Notifies of state changes for the Bluetooth Device. |
+
+
+## Troubleshooting
+### Scanning for service UUID's doesn't return any results
+Make sure the device is advertising which service UUID's it supports.  This is found in the advertisement
+packet as **UUID 16 bit complete list** or **UUID 128 bit complete list**.
diff --git a/android/build.gradle b/android/build.gradle
@@ -28,7 +28,7 @@ android {
 
     defaultConfig {
         minSdkVersion 19
-        targetSdkVersion 26
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -39,6 +39,7 @@ android {
     dependencies {
         // Required for local unit tests (JUnit 4 framework)
         testImplementation 'junit:junit:4.12'
+        implementation 'com.android.support:support-v4:27.1.0'
         //compile files('/home/paul/flutter/bin/cache/artifacts/engine/android-arm/flutter.jar')
     }
     sourceSets {

diff --git a/android/src/main/AndroidManifest.xml b/android/src/main/AndroidManifest.xml
@@ -2,5 +2,5 @@
   package="com.pauldemarco.flutterblue">
   <uses-permission android:name="android.permission.BLUETOOTH" />
   <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
-  <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
+  <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
 </manifest>
diff --git a/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java b/android/src/main/java/com/pauldemarco/flutterblue/FlutterBluePlugin.java
@@ -4,6 +4,7 @@
 
 package com.pauldemarco.flutterblue;
 
+import android.Manifest;
 import android.annotation.TargetApi;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
@@ -22,8 +23,11 @@
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.ParcelUuid;
+import android.support.v4.app.ActivityCompat;
+import android.support.v4.content.ContextCompat;
 import android.util.Log;
 
 import com.google.protobuf.ByteString;
@@ -43,14 +47,16 @@
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
 import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugin.common.PluginRegistry.Registrar;
+import io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener;
 
 
 /**
  * FlutterBluePlugin
  */
-public class FlutterBluePlugin implements MethodCallHandler {
+public class FlutterBluePlugin implements MethodCallHandler, RequestPermissionsResultListener  {
     private static final String TAG = "FlutterBluePlugin";
     private static final String NAMESPACE = "plugins.pauldemarco.com/flutter_blue";
+    private static final int REQUEST_COARSE_LOCATION_PERMISSIONS = 1452;
     static final private UUID CCCD_ID = UUID.fromString("000002902-0000-1000-8000-00805f9b34fb");
     private final Registrar registrar;
     private final MethodChannel channel;
@@ -63,11 +69,16 @@ public class FlutterBluePlugin implements MethodCallHandler {
     private BluetoothAdapter mBluetoothAdapter;
     private final Map<String, BluetoothGatt> mGattServers = new HashMap<>();
 
+    // Pending call and result for startScan, in the case where permissions are needed
+    private MethodCall pendingCall;
+    private Result pendingResult;
+
     /**
      * Plugin registration.
      */
     public static void registerWith(Registrar registrar) {
         final FlutterBluePlugin instance = new FlutterBluePlugin(registrar);
+        registrar.addRequestPermissionsResultListener(instance);
     }
 
     FlutterBluePlugin(Registrar r){
@@ -138,17 +149,19 @@ public void onMethodCall(MethodCall call, Result result) {
 
             case "startScan":
             {
-                // TODO: Request permission.
-                byte[] data = call.arguments();
-                Protos.ScanSettings request;
-                try {
-                    request = Protos.ScanSettings.newBuilder().mergeFrom(data).build();
-                } catch (InvalidProtocolBufferException e) {
-                    result.error("RuntimeException", e.getMessage(), e);
+                if (ContextCompat.checkSelfPermission(registrar.activity(), Manifest.permission.ACCESS_COARSE_LOCATION)
+                        != PackageManager.PERMISSION_GRANTED) {
+                    ActivityCompat.requestPermissions(
+                            registrar.activity(),
+                            new String[] {
+                                    Manifest.permission.ACCESS_COARSE_LOCATION
+                            },
+                            REQUEST_COARSE_LOCATION_PERMISSIONS);
+                    pendingCall = call;
+                    pendingResult = result;
                     break;
                 }
-                startScan(request);
-                result.success(null);
+                startScan(call, result);
                 break;
             }
 
@@ -473,6 +486,23 @@ public void onMethodCall(MethodCall call, Result result) {
         }
     }
 
+    @Override
+    public boolean onRequestPermissionsResult(
+            int requestCode, String[] permissions, int[] grantResults) {
+        if (requestCode == REQUEST_COARSE_LOCATION_PERMISSIONS) {
+            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                startScan(pendingCall, pendingResult);
+            } else {
+                pendingResult.error(
+                        "no_permissions", "flutter_blue plugin requires location permissions for scanning", null);
+                pendingResult = null;
+                pendingCall = null;
+            }
+            return true;
+        }
+        return false;
+    }
+
     private BluetoothGatt locateGatt(String remoteId) throws Exception {
         BluetoothGatt gattServer = mGattServers.get(remoteId);
         if(gattServer == null) {
@@ -556,12 +586,21 @@ public void onCancel(Object o) {
         }
     };
 
-    private void startScan(Protos.ScanSettings settings) {
+    private void startScan(MethodCall call, Result result) {
+        byte[] data = call.arguments();
+        Protos.ScanSettings settings;
+        try {
+            settings = Protos.ScanSettings.newBuilder().mergeFrom(data).build();
+        } catch (InvalidProtocolBufferException e) {
+            result.error("RuntimeException", e.getMessage(), e);
+            return;
+        }
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
             startScan21(settings);
         } else {
             startScan18(settings);
         }
+        result.success(null);
     }
 
     private void stopScan() {

diff --git a/example/android/app/build.gradle b/example/android/app/build.gradle
@@ -25,7 +25,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.pauldemarco.flutterblueexample"
         minSdkVersion 19
-        targetSdkVersion 27
+        targetSdkVersion 21
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"

diff --git a/example/lib/main.dart b/example/lib/main.dart
@@ -74,7 +74,7 @@ class _FlutterBlueAppState extends State<FlutterBlueApp> {
     _scanSubscription = _flutterBlue.scan(
         timeout: const Duration(seconds: 5),
         withServices: [
-          new Guid('0000180f-0000-1000-8000-00805f9b34fb')
+          new Guid('0000180F-0000-1000-8000-00805F9B34FB')
         ]).listen((scanResult) {
       setState(() {
         scanResults[scanResult.device.id] = scanResult;