New hearing device pairing page (2/2): MFi devices

Some of the hearing aids support both ASHA + MFi, however, they only
advertise MFi service uuid in advertisement packets.

We can filter the devices with MFi uuid while scanning and then connect
gatt to discover the remote services before pairing to make sure if the
devices are compatible with Android or not. Only devices that support
ASHA/HAP will be shown.

Bug: 307890347
Test: atest HearingDevicePairingFragmentTest
Change-Id: Ie1f4eedddd4c43fad0fcbcd35f436dea5ab06925

src/com/android/settings/accessibility/HearingDevicePairingFragment.java

@@ -22,15 +22,20 @@ import static android.os.UserManager.DISALLOW_CONFIG_BLUETOOTH;
 import android.app.settings.SettingsEnums;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
+import android.bluetooth.BluetoothGatt;
+import android.bluetooth.BluetoothGattCallback;
 import android.bluetooth.BluetoothManager;
+import android.bluetooth.BluetoothProfile;
 import android.bluetooth.BluetoothUuid;
 import android.bluetooth.le.BluetoothLeScanner;
 import android.bluetooth.le.ScanCallback;
 import android.bluetooth.le.ScanFilter;
+import android.bluetooth.le.ScanRecord;
 import android.bluetooth.le.ScanResult;
 import android.bluetooth.le.ScanSettings;
 import android.content.Context;
 import android.os.Bundle;
+import android.os.ParcelUuid;
 import android.os.SystemProperties;
 import android.util.Log;
 import android.widget.Toast;
@@ -83,6 +88,7 @@ public class HearingDevicePairingFragment extends RestrictedDashboardFragment im
     @Nullable
     BluetoothDevice mSelectedDevice;
     final List<BluetoothDevice> mSelectedDeviceList = new ArrayList<>();
+    final List<BluetoothGatt> mConnectingGattList = new ArrayList<>();
     final Map<CachedBluetoothDevice, BluetoothDevicePreference> mDevicePreferenceMap =
             new HashMap<>();
 
@@ -140,6 +146,9 @@ public class HearingDevicePairingFragment extends RestrictedDashboardFragment im
         }
         stopScanning();
         removeAllDevices();
+        for (BluetoothGatt gatt: mConnectingGattList) {
+            gatt.disconnect();
+        }
         mLocalManager.setForegroundActivity(null);
         mLocalManager.getEventManager().unregisterCallback(this);
     }
@@ -325,7 +334,16 @@ public class HearingDevicePairingFragment extends RestrictedDashboardFragment im
             }
             cachedDevice.setHearingAidInfo(new HearingAidInfo.Builder().build());
         }
-        addDevice(cachedDevice);
+        // No need to handle the device if the device is already in the list or discovering services
+        if (mDevicePreferenceMap.get(cachedDevice) == null
+                && mConnectingGattList.stream().noneMatch(
+                        gatt -> gatt.getDevice().equals(device))) {
+            if (isAndroidCompatibleHearingAid(result)) {
+                addDevice(cachedDevice);
+            } else {
+                discoverServices(cachedDevice);
+            }
+        }
     }
 
     void startLeScanning() {
@@ -388,6 +406,82 @@ public class HearingDevicePairingFragment extends RestrictedDashboardFragment im
         mLeScanFilters.add(new ScanFilter.Builder().setServiceUuid(BluetoothUuid.HAS).build());
         mLeScanFilters.add(new ScanFilter.Builder()
                 .setServiceData(BluetoothUuid.HAS, new byte[0]).build());
+        // Filters for MFi hearing aids
+        mLeScanFilters.add(new ScanFilter.Builder().setServiceUuid(BluetoothUuid.MFI_HAS).build());
+        mLeScanFilters.add(new ScanFilter.Builder()
+                .setServiceData(BluetoothUuid.MFI_HAS, new byte[0]).build());
+    }
+
+    boolean isAndroidCompatibleHearingAid(ScanResult scanResult) {
+        ScanRecord scanRecord = scanResult.getScanRecord();
+        if (scanRecord == null) {
+            if (DEBUG) {
+                Log.d(TAG, "Scan record is null, not compatible with Android. device: "
+                        + scanResult.getDevice());
+            }
+            return false;
+        }
+        List<ParcelUuid> uuids = scanRecord.getServiceUuids();
+        if (uuids != null) {
+            if (uuids.contains(BluetoothUuid.HEARING_AID) || uuids.contains(BluetoothUuid.HAS)) {
+                if (DEBUG) {
+                    Log.d(TAG, "Scan record uuid matched, compatible with Android. device: "
+                            + scanResult.getDevice());
+                }
+                return true;
+            }
+        }
+        if (scanRecord.getServiceData(BluetoothUuid.HEARING_AID) != null
+                || scanRecord.getServiceData(BluetoothUuid.HAS) != null) {
+            if (DEBUG) {
+                Log.d(TAG, "Scan record service data matched, compatible with Android. device: "
+                        + scanResult.getDevice());
+            }
+            return true;
+        }
+        if (DEBUG) {
+            Log.d(TAG, "Scan record mismatched, not compatible with Android. device: "
+                    + scanResult.getDevice());
+        }
+        return false;
+    }
+
+    void discoverServices(CachedBluetoothDevice cachedDevice) {
+        if (DEBUG) {
+            Log.d(TAG, "connectGattToCheckCompatibility, device: " + cachedDevice);
+        }
+        BluetoothGatt gatt = cachedDevice.getDevice().connectGatt(getContext(), false,
+                new BluetoothGattCallback() {
+                    @Override
+                    public void onConnectionStateChange(BluetoothGatt gatt, int status,
+                            int newState) {
+                        super.onConnectionStateChange(gatt, status, newState);
+                        if (DEBUG) {
+                            Log.d(TAG, "onConnectionStateChange, status: " + status + ", newState: "
+                                    + newState + ", device: " + cachedDevice);
+                        }
+                        if (newState == BluetoothProfile.STATE_CONNECTED) {
+                            gatt.discoverServices();
+                        }
+                    }
+
+                    @Override
+                    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
+                        super.onServicesDiscovered(gatt, status);
+                        boolean isCompatible = gatt.getService(BluetoothUuid.HEARING_AID.getUuid())
+                                != null
+                                || gatt.getService(BluetoothUuid.HAS.getUuid()) != null;
+                        if (DEBUG) {
+                            Log.d(TAG,
+                                    "onServicesDiscovered, compatible with Android: " + isCompatible
+                                            + ", device: " + cachedDevice);
+                        }
+                        if (isCompatible) {
+                            addDevice(cachedDevice);
+                        }
+                    }
+                });
+        mConnectingGattList.add(gatt);
     }
 
     void showBluetoothTurnedOnToast() {