Re-design BLE beacons logic. Add support for Eddystone beacons.

Signed-off-by: Chengzhi Hu <tony.hu1213@gmail.com>

mobile/src/main/AndroidManifest.xml

@@ -7,13 +7,19 @@
     <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
     <uses-permission android:name="android.permission.NFC" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <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-feature
         android:name="android.hardware.location.gps"
         android:required="false" />
     <uses-feature
         android:name="android.hardware.nfc"
         android:required="false" />
+    <uses-feature
+        android:name="android.hardware.bluetooth_le"
+        android:required="false" />
 
     <application
         android:allowBackup="true"

mobile/src/main/java/org/openhab/habdroid/util/BleBeaconConnector.java

@@ -0,0 +1,162 @@
+package org.openhab.habdroid.util;
+
+import android.annotation.TargetApi;
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothManager;
+import android.content.Context;
+import android.content.Intent;
+import android.os.Handler;
+import android.os.ParcelUuid;
+import android.support.v7.app.AppCompatActivity;
+import android.util.Log;
+
+import java.lang.annotation.Target;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+@TargetApi(18)
+public class BleBeaconConnector {
+    private static final String TAG = BleBeaconConnector.class.getSimpleName();
+
+    private static final int REQUEST_ENABLE_BT = 0;
+    private static final int SCAN_PERIOD = 10000;
+    public static final ParcelUuid BASE_UUID =
+            ParcelUuid.fromString("00000000-0000-1000-8000-00805F9B34FB");
+    private static final ParcelUuid EDDYSTONE_URL_SERVICE_UUID =
+            ParcelUuid.fromString("0000FEAA-0000-1000-8000-00805F9B34FB");
+    private static final int UUID_BYTES_16_BIT = 2;
+    private static final int UUID_BYTES_32_BIT = 4;
+    private static final int UUID_BYTES_128_BIT = 16;
+    private static final int DATA_TYPE_SERVICE_UUIDS_16_BIT_PARTIAL = 0x02;
+    private static final int DATA_TYPE_SERVICE_UUIDS_16_BIT_COMPLETE = 0x03;
+    private static final int DATA_TYPE_SERVICE_UUIDS_32_BIT_PARTIAL = 0x04;
+    private static final int DATA_TYPE_SERVICE_UUIDS_32_BIT_COMPLETE = 0x05;
+    private static final int DATA_TYPE_SERVICE_UUIDS_128_BIT_PARTIAL = 0x06;
+    private static final int DATA_TYPE_SERVICE_UUIDS_128_BIT_COMPLETE = 0x07;
+
+    private static BleBeaconConnector INSTANCE;
+
+    private BluetoothAdapter bluetoothAdapter;
+    private Handler handler;
+    private BluetoothAdapter.LeScanCallback leScanCallback = (bluetoothDevice, i, bytes) -> {
+        if (!isEddyStoneBeacon(bytes)){
+            return;
+        }
+        Log.d(TAG, "Device:" + bluetoothDevice.getName() + " address: " + bluetoothDevice.getAddress());
+    };
+
+    //Enforce singleton by using private constructors
+    private BleBeaconConnector(){}
+
+    private BleBeaconConnector(AppCompatActivity activity){
+        handler = new Handler();
+        final BluetoothManager manager = (BluetoothManager) activity.getSystemService(Context.BLUETOOTH_SERVICE);
+        bluetoothAdapter = manager.getAdapter();
+
+        if (bluetoothAdapter == null || !bluetoothAdapter.isEnabled()){
+            Intent enableBluetoothIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
+            activity.startActivityForResult(enableBluetoothIntent, REQUEST_ENABLE_BT);
+        }
+
+        scanLeServiceCompact();
+    }
+
+    @SuppressWarnings("deprecation")
+    private void scanLeServiceCompact(){
+        handler.postDelayed(() -> bluetoothAdapter.stopLeScan(leScanCallback), SCAN_PERIOD);
+        bluetoothAdapter.startLeScan(leScanCallback);
+    }
+
+    public static BleBeaconConnector getInstance(AppCompatActivity activity) {
+        if (INSTANCE == null){
+            INSTANCE = new BleBeaconConnector(activity);
+        }
+        return INSTANCE;
+    }
+
+    private boolean isEddyStoneBeacon(byte[] bytes){
+        List<ParcelUuid> serviceUuids = parseFromBytes(bytes);
+        return serviceUuids.contains(EDDYSTONE_URL_SERVICE_UUID);
+    }
+
+    private List<ParcelUuid> parseFromBytes(byte[] bytes){
+        int length;
+        int fieldType;
+        int currentPos = 0;
+        List<ParcelUuid> serviceUuids = new ArrayList<>();
+        while (currentPos < bytes.length) {
+            length = bytes[currentPos++] & 0xFF;
+            if (length == 0){
+                break;
+            }
+            fieldType = bytes[currentPos++] & 0xFF;
+            switch (fieldType) {
+                case DATA_TYPE_SERVICE_UUIDS_16_BIT_PARTIAL:
+                case DATA_TYPE_SERVICE_UUIDS_16_BIT_COMPLETE:
+                    parseServiceUuid(bytes, currentPos, length, UUID_BYTES_16_BIT, serviceUuids);
+                case DATA_TYPE_SERVICE_UUIDS_32_BIT_PARTIAL:
+                case DATA_TYPE_SERVICE_UUIDS_32_BIT_COMPLETE:
+                    parseServiceUuid(bytes, currentPos, length, UUID_BYTES_32_BIT, serviceUuids);
+                case DATA_TYPE_SERVICE_UUIDS_128_BIT_PARTIAL:
+                case DATA_TYPE_SERVICE_UUIDS_128_BIT_COMPLETE:
+                    parseServiceUuid(bytes, currentPos, length, UUID_BYTES_128_BIT, serviceUuids);
+            }
+            currentPos += length - 1;
+        }
+        return serviceUuids;
+    }
+
+    private void parseServiceUuid(byte[] scanRecord, int currentPos, int dataLength,
+                                  int uuidLength, List<ParcelUuid> serviceUuids) {
+        while (dataLength > 0) {
+            byte[] uuidBytes = new byte[uuidLength];
+            System.arraycopy(scanRecord, currentPos, uuidBytes, 0, uuidLength);
+            serviceUuids.add(parseUuidFrom(uuidBytes));
+            dataLength -= uuidLength;
+            currentPos += uuidLength;
+        }
+    }
+
+    private ParcelUuid parseUuidFrom(byte[] uuidBytes) {
+        if (uuidBytes == null) {
+            throw new IllegalArgumentException("uuidBytes cannot be null");
+        }
+        int length = uuidBytes.length;
+        if (length != UUID_BYTES_16_BIT && length != UUID_BYTES_32_BIT &&
+                length != UUID_BYTES_128_BIT) {
+            throw new IllegalArgumentException("uuidBytes length invalid - " + length);
+        }
+        // Construct a 128 bit UUID.
+        if (length == UUID_BYTES_128_BIT) {
+            ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
+            long msb = buf.getLong(8);
+            long lsb = buf.getLong(0);
+            return new ParcelUuid(new UUID(msb, lsb));
+        }
+        // For 16 bit and 32 bit UUID we need to convert them to 128 bit value.
+        // 128_bit_value = uuid * 2^96 + BASE_UUID
+        long shortUuid;
+        if (length == UUID_BYTES_16_BIT) {
+            shortUuid = uuidBytes[0] & 0xFF;
+            shortUuid += (uuidBytes[1] & 0xFF) << 8;
+        } else {
+            shortUuid = uuidBytes[0] & 0xFF;
+            shortUuid += (uuidBytes[1] & 0xFF) << 8;
+            shortUuid += (uuidBytes[2] & 0xFF) << 16;
+            shortUuid += (uuidBytes[3] & 0xFF) << 24;
+        }
+        long msb = BASE_UUID.getUuid().getMostSignificantBits() + (shortUuid << 32);
+        long lsb = BASE_UUID.getUuid().getLeastSignificantBits();
+        StringBuilder sb = new StringBuilder();
+        sb.append("Unconverted: size: ").append(uuidBytes.length).append("\n");
+        for (byte uuid : uuidBytes){
+            sb.append(uuid).append(" ");
+        }
+        sb.append("\n");
+        Log.d(TAG, sb.toString() + "Convtered: " + new UUID(msb, lsb));
+        return new ParcelUuid(new UUID(msb, lsb));
+    }
+}