Settings: scan for Bluetooth sensors rather than using bonded devices.

Bonded devices do no provide information what services (e.g., heart rate) they support.

src/main/java/de/dennisguse/opentracks/services/sensors/BluetoothConnectionManager.java

@@ -45,7 +45,7 @@ public class BluetoothConnectionManager {
     static final int MESSAGE_READ = 3;
     static final int MESSAGE_DISCONNECTED = 4;
 
-    private static final UUID HEART_RATE_SERVICE_UUID = new UUID(0x180D00001000L, 0x800000805f9b34fbL);
+    public static final UUID HEART_RATE_SERVICE_UUID = new UUID(0x180D00001000L, 0x800000805f9b34fbL);
     private static final UUID HEART_RATE_MEASUREMENT_CHAR_UUID = new UUID(0x2A3700001000L, 0x800000805f9b34fbL);
     private static final UUID CLIENT_CHARACTERISTIC_CONFIG_UUID = new UUID(0x290200001000L, 0x800000805f9b34fbL);
 
@@ -131,8 +131,9 @@ public class BluetoothConnectionManager {
 
         Log.d(TAG, "Connecting to: " + bluetoothDevice);
 
-        setState(SensorState.CONNECTING);
         bluetoothGatt = bluetoothDevice.connectGatt(this.context, true, this.connectCallback);
+
+        setState(SensorState.CONNECTING);
     }
 
     public synchronized void disconnect() {

src/main/java/de/dennisguse/opentracks/settings/BluetoothLeAdapter.java

@@ -0,0 +1,112 @@
+package de.dennisguse.opentracks.settings;
+
+import android.bluetooth.BluetoothDevice;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.BaseAdapter;
+import android.widget.TextView;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+
+public class BluetoothLeAdapter extends BaseAdapter {
+
+    /**
+     * Contains a unique list (by address) of devices.
+     */
+    private final List<Device> devices = new ArrayList<>();
+
+    @Override
+    public int getCount() {
+        return devices.size();
+    }
+
+    @Override
+    public Object getItem(int position) {
+        return devices.get(position);
+    }
+
+    @Override
+    public long getItemId(int position) {
+        return devices.get(position).hashCode();
+    }
+
+    @Override
+    public View getView(int position, View convertView, ViewGroup parent) {
+        View currentView = convertView;
+        if (convertView == null) {
+            LayoutInflater inflater = LayoutInflater.from(parent.getContext());
+            //TODO Check if there is a better way to achieve identical look and feel to ListPreference.
+            //Use material design single choice; for old style use: android.R.layout.select_dialog_singlechoice
+            currentView = inflater.inflate(androidx.appcompat.R.layout.select_dialog_singlechoice_material, null);
+        }
+
+        Device device = devices.get(position);
+        TextView textView = currentView.findViewById(android.R.id.text1);
+        textView.setText(device.getName());
+
+        return currentView;
+    }
+
+    public void add(String name, String address) {
+        Device device = new Device(name, address);
+        if (!devices.contains(device)) {
+            devices.add(new Device(name, address));
+        } else {
+            for (Device currentDevice : devices) {
+                if (currentDevice.getAddress().equals(address)) {
+                    currentDevice.setName(name);
+                }
+            }
+        }
+        notifyDataSetChanged();
+    }
+
+    public void add(BluetoothDevice bluetoothDevice) {
+        add(bluetoothDevice.getName(), bluetoothDevice.getAddress());
+    }
+
+    public Device get(int index) {
+        return devices.get(index);
+    }
+
+    public class Device {
+        private String name;
+        private String address;
+
+        public Device(String name, String address) {
+            this.name = name;
+            this.address = address;
+        }
+
+        public String getName() {
+            return name;
+        }
+
+        public void setName(String name) {
+            this.name = name;
+        }
+
+        public String getAddress() {
+            return address;
+        }
+
+        /**
+         * Check if the address is identical.
+         */
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (!(o instanceof Device)) return false;
+            Device device = (Device) o;
+            return address.equals(device.address);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(name, address);
+        }
+    }
+}

src/main/java/de/dennisguse/opentracks/settings/BluetoothLeListPreference.java

@@ -0,0 +1,200 @@
+package de.dennisguse.opentracks.settings;
+
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.le.BluetoothLeScanner;
+import android.bluetooth.le.ScanCallback;
+import android.bluetooth.le.ScanFilter;
+import android.bluetooth.le.ScanResult;
+import android.bluetooth.le.ScanSettings;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.os.ParcelUuid;
+import android.text.TextUtils;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.widget.Toast;
+
+import androidx.appcompat.app.AlertDialog;
+import androidx.preference.DialogPreference;
+import androidx.preference.PreferenceDialogFragmentCompat;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import de.dennisguse.opentracks.R;
+import de.dennisguse.opentracks.services.sensors.BluetoothConnectionManager;
+import de.dennisguse.opentracks.util.BluetoothUtils;
+
+/**
+ * Preference to select a discoverable Bluetooth LE device.
+ * Based upon ListPreference.
+ */
+public class BluetoothLeListPreference extends DialogPreference {
+
+    private final static String TAG = BluetoothLeListPreference.class.getSimpleName();
+
+    public BluetoothLeListPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public BluetoothLeListPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public BluetoothLeListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public BluetoothLeListPreference(Context context) {
+        super(context);
+    }
+
+    private String value;
+    private boolean valueSet = false;
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        final boolean changed = !TextUtils.equals(this.value, value);
+        if (changed || !valueSet) {
+            this.value = value;
+            valueSet = true;
+            persistString(value);
+            if (changed) {
+                notifyChanged();
+            }
+        }
+    }
+
+    @Override
+    protected void onSetInitialValue(Object defaultValue) {
+        setValue(getPersistedString((String) defaultValue));
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        return getValue();
+    }
+
+    public static class BluetoothLeListPreferenceDialog extends PreferenceDialogFragmentCompat {
+
+        private int selectedEntryIndex;
+        private BluetoothLeAdapter listAdapter = new BluetoothLeAdapter();
+
+        private BluetoothLeScanner scanner = null;
+        private ScanCallback scanCallback = new ScanCallback() {
+            @Override
+            public void onScanResult(int callbackType, ScanResult result) {
+                super.onScanResult(callbackType, result);
+                Log.d(TAG, "Found device " + result.getDevice().getName() + " " + result);
+
+                listAdapter.add(result.getDevice());
+            }
+
+            @Override
+            public void onBatchScanResults(List<ScanResult> results) {
+                for (ScanResult scanResult : results) {
+                    listAdapter.add(scanResult.getDevice());
+                }
+            }
+
+            @Override
+            public void onScanFailed(int errorCode) {
+                super.onScanFailed(errorCode);
+                Log.e(TAG, "Bluetooth scan failed with errorCode " + errorCode);
+                Toast.makeText(getContext(), R.string.sensor_could_not_scan, Toast.LENGTH_LONG).show();
+                dismiss();
+            }
+        };
+
+        static BluetoothLeListPreferenceDialog newInstance(String key) {
+            final BluetoothLeListPreferenceDialog fragment = new BluetoothLeListPreferenceDialog();
+            final Bundle b = new Bundle(1);
+            b.putString(ARG_KEY, key);
+            fragment.setArguments(b);
+            return fragment;
+        }
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+
+            BluetoothAdapter bluetoothAdapter = BluetoothUtils.getDefaultBluetoothAdapter(TAG);
+            if (bluetoothAdapter == null || !bluetoothAdapter.isEnabled()) {
+                Log.w(TAG, "Bluetooth adapter is present or not enabled.");
+                Toast.makeText(getContext(), R.string.bluetooth_disabled, Toast.LENGTH_SHORT).show();
+                dismiss();
+                return;
+            }
+
+            if (bluetoothAdapter.isDiscovering()) {
+                Log.i(TAG, "Cancelling ongoing bluetooth discovery.");
+                bluetoothAdapter.cancelDiscovery();
+            }
+
+            scanner = bluetoothAdapter.getBluetoothLeScanner();
+            if (scanner == null) {
+                Log.e(TAG, "BluetoothLeScanner is null.");
+                dismiss();
+                return;
+            }
+
+            String deviceNone = getContext().getString(R.string.sensor_type_value_none);
+            listAdapter.add(getContext().getString(R.string.value_none), deviceNone);
+            selectedEntryIndex = 0;
+
+            BluetoothLeListPreference preference = (BluetoothLeListPreference) getPreference();
+            String deviceSelected = preference.getValue();
+            if (!deviceNone.equals(deviceSelected)) {
+                listAdapter.add(preference.getValue(), preference.getValue());
+                selectedEntryIndex = 1;
+            }
+
+            ScanFilter.Builder scanFilterBuilder = new ScanFilter.Builder().setServiceUuid(new ParcelUuid(BluetoothConnectionManager.HEART_RATE_SERVICE_UUID));
+            List<ScanFilter> scanFilter = new ArrayList<>();
+            scanFilter.add(scanFilterBuilder.build());
+
+            ScanSettings.Builder scanSettingsBuilder = new ScanSettings.Builder();
+            scanSettingsBuilder.setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY);
+
+            scanner.startScan(scanFilter, scanSettingsBuilder.build(), scanCallback);
+        }
+
+        //Behave like ListPreferenceDialogFragmentCompat, but uses a custom listAdapter.
+        @Override
+        protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
+            super.onPrepareDialogBuilder(builder);
+
+            builder.setSingleChoiceItems(listAdapter, selectedEntryIndex,
+                    new DialogInterface.OnClickListener() {
+                        @Override
+                        public void onClick(DialogInterface dialog, int which) {
+                            selectedEntryIndex = which;
+
+                            BluetoothLeListPreferenceDialog.this.onClick(dialog, DialogInterface.BUTTON_POSITIVE);
+                            dialog.dismiss();
+                        }
+                    });
+            builder.setIcon(android.R.drawable.stat_sys_data_bluetooth);
+            builder.setPositiveButton(null, null);
+        }
+
+        @Override
+        public void onDialogClosed(boolean positiveResult) {
+            if (scanner != null) {
+                scanner.stopScan(scanCallback);
+            }
+
+            if (positiveResult && selectedEntryIndex >= 0) {
+                String value = listAdapter.get(selectedEntryIndex).getAddress();
+                BluetoothLeListPreference preference = (BluetoothLeListPreference) getPreference();
+                if (preference.callChangeListener(value)) {
+                    preference.setValue(value);
+                }
+            }
+        }
+    }
+}

src/main/java/de/dennisguse/opentracks/settings/PreferenceHelper.java

@@ -1,15 +1,8 @@
 package de.dennisguse.opentracks.settings;
 
-import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 
-import androidx.preference.ListPreference;
-
-import java.util.ArrayList;
-import java.util.List;
-
 import de.dennisguse.opentracks.R;
-import de.dennisguse.opentracks.util.BluetoothUtils;
 import de.dennisguse.opentracks.util.PreferencesUtils;
 import de.dennisguse.opentracks.util.UnitConversions;
 
@@ -167,34 +160,4 @@ final class PreferenceHelper {
 
         return entries;
     }
-
-    /**
-     * Configures the bluetooth sensor.
-     */
-    static void configureBluetoothSensorList(ListPreference preference) {
-        Context context = preference.getContext();
-
-        String value = PreferencesUtils.getString(context, R.string.settings_sensor_bluetooth_sensor_key, PreferencesUtils.BLUETOOTH_SENSOR_DEFAULT);
-        List<String> devicesNameList = new ArrayList<>();
-        List<String> devicesAddressList = new ArrayList<>();
-        BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
-        if (bluetoothAdapter != null) {
-            BluetoothUtils.populateDeviceLists(bluetoothAdapter, devicesNameList, devicesAddressList);
-        }
-
-        // Was the previously configured device unpaired? Then forget it.
-        if (!devicesAddressList.contains(value)) {
-            value = PreferencesUtils.BLUETOOTH_SENSOR_DEFAULT;
-            PreferencesUtils.setString(context, R.string.settings_sensor_bluetooth_sensor_key, value);
-        }
-
-        devicesNameList.add(0, context.getString(R.string.value_none));
-        devicesAddressList.add(0, PreferencesUtils.BLUETOOTH_SENSOR_DEFAULT);
-
-        String[] values = devicesAddressList.toArray(new String[0]);
-        preference.setEntryValues(values);
-
-        String[] options = devicesNameList.toArray(new String[0]);
-        preference.setEntries(options);
-    }
 }

src/main/java/de/dennisguse/opentracks/settings/SettingsActivity.java

@@ -13,12 +13,15 @@ import androidx.preference.PreferenceFragmentCompat;
 
 import de.dennisguse.opentracks.R;
 import de.dennisguse.opentracks.fragments.ChooseActivityTypeDialogFragment;
+import de.dennisguse.opentracks.util.BluetoothUtils;
 import de.dennisguse.opentracks.util.HackUtils;
 import de.dennisguse.opentracks.util.PreferencesUtils;
 import de.dennisguse.opentracks.util.StringUtils;
 
 public class SettingsActivity extends AppCompatActivity implements ChooseActivityTypeDialogFragment.ChooseActivityTypeCaller, ResetDialogPreference.ResetCallback {
 
+    private static final String TAG = SettingsActivity.class.getSimpleName();
+
     private PrefsFragment prefsFragment;
 
     @Override
@@ -54,13 +57,14 @@ public class SettingsActivity extends AppCompatActivity implements ChooseActivit
         private final SharedPreferences.OnSharedPreferenceChangeListener sharedPreferenceChangeListener = new SharedPreferences.OnSharedPreferenceChangeListener() {
             @Override
             public void onSharedPreferenceChanged(SharedPreferences preferences, String key) {
-                getActivity().runOnUiThread(new Runnable() {
-                    @Override
-                    public void run() {
-                        updateUI();
-                    }
-                });
-
+                if (PreferencesUtils.isKey(getActivity(), R.string.recording_track_id_key, key)) {
+                    getActivity().runOnUiThread(new Runnable() {
+                        @Override
+                        public void run() {
+                            updateReset();
+                        }
+                    });
+                }
                 if (PreferencesUtils.isKey(getActivity(), R.string.stats_units_key, key)) {
                     getActivity().runOnUiThread(new Runnable() {
                         @Override
@@ -69,6 +73,14 @@ public class SettingsActivity extends AppCompatActivity implements ChooseActivit
                         }
                     });
                 }
+                if (PreferencesUtils.isKey(getActivity(), R.string.chart_show_speed_key, key)) {
+                    getActivity().runOnUiThread(new Runnable() {
+                        @Override
+                        public void run() {
+                            updateSpeed();
+                        }
+                    });
+                }
             }
         };
 
@@ -93,7 +105,8 @@ public class SettingsActivity extends AppCompatActivity implements ChooseActivit
         public void onResume() {
             super.onResume();
             PreferencesUtils.getSharedPreferences(getActivity()).registerOnSharedPreferenceChangeListener(sharedPreferenceChangeListener);
-            updateUI();
+            updateReset();
+            updateBluetooth();
         }
 
         @Override
@@ -110,6 +123,8 @@ public class SettingsActivity extends AppCompatActivity implements ChooseActivit
             } else if (preference instanceof ActivityTypePreference) {
                 activityPreferenceDialog = ActivityTypePreference.ActivityPreferenceDialog.newInstance(preference.getKey());
                 dialogFragment = activityPreferenceDialog;
+            } else if (preference instanceof BluetoothLeListPreference) {
+                dialogFragment = BluetoothLeListPreference.BluetoothLeListPreferenceDialog.newInstance(preference.getKey());
             }
 
             if (dialogFragment != null) {
@@ -127,17 +142,22 @@ public class SettingsActivity extends AppCompatActivity implements ChooseActivit
             }
         }
 
-        private void updateUI() {
+        private void updateReset() {
             final boolean isRecording = PreferencesUtils.isRecording(getActivity());
             Preference resetPreference = findPreference(getString(R.string.settings_reset_key));
             resetPreference.setSummary(isRecording ? getString(R.string.settings_not_while_recording) : "");
             resetPreference.setEnabled(!isRecording);
+        }
 
+        private void updateSpeed() {
             Preference speedCheckBoxPreference = findPreference(getString(R.string.chart_show_speed_key));
             speedCheckBoxPreference.setTitle(PreferencesUtils.isReportSpeed(getActivity()) ? R.string.stats_speed : R.string.stats_pace);
+        }
 
-            ListPreference bluetoothPreference = findPreference(getString(R.string.settings_sensor_bluetooth_sensor_key));
-            PreferenceHelper.configureBluetoothSensorList(bluetoothPreference);
+        private void updateBluetooth() {
+            // Disable Bluetooth preference if device does not have Bluetooth
+            BluetoothLeListPreference bluetoothPreference = findPreference(getString(R.string.settings_sensor_bluetooth_sensor_key));
+            bluetoothPreference.setVisible(BluetoothUtils.hasBluetooth(TAG));
         }
 
         private void updateUnits() {

src/main/java/de/dennisguse/opentracks/util/BluetoothUtils.java

@@ -16,16 +16,12 @@
 package de.dennisguse.opentracks.util;
 
 import android.bluetooth.BluetoothAdapter;
-import android.bluetooth.BluetoothClass;
-import android.bluetooth.BluetoothDevice;
 import android.bluetooth.BluetoothGattCharacteristic;
 import android.os.Handler;
 import android.os.Looper;
 import android.util.Log;
 
 import java.util.ArrayList;
-import java.util.List;
-import java.util.Set;
 
 /**
  * Utilities for dealing with bluetooth devices.
@@ -74,26 +70,8 @@ public class BluetoothUtils {
         return adapters.get(0);
     }
 
-    /**
-     * Populates the device names and the device addresses with all the suitable
-     * bluetooth devices.
-     *
-     * @param bluetoothAdapter the bluetooth adapter
-     * @param deviceNames      list of device names
-     * @param deviceAddresses  list of device addresses
-     */
-    public static void populateDeviceLists(BluetoothAdapter bluetoothAdapter, List<String> deviceNames, List<String> deviceAddresses) {
-        // Ensure the bluetooth adapter is not in discovery mode.
-        bluetoothAdapter.cancelDiscovery();
-
-        Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
-        for (BluetoothDevice device : pairedDevices) {
-            BluetoothClass bluetoothClass = device.getBluetoothClass();
-            if (bluetoothClass != null && (bluetoothClass.getDeviceClass() & BluetoothClass.Device.HEALTH_PULSE_RATE) != 0) {
-                deviceAddresses.add(device.getAddress());
-                deviceNames.add(device.getName());
-            }
-        }
+    public static boolean hasBluetooth(final String TAG) {
+        return BluetoothUtils.getDefaultBluetoothAdapter(TAG) != null;
     }
 
     public static int parseHeartRate(BluetoothGattCharacteristic characteristic) {