Decouple BluetoothDevicePreference and DeviceListPreferenceFragment

The BluetoothDevicePreference need to know whether to display with an
invalid name. However pass in the whole fragment is over-killing.

This cl decouple it for several reasons:
1. In P, BluetoothDevicePreference will be used in other fragment.
2. In preference lifecycle from end user side, this flag is constant.

Bug: 69333961
Test: RunSettingsRoboTests
Change-Id: I3dbcd2a4aafa3ead74371534250e5e7c3ee221f7

src/com/android/settings/bluetooth/BluetoothDevicePreference.java

@@ -52,19 +52,19 @@ public final class BluetoothDevicePreference extends GearPreference implements
 
     private final CachedBluetoothDevice mCachedDevice;
     private final UserManager mUserManager;
+    private final boolean mShowDevicesWithoutNames;
 
     private AlertDialog mDisconnectDialog;
     private String contentDescription = null;
-    private DeviceListPreferenceFragment mDeviceListPreferenceFragment;
     /* Talk-back descriptions for various BT icons */
     Resources mResources;
 
     public BluetoothDevicePreference(Context context, CachedBluetoothDevice cachedDevice,
-            DeviceListPreferenceFragment deviceListPreferenceFragment) {
+            boolean showDeviceWithoutNames) {
         super(context, null);
         mResources = getContext().getResources();
         mUserManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
-        mDeviceListPreferenceFragment = deviceListPreferenceFragment;
+        mShowDevicesWithoutNames = showDeviceWithoutNames;
 
         if (sDimAlpha == Integer.MIN_VALUE) {
             TypedValue outValue = new TypedValue();
@@ -134,8 +134,7 @@ public final class BluetoothDevicePreference extends GearPreference implements
 
         // Device is only visible in the UI if it has a valid name besides MAC address or when user
         // allows showing devices without user-friendly name in developer settings
-        setVisible(mDeviceListPreferenceFragment.shouldShowDevicesWithoutNames()
-                || mCachedDevice.hasHumanReadableName());
+        setVisible(mShowDevicesWithoutNames || mCachedDevice.hasHumanReadableName());
 
         // This could affect ordering, so notify that
         notifyHierarchyChanged();

src/com/android/settings/bluetooth/DeviceListPreferenceFragment.java

@@ -98,6 +98,8 @@ public abstract class DeviceListPreferenceFragment extends
             return;
         }
         mLocalAdapter = mLocalManager.getBluetoothAdapter();
+        mShowDevicesWithoutNames = SystemProperties.getBoolean(
+                BLUETOOTH_SHOW_DEVICES_WITHOUT_NAMES_PROPERTY, false);
 
         initPreferencesFromPreferenceScreen();
 
@@ -110,8 +112,6 @@ public abstract class DeviceListPreferenceFragment extends
     @Override
     public void onStart() {
         super.onStart();
-        mShowDevicesWithoutNames = SystemProperties.getBoolean(
-                BLUETOOTH_SHOW_DEVICES_WITHOUT_NAMES_PROPERTY, false);
         if (mLocalManager == null || isUiRestricted()) return;
 
         mLocalManager.setForegroundActivity(getActivity());
@@ -190,7 +190,8 @@ public abstract class DeviceListPreferenceFragment extends
         BluetoothDevicePreference preference = (BluetoothDevicePreference) getCachedPreference(key);
 
         if (preference == null) {
-            preference = new BluetoothDevicePreference(getPrefContext(), cachedDevice, this);
+            preference = new BluetoothDevicePreference(getPrefContext(), cachedDevice,
+                    mShowDevicesWithoutNames);
             preference.setKey(key);
             mDeviceListGroup.addPreference(preference);
         } else {