Crash in Settings observed while changing the device orientation after renamed tablet

There was a fundamental flow in the BT code. Basically BluetoothSettings is using
a singleton BluetoothDiscoverableEnabler.

BluetoothDiscoverableEnabler is keeping (thru its constructor) a reference on a Context
for registering/unregistering some broadcast receiver. BUMMER! When you change orientation
(or more generally the device Configuration), your Context is no more the same!

Hence the crash as we were  trying to unregister a Receiver on a Context that is no more valid.

Fix that issue by passing an updated Context to the BluetoothDiscoverableEnabler.resume() API.

Bug #12991455
Change-Id: I77db15d2b59b6dd973907e26f9e6bb022202a8b5

3 files changed, 12 insertions, 9 deletions

diff --git a/src/com/android/settings/bluetooth/BluetoothDiscoverableEnabler.java b/src/com/android/settings/bluetooth/BluetoothDiscoverableEnabler.java
index 79dbbbd..f47fecc 100755
--- a/src/com/android/settings/bluetooth/BluetoothDiscoverableEnabler.java
+++ b/src/com/android/settings/bluetooth/BluetoothDiscoverableEnabler.java
@@ -57,7 +57,7 @@ final class BluetoothDiscoverableEnabler implements Preference.OnPreferenceClick
 
     static final int DEFAULT_DISCOVERABLE_TIMEOUT = DISCOVERABLE_TIMEOUT_TWO_MINUTES;
 
-    private final Context mContext;
+    private Context mContext;
     private final Handler mUiHandler;
     private final Preference mDiscoveryPreference;
     // Preference for visibility time out.  Not final as it needs to be set through setter.
@@ -91,9 +91,8 @@ final class BluetoothDiscoverableEnabler implements Preference.OnPreferenceClick
         }
     };
 
-    BluetoothDiscoverableEnabler(Context context, LocalBluetoothAdapter adapter,
+    BluetoothDiscoverableEnabler(LocalBluetoothAdapter adapter,
             Preference discoveryPreference) {
-        mContext = context;
         mUiHandler = new Handler();
         mLocalAdapter = adapter;
         mDiscoveryPreference = discoveryPreference;
@@ -105,11 +104,15 @@ final class BluetoothDiscoverableEnabler implements Preference.OnPreferenceClick
         mVisibilityTimeoutPreference = visibilityPreference;
     }
 
-    public void resume() {
+    public void resume(Context context) {
         if (mLocalAdapter == null) {
             return;
         }
 
+        if (mContext != context) {
+            mContext = context;
+        }
+
         IntentFilter filter = new IntentFilter(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED);
         mContext.registerReceiver(mReceiver, filter);
         mDiscoveryPreference.setOnPreferenceClickListener(this);
diff --git a/src/com/android/settings/bluetooth/BluetoothSettings.java b/src/com/android/settings/bluetooth/BluetoothSettings.java
index 14c6054..68cf37a 100755
--- a/src/com/android/settings/bluetooth/BluetoothSettings.java
+++ b/src/com/android/settings/bluetooth/BluetoothSettings.java
@@ -156,7 +156,7 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment {
         super.onResume();
 
         if (mDiscoverableEnabler != null) {
-            mDiscoverableEnabler.resume();
+            mDiscoverableEnabler.resume(getActivity());
         }
         getActivity().registerReceiver(mReceiver, mIntentFilter);
         if (mLocalAdapter != null) {
@@ -262,9 +262,9 @@ public final class BluetoothSettings extends DeviceListPreferenceFragment {
 
                 if (!isRestrictedAndNotPinProtected()) {
                     if (mDiscoverableEnabler == null) {
-                        mDiscoverableEnabler = new BluetoothDiscoverableEnabler(getActivity(),
-                                mLocalAdapter, mMyDevicePreference);
-                        mDiscoverableEnabler.resume();
+                        mDiscoverableEnabler = new BluetoothDiscoverableEnabler(mLocalAdapter,
+                                mMyDevicePreference);
+                        mDiscoverableEnabler.resume(getActivity());
                         LocalBluetoothManager.getInstance(getActivity()).setDiscoverableEnabler(
                                 mDiscoverableEnabler);
                     }
diff --git a/src/com/android/settings/bluetooth/LocalDeviceProfilesSettings.java b/src/com/android/settings/bluetooth/LocalDeviceProfilesSettings.java
index 8d71007..ed27697 100644
--- a/src/com/android/settings/bluetooth/LocalDeviceProfilesSettings.java
+++ b/src/com/android/settings/bluetooth/LocalDeviceProfilesSettings.java
@@ -82,7 +82,7 @@ public final class LocalDeviceProfilesSettings extends SettingsPreferenceFragmen
         super.onResume();
         mManager.setForegroundActivity(getActivity());
         mAdvertisingEnabler.resume();
-        mDiscoverableEnabler.resume();
+        mDiscoverableEnabler.resume(getActivity());
     }
 
     @Override