Do not start suggestion loader if host isn't attached.

Change-Id: I1ab1de8f0bea6c66d8415e06aedcc7cbc6baf89c
Fixes: 68759380
Test: robotests

src/com/android/settings/dashboard/DashboardSummary.java

@@ -17,6 +17,7 @@
 package com.android.settings.dashboard;
 
 import android.app.Activity;
+import android.app.LoaderManager;
 import android.content.Context;
 import android.os.AsyncTask;
 import android.os.Bundle;
@@ -95,6 +96,14 @@ public class DashboardSummary extends InstrumentedFragment
         }
     }
 
+    @Override
+    public LoaderManager getLoaderManager() {
+        if (!isAdded()) {
+            return null;
+        }
+        return super.getLoaderManager();
+    }
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         long startTime = System.currentTimeMillis();

src/com/android/settings/dashboard/suggestions/SuggestionControllerMixin.java

@@ -21,6 +21,7 @@ import android.content.Context;
 import android.content.Loader;
 import android.os.Bundle;
 import android.service.settings.suggestions.Suggestion;
+import android.support.annotation.Nullable;
 import android.util.Log;
 
 import com.android.settings.overlay.FeatureFactory;
@@ -44,8 +45,10 @@ public class SuggestionControllerMixin implements SuggestionController.ServiceCo
         void onSuggestionReady(List<Suggestion> data);
 
         /**
-         * Returns {@link LoaderManager} associated with the host.
+         * Returns {@link LoaderManager} associated with the host. If host is not attached to
+         * activity then return null.
          */
+        @Nullable
         LoaderManager getLoaderManager();
     }
 
@@ -82,9 +85,12 @@ public class SuggestionControllerMixin implements SuggestionController.ServiceCo
 
     @Override
     public void onServiceConnected() {
-        mHost.getLoaderManager().restartLoader(SuggestionLoader.LOADER_ID_SUGGESTIONS,
+        final LoaderManager loaderManager = mHost.getLoaderManager();
+        if (loaderManager != null) {
+            loaderManager.restartLoader(SuggestionLoader.LOADER_ID_SUGGESTIONS,
                     null /* args */, this /* callback */);
         }
+    }
 
     @Override
     public void onServiceDisconnected() {

tests/robotests/src/com/android/settings/dashboard/suggestions/SuggestionControllerMixinTest.java

@@ -23,7 +23,6 @@ import static org.mockito.Mockito.when;
 
 import android.app.LoaderManager;
 import android.content.Context;
-import android.database.MatrixCursor;
 
 import com.android.settings.TestConfig;
 import com.android.settings.testutils.FakeFeatureFactory;
@@ -88,4 +87,14 @@ public class SuggestionControllerMixinTest {
         verify(loaderManager).restartLoader(SuggestionLoader.LOADER_ID_SUGGESTIONS,
                 null /* args */, mMixin /* callback */);
     }
+
+    @Test
+    public void onServiceConnected_hostNotAttached_shouldDoNothing() {
+        when(mHost.getLoaderManager()).thenReturn(null);
+
+        mMixin = new SuggestionControllerMixin(mContext, mHost, mLifecycle);
+        mMixin.onServiceConnected();
+
+        verify(mHost).getLoaderManager();
+    }
 }