Add null check before setting the visibility of swipe background

Some contextual cards does not allow card dismissal, so they won't have
swipe background declared in the layout file. Add null check to prevent
from NPE.

Fixes: 132209310
Test: robotests & launch Settings
Change-Id: I31f897f445c4901d007c8187fe69aea416b915d1

src/com/android/settings/homepage/contextualcards/slices/SliceContextualCardRenderer.java

@@ -112,8 +112,10 @@ public class SliceContextualCardRenderer implements ContextualCardRenderer, Life
 
         final View swipeBackground = holder.itemView.findViewById(R.id.dismissal_swipe_background);
         sliceLiveData.removeObservers(mLifecycleOwner);
-        // set the background to Gone in case the holder is reused.
+        // set the background to GONE in case the holder is reused.
+        if (swipeBackground != null) {
             swipeBackground.setVisibility(View.GONE);
+        }
         sliceLiveData.observe(mLifecycleOwner, slice -> {
             if (slice == null) {
                 Log.w(TAG, "Slice is null");
@@ -140,8 +142,9 @@ public class SliceContextualCardRenderer implements ContextualCardRenderer, Life
                 default:
                     mFullCardHelper.bindView(holder, card, slice);
             }
-
+            if (swipeBackground != null) {
                 swipeBackground.setVisibility(View.VISIBLE);
+            }
         });
 
         switch (holder.getItemViewType()) {

tests/robotests/src/com/android/settings/homepage/contextualcards/slices/SliceContextualCardRendererTest.java

@@ -16,11 +16,13 @@
 
 package com.android.settings.homepage.contextualcards.slices;
 
+import static com.android.settings.homepage.contextualcards.slices.SliceContextualCardRenderer.VIEW_TYPE_DEFERRED_SETUP;
 import static com.android.settings.homepage.contextualcards.slices.SliceContextualCardRenderer.VIEW_TYPE_FULL_WIDTH;
 
 import static com.google.common.truth.Truth.assertThat;
 
 import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
 import android.app.Activity;
@@ -160,6 +162,15 @@ public class SliceContextualCardRendererTest {
         assertThat(swipeBg.getVisibility()).isEqualTo(View.GONE);
     }
 
+    @Test
+    public void bindView_deferredSetupCard_shouldNotCrash() {
+        final RecyclerView.ViewHolder viewHolder = getDeferredSetupViewHolder();
+        final ContextualCard card = buildContextualCard(TEST_SLICE_URI);
+        mRenderer.mSliceLiveDataMap.put(TEST_SLICE_URI, mSliceLiveData);
+
+        mRenderer.bindView(viewHolder, card);
+    }
+
     @Test
     public void viewClick_keepCard_shouldShowSlice() {
         final RecyclerView.ViewHolder viewHolder = getSliceViewHolder();
@@ -246,6 +257,18 @@ public class SliceContextualCardRendererTest {
         return mRenderer.createViewHolder(view, VIEW_TYPE_FULL_WIDTH);
     }
 
+    private RecyclerView.ViewHolder getDeferredSetupViewHolder() {
+        final RecyclerView recyclerView = new RecyclerView(mActivity);
+        recyclerView.setLayoutManager(new LinearLayoutManager(mActivity));
+        final View view = LayoutInflater.from(mActivity)
+                .inflate(VIEW_TYPE_DEFERRED_SETUP, recyclerView, false);
+        final RecyclerView.ViewHolder viewHolder = spy(
+                new SliceDeferredSetupCardRendererHelper.DeferredSetupCardViewHolder(view));
+        doReturn(VIEW_TYPE_DEFERRED_SETUP).when(viewHolder).getItemViewType();
+
+        return viewHolder;
+    }
+
     private ContextualCard buildContextualCard(Uri sliceUri) {
         return new ContextualCard.Builder()
                 .setName("test_name")