Customize Item callbacks and support existing background in

RecycleItemAdapter

- Added support for custom backgrounds in RecyclerItemAdapter.
- Added callbacks in Item to allow overriding state/level
  that gets copied from icon to drawable

Test: Tests added, verified that changes work
Change-Id: I33c883e0a1a0b76ccccaf8a61ab0bb49f46da3fb

library/main/src/com/android/setupwizardlib/items/Item.java

@@ -155,8 +155,7 @@ public class Item extends AbstractItem {
             // Set the image drawable to null before setting the state and level to avoid affecting
             // any recycled drawable in the ImageView
             iconView.setImageDrawable(null);
-            iconView.setImageState(icon.getState(), false /* merge */);
-            iconView.setImageLevel(icon.getLevel());
+            onMergeIconStateAndLevels(iconView, icon);
             iconView.setImageDrawable(icon);
             iconContainer.setVisibility(View.VISIBLE);
         } else {
@@ -165,4 +164,14 @@ public class Item extends AbstractItem {
 
         view.setId(getViewId());
     }
+
+    /**
+     * Copies state and level information from {@link #getIcon()} to the currently bound view's
+     * ImageView. Subclasses can override this method to change whats being copied from the icon
+     * to the ImageView.
+     */
+    protected void onMergeIconStateAndLevels(ImageView iconView, Drawable icon) {
+        iconView.setImageState(icon.getState(), false /* merge */);
+        iconView.setImageLevel(icon.getLevel());
+    }
 }

library/recyclerview/res/drawable/item_bg.xml

@@ -0,0 +1,19 @@
+<!--
+    Copyright (C) 2015 The Android Open Source Project
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+-->
+
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <corners android:radius="1dp"/>
+</shape>

library/recyclerview/res/layout/test_existing_background.xml

@@ -0,0 +1,20 @@
+<!--
+    Copyright (C) 2017 The Android Open Source Project
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+         http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+-->
+
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    android:background="@drawable/item_bg" />

library/recyclerview/src/com/android/setupwizardlib/items/RecyclerItemAdapter.java

@@ -109,8 +109,11 @@ public class RecyclerItemAdapter extends RecyclerView.Adapter<ItemViewHolder>
                         R.styleable.SuwRecyclerItemAdapter_selectableItemBackground);
             }
 
-            final Drawable background = typedArray.getDrawable(
-                    R.styleable.SuwRecyclerItemAdapter_android_colorBackground);
+            Drawable background = view.getBackground();
+            if (background == null) {
+                background = typedArray.getDrawable(
+                        R.styleable.SuwRecyclerItemAdapter_android_colorBackground);
+            }
 
             if (selectableItemBackground == null || background == null) {
                 Log.e(TAG, "Cannot resolve required attributes."

library/recyclerview/test/instrumentation/src/com/android/setupwizardlib/items/RecyclerItemAdapterTest.java

@@ -29,6 +29,7 @@ import static org.mockito.Mockito.verify;
 
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
+import android.graphics.drawable.GradientDrawable;
 import android.graphics.drawable.ShapeDrawable;
 import android.graphics.drawable.shapes.RectShape;
 import android.support.test.InstrumentationRegistry;
@@ -133,7 +134,7 @@ public class RecyclerItemAdapterTest {
     }
 
     @Test
-    public void testCreateViewHolderNoBcakground() {
+    public void testCreateViewHolderNoBackground() {
         RecyclerItemAdapter adapter = new RecyclerItemAdapter(mItemGroup);
         FrameLayout parent = new FrameLayout(InstrumentationRegistry.getContext());
 
@@ -141,4 +142,18 @@ public class RecyclerItemAdapterTest {
                 adapter.onCreateViewHolder(parent, R.layout.test_list_item_no_background);
         assertNull("Background should be null", viewHolder.itemView.getBackground());
     }
+
+    @Test
+    public void testCreateViewHolderWithExistingBackground() {
+        RecyclerItemAdapter adapter = new RecyclerItemAdapter(mItemGroup);
+        FrameLayout parent = new FrameLayout(InstrumentationRegistry.getContext());
+
+        final ItemViewHolder viewHolder =
+                adapter.onCreateViewHolder(parent, R.layout.test_existing_background);
+        Drawable background = viewHolder.itemView.getBackground();
+        assertTrue(background instanceof PatchedLayerDrawable);
+
+        PatchedLayerDrawable layerDrawable = (PatchedLayerDrawable) background;
+        assertTrue(layerDrawable.getDrawable(0) instanceof GradientDrawable);
+    }
 }