Set up test infrastructure for WallpaperPicker2

Add instrumented and robolectric tests support.

Bug: 141954442

Change-Id: Id9331b5962819d126f29d4854b7b7d87bf5e79ea
diff --git a/tests/src/com/android/wallpaper/testing/TestWallpaperRefresher.java b/tests/src/com/android/wallpaper/testing/TestWallpaperRefresher.java
new file mode 100644
index 0000000..97961fe
--- /dev/null
+++ b/tests/src/com/android/wallpaper/testing/TestWallpaperRefresher.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+package com.android.wallpaper.testing;
+
+
+import android.app.WallpaperManager;
+import android.content.Context;
+
+import com.android.wallpaper.compat.BuildCompat;
+import com.android.wallpaper.model.WallpaperMetadata;
+import com.android.wallpaper.module.InjectorProvider;
+import com.android.wallpaper.module.WallpaperPreferences;
+import com.android.wallpaper.module.WallpaperRefresher;
+
+/**
+ * Test implementation of {@link WallpaperRefresher} which simply provides whatever metadata is
+ * saved in WallpaperPreferences and the image wallpaper set to {@link WallpaperManager}.
+ */
+public class TestWallpaperRefresher implements WallpaperRefresher {
+
+    private final Context mAppContext;
+
+    /**
+     * @param context The application's context.
+     */
+    public TestWallpaperRefresher(Context context) {
+        mAppContext = context.getApplicationContext();
+    }
+
+    @Override
+    public void refresh(RefreshListener listener) {
+
+        WallpaperPreferences prefs = InjectorProvider.getInjector().getPreferences(mAppContext);
+
+        if (BuildCompat.isAtLeastN() && prefs.getLockWallpaperId() > 0) {
+            listener.onRefreshed(
+                    new WallpaperMetadata(
+                            prefs.getHomeWallpaperAttributions(),
+                            prefs.getHomeWallpaperActionUrl(),
+                            prefs.getHomeWallpaperActionLabelRes(),
+                            prefs.getHomeWallpaperActionIconRes(),
+                            prefs.getHomeWallpaperCollectionId(),
+                            prefs.getHomeWallpaperBackingFileName(),
+                            null /* wallpaperComponent */),
+                    new WallpaperMetadata(
+                            prefs.getLockWallpaperAttributions(),
+                            prefs.getLockWallpaperActionUrl(),
+                            prefs.getLockWallpaperActionLabelRes(),
+                            prefs.getLockWallpaperActionIconRes(),
+                            prefs.getLockWallpaperCollectionId(),
+                            prefs.getLockWallpaperBackingFileName(),
+                            null /* wallpaperComponent */),
+                    prefs.getWallpaperPresentationMode());
+        } else {
+            listener.onRefreshed(
+                    new WallpaperMetadata(
+                            prefs.getHomeWallpaperAttributions(),
+                            prefs.getHomeWallpaperActionUrl(),
+                            prefs.getHomeWallpaperActionLabelRes(),
+                            prefs.getHomeWallpaperActionIconRes(),
+                            prefs.getHomeWallpaperCollectionId(),
+                            prefs.getHomeWallpaperBackingFileName(),
+                            null /* wallpaperComponent */),
+                    null,
+                    prefs.getWallpaperPresentationMode());
+        }
+    }
+}