Hide "additional info" when active dream does not support.

Only show the "additional info", which displays dream complications,
when supported by the user selected dream.

Test: make -j86 RunSettingsRoboTests
ROBOTEST_FILTER="com.android.settings.dream.DreamSettingsTest"
Test: verified on device switching between different dreams
Bug: 223860510
Fix: 223860510

Change-Id: I63872ea9ab9f42be47f8e2f7c3835b55056e6588

src/com/android/settings/dream/DreamPickerController.java

@@ -33,6 +33,7 @@ import com.android.settingslib.dream.DreamBackend;
 import com.android.settingslib.dream.DreamBackend.DreamInfo;
 import com.android.settingslib.widget.LayoutPreference;
 
+import java.util.HashSet;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -40,6 +41,7 @@ import java.util.stream.Collectors;
  * Controller for the dream picker where the user can select a screensaver.
  */
 public class DreamPickerController extends BasePreferenceController {
+    public static final String PREF_KEY = "dream_picker";
 
     private final DreamBackend mBackend;
     private final MetricsFeatureProvider mMetricsFeatureProvider;
@@ -48,12 +50,14 @@ public class DreamPickerController extends BasePreferenceController {
     private DreamInfo mActiveDream;
     private DreamAdapter mAdapter;
 
-    public DreamPickerController(Context context, String key) {
-        this(context, key, DreamBackend.getInstance(context));
+    private final HashSet<Callback> mCallbacks = new HashSet<>();
+
+    public DreamPickerController(Context context) {
+        this(context, DreamBackend.getInstance(context));
     }
 
-    public DreamPickerController(Context context, String key, DreamBackend backend) {
-        super(context, key);
+    public DreamPickerController(Context context, DreamBackend backend) {
+        super(context, PREF_KEY);
         mBackend = backend;
         mDreamInfos = mBackend.getDreamInfos();
         mActiveDream = getActiveDreamInfo(mDreamInfos);
@@ -96,6 +100,11 @@ public class DreamPickerController extends BasePreferenceController {
         }
     }
 
+    @Nullable
+    public DreamInfo getActiveDreamInfo() {
+        return mActiveDream;
+    }
+
     @Nullable
     private static DreamInfo getActiveDreamInfo(List<DreamInfo> dreamInfos) {
         return dreamInfos
@@ -105,6 +114,19 @@ public class DreamPickerController extends BasePreferenceController {
                 .orElse(null);
     }
 
+    void addCallback(Callback callback) {
+        mCallbacks.add(callback);
+    }
+
+    void removeCallback(Callback callback) {
+        mCallbacks.remove(callback);
+    }
+
+    interface Callback {
+        // Triggered when the selected dream changes.
+        void onActiveDreamChanged();
+    }
+
     private class DreamItem implements IDreamItem {
         DreamInfo mDreamInfo;
 
@@ -131,6 +153,7 @@ public class DreamPickerController extends BasePreferenceController {
         public void onItemClicked() {
             mActiveDream = mDreamInfo;
             mBackend.setActiveDream(mDreamInfo.componentName);
+            mCallbacks.forEach(Callback::onActiveDreamChanged);
             mMetricsFeatureProvider.action(SettingsEnums.PAGE_UNKNOWN,
                     SettingsEnums.ACTION_DREAM_SELECT_TYPE, SettingsEnums.DREAM,
                     mDreamInfo.componentName.flattenToString(), 1);