[Settings] Support pure switch of inline toggle of Settings Injection v2

Bug: 132808482
Test: robotest
Change-Id: Ib24614fb46fe990925edad721e3b7d5d032854fc

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

@@ -0,0 +1,42 @@
+/*
+ * 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.settings.dashboard;
+
+import android.database.ContentObserver;
+import android.net.Uri;
+import android.os.Handler;
+import android.os.Looper;
+
+/**
+ * Observer for updating injected dynamic data.
+ */
+public abstract class DynamicDataObserver extends ContentObserver {
+
+    protected DynamicDataObserver() {
+        super(new Handler(Looper.getMainLooper()));
+    }
+
+    /** Returns the uri of the callback. */
+    public abstract Uri getUri();
+
+    /** Called when data changes. */
+    public abstract void onDataChanged();
+
+    @Override
+    public void onChange(boolean selfChange) {
+        onDataChanged();
+    }
+}