Handle special case slices

Create a handler for any slice that doesn't include anything
from a PreferenceController.

Test: robotests
Change-Id: If23947152d61877537d0cac6240e96b9ab977bce
Bug: 80263568

src/com/android/settings/slices/CustomSliceable.java

@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2018 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.slices;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.net.Uri;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import androidx.slice.Slice;
+
+
+/**
+ * Common functions for custom Slices.
+ * <p>
+ *     A template for all Settings slices which are not represented by a Preference. By
+ *     standardizing the methods used by the Slice helpers, we can use generically take actions
+ *     rather than maintaining a list of all of the custom slices every time we reference Slices in
+ *     Settings.
+ * <p>
+ *     By default, all Slices in Settings should be built through Preference Controllers extending
+ *     {@link com.android.settings.core.BasePreferenceController}, which are automatically piped
+ *     into Settings-Slices infrastructure. Cases where you should implement this interface are:
+ *     <ul>
+ *         <li>Multi-line slices</li>
+ *         <li>Slices that don't exist in the UI</li>
+ *         <li>Preferences that use a supported component, like a Switch Bar</li>
+ *     </ul>
+ * <p>
+ *      Note that if your UI is supported because the Preference is not backed by a
+ *      {@link com.android.settings.dashboard.DashboardFragment}, then you should first convert the
+ *      existing fragment into a dashboard fragment, and then extend
+ *      {@link com.android.settings.core.BasePreferenceController}.
+ * <p>
+ *     If you implement this interface, you should add your Slice to {@link CustomSliceManager}.
+ */
+public interface CustomSliceable {
+
+    /**
+     * @return an complete instance of the {@link Slice}.
+     */
+    Slice getSlice(Context context);
+
+    /**
+     * @return a {@link android.content.ContentResolver#SCHEME_CONTENT content} {@link Uri} which
+     * backs the {@link Slice} returned by {@link #getSlice(Context)}.
+     */
+    Uri getUri();
+
+    /**
+     * Handles the actions sent by the {@link Intent intents} bound to the {@link Slice} returned by
+     * {@link #getSlice(Context)}.
+     *
+     * @param intent which has the action taken on a {@link Slice}.
+     */
+    void onNotifyChange(Intent intent);
+
+    /**
+     * Settings Slices which can represent components that are updatable by the framework should
+     * listen to changes matched to the {@link IntentFilter} returned here.
+     *
+     * @return an {@link IntentFilter} for updates related to the {@link Slice} returned by
+     * {@link #getSlice(Context)}.
+     */
+    default IntentFilter getIntentFilter() {
+        return null;
+    }
+
+    /**
+     * Build an instance of a {@link CustomSliceable} which has a {@link Context}-only constructor.
+     */
+    static CustomSliceable createInstance(Context context, Class<CustomSliceable> sliceableClass) {
+        try {
+            //final Class<CustomSliceable> clazz = Class.forName(sliceableClassName);
+            final Constructor<CustomSliceable> sliceable =
+                    sliceableClass.getConstructor(Context.class);
+            final Object[] params = new Object[]{context};
+            return sliceable.newInstance(params);
+        } catch (NoSuchMethodException | InstantiationException |
+                IllegalArgumentException | InvocationTargetException | IllegalAccessException e) {
+            throw new IllegalStateException(
+                    "Invalid sliceable class: " + sliceableClass, e);
+        }
+    }
+}