Update SettingsPanel UI

UI changes include:
- RecyclerView to host slices
- Font family to headline font
- Title is now centered
- Added SeeMore & Done buttons
- Horizontal Dividers between slices
- Indented Slices
- Landscape layout is fullscreen

Change-Id: I3549c847fc88edd81f670ddfa2907dd3741441e0
Screenshot: https://screenshot.googleplex.com/RzWktzOZJkc
Test: Robolectric
Test: Manual app
Bug: 118622007

src/com/android/settings/panel/PanelSlicesAdapter.java

@@ -0,0 +1,100 @@
+/*
+ * 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.panel;
+
+import android.content.Context;
+import android.net.Uri;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import androidx.lifecycle.LiveData;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.slice.Slice;
+import androidx.slice.widget.SliceLiveData;
+import androidx.slice.widget.SliceView;
+
+import com.android.settings.R;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * RecyclerView adapter for Slices in Settings Panels.
+ */
+public class PanelSlicesAdapter
+        extends RecyclerView.Adapter<PanelSlicesAdapter.SliceRowViewHolder> {
+
+    private final List<Uri> mSliceUris;
+    private final PanelFragment mPanelFragment;
+
+    public PanelSlicesAdapter(PanelFragment fragment, List<Uri> sliceUris) {
+        mPanelFragment = fragment;
+        mSliceUris = new ArrayList<>(sliceUris);
+    }
+
+    @NonNull
+    @Override
+    public SliceRowViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
+        final Context context = viewGroup.getContext();
+        final LayoutInflater inflater = LayoutInflater.from(context);
+        final View view = inflater.inflate(R.layout.panel_slice_row, viewGroup, false);
+
+        return new SliceRowViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull SliceRowViewHolder sliceRowViewHolder, int position) {
+        sliceRowViewHolder.onBind(mPanelFragment, mSliceUris.get(position));
+    }
+
+    @Override
+    public int getItemCount() {
+        return mSliceUris.size();
+    }
+
+    @VisibleForTesting
+    List<Uri> getData() {
+        return mSliceUris;
+    }
+
+    /**
+     * ViewHolder for binding Slices to SliceViews.
+     */
+    public static class SliceRowViewHolder extends RecyclerView.ViewHolder {
+
+        @VisibleForTesting
+        LiveData<Slice> sliceLiveData;
+
+        @VisibleForTesting
+        final SliceView sliceView;
+
+        public SliceRowViewHolder(View view) {
+            super(view);
+            sliceView = view.findViewById(R.id.slice_view);
+            sliceView.setMode(SliceView.MODE_LARGE);
+        }
+
+        public void onBind(PanelFragment fragment, Uri sliceUri) {
+            final Context context = sliceView.getContext();
+            sliceLiveData = SliceLiveData.fromUri(context, sliceUri);
+            sliceLiveData.observe(fragment.getViewLifecycleOwner(), sliceView);
+        }
+    }
+}