First commit for settings panels

Establish the Activity which hosts Settings panels through the
PanelFragment. The Activity's purpose is to validate the intent
data coming in, including:
- Called with startActivityForResult (so we can log who is calling)
- Intent has the proper intent extra to link to a Panel

The fragment takes the Panelable data and builds a Settings Panel.
Each panel will have:
- Title
- List of Slices
- Link to underlying content

The Panelable interface is created to provide all of those datums, and
the new FetureProvider provides the Panelables by linking them with
keys. The keys will eventually become public APIs with CTS tests.For
now, we store them locally.

I included an exmaple panel, the InternetConnectivityPanel which
currently shows Wifi and Airplane mode.

Screenshot: https://screenshot.googleplex.com/c6sv7ZzQ5OJ
Bug: 117804089
Test: make -j40 RunSettingsRobotest
Test: Manual app
Change-Id: I1932f7179cc32088acd6413a736901ddf9651892

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

@@ -0,0 +1,103 @@
+/*
+ * 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.ComponentName;
+import android.content.Intent;
+import android.os.Bundle;
+
+import android.text.TextUtils;
+import android.util.Log;
+import android.view.Gravity;
+import android.view.Window;
+import android.view.WindowManager;
+
+import androidx.annotation.Nullable;
+import androidx.fragment.app.Fragment;
+import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentManager;
+
+import com.android.settings.R;
+
+/**
+ * Dialog Activity to host Settings Slices.
+ *
+ * TODO link to action / framework API
+ */
+public class SettingsPanelActivity extends FragmentActivity {
+
+    private final String TAG = "panel_activity";
+
+    /**
+     * Key specifying which Panel the app is requesting.
+     */
+    public static final String KEY_PANEL_TYPE_ARGUMENT = "PANEL_TYPE_ARGUMENT";
+
+
+    // TODO (b/117804442) move to framework
+    public static final String EXTRA_PANEL_TYPE = "com.android.settings.panel.extra";
+
+    // TODO (b/117804442) move to framework
+    public static final String PANEL_TYPE_WIFI = "wifi_panel";
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        final ComponentName callingActivityName = getCallingActivity();
+
+        if (callingActivityName == null) {
+            Log.e(TAG, "Must start with startActivityForResult. Closing.");
+            finish();
+            return;
+        }
+
+        final Intent callingIntent = getIntent();
+        if (callingIntent == null) {
+            Log.e(TAG, "Null intent, closing Panel Activity");
+            finish();
+            return;
+        }
+
+        final String typeExtra = callingIntent.getStringExtra(EXTRA_PANEL_TYPE);
+        if (TextUtils.isEmpty(typeExtra)) {
+            Log.e(TAG, "No intent passed, closing Panel Activity");
+            return;
+        }
+
+        setContentView(R.layout.settings_panel);
+
+        // Move the window to the bottom of screen, and make it take up the entire screen width.
+        final Window window = getWindow();
+        window.setGravity(Gravity.BOTTOM);
+        window.setLayout(WindowManager.LayoutParams.MATCH_PARENT,
+                WindowManager.LayoutParams.WRAP_CONTENT);
+
+
+        final Bundle bundle = new Bundle();
+        bundle.putString(KEY_PANEL_TYPE_ARGUMENT, typeExtra);
+
+        final PanelFragment panelFragment = new PanelFragment();
+        panelFragment.setArguments(bundle);
+
+        final FragmentManager fragmentManager = getSupportFragmentManager();
+        final Fragment fragment = fragmentManager.findFragmentById(R.id.main_content);
+        if (fragment == null) {
+            fragmentManager.beginTransaction().add(R.id.main_content, panelFragment).commit();
+        }
+    }
+}