Updating launcher settings so that they become split-screen

Following this guide:
https://developer.android.com/guide/topics/large-screens/activity-embedding#extract_an_activity_from_a_split_to_full_window

Bug: 204463748
Test: Open the settings app and open multiple settings, for now
only the options inside of the launcher3 package work
Flag: ACONFIG com.android.launcher3.Flags.enableTwoPaneLauncherSettings DEVELOPMENT

Change-Id: Ie6a9eb3760171da92d94cf06376127b02afff8df

Android.bp

@@ -175,6 +175,7 @@ android_library {
         "androidx.preference_preference",
         "androidx.slice_slice-view",
         "androidx.cardview_cardview",
+        "androidx.window_window",
         "com.google.android.material_material",
         "iconloader_base",
         "view_capture",

AndroidManifest-common.xml

@@ -184,5 +184,9 @@
             android:name="androidx.startup.InitializationProvider"
             android:authorities="${applicationId}.androidx-startup"
             tools:node="remove" />
+
+        <property
+            android:name="android.window.PROPERTY_ACTIVITY_EMBEDDING_SPLITS_ENABLED"
+            android:value="true" />
     </application>
 </manifest>

aconfig/launcher.aconfig

@@ -85,6 +85,13 @@ flag {
     bug: "315055849"
 }
 
+flag {
+    name: "enable_two_pane_launcher_settings"
+    namespace: "launcher"
+    description: "Enables two panel settings when on large enough displays"
+    bug: "204463748"
+}
+
 flag {
     name: "enable_shortcut_dont_suggest_app"
     namespace: "launcher"

res/values/config.xml

@@ -252,6 +252,9 @@
     <!--  Used for custom widgets  -->
     <array name="custom_widget_providers"/>
 
+    <!-- Embed parameters -->
+    <dimen name="activity_split_ratio"  format="float">0.5</dimen>
+    <integer name="min_width_split">720</integer>
 
     <!-- Skip "Install to private" long-press shortcut packages name -->
     <string-array name="skip_private_profile_shortcut_packages" translatable="false">

res/xml/split_configuration.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources
+    xmlns:window="http://schemas.android.com/apk/res-auto">
+    <!-- Automatically split the following activity pairs. -->
+    <SplitPairRule
+        window:splitRatio="@dimen/activity_split_ratio"
+        window:splitLayoutDirection="locale"
+        window:splitMinWidthDp="@integer/min_width_split"
+        window:splitMaxAspectRatioInPortrait="alwaysAllow"
+        window:finishPrimaryWithSecondary="never"
+        window:finishSecondaryWithPrimary="always"
+        window:clearTop="false">
+        <SplitPairFilter
+            window:primaryActivityName="com.android.launcher3.settings.SettingsActivity"
+            window:secondaryActivityName="com.android.launcher3.settings.SettingsActivity"/>
+
+    </SplitPairRule>
+</resources>

src/com/android/launcher3/Launcher.java

@@ -152,6 +152,7 @@ import androidx.annotation.RequiresApi;
 import androidx.annotation.StringRes;
 import androidx.annotation.UiThread;
 import androidx.annotation.VisibleForTesting;
+import androidx.window.embedding.RuleController;
 
 import com.android.launcher3.DropTarget.DragObject;
 import com.android.launcher3.accessibility.LauncherAccessibilityDelegate;
@@ -580,6 +581,11 @@ public class Launcher extends StatefulActivity<LauncherState>
         }
         setTitle(R.string.home_screen);
         mStartupLatencyLogger.logEnd(LAUNCHER_LATENCY_STARTUP_ACTIVITY_ON_CREATE);
+
+        if (com.android.launcher3.Flags.enableTwoPaneLauncherSettings()) {
+            RuleController.getInstance(this).setRules(
+                    RuleController.parseRules(this, R.xml.split_configuration));
+        }
     }
 
     protected ModelCallbacks createModelCallbacks() {