From 9bd0b2f9d067b917399c56f979ffc6a3e5a3860b Mon Sep 17 00:00:00 2001
From: Collin Fijalkovich <cfijalkovich@google.com>
Date: Mon, 5 Oct 2020 13:10:33 -0700
Subject: [PATCH] Disallow overlays for ResolverActivity

Prevents non-system apps from placing a window over the app selection
screen.

Bug: 143559931
Test: Installed test app and attempted to overlay
Change-Id: Ied05088a5007e0f10cd3e1abd8d7da8ffeb3b674
Merged-In: Ied05088a5007e0f10cd3e1abd8d7da8ffeb3b674
(cherry picked from commit 34534e1fd2057ea6d858ce82f8505cbdb1026d9a)
---
 .../android/internal/app/ResolverActivity.java   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/core/java/com/android/internal/app/ResolverActivity.java b/core/java/com/android/internal/app/ResolverActivity.java
index 5fe5f3cb4edc5..be34e194bac85 100644
--- a/core/java/com/android/internal/app/ResolverActivity.java
+++ b/core/java/com/android/internal/app/ResolverActivity.java
@@ -17,6 +17,7 @@
 package com.android.internal.app;
 
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
+import static android.view.WindowManager.LayoutParams.SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
 
 import android.annotation.Nullable;
 import android.annotation.StringRes;
@@ -68,7 +69,9 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewGroup.LayoutParams;
+import android.view.Window;
 import android.view.WindowInsets;
+import android.view.WindowManager;
 import android.widget.AbsListView;
 import android.widget.AdapterView;
 import android.widget.BaseAdapter;
@@ -778,9 +781,22 @@ public class ResolverActivity extends Activity {
         bindProfileView();
     }
 
+    @Override
+    protected void onStart() {
+        super.onStart();
+
+        this.getWindow().addSystemFlags(SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS);
+    }
+
     @Override
     protected void onStop() {
         super.onStop();
+
+        final Window window = this.getWindow();
+        final WindowManager.LayoutParams attrs = window.getAttributes();
+        attrs.privateFlags &= ~SYSTEM_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
+        window.setAttributes(attrs);
+
         if (mRegistered) {
             mPackageMonitor.unregister();
             mRegistered = false;