From ac244bc17bece741fcca5d1b492d3c7f3764019b Mon Sep 17 00:00:00 2001
From: Fredrik Hubinette <hubbe@meta.com>
Date: Fri, 13 Dec 2024 17:24:13 -0800
Subject: [PATCH] Added HorizonOSQualityEnforcer to handle finish task command
 from thhe browser to shutdown TWA LauncherActivity

---
 .../trusted/HorizonOSQualityEnforcer.java     | 92 +++++++++++++++++++
 .../trusted/LauncherActivity.java             |  7 +-
 2 files changed, 98 insertions(+), 1 deletion(-)
 create mode 100644 androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/HorizonOSQualityEnforcer.java

diff --git a/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/HorizonOSQualityEnforcer.java b/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/HorizonOSQualityEnforcer.java
new file mode 100644
index 00000000..5c4b9be3
--- /dev/null
+++ b/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/HorizonOSQualityEnforcer.java
@@ -0,0 +1,92 @@
+// Copyright (c) Meta Platforms, Inc. and affiliates.
+//
+// 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.google.androidbrowserhelper.trusted;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.os.Handler;
+import android.os.Looper;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.browser.customtabs.CustomTabsCallback;
+
+/**
+ * This class handles the quality enforcement messages from the browser to enforce the quality bar
+ * on the websites shown inside Trusted Web Activities.
+ * Browser should send a message when violation occurs. For example if a link from a page on the
+ * verified origin 404s or if a page cannot be displayed while offline.
+ *
+ * The purpose of this is to bring TWAs in line with native applications - if a native application
+ * tries to start an Activity that doesn't exist, it will crash. We should hold web apps to the
+ * same standard.
+ */
+public class HorizonOSQualityEnforcer extends CustomTabsCallback {
+    private static final  String TAG = "HzOSTwaQualityEnforcer";
+    static final String CRASH = "quality_enforcement.crash";
+    static final String FINISH_TASK_COMMAND_NAME = "finishAndRemoveTask";
+    static final String KEY_CRASH_REASON = "crash_reason";
+    static final String KEY_SUCCESS = "success";
+
+    private final Delegate mDelegate;
+    private Activity mActivity;
+
+    /**
+     * A Delegate interface that provides implementations for handling quality enforcement messages.
+     */
+    interface Delegate {
+        /* Handling the CRASH message from browser. */
+        void crash(String message);
+    }
+
+    /* Constructor to be used in prod that throws a RuntimeException. */
+    public HorizonOSQualityEnforcer() {
+        mDelegate = (message) -> {
+            // Put the exception in a looper so that the crash will not prevent returning the
+            // execution result to browser.
+            new Handler(Looper.getMainLooper()).post(() -> {
+                throw new RuntimeException(message);
+            });
+        };
+    }
+
+    public HorizonOSQualityEnforcer(Activity activity) {
+        this();
+        mActivity = activity;
+    }
+
+    /* Constructor for use in tests. */
+    HorizonOSQualityEnforcer(Delegate delegate) { mDelegate = delegate; }
+
+    @Nullable
+    @Override
+    public Bundle extraCallbackWithResult(
+            @NonNull String callbackName, @Nullable Bundle args) {
+        Bundle result = new Bundle();
+        if (callbackName.equals(CRASH)) {
+            result.putBoolean(KEY_SUCCESS, true);
+            String message = (args != null) ? args.getString(KEY_CRASH_REASON) : null;
+            if (message == null) return Bundle.EMPTY;
+            mDelegate.crash(message);
+        } else if (callbackName.equals(FINISH_TASK_COMMAND_NAME)) {
+            Log.d(TAG, "Received finishAndRemoveTask command from browser.");
+            if (mActivity != null) {
+                mActivity.finish(); 
+            }
+        }
+        return result;
+    }
+};
diff --git a/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/LauncherActivity.java b/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/LauncherActivity.java
index c3237af7..9486a7fc 100644
--- a/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/LauncherActivity.java
+++ b/androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/LauncherActivity.java
@@ -243,7 +243,12 @@ protected void launchTwa() {
     }
 
     protected CustomTabsCallback getCustomTabsCallback() {
-        return new QualityEnforcer();
+        if (mMetadata.horizonOSAppMode != null) {
+            Log.d(TAG, "Creating HorizonOSQualityEnforcer.");
+            return new HorizonOSQualityEnforcer(this);
+        } else {
+            return new QualityEnforcer();
+        }
     }
 
     protected TwaLauncher createTwaLauncher() {