Bug 1550291 - Android Q: Use the overlay permission or a foreground notification to start the crash handler; r=VladBaicu

Android Q doesn't allow starting Activities from background.
https://developer.android.com/preview/privacy/background-activity-starts

We can either piggy-back the SYSTEM_ALERT_WINDOW permission given by the user
for the Tab Queue functionality or use a foreground notification from where
users could start `CrashReporterActivity`.

Differential Revision: https://phabricator.services.mozilla.com/D33029

--HG--
extra : moz-landing-system : lando

mobile/android/app/src/main/res/values/ids.xml

@@ -23,4 +23,5 @@
     <item type="id" name="action_button"/>
     <item type="id" name="page_progress"/>
     <item type="id" name="mediaControlNotification"/>
+    <item type="id" name="crashReporterNotification"/>
 </resources>

mobile/android/base/java/org/mozilla/gecko/CrashHandlerService.java

@@ -1,23 +1,92 @@
 package org.mozilla.gecko;
 
-import android.app.IntentService;
+import android.annotation.TargetApi;
+import android.app.Notification;
+import android.app.PendingIntent;
+import android.app.Service;
+import android.content.Context;
 import android.content.Intent;
-import android.support.annotation.Nullable;
+import android.os.IBinder;
+import android.provider.Settings;
 
+import org.mozilla.gecko.notifications.NotificationHelper;
 
-public class CrashHandlerService extends IntentService {
-
-    public CrashHandlerService() {
-        super("Crash Handler");
-    }
+public class CrashHandlerService extends Service {
+    private static final String ACTION_STOP = "action_stop";
+    // Build.VERSION_CODES.Q placeholder. While Android Q is in Beta it shares API 28 with Android P.
+    private static final int ANDROID_Q = 29;
 
     @Override
-    protected void onHandleIntent(@Nullable Intent intent) {
+    public int onStartCommand(Intent intent, int flags, int startId) {
+        if (ACTION_STOP.equals(intent.getAction())) {
+            dismissNotification();
+        } else {
             intent.setClass(this, CrashReporterActivity.class);
             intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+
+            if (AppConstants.Versions.feature29Plus) {
+                startCrashHandling(intent);
+            } else {
                 startActivity(intent);
 
                 // Avoid ANR due to background limitations on Oreo+
                 System.exit(0);
             }
         }
+
+        return Service.START_NOT_STICKY;
+    }
+
+    @Override
+    public IBinder onBind(Intent intent) {
+        return null;
+    }
+
+    /**
+     * Call this for any necessary cleanup like removing the foreground notification shown on Android Q+.
+     */
+    public static void reportingStarted(final Context context) {
+        if (AppConstants.Versions.feature29Plus) {
+            final Intent intent = new Intent(context, CrashHandlerService.class);
+            intent.setAction(ACTION_STOP);
+            context.startService(intent);
+        }
+    }
+
+    @TargetApi(ANDROID_Q)
+    private Notification getActivityNotification(final Context context, final Intent activityIntent) {
+        final Intent dismissNotificationIntent = new Intent(ACTION_STOP, null, this, this.getClass());
+        final PendingIntent dismissNotification = PendingIntent.getService(this, 0, dismissNotificationIntent, PendingIntent.FLAG_CANCEL_CURRENT);
+        final PendingIntent startReporterActivity = PendingIntent.getActivity(this, 0, activityIntent, 0);
+        final String notificationChannelId = NotificationHelper.getInstance(context)
+                .getNotificationChannel(NotificationHelper.Channel.CRASH_HANDLER).getId();
+
+        return new Notification.Builder(this, notificationChannelId)
+                .setSmallIcon(R.drawable.ic_status_logo)
+                .setContentTitle(getString(R.string.crash_notification_title))
+                .setContentText(getString(R.string.crash_notification_message))
+                .setDefaults(Notification.DEFAULT_ALL)
+                .setContentIntent(startReporterActivity)
+                .addAction(0, getString(R.string.crash_notification_negative_button_text), dismissNotification)
+                .build();
+    }
+
+    @TargetApi(ANDROID_Q)
+    private void dismissNotification() {
+        stopForeground(Service.STOP_FOREGROUND_REMOVE);
+    }
+
+    @TargetApi(ANDROID_Q)
+    private void startCrashHandling(final Intent activityIntent) {
+        // Piggy-back the SYSTEM_ALERT_WINDOW permission given by the user for the Tab Queue functionality.
+        // Otherwise fallback to display a foreground notification, this being the only way we can
+        // start an activity from background.
+        // https://developer.android.com/preview/privacy/background-activity-starts#conditions-allow-activity-starts
+        if (Settings.canDrawOverlays(this)) {
+            startActivity(activityIntent);
+        } else {
+            final Notification notification = getActivityNotification(this, activityIntent);
+            startForeground(R.id.mediaControlNotification, notification);
+        }
+    }
+}

mobile/android/base/java/org/mozilla/gecko/CrashReporterActivity.java

@@ -139,6 +139,8 @@ public class CrashReporterActivity extends AppCompatActivity
     @Override
     @SuppressLint("WrongThread") // We don't have a worker thread for the TelemetryDispatcher
     public void onCreate(Bundle savedInstanceState) {
+        informReporterStarted();
+
         super.onCreate(savedInstanceState);
         // mHandler is created here so runnables can be run on the main thread
         mHandler = new Handler();
@@ -596,4 +598,11 @@ public class CrashReporterActivity extends AppCompatActivity
     private String unescape(String string) {
         return string.replaceAll("\\\\\\\\", "\\").replaceAll("\\\\n", "\n").replaceAll("\\\\t", "\t");
     }
+
+    /**
+     * Inform other parts of the app that user started the crash reporting process.
+     */
+    private void informReporterStarted() {
+        CrashHandlerService.reportingStarted(this);
+    }
 }

mobile/android/base/locales/en-US/android_strings.dtd

@@ -68,6 +68,11 @@
 <!ENTITY  sending_crash_report "Sending crash report\u2026">
 <!ENTITY  crash_close_label "Close">
 <!ENTITY  crash_restart_label "Restart &brandShortName;">
+<!-- Localization note (crash_notification_title, crash_notification_message, crash_notification_negative_button_text)
+     Text displayed in a system notification to allow starting the Crash Reporter (Android Q and later).-->
+<!ENTITY  crash_notification_title "&brandShortName; crashed">
+<!ENTITY  crash_notification_message "Tap to report to &vendorShortName;">
+<!ENTITY  crash_notification_negative_button_text "Ignore">
 
 <!ENTITY url_bar_default_text2 "Search or enter address">
 

mobile/android/base/strings.xml.in

@@ -71,6 +71,9 @@
   <string name="sending_crash_report">&sending_crash_report;</string>
   <string name="crash_close_label">&crash_close_label;</string>
   <string name="crash_restart_label">&crash_restart_label;</string>
+  <string name="crash_notification_title">&crash_notification_title;</string>
+  <string name="crash_notification_message">&crash_notification_message;</string>
+  <string name="crash_notification_negative_button_text">&crash_notification_negative_button_text;</string>
 
   <string name="url_bar_default_text">&url_bar_default_text2;</string>
   <string name="url_bar_qrcode_text">&url_bar_qrcode_text2;</string>