Allow foreground activity when accessibility service enabled

app/src/main/AndroidManifest.xml

@@ -177,6 +177,18 @@
             </intent-filter>
         </service>
 
+        <service
+            android:name=".Accessibility"
+            android:label="@string/app_name"
+            android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
+            <intent-filter>
+                <action android:name="android.accessibilityservice.AccessibilityService" />
+            </intent-filter>
+            <meta-data
+                android:name="android.accessibilityservice"
+                android:resource="@xml/accessibility" />
+        </service>
+
         <receiver
             android:name=".Receiver"
             android:label="@string/app_name">

app/src/main/java/eu/faircode/netguard/Accessibility.java

@@ -0,0 +1,80 @@
+package eu.faircode.netguard;
+
+/*
+    This file is part of NetGuard.
+
+    NetGuard is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    NetGuard is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with NetGuard.  If not, see <http://www.gnu.org/licenses/>.
+
+    Copyright 2015-2016 by Marcel Bokhorst (M66B)
+*/
+
+import android.accessibilityservice.AccessibilityService;
+import android.content.ComponentName;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.support.v4.content.LocalBroadcastManager;
+import android.util.Log;
+import android.view.accessibility.AccessibilityEvent;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Accessibility extends AccessibilityService {
+    private String lastActivePackageName = null;
+    private Map<ComponentName, Boolean> mapComponentNameActivity = new HashMap<>();
+
+    public static final String ACTION_FOREGROUND_ACTIVITY_CHANGED = "eu.faircode.netguard.ACTION_FOREGROUND_ACTIVITY_CHANGED";
+    public static final String EXTRA_PACKAGE_NAME = "Package";
+
+    private static final String TAG = "NetGuard.Accessibility";
+
+    @Override
+    public void onAccessibilityEvent(AccessibilityEvent event) {
+        if (event.getEventType() == AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED) {
+            ComponentName componentName = new ComponentName(
+                    event.getPackageName().toString(),
+                    event.getClassName().toString()
+            );
+
+            synchronized (this) {
+                boolean activity = false;
+                if (mapComponentNameActivity.containsKey(componentName))
+                    activity = mapComponentNameActivity.get(componentName);
+                else {
+                    try {
+                        getPackageManager().getActivityInfo(componentName, 0);
+                        activity = true;
+                    } catch (PackageManager.NameNotFoundException ignored) {
+                    }
+                    mapComponentNameActivity.put(componentName, activity);
+                }
+
+                Log.i(TAG, componentName + "=" + activity);
+
+                if (activity && (lastActivePackageName == null || !lastActivePackageName.equals((event.getPackageName().toString())))) {
+                    lastActivePackageName = event.getPackageName().toString();
+                    Log.i(TAG, "Foreground activity=" + lastActivePackageName);
+
+                    Intent intent = new Intent(ACTION_FOREGROUND_ACTIVITY_CHANGED);
+                    intent.putExtra(EXTRA_PACKAGE_NAME, lastActivePackageName);
+                    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
+                }
+            }
+        }
+    }
+
+    @Override
+    public void onInterrupt() {
+    }
+}

app/src/main/java/eu/faircode/netguard/ServiceSinkhole.java

@@ -112,12 +112,14 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
     private boolean registeredIdleState = false;
     private boolean registeredConnectivityChanged = false;
     private boolean registeredPackageAdded = false;
+    private boolean registeredActivityChanged = false;
 
     private State state = State.none;
     private boolean user_foreground = true;
     private boolean last_connected = false;
     private boolean last_metered = true;
     private boolean last_interactive = false;
+    private String last_activity = null;
     private boolean powersaving = false;
     private boolean phone_state = false;
     private Object subscriptionsChangedListener = null;
@@ -1387,6 +1389,7 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
                 " generation=" + generation +
                 " roaming=" + roaming + "/" + org_roaming +
                 " interactive=" + last_interactive +
+                " activity=" + last_activity +
                 " tethering=" + tethering +
                 " filter=" + filter);
 
@@ -1396,6 +1399,10 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
                 boolean screen = (metered ? rule.screen_other : rule.screen_wifi);
                 if ((!blocked || (screen && last_interactive)) && (!metered || !(rule.roaming && roaming)))
                     listAllowed.add(rule);
+                else if (last_activity != null && last_activity.equals(rule.info.packageName)) {
+                    listAllowed.add(rule);
+                    Log.i(TAG, "Allowed foreground activity=" + rule.info.packageName);
+                }
             }
 
         Log.i(TAG, "Allowed " + listAllowed.size() + " of " + listRule.size());
@@ -1668,6 +1675,16 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
         }
     };
 
+    private BroadcastReceiver activityChangedReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            Log.i(TAG, "Received " + intent);
+            Util.logExtras(intent);
+            last_activity = intent.getStringExtra(Accessibility.EXTRA_PACKAGE_NAME);
+            reload("activity changed", ServiceSinkhole.this);
+        }
+    };
+
     private PhoneStateListener phoneStateListener = new PhoneStateListener() {
         private String last_generation = null;
         private int last_international = -1;
@@ -1789,6 +1806,11 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
         registerReceiver(packageAddedReceiver, ifPackage);
         registeredPackageAdded = true;
 
+        // Listen for foreground activity changes
+        IntentFilter ifActivity = new IntentFilter(Accessibility.ACTION_FOREGROUND_ACTIVITY_CHANGED);
+        LocalBroadcastManager.getInstance(this).registerReceiver(activityChangedReceiver, ifActivity);
+        registeredActivityChanged = true;
+
         // Setup house holding
         Intent alarmIntent = new Intent(this, ServiceSinkhole.class);
         alarmIntent.setAction(ACTION_HOUSE_HOLDING);
@@ -1937,6 +1959,10 @@ public class ServiceSinkhole extends VpnService implements SharedPreferences.OnS
             unregisterReceiver(packageAddedReceiver);
             registeredPackageAdded = false;
         }
+        if (registeredActivityChanged) {
+            LocalBroadcastManager.getInstance(this).unregisterReceiver(activityChangedReceiver);
+            registeredActivityChanged = false;
+        }
 
         if (phone_state) {
             TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);

app/src/main/res/xml/accessibility.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<accessibility-service xmlns:android="http://schemas.android.com/apk/res/android"
+    android:accessibilityEventTypes="typeWindowStateChanged"
+    android:accessibilityFeedbackType="feedbackGeneric"
+    android:accessibilityFlags="flagIncludeNotImportantViews"
+    android:description="@string/app_name" />