Fixed StrictMode problems, created a reactive implementation class, fixed potential NPEs, fixed memory leak

* Fixed places where IO was done on main thread
* Created reactive class Observable so that work could easily be done on
other threads
* Fixed potential NPEs in LightningView
* Fixed memory leak where ConnectivityManager was leaking activity

app/src/main/java/acr/browser/lightning/activity/BrowserActivity.java

@@ -27,6 +27,7 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
+import android.os.StrictMode;
 import android.provider.MediaStore;
 import android.support.annotation.ColorInt;
 import android.support.annotation.IdRes;
@@ -89,6 +90,7 @@ import java.io.IOException;
 
 import javax.inject.Inject;
 
+import acr.browser.lightning.BuildConfig;
 import acr.browser.lightning.R;
 import acr.browser.lightning.app.BrowserApp;
 import acr.browser.lightning.browser.BrowserPresenter;
@@ -108,10 +110,13 @@ import acr.browser.lightning.dialog.LightningDialogBuilder;
 import acr.browser.lightning.fragment.BookmarksFragment;
 import acr.browser.lightning.fragment.TabsFragment;
 import acr.browser.lightning.object.SearchAdapter;
+import acr.browser.lightning.react.Schedulers;
+import acr.browser.lightning.react.Subscription;
 import acr.browser.lightning.receiver.NetworkReceiver;
 
 import com.anthonycr.grant.PermissionsManager;
 
+import acr.browser.lightning.react.Observable;
 import acr.browser.lightning.utils.ProxyUtils;
 import acr.browser.lightning.utils.ThemeUtils;
 import acr.browser.lightning.utils.UrlUtils;
@@ -217,11 +222,26 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
 
     public abstract void updateHistory(@Nullable final String title, @NonNull final String url);
 
-    abstract void updateCookiePreference();
+    abstract Observable<Void> updateCookiePreference();
 
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
+
+        if (BuildConfig.DEBUG) {
+            StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
+                    .detectDiskReads()
+                    .detectDiskWrites()
+                    .detectNetwork()
+                    .penaltyLog()
+                    .build());
+            StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder()
+                    .detectLeakedClosableObjects()
+                    .detectLeakedSqlLiteObjects()
+                    .penaltyLog()
+                    .build());
+        }
+
         super.onCreate(savedInstanceState);
         BrowserApp.getAppComponent().inject(this);
         setContentView(R.layout.activity_main);
@@ -339,11 +359,21 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
             WebIconDatabase.getInstance().open(getDir("icons", MODE_PRIVATE).getPath());
         }
 
-        mTabsManager.restoreTabsAndHandleIntent(this, getIntent(), isIncognito());
+        mTabsManager.restoreTabsAndHandleIntent(this, getIntent(), isIncognito())
+                .subscribe(new Subscription<Void>() {
+                    @Override
+                    public void onComplete() {
                         // At this point we always have at least a tab in the tab manager
                         showTab(0);
 
-        mProxyUtils.checkForProxy(this);
+                        mProxyUtils.checkForProxy(BrowserActivity.this);
+                    }
+
+                    @Override
+                    public void onNext(Void item) {
+
+                    }
+                });
     }
 
     private class SearchListenerClass implements OnKeyListener, OnEditorActionListener, OnFocusChangeListener, OnTouchListener {
@@ -624,7 +654,7 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
                 break;
         }
 
-        updateCookiePreference();
+        updateCookiePreference().subscribeOn(Schedulers.worker()).subscribe();
         mProxyUtils.updateProxySettings(this);
     }
 
@@ -1080,7 +1110,7 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
             currentTab.onPause();
         }
         try {
-            unregisterReceiver(mNetworkReceiver);
+            BrowserApp.get(this).unregisterReceiver(mNetworkReceiver);
         } catch (IllegalArgumentException e) {
             e.printStackTrace();
         }
@@ -1142,7 +1172,7 @@ public abstract class BrowserActivity extends ThemableBrowserActivity implements
 
         IntentFilter filter = new IntentFilter();
         filter.addAction(NETWORK_BROADCAST_ACTION);
-        registerReceiver(mNetworkReceiver, filter);
+        BrowserApp.get(this).registerReceiver(mNetworkReceiver, filter);
 
         mEventBus.register(mBusEventListener);
     }

app/src/main/java/acr/browser/lightning/activity/IncognitoActivity.java

@@ -9,17 +9,26 @@ import android.webkit.CookieManager;
 import android.webkit.CookieSyncManager;
 
 import acr.browser.lightning.R;
+import acr.browser.lightning.react.Action;
+import acr.browser.lightning.react.Observable;
+import acr.browser.lightning.react.Subscriber;
 
 @SuppressWarnings("deprecation")
 public class IncognitoActivity extends BrowserActivity {
 
     @Override
-    public void updateCookiePreference() {
+    public Observable<Void> updateCookiePreference() {
+        return Observable.create(new Action<Void>() {
+            @Override
+            public void onSubscribe(Subscriber<Void> subscriber) {
                 CookieManager cookieManager = CookieManager.getInstance();
                 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            CookieSyncManager.createInstance(this);
+                    CookieSyncManager.createInstance(IncognitoActivity.this);
                 }
                 cookieManager.setAcceptCookie(mPreferences.getIncognitoCookiesEnabled());
+                subscriber.onComplete();
+            }
+        });
     }
 
     @Override

app/src/main/java/acr/browser/lightning/activity/MainActivity.java

@@ -9,17 +9,26 @@ import android.webkit.CookieManager;
 import android.webkit.CookieSyncManager;
 
 import acr.browser.lightning.R;
+import acr.browser.lightning.react.Action;
+import acr.browser.lightning.react.Observable;
+import acr.browser.lightning.react.Subscriber;
 
 @SuppressWarnings("deprecation")
 public class MainActivity extends BrowserActivity {
 
     @Override
-    public void updateCookiePreference() {
+    public Observable<Void> updateCookiePreference() {
+        return Observable.create(new Action<Void>() {
+            @Override
+            public void onSubscribe(Subscriber<Void> subscriber) {
                 CookieManager cookieManager = CookieManager.getInstance();
                 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
-            CookieSyncManager.createInstance(this);
+                    CookieSyncManager.createInstance(MainActivity.this);
                 }
                 cookieManager.setAcceptCookie(mPreferences.getCookiesEnabled());
+                subscriber.onComplete();
+            }
+        });
     }
 
     @Override

app/src/main/java/acr/browser/lightning/activity/TabsManager.java

@@ -23,7 +23,12 @@ import javax.inject.Singleton;
 import acr.browser.lightning.R;
 import acr.browser.lightning.constant.Constants;
 import acr.browser.lightning.preference.PreferenceManager;
+import acr.browser.lightning.react.Action;
+import acr.browser.lightning.react.Schedulers;
+import acr.browser.lightning.react.Subscriber;
+import acr.browser.lightning.react.Subscription;
 import acr.browser.lightning.utils.FileUtils;
+import acr.browser.lightning.react.Observable;
 import acr.browser.lightning.view.LightningView;
 
 /**
@@ -56,28 +61,38 @@ public class TabsManager {
      * @param intent    the intent that started the browser activity.
      * @param incognito whether or not we are in incognito mode.
      */
-    public synchronized void restoreTabsAndHandleIntent(@NonNull final Activity activity,
+    public synchronized Observable<Void> restoreTabsAndHandleIntent(@NonNull final Activity activity,
                                                                     @Nullable final Intent intent,
                                                                     final boolean incognito) {
+        return Observable.create(new Action<Void>() {
+            @Override
+            public void onSubscribe(final Subscriber<Void> subscriber) {
+
+
                 // If incognito, only create one tab, do not handle intent
                 // in order to protect user privacy
                 if (incognito && mTabList.isEmpty()) {
                     newTab(activity, null, true);
+                    subscriber.onComplete();
                     return;
                 }
 
-        String url = null;
+                String dataString = null;
                 if (intent != null) {
-            url = intent.getDataString();
+                    dataString = intent.getDataString();
                 }
+                final String url = dataString;
                 mTabList.clear();
                 mCurrentTab = null;
                 if (mPreferenceManager.getRestoreLostTabsEnabled()) {
-            restoreState(activity);
-        }
+                    restoreState()
+                            .subscribeOn(Schedulers.worker())
+                            .observeOn(Schedulers.main())
+                            .subscribe(new Subscription<Bundle>() {
+                                @Override
+                                public void onComplete() {
                                     if (url != null) {
                                         if (url.startsWith(Constants.FILE)) {
-                final String urlToLoad = url;
                                             AlertDialog.Builder builder = new AlertDialog.Builder(activity);
                                             builder.setCancelable(true)
                                                     .setTitle(R.string.title_warning)
@@ -86,10 +101,9 @@ public class TabsManager {
                                                     .setPositiveButton(R.string.action_open, new DialogInterface.OnClickListener() {
                                                         @Override
                                                         public void onClick(DialogInterface dialog, int which) {
-                                newTab(activity, urlToLoad, false);
+                                                            newTab(activity, url, false);
                                                         }
-                        })
-                        .show();
+                                                    }).show();
                                         } else {
                                             newTab(activity, url, false);
                                         }
@@ -97,6 +111,22 @@ public class TabsManager {
                                     if (mTabList.size() == 0) {
                                         newTab(activity, null, false);
                                     }
+                                    subscriber.onComplete();
+                                }
+
+                                @Override
+                                public void onNext(Bundle item) {
+                                    LightningView tab = newTab(activity, "", false);
+                                    if (tab.getWebView() != null) {
+                                        tab.getWebView().restoreState(item);
+                                    }
+                                }
+                            });
+                }
+
+            }
+        });
+
     }
 
     /**
@@ -285,22 +315,23 @@ public class TabsManager {
      * It will create new tabs for each tab saved
      * and will delete the saved instance file when
      * restoration is complete.
-     *
-     * @param activity the Activity needed to create tabs.
      */
-    private void restoreState(@NonNull Activity activity) {
+    private Observable<Bundle> restoreState() {
+        return Observable.create(new Action<Bundle>() {
+            @Override
+            public void onSubscribe(Subscriber<Bundle> subscriber) {
                 Bundle savedState = FileUtils.readBundleFromStorage(mApp, BUNDLE_STORAGE);
                 if (savedState != null) {
                     Log.d(Constants.TAG, "Restoring previous WebView state now");
                     for (String key : savedState.keySet()) {
                         if (key.startsWith(BUNDLE_KEY)) {
-                    LightningView tab = newTab(activity, "", false);
-                    if (tab.getWebView() != null) {
-                        tab.getWebView().restoreState(savedState.getBundle(key));
+                            subscriber.onNext(savedState.getBundle(key));
                         }
                     }
                 }
+                subscriber.onComplete();
             }
+        });
     }
 
     /**

app/src/main/java/acr/browser/lightning/async/ImageDownloadTask.java

@@ -25,8 +25,8 @@ import acr.browser.lightning.utils.Utils;
 public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
 
     private static final String TAG = ImageDownloadTask.class.getSimpleName();
-    private final File mCacheDir;
     @NonNull private final WeakReference<ImageView> mFaviconImage;
+    @NonNull private final WeakReference<Context> mContextReference;
     @NonNull private final HistoryItem mWeb;
     private final String mUrl;
     @NonNull private final Bitmap mDefaultBitmap;
@@ -42,7 +42,7 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
         this.mWeb = web;
         this.mUrl = web.getUrl();
         this.mDefaultBitmap = defaultBitmap;
-        this.mCacheDir = BrowserApp.get(context).getCacheDir();
+        this.mContextReference = new WeakReference<>(context.getApplicationContext());
     }
 
     @Nullable
@@ -53,12 +53,17 @@ public class ImageDownloadTask extends AsyncTask<Void, Void, Bitmap> {
         if (mUrl == null) {
             return mDefaultBitmap;
         }
+        Context context = mContextReference.get();
+        if (context == null) {
+            return mDefaultBitmap;
+        }
+        File cache = context.getCacheDir();
         final Uri uri = Uri.parse(mUrl);
         if (uri.getHost() == null || uri.getScheme() == null) {
             return mDefaultBitmap;
         }
         final String hash = String.valueOf(uri.getHost().hashCode());
-        final File image = new File(mCacheDir, hash + ".png");
+        final File image = new File(cache, hash + ".png");
         final String urlDisplay = uri.getScheme() + "://" + uri.getHost() + "/favicon.ico";
         // checks to see if the image exists
         if (!image.exists()) {

app/src/main/java/acr/browser/lightning/constant/BookmarkPage.java

@@ -60,17 +60,17 @@ public final class BookmarkPage extends AsyncTask<Void, Void, Void> {
 
     private static final String END = "</div></body></html>";
 
-    private final File mFilesDir;
-    private final File mCacheDir;
+    private File mFilesDir;
+    private File mCacheDir;
 
+    private Application mApp;
     private final BookmarkManager mManager;
     @NonNull private final WeakReference<LightningView> mTabReference;
     private final Bitmap mFolderIcon;
     @NonNull private final String mTitle;
 
     public BookmarkPage(LightningView tab, @NonNull Application app, BookmarkManager manager, Bitmap folderIcon) {
-        mFilesDir = app.getFilesDir();
-        mCacheDir = app.getCacheDir();
+        mApp = app;
         mTitle = app.getString(R.string.action_bookmarks);
         mManager = manager;
         mTabReference = new WeakReference<>(tab);
@@ -79,6 +79,8 @@ public final class BookmarkPage extends AsyncTask<Void, Void, Void> {
 
     @Override
     protected Void doInBackground(Void... params) {
+        mCacheDir = mApp.getCacheDir();
+        mFilesDir = mApp.getFilesDir();
         cacheDefaultFolderIcon();
         buildBookmarkPage(null, mManager);
         return null;

app/src/main/java/acr/browser/lightning/constant/HistoryPage.java

@@ -41,7 +41,7 @@ public class HistoryPage extends AsyncTask<Void, Void, Void> {
     private static final String END = "</div></body></html>";
 
     @NonNull private final WeakReference<LightningView> mTabReference;
-    private final File mFilesDir;
+    @NonNull private final Application mApp;
     @NonNull private final String mTitle;
     private final HistoryDatabase mHistoryDatabase;
 
@@ -49,7 +49,7 @@ public class HistoryPage extends AsyncTask<Void, Void, Void> {
 
     public HistoryPage(LightningView tab, @NonNull Application app, HistoryDatabase database) {
         mTabReference = new WeakReference<>(tab);
-        mFilesDir = app.getFilesDir();
+        mApp = app;
         mTitle = app.getString(R.string.action_history);
         mHistoryDatabase = database;
     }
@@ -88,7 +88,7 @@ public class HistoryPage extends AsyncTask<Void, Void, Void> {
         }
 
         historyBuilder.append(END);
-        File historyWebPage = new File(mFilesDir, FILENAME);
+        File historyWebPage = new File(mApp.getFilesDir(), FILENAME);
         FileWriter historyWriter = null;
         try {
             //noinspection IOResourceOpenedButNotSafelyClosed

app/src/main/java/acr/browser/lightning/constant/StartPage.java

@@ -55,7 +55,7 @@ public class StartPage extends AsyncTask<Void, Void, Void> {
     private static final String END = "\" + document.getElementById(\"search_input\").value;document.getElementById(\"search_input\").value = \"\";}return false;}</script></body></html>";
 
     @NonNull private final String mTitle;
-    private final File mFilesDir;
+    @NonNull private final Application mApp;
     @NonNull private final WeakReference<LightningView> mTabReference;
 
     @Inject PreferenceManager mPreferenceManager;
@@ -65,7 +65,7 @@ public class StartPage extends AsyncTask<Void, Void, Void> {
     public StartPage(LightningView tab, @NonNull Application app) {
         BrowserApp.getAppComponent().inject(this);
         mTitle = app.getString(R.string.home);
-        mFilesDir = app.getFilesDir();
+        mApp = app;
         mTabReference = new WeakReference<>(tab);
     }
 
@@ -174,7 +174,7 @@ public class StartPage extends AsyncTask<Void, Void, Void> {
         homepageBuilder.append(searchUrl);
         homepageBuilder.append(END);
 
-        File homepage = new File(mFilesDir, FILENAME);
+        File homepage = new File(mApp.getFilesDir(), FILENAME);
         FileWriter hWriter = null;
         try {
             //noinspection IOResourceOpenedButNotSafelyClosed

app/src/main/java/acr/browser/lightning/database/BookmarkManager.java

@@ -55,12 +55,11 @@ public class BookmarkManager {
     private Map<String, HistoryItem> mBookmarksMap;
     @NonNull private String mCurrentFolder = "";
     @NonNull private final ExecutorService mExecutor;
-    private final File mFilesDir;
+    private File mFilesDir;
 
     @Inject
     public BookmarkManager(@NonNull Context context) {
         mExecutor = Executors.newSingleThreadExecutor();
-        mFilesDir = context.getFilesDir();
         DEFAULT_BOOKMARK_TITLE = context.getString(R.string.untitled);
         mExecutor.execute(new BookmarkInitializer(context));
     }
@@ -90,6 +89,7 @@ public class BookmarkManager {
         @Override
         public void run() {
             synchronized (BookmarkManager.this) {
+                mFilesDir = mContext.getFilesDir();
                 final Map<String, HistoryItem> bookmarks = new HashMap<>();
                 final File bookmarksFile = new File(mFilesDir, FILE_BOOKMARKS);
 

app/src/main/java/acr/browser/lightning/database/HistoryDatabase.java

@@ -18,6 +18,7 @@ import javax.inject.Inject;
 import javax.inject.Singleton;
 
 import acr.browser.lightning.R;
+import acr.browser.lightning.app.BrowserApp;
 
 @Singleton
 public class HistoryDatabase extends SQLiteOpenHelper {
@@ -43,7 +44,18 @@ public class HistoryDatabase extends SQLiteOpenHelper {
     @Inject
     public HistoryDatabase(@NonNull Context context) {
         super(context.getApplicationContext(), DATABASE_NAME, null, DATABASE_VERSION);
-        mDatabase = this.getWritableDatabase();
+        initialize();
+    }
+
+    private void initialize() {
+        BrowserApp.getTaskThread().execute(new Runnable() {
+            @Override
+            public void run() {
+                synchronized (HistoryDatabase.this) {
+                    mDatabase = HistoryDatabase.this.getWritableDatabase();
+                }
+            }
+        });
     }
 
     // Creating Tables

app/src/main/java/acr/browser/lightning/object/SearchAdapter.java

@@ -430,6 +430,7 @@ public class SearchAdapter extends BaseAdapter implements Filterable {
 
     private static NetworkInfo getActiveNetworkInfo(@NonNull Context context) {
         ConnectivityManager connectivity = (ConnectivityManager) context
+                .getApplicationContext()
                 .getSystemService(Context.CONNECTIVITY_SERVICE);
         if (connectivity == null) {
             return null;

app/src/main/java/acr/browser/lightning/react/Action.java

@@ -0,0 +1,5 @@
+package acr.browser.lightning.react;
+
+public interface Action<T> {
+    void onSubscribe(Subscriber<T> subscriber);
+}

app/src/main/java/acr/browser/lightning/react/Observable.java

@@ -0,0 +1,130 @@
+package acr.browser.lightning.react;
+
+import android.os.Looper;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import java.util.concurrent.Executor;
+
+import acr.browser.lightning.utils.Preconditions;
+
+/**
+ * An RxJava implementation. This class allows work
+ * to be done on a certain thread and then allows
+ * items to be emitted on a different thread. It is
+ * a replacement for {@link android.os.AsyncTask}.
+ *
+ * @param <T> the type that the Observable will emit.
+ */
+public class Observable<T> {
+
+    private Action<T> mAction;
+    @Nullable private Executor mSubscriber;
+    @Nullable private Executor mObserver;
+    private final Executor mDefault;
+
+    public Observable(Action<T> action) {
+        mAction = action;
+        Looper looper = Looper.myLooper();
+        Preconditions.checkNonNull(looper);
+        mDefault = new ThreadExecutor(looper);
+    }
+
+    public static <T> Observable<T> create(@NonNull Action<T> action) {
+        Preconditions.checkNonNull(action);
+        return new Observable<>(action);
+    }
+
+    public Observable<T> subscribeOn(@NonNull Executor subscribeExecutor) {
+        mSubscriber = subscribeExecutor;
+        return this;
+    }
+
+    public Observable<T> observeOn(@NonNull Executor observerExecutor) {
+        mObserver = observerExecutor;
+        return this;
+    }
+
+    public void subscribe() {
+        executeOnSubscriberThread(new Runnable() {
+            @Override
+            public void run() {
+                mAction.onSubscribe(new Subscriber<T>() {
+                    @Override
+                    public void onComplete() {
+
+                    }
+
+                    @Override
+                    public void onNext(T item) {
+
+                    }
+                });
+            }
+        });
+    }
+
+    public void subscribe(@NonNull final Subscription<T> subscription) {
+        Preconditions.checkNonNull(subscription);
+        executeOnSubscriberThread(new Runnable() {
+            @Override
+            public void run() {
+                mAction.onSubscribe(new Subscriber<T>() {
+                    @Override
+                    public void onComplete() {
+                        executeOnObserverThread(new OnCompleteRunnable(subscription));
+                    }
+
+                    @Override
+                    public void onNext(final T item) {
+                        executeOnObserverThread(new OnNextRunnable(subscription, item));
+                    }
+                });
+
+            }
+        });
+    }
+
+    private void executeOnObserverThread(@NonNull Runnable runnable) {
+        if (mObserver != null) {
+            mObserver.execute(runnable);
+        } else {
+            mDefault.execute(runnable);
+        }
+    }
+
+    private void executeOnSubscriberThread(@NonNull Runnable runnable) {
+        if (mSubscriber != null) {
+            mSubscriber.execute(runnable);
+        } else {
+            mDefault.execute(runnable);
+        }
+    }
+
+    private static class OnCompleteRunnable implements Runnable {
+        private final Subscription subscription;
+
+        public OnCompleteRunnable(Subscription subscription) {this.subscription = subscription;}
+
+        @Override
+        public void run() {
+            subscription.onComplete();
+        }
+    }
+
+    private class OnNextRunnable implements Runnable {
+        private final Subscription<T> subscription;
+        private final T item;
+
+        public OnNextRunnable(Subscription<T> subscription, T item) {
+            this.subscription = subscription;
+            this.item = item;
+        }
+
+        @Override
+        public void run() {
+            subscription.onNext(item);
+        }
+    }
+}
+

app/src/main/java/acr/browser/lightning/react/Schedulers.java

@@ -0,0 +1,19 @@
+package acr.browser.lightning.react;
+
+import android.os.Looper;
+
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+public class Schedulers {
+    private static final Executor sWorker = Executors.newCachedThreadPool();
+    private static final Executor sMain = new ThreadExecutor(Looper.getMainLooper());
+
+    public static Executor worker() {
+        return sWorker;
+    }
+
+    public static Executor main() {
+        return sMain;
+    }
+}

app/src/main/java/acr/browser/lightning/react/Subscriber.java

@@ -0,0 +1,7 @@
+package acr.browser.lightning.react;
+
+public interface Subscriber<T> {
+    void onComplete();
+
+    void onNext(T item);
+}

app/src/main/java/acr/browser/lightning/react/Subscription.java

@@ -0,0 +1,7 @@
+package acr.browser.lightning.react;
+
+public interface Subscription<T> {
+    void onComplete();
+
+    void onNext(T item);
+}

app/src/main/java/acr/browser/lightning/react/ThreadExecutor.java

@@ -0,0 +1,21 @@
+package acr.browser.lightning.react;
+
+import android.os.Handler;
+import android.os.Looper;
+import android.support.annotation.NonNull;
+
+import java.util.concurrent.Executor;
+
+class ThreadExecutor implements Executor {
+
+    private final Handler mHandler;
+
+    public ThreadExecutor(@NonNull Looper looper) {
+        mHandler = new Handler(looper);
+    }
+
+    @Override
+    public void execute(@NonNull Runnable command) {
+        mHandler.post(command);
+    }
+}

app/src/main/java/acr/browser/lightning/utils/FileUtils.java

@@ -13,6 +13,7 @@ import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 
+import acr.browser.lightning.app.BrowserApp;
 import acr.browser.lightning.constant.Constants;
 
 /**
@@ -30,7 +31,10 @@ public class FileUtils {
      * @param bundle the bundle to store in persistent storage.
      * @param name   the name of the file to store the bundle in.
      */
-    public static void writeBundleToStorage(@NonNull Application app, Bundle bundle, @NonNull String name) {
+    public static void writeBundleToStorage(final @NonNull Application app, final Bundle bundle, final @NonNull String name) {
+        BrowserApp.getIOThread().execute(new Runnable() {
+            @Override
+            public void run() {
                 File outputFile = new File(app.getFilesDir(), name);
                 FileOutputStream outputStream = null;
                 try {
@@ -47,6 +51,8 @@ public class FileUtils {
                     Utils.close(outputStream);
                 }
             }
+        });
+    }
 
     /**
      * Reads a bundle from the file with the specified

app/src/main/java/acr/browser/lightning/view/LightningView.java

@@ -34,6 +34,7 @@ import android.webkit.WebView;
 
 import com.squareup.otto.Bus;
 
+import java.io.File;
 import java.lang.ref.WeakReference;
 import java.util.Map;
 
@@ -51,6 +52,11 @@ import acr.browser.lightning.database.BookmarkManager;
 import acr.browser.lightning.dialog.LightningDialogBuilder;
 import acr.browser.lightning.download.LightningDownloadListener;
 import acr.browser.lightning.preference.PreferenceManager;
+import acr.browser.lightning.react.Action;
+import acr.browser.lightning.react.Observable;
+import acr.browser.lightning.react.Schedulers;
+import acr.browser.lightning.react.Subscriber;
+import acr.browser.lightning.react.Subscription;
 import acr.browser.lightning.utils.ProxyUtils;
 import acr.browser.lightning.utils.ThemeUtils;
 import acr.browser.lightning.utils.UrlUtils;
@@ -325,7 +331,10 @@ public class LightningView {
      */
     @SuppressLint("NewApi")
     private void initializeSettings() {
-        WebSettings settings = mWebView.getSettings();
+        if (mWebView == null) {
+            return;
+        }
+        final WebSettings settings = mWebView.getSettings();
         if (API < Build.VERSION_CODES.JELLY_BEAN_MR2) {
             //noinspection deprecation
             settings.setAppCacheMaxSize(Long.MAX_VALUE);
@@ -364,12 +373,56 @@ public class LightningView {
             settings.setAllowUniversalAccessFromFileURLs(false);
         }
 
-        settings.setAppCachePath(BrowserApp.get(mActivity).getDir("appcache", 0).getPath());
-        settings.setGeolocationDatabasePath(BrowserApp.get(mActivity).getDir("geolocation", 0).getPath());
+        getPathObservable("appcache")
+                .subscribeOn(Schedulers.worker())
+                .subscribe(new Subscription<File>() {
+                    @Override
+                    public void onComplete() {}
+
+                    @Override
+                    public void onNext(File item) {
+                        settings.setAppCachePath(item.getPath());
+                    }
+                });
+
+        getPathObservable("geolocation")
+                .subscribeOn(Schedulers.worker())
+                .subscribe(new Subscription<File>() {
+                    @Override
+                    public void onComplete() {}
+
+                    @Override
+                    public void onNext(File item) {
+                        settings.setGeolocationDatabasePath(item.getPath());
+                    }
+                });
+
+        getPathObservable("databases")
+                .subscribeOn(Schedulers.worker())
+                .subscribe(new Subscription<File>() {
+                    @Override
+                    public void onComplete() {}
+
+                    @Override
+                    public void onNext(File item) {
                         if (API < Build.VERSION_CODES.KITKAT) {
                             //noinspection deprecation
-            settings.setDatabasePath(BrowserApp.get(mActivity).getDir("databases", 0).getPath());
+                            settings.setDatabasePath(item.getPath());
+                        }
+                    }
+                });
+
     }
+
+    private Observable<File> getPathObservable(final String subFolder) {
+        return Observable.create(new Action<File>() {
+            @Override
+            public void onSubscribe(Subscriber<File> subscriber) {
+                File file = BrowserApp.get(mActivity).getDir(subFolder, 0);
+                subscriber.onNext(file);
+                subscriber.onComplete();
+            }
+        });
     }
 
     /**
@@ -554,6 +607,9 @@ public class LightningView {
      * of the current LightningView.
      */
     private void setHardwareRendering() {
+        if (mWebView == null) {
+            return;
+        }
         mWebView.setLayerType(View.LAYER_TYPE_HARDWARE, mPaint);
     }
 
@@ -563,6 +619,9 @@ public class LightningView {
      * the layers when necessary.
      */
     private void setNormalRendering() {
+        if (mWebView == null) {
+            return;
+        }
         mWebView.setLayerType(View.LAYER_TYPE_NONE, null);
     }
 
@@ -573,6 +632,9 @@ public class LightningView {
      * the view.
      */
     public void setSoftwareRendering() {
+        if (mWebView == null) {
+            return;
+        }
         mWebView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
     }
 
@@ -839,6 +901,9 @@ public class LightningView {
      *            a workaround.
      */
     private void longClickPage(@Nullable final String url) {
+        if (mWebView == null) {
+            return;
+        }
         final WebView.HitTestResult result = mWebView.getHitTestResult();
         String currentUrl = mWebView.getUrl();
         if (currentUrl != null && UrlUtils.isSpecialUrl(currentUrl)) {
@@ -1043,6 +1108,9 @@ public class LightningView {
                 Message msg = mWebViewHandler.obtainMessage();
                 if (msg != null) {
                     msg.setTarget(mWebViewHandler);
+                    if (mWebView == null) {
+                        return;
+                    }
                     mWebView.requestFocusNodeHref(msg);
                 }
             }