Merge pull request #4499 from Isira-Seneviratne/Replace_AsyncTasks_with_ReactiveX

Use RxJava instead of AsyncTask.

app/src/main/java/org/schabi/newpipe/App.java

@@ -36,6 +36,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
+import io.reactivex.disposables.Disposable;
 import io.reactivex.exceptions.CompositeException;
 import io.reactivex.exceptions.MissingBackpressureException;
 import io.reactivex.exceptions.OnErrorNotImplementedException;
@@ -65,6 +66,9 @@ public class App extends MultiDexApplication {
     protected static final String TAG = App.class.toString();
     private static App app;
 
+    private Disposable disposable = null;
+
+    @NonNull
     public static App getApp() {
         return app;
     }
@@ -100,7 +104,15 @@ public class App extends MultiDexApplication {
         configureRxJavaErrorHandler();
 
         // Check for new version
-        new CheckForNewAppVersionTask().execute();
+        disposable = CheckForNewAppVersion.checkNewVersion(this);
+    }
+
+    @Override
+    public void onTerminate() {
+        if (disposable != null) {
+            disposable.dispose();
+        }
+        super.onTerminate();
     }
 
     protected Downloader getDownloader() {

app/src/main/java/org/schabi/newpipe/CheckForNewAppVersion.java

@@ -9,9 +9,9 @@ import android.content.pm.PackageManager;
 import android.content.pm.Signature;
 import android.net.ConnectivityManager;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.util.Log;
 
+import androidx.annotation.NonNull;
 import androidx.core.app.NotificationCompat;
 import androidx.core.app.NotificationManagerCompat;
 import androidx.core.content.ContextCompat;
@@ -35,16 +35,18 @@ import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
 
-/**
+import io.reactivex.Observable;
- * AsyncTask to check if there is a newer version of the NewPipe github apk available or not.
+import io.reactivex.android.schedulers.AndroidSchedulers;
- * If there is a newer version we show a notification, informing the user. On tapping
+import io.reactivex.disposables.Disposable;
- * the notification, the user will be directed to the download link.
+import io.reactivex.disposables.Disposables;
- */
+import io.reactivex.schedulers.Schedulers;
-public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
+
-    private static final boolean DEBUG = MainActivity.DEBUG;
+public final class CheckForNewAppVersion {
-    private static final String TAG = CheckForNewAppVersionTask.class.getSimpleName();
+    private CheckForNewAppVersion() { }
+
+    private static final boolean DEBUG = MainActivity.DEBUG;
+    private static final String TAG = CheckForNewAppVersion.class.getSimpleName();
 
-    private static final Application APP = App.getApp();
     private static final String GITHUB_APK_SHA1
             = "B0:2E:90:7C:1C:D6:FC:57:C3:35:F0:88:D0:8F:50:5F:94:E4:D2:15";
     private static final String NEWPIPE_API_URL = "https://newpipe.schabi.org/api/data.json";
@@ -52,18 +54,19 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
     /**
      * Method to get the apk's SHA1 key. See https://stackoverflow.com/questions/9293019/#22506133.
      *
+     * @param application The application
      * @return String with the apk's SHA1 fingeprint in hexadecimal
      */
-    private static String getCertificateSHA1Fingerprint() {
+    private static String getCertificateSHA1Fingerprint(@NonNull final Application application) {
-        final PackageManager pm = APP.getPackageManager();
+        final PackageManager pm = application.getPackageManager();
-        final String packageName = APP.getPackageName();
+        final String packageName = application.getPackageName();
         final int flags = PackageManager.GET_SIGNATURES;
         PackageInfo packageInfo = null;
 
         try {
             packageInfo = pm.getPackageInfo(packageName, flags);
         } catch (final PackageManager.NameNotFoundException e) {
-            ErrorActivity.reportError(APP, e, null, null,
+            ErrorActivity.reportError(application, e, null, null,
                     ErrorActivity.ErrorInfo.make(UserAction.SOMETHING_ELSE, "none",
                             "Could not find package info", R.string.app_ui_crash));
         }
@@ -78,7 +81,7 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
             final CertificateFactory cf = CertificateFactory.getInstance("X509");
             c = (X509Certificate) cf.generateCertificate(input);
         } catch (final CertificateException e) {
-            ErrorActivity.reportError(APP, e, null, null,
+            ErrorActivity.reportError(application, e, null, null,
                     ErrorActivity.ErrorInfo.make(UserAction.SOMETHING_ELSE, "none",
                             "Certificate error", R.string.app_ui_crash));
         }
@@ -90,7 +93,7 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
             final byte[] publicKey = md.digest(c.getEncoded());
             hexString = byte2HexFormatted(publicKey);
         } catch (NoSuchAlgorithmException | CertificateEncodingException e) {
-            ErrorActivity.reportError(APP, e, null, null,
+            ErrorActivity.reportError(application, e, null, null,
                     ErrorActivity.ErrorInfo.make(UserAction.SOMETHING_ELSE, "none",
                             "Could not retrieve SHA1 key", R.string.app_ui_crash));
         }
@@ -118,24 +121,71 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
         return str.toString();
     }
 
-    public static boolean isGithubApk() {
+    /**
-        return getCertificateSHA1Fingerprint().equals(GITHUB_APK_SHA1);
+     * Method to compare the current and latest available app version.
+     * If a newer version is available, we show the update notification.
+     *
+     * @param application    The application
+     * @param versionName    Name of new version
+     * @param apkLocationUrl Url with the new apk
+     * @param versionCode    Code of new version
+     */
+    private static void compareAppVersionAndShowNotification(@NonNull final Application application,
+                                                             final String versionName,
+                                                             final String apkLocationUrl,
+                                                             final int versionCode) {
+        final int notificationId = 2000;
+
+        if (BuildConfig.VERSION_CODE < versionCode) {
+            // A pending intent to open the apk location url in the browser.
+            final Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(apkLocationUrl));
+            final PendingIntent pendingIntent
+                    = PendingIntent.getActivity(application, 0, intent, 0);
+
+            final String channelId = application
+                    .getString(R.string.app_update_notification_channel_id);
+            final NotificationCompat.Builder notificationBuilder
+                    = new NotificationCompat.Builder(application, channelId)
+                    .setSmallIcon(R.drawable.ic_newpipe_update)
+                    .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
+                    .setContentIntent(pendingIntent)
+                    .setAutoCancel(true)
+                    .setContentTitle(application
+                            .getString(R.string.app_update_notification_content_title))
+                    .setContentText(application
+                            .getString(R.string.app_update_notification_content_text)
+                            + " " + versionName);
+
+            final NotificationManagerCompat notificationManager
+                    = NotificationManagerCompat.from(application);
+            notificationManager.notify(notificationId, notificationBuilder.build());
+        }
     }
 
-    @Override
+    private static boolean isConnected(@NonNull final App app) {
-    protected void onPreExecute() {
+        final ConnectivityManager cm = ContextCompat.getSystemService(app,
-        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(APP);
+                ConnectivityManager.class);
+        return cm.getActiveNetworkInfo() != null
+                && cm.getActiveNetworkInfo().isConnected();
+    }
+
+    public static boolean isGithubApk(@NonNull final App app) {
+        return getCertificateSHA1Fingerprint(app).equals(GITHUB_APK_SHA1);
+    }
+
+    @NonNull
+    public static Disposable checkNewVersion(@NonNull final App app) {
+        final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(app);
 
         // Check if user has enabled/disabled update checking
         // and if the current apk is a github one or not.
-        if (!prefs.getBoolean(APP.getString(R.string.update_app_key), true) || !isGithubApk()) {
+        if (!prefs.getBoolean(app.getString(R.string.update_app_key), true)
-            this.cancel(true);
+                || !isGithubApk(app)) {
-        }
+            return Disposables.empty();
         }
 
-    @Override
+        return Observable.fromCallable(() -> {
-    protected String doInBackground(final Void... voids) {
+            if (!isConnected(app)) {
-        if (isCancelled() || !isConnected()) {
                 return null;
             }
 
@@ -150,13 +200,12 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
             }
 
             return null;
-    }
+        })
-
+                .subscribeOn(Schedulers.io())
-    @Override
+                .observeOn(AndroidSchedulers.mainThread())
-    protected void onPostExecute(final String response) {
+                .subscribe(response -> {
                     // Parse the json from the response.
                     if (response != null) {
-
                         try {
                             final JsonObject githubStableObject = JsonParser.object().from(response)
                                     .getObject("flavors").getObject("github").getObject("stable");
@@ -165,8 +214,8 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
                             final int versionCode = githubStableObject.getInt("version_code");
                             final String apkLocationUrl = githubStableObject.getString("apk");
 
-                compareAppVersionAndShowNotification(versionName, apkLocationUrl, versionCode);
+                            compareAppVersionAndShowNotification(app, versionName, apkLocationUrl,
-
+                                    versionCode);
                         } catch (final JsonParserException e) {
                             // connectivity problems, do not alarm user and fail silently
                             if (DEBUG) {
@@ -174,48 +223,6 @@ public class CheckForNewAppVersionTask extends AsyncTask<Void, Void, String> {
                             }
                         }
                     }
-    }
+                });
-
-    /**
-     * Method to compare the current and latest available app version.
-     * If a newer version is available, we show the update notification.
-     *
-     * @param versionName    Name of new version
-     * @param apkLocationUrl Url with the new apk
-     * @param versionCode    Code of new version
-     */
-    private void compareAppVersionAndShowNotification(final String versionName,
-                                                      final String apkLocationUrl,
-                                                      final int versionCode) {
-        final int notificationId = 2000;
-
-        if (BuildConfig.VERSION_CODE < versionCode) {
-
-            // A pending intent to open the apk location url in the browser.
-            final Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(apkLocationUrl));
-            final PendingIntent pendingIntent
-                    = PendingIntent.getActivity(APP, 0, intent, 0);
-
-            final NotificationCompat.Builder notificationBuilder = new NotificationCompat
-                    .Builder(APP, APP.getString(R.string.app_update_notification_channel_id))
-                    .setSmallIcon(R.drawable.ic_newpipe_update)
-                    .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
-                    .setContentIntent(pendingIntent)
-                    .setAutoCancel(true)
-                    .setContentTitle(APP.getString(R.string.app_update_notification_content_title))
-                    .setContentText(APP.getString(R.string.app_update_notification_content_text)
-                            + " " + versionName);
-
-            final NotificationManagerCompat notificationManager
-                    = NotificationManagerCompat.from(APP);
-            notificationManager.notify(notificationId, notificationBuilder.build());
-        }
-    }
-
-    private boolean isConnected() {
-        final ConnectivityManager cm = ContextCompat.getSystemService(APP,
-                ConnectivityManager.class);
-        return cm.getActiveNetworkInfo() != null
-                && cm.getActiveNetworkInfo().isConnected();
     }
 }

app/src/main/java/org/schabi/newpipe/about/LicenseFragment.java

@@ -1,6 +1,5 @@
 package org.schabi.newpipe.about;
 
-import android.app.Activity;
 import android.os.Bundle;
 import android.view.ContextMenu;
 import android.view.LayoutInflater;
@@ -21,15 +20,19 @@ import java.io.Serializable;
 import java.util.Arrays;
 import java.util.Comparator;
 
+import io.reactivex.disposables.CompositeDisposable;
+
 /**
  * Fragment containing the software licenses.
  */
 public class LicenseFragment extends Fragment {
     private static final String ARG_COMPONENTS = "components";
+    private static final String LICENSE_KEY = "ACTIVE_LICENSE";
+
     private SoftwareComponent[] softwareComponents;
     private SoftwareComponent componentForContextMenu;
     private License activeLicense;
-    private static final String LICENSE_KEY = "ACTIVE_LICENSE";
+    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
 
     public static LicenseFragment newInstance(final SoftwareComponent[] softwareComponents) {
         if (softwareComponents == null) {
@@ -42,16 +45,6 @@ public class LicenseFragment extends Fragment {
         return fragment;
     }
 
-    /**
-     * Shows a popup containing the license.
-     *
-     * @param context the context to use
-     * @param license the license to show
-     */
-    private static void showLicense(final Activity context, final License license) {
-        new LicenseFragmentHelper(context).execute(license);
-    }
-
     @Override
     public void onCreate(@Nullable final Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -68,6 +61,12 @@ public class LicenseFragment extends Fragment {
         Arrays.sort(softwareComponents, Comparator.comparing(SoftwareComponent::getName));
     }
 
+    @Override
+    public void onDestroy() {
+        compositeDisposable.dispose();
+        super.onDestroy();
+    }
+
     @Nullable
     @Override
     public View onCreateView(final LayoutInflater inflater, @Nullable final ViewGroup container,
@@ -78,7 +77,8 @@ public class LicenseFragment extends Fragment {
         final View licenseLink = rootView.findViewById(R.id.app_read_license);
         licenseLink.setOnClickListener(v -> {
             activeLicense = StandardLicenses.GPL3;
-                showLicense(getActivity(), StandardLicenses.GPL3);
+            compositeDisposable.add(LicenseFragmentHelper.showLicense(getActivity(),
+                    StandardLicenses.GPL3));
         });
 
         for (final SoftwareComponent component : softwareComponents) {
@@ -95,13 +95,15 @@ public class LicenseFragment extends Fragment {
             componentView.setTag(component);
             componentView.setOnClickListener(v -> {
                 activeLicense = component.getLicense();
-                showLicense(getActivity(), component.getLicense());
+                compositeDisposable.add(LicenseFragmentHelper.showLicense(getActivity(),
+                        component.getLicense()));
             });
             softwareComponentsView.addView(componentView);
             registerForContextMenu(componentView);
         }
         if (activeLicense != null) {
-            showLicense(getActivity(), activeLicense);
+            compositeDisposable.add(LicenseFragmentHelper.showLicense(getActivity(),
+                    activeLicense));
         }
         return rootView;
     }
@@ -129,7 +131,8 @@ public class LicenseFragment extends Fragment {
                 ShareUtils.openUrlInBrowser(getActivity(), component.getLink());
                 return true;
             case R.id.action_show_license:
-                showLicense(getActivity(), component.getLicense());
+                compositeDisposable.add(LicenseFragmentHelper.showLicense(getActivity(),
+                        component.getLicense()));
         }
         return false;
     }

app/src/main/java/org/schabi/newpipe/about/LicenseFragmentHelper.java

@@ -1,8 +1,6 @@
 package org.schabi.newpipe.about;
 
-import android.app.Activity;
 import android.content.Context;
-import android.os.AsyncTask;
 import android.util.Base64;
 import android.webkit.WebView;
 
@@ -16,18 +14,18 @@ import org.schabi.newpipe.util.ThemeHelper;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.lang.ref.WeakReference;
 import java.nio.charset.StandardCharsets;
 
+import io.reactivex.Observable;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.disposables.Disposables;
+import io.reactivex.schedulers.Schedulers;
+
 import static org.schabi.newpipe.util.Localization.assureCorrectAppLanguage;
 
-public class LicenseFragmentHelper extends AsyncTask<Object, Void, Integer> {
+public final class LicenseFragmentHelper {
-    private final WeakReference<Activity> weakReference;
+    private LicenseFragmentHelper() { }
-    private License license;
-
-    public LicenseFragmentHelper(@Nullable final Activity activity) {
-        weakReference = new WeakReference<>(activity);
-    }
 
     /**
      * @param context the context to use
@@ -62,7 +60,7 @@ public class LicenseFragmentHelper extends AsyncTask<Object, Void, Integer> {
      * @param context
      * @return String which is a CSS stylesheet according to the context's theme
      */
-    private static String getLicenseStylesheet(final Context context) {
+    private static String getLicenseStylesheet(@NonNull final Context context) {
         final boolean isLightTheme = ThemeHelper.isLightThemeSelected(context);
         return "body{padding:12px 15px;margin:0;"
                 + "background:#" + getHexRGBColor(context, isLightTheme
@@ -84,45 +82,31 @@ public class LicenseFragmentHelper extends AsyncTask<Object, Void, Integer> {
      * @param color   the color number from R.color
      * @return a six characters long String with hexadecimal RGB values
      */
-    private static String getHexRGBColor(final Context context, final int color) {
+    private static String getHexRGBColor(@NonNull final Context context, final int color) {
         return context.getResources().getString(color).substring(3);
     }
 
-    @Nullable
+    static Disposable showLicense(@Nullable final Context context, @NonNull final License license) {
-    private Activity getActivity() {
+        if (context == null) {
-        final Activity activity = weakReference.get();
+            return Disposables.empty();
-
-        if (activity != null && activity.isFinishing()) {
-            return null;
-        } else {
-            return activity;
-        }
         }
 
-    @Override
+        return Observable.fromCallable(() -> getFormattedLicense(context, license))
-    protected Integer doInBackground(final Object... objects) {
+                .subscribeOn(Schedulers.io())
-        license = (License) objects[0];
+                .observeOn(AndroidSchedulers.mainThread())
-        return 1;
+                .subscribe(formattedLicense -> {
-    }
+                    final String webViewData = Base64.encodeToString(formattedLicense
-
-    @Override
-    protected void onPostExecute(final Integer result) {
-        final Activity activity = getActivity();
-        if (activity == null) {
-            return;
-        }
-
-        final String webViewData = Base64.encodeToString(getFormattedLicense(activity, license)
                             .getBytes(StandardCharsets.UTF_8), Base64.NO_PADDING);
-        final WebView webView = new WebView(activity);
+                    final WebView webView = new WebView(context);
                     webView.loadData(webViewData, "text/html; charset=UTF-8", "base64");
 
-        final AlertDialog.Builder alert = new AlertDialog.Builder(activity);
+                    final AlertDialog.Builder alert = new AlertDialog.Builder(context);
                     alert.setTitle(license.getName());
                     alert.setView(webView);
-        assureCorrectAppLanguage(activity);
+                    assureCorrectAppLanguage(context);
-        alert.setNegativeButton(activity.getString(R.string.finish),
+                    alert.setNegativeButton(context.getString(R.string.finish),
                             (dialog, which) -> dialog.dismiss());
                     alert.show();
+                });
     }
 }

app/src/main/java/org/schabi/newpipe/settings/MainSettingsFragment.java

@@ -4,7 +4,8 @@ import android.os.Bundle;
 
 import androidx.preference.Preference;
 
-import org.schabi.newpipe.CheckForNewAppVersionTask;
+import org.schabi.newpipe.App;
+import org.schabi.newpipe.CheckForNewAppVersion;
 import org.schabi.newpipe.MainActivity;
 import org.schabi.newpipe.R;
 
@@ -15,7 +16,7 @@ public class MainSettingsFragment extends BasePreferenceFragment {
     public void onCreatePreferences(final Bundle savedInstanceState, final String rootKey) {
         addPreferencesFromResource(R.xml.main_settings);
 
-        if (!CheckForNewAppVersionTask.isGithubApk()) {
+        if (!CheckForNewAppVersion.isGithubApk(App.getApp())) {
             final Preference update = findPreference(getString(R.string.update_pref_screen_key));
             getPreferenceScreen().removePreference(update);
 

app/src/main/java/us/shandian/giga/ui/adapter/MissionAdapter.java

@@ -1,13 +1,11 @@
 package us.shandian.giga.ui.adapter;
 
 import android.annotation.SuppressLint;
-import android.app.Activity;
 import android.app.ProgressDialog;
 import android.content.Context;
 import android.content.Intent;
 import android.graphics.Color;
 import android.net.Uri;
-import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Handler;
 import android.os.Message;
@@ -26,7 +24,6 @@ import android.widget.TextView;
 import android.widget.Toast;
 
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.appcompat.app.AlertDialog;
 import androidx.core.content.FileProvider;
@@ -46,12 +43,15 @@ import org.schabi.newpipe.report.UserAction;
 import org.schabi.newpipe.util.NavigationHelper;
 
 import java.io.File;
-import java.lang.ref.WeakReference;
 import java.net.URI;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Iterator;
 
+import io.reactivex.Observable;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.CompositeDisposable;
+import io.reactivex.schedulers.Schedulers;
 import us.shandian.giga.get.DownloadMission;
 import us.shandian.giga.get.FinishedMission;
 import us.shandian.giga.get.Mission;
@@ -116,6 +116,8 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
     private final Runnable rUpdater = this::updater;
     private final Runnable rDelete = this::deleteFinishedDownloads;
 
+    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
+
     public MissionAdapter(Context context, @NonNull DownloadManager downloadManager, View emptyMessage, View root) {
         mContext = context;
         mDownloadManager = downloadManager;
@@ -675,7 +677,30 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
                 return true;
             case R.id.md5:
             case R.id.sha1:
-                new ChecksumTask(mContext).execute(h.item.mission.storage, ALGORITHMS.get(id));
+                ProgressDialog progressDialog = null;
+                if (mContext != null) {
+                    // Create dialog
+                    progressDialog = new ProgressDialog(mContext);
+                    progressDialog.setCancelable(false);
+                    progressDialog.setMessage(mContext.getString(R.string.msg_wait));
+                    progressDialog.show();
+                }
+                final ProgressDialog finalProgressDialog = progressDialog;
+                final StoredFileHelper storage = h.item.mission.storage;
+                compositeDisposable.add(
+                        Observable.fromCallable(() -> Utility.checksum(storage, ALGORITHMS.get(id)))
+                                .subscribeOn(Schedulers.computation())
+                                .observeOn(AndroidSchedulers.mainThread())
+                                .subscribe(result -> {
+                                    if (finalProgressDialog != null) {
+                                        Utility.copyToClipboard(finalProgressDialog.getContext(),
+                                                result);
+                                        if (mContext != null) {
+                                            finalProgressDialog.dismiss();
+                                        }
+                                    }
+                                })
+                );
                 return true;
             case R.id.source:
                 /*Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(h.item.mission.source));
@@ -758,8 +783,8 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
         }
     }
 
-
     public void onDestroy() {
+        compositeDisposable.dispose();
         mDeleter.dispose();
     }
 
@@ -960,60 +985,7 @@ public class MissionAdapter extends Adapter<ViewHolder> implements Handler.Callb
         }
     }
 
-
-    static class ChecksumTask extends AsyncTask<Object, Void, String> {
-        ProgressDialog progressDialog;
-        WeakReference<Activity> weakReference;
-
-        ChecksumTask(@NonNull Context context) {
-            weakReference = new WeakReference<>((Activity) context);
-        }
-
-        @Override
-        protected void onPreExecute() {
-            super.onPreExecute();
-
-            Activity activity = getActivity();
-            if (activity != null) {
-                // Create dialog
-                progressDialog = new ProgressDialog(activity);
-                progressDialog.setCancelable(false);
-                progressDialog.setMessage(activity.getString(R.string.msg_wait));
-                progressDialog.show();
-            }
-        }
-
-        @Override
-        protected String doInBackground(Object... params) {
-            return Utility.checksum((StoredFileHelper) params[0], (String) params[1]);
-        }
-
-        @Override
-        protected void onPostExecute(String result) {
-            super.onPostExecute(result);
-
-            if (progressDialog != null) {
-                Utility.copyToClipboard(progressDialog.getContext(), result);
-                if (getActivity() != null) {
-                    progressDialog.dismiss();
-                }
-            }
-        }
-
-        @Nullable
-        private Activity getActivity() {
-            Activity activity = weakReference.get();
-
-            if (activity != null && activity.isFinishing()) {
-                return null;
-            } else {
-                return activity;
-            }
-        }
-    }
-
     public interface RecoverHelper {
         void tryRecover(DownloadMission mission);
     }
-
 }