app/build.gradle

@@ -21,16 +21,16 @@ def basicApplicationId = "org.fdroid.basic"
 def privilegedExtensionApplicationId = '"org.fdroid.fdroid.privileged"'
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 29
 
     defaultConfig {
         versionCode 1013001
         versionName getVersionName()
 
         testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
-        minSdkVersion 24
+        minSdkVersion 22
         //noinspection ExpiredTargetSdkVersion
-        targetSdkVersion 28
+        targetSdkVersion 25
         /*
           The Android Testing Support Library collects analytics to continuously improve the testing
           experience. More specifically, it uploads a hash of the package name of the application
@@ -142,9 +142,10 @@ android {
 }
 
 dependencies {
-    implementation 'androidx.appcompat:appcompat:1.3.0'
+    implementation 'androidx.appcompat:appcompat:1.2.0'
     implementation 'androidx.preference:preference:1.1.1'
     implementation 'androidx.gridlayout:gridlayout:1.0.0'
+    implementation 'androidx.annotation:annotation:1.1.0'
     implementation 'androidx.recyclerview:recyclerview:1.1.0'
     implementation 'androidx.cardview:cardview:1.0.0'
     implementation 'androidx.vectordrawable:vectordrawable:1.1.0'
@@ -161,11 +162,9 @@ dependencies {
     implementation 'commons-io:commons-io:2.6'
     implementation 'commons-net:commons-net:3.6'
     implementation 'ch.acra:acra:4.9.1'
+    implementation 'io.reactivex:rxjava:1.1.0'
     implementation 'com.hannesdorfmann:adapterdelegates3:3.0.1'
 
-    implementation 'io.reactivex.rxjava3:rxandroid:3.0.0'
-    implementation 'io.reactivex.rxjava3:rxjava:3.0.9'
-
     implementation 'com.fasterxml.jackson.core:jackson-core:2.11.1'
     implementation 'com.fasterxml.jackson.core:jackson-annotations:2.11.1'
     implementation 'com.fasterxml.jackson.core:jackson-databind:2.11.1'

app/proguard-rules.pro

@@ -31,6 +31,13 @@
     public *;
 }
 
+# The rxjava library depends on sun.misc.Unsafe, which is unavailable on Android
+# The rxjava team is aware of this, and mention in the docs that they only use
+# the unsafe functionality if the platform supports it.
+#  - https://github.com/ReactiveX/RxJava/issues/1415#issuecomment-48390883
+#  - https://github.com/ReactiveX/RxJava/blob/1.x/src/main/java/rx/internal/util/unsafe/UnsafeAccess.java#L23
+-dontwarn rx.internal.util.**
+
 -keepattributes *Annotation*,EnclosingMethod,Signature
 -keepnames class com.fasterxml.jackson.** { *; }
 -dontwarn com.fasterxml.jackson.databind.ext.**

app/src/full/java/org/fdroid/fdroid/nearby/SwapService.java

@@ -1,5 +1,6 @@
 package org.fdroid.fdroid.nearby;
 
+import android.annotation.SuppressLint;
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.app.Service;
@@ -12,17 +13,11 @@ import android.content.IntentFilter;
 import android.content.SharedPreferences;
 import android.net.Uri;
 import android.net.wifi.WifiManager;
+import android.os.AsyncTask;
 import android.os.IBinder;
 import android.text.TextUtils;
 import android.util.Log;
 
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.core.app.NotificationCompat;
-import androidx.core.app.ServiceCompat;
-import androidx.core.content.ContextCompat;
-import androidx.localbroadcastmanager.content.LocalBroadcastManager;
-
 import org.fdroid.fdroid.FDroidApp;
 import org.fdroid.fdroid.NotificationHelper;
 import org.fdroid.fdroid.Preferences;
@@ -35,6 +30,7 @@ import org.fdroid.fdroid.data.Schema;
 import org.fdroid.fdroid.nearby.peers.Peer;
 import org.fdroid.fdroid.net.Downloader;
 
+import java.io.IOException;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.net.HttpURLConnection;
@@ -45,11 +41,13 @@ import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
 
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.core.app.NotificationCompat;
+import androidx.core.app.ServiceCompat;
+import androidx.core.content.ContextCompat;
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import cc.mvdan.accesspoint.WifiApControl;
-import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
-import io.reactivex.rxjava3.core.Completable;
-import io.reactivex.rxjava3.disposables.CompositeDisposable;
-import io.reactivex.rxjava3.schedulers.Schedulers;
 
 /**
  * Central service which manages all of the different moving parts of swap which are required
@@ -111,6 +109,46 @@ public class SwapService extends Service {
         UpdateService.updateRepoNow(this, peer.getRepoAddress());
     }
 
+    @SuppressLint("StaticFieldLeak")
+    private void askServerToSwapWithUs(final Repo repo) {
+        new AsyncTask<Void, Void, Void>() {
+            @Override
+            protected Void doInBackground(Void... args) {
+                String swapBackUri = Utils.getLocalRepoUri(FDroidApp.repo).toString();
+                HttpURLConnection conn = null;
+                try {
+                    URL url = new URL(repo.address.replace("/fdroid/repo", "/request-swap"));
+                    conn = (HttpURLConnection) url.openConnection();
+                    conn.setRequestMethod("POST");
+                    conn.setDoInput(true);
+                    conn.setDoOutput(true);
+
+                    OutputStream outputStream = conn.getOutputStream();
+                    OutputStreamWriter writer = new OutputStreamWriter(outputStream);
+                    writer.write("repo=" + swapBackUri);
+                    writer.flush();
+                    writer.close();
+                    outputStream.close();
+
+                    int responseCode = conn.getResponseCode();
+                    Utils.debugLog(TAG, "Asking server at " + repo.address + " to swap with us in return (by " +
+                            "POSTing to \"/request-swap\" with repo \"" + swapBackUri + "\"): " + responseCode);
+                } catch (IOException e) {
+                    Log.e(TAG, "Error while asking server to swap with us", e);
+                    Intent intent = new Intent(Downloader.ACTION_INTERRUPTED);
+                    intent.setData(Uri.parse(repo.address));
+                    intent.putExtra(Downloader.EXTRA_ERROR_MESSAGE, e.getLocalizedMessage());
+                    LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
+                } finally {
+                    if (conn != null) {
+                        conn.disconnect();
+                    }
+                }
+                return null;
+            }
+        }.execute();
+    }
+
     private Repo ensureRepoExists(@NonNull Peer peer) {
         // TODO: newRepoConfig.getParsedUri() will include a fingerprint, which may not match with
         // the repos address in the database. Not sure on best behaviour in this situation.
@@ -304,15 +342,12 @@ public class SwapService extends Service {
     @Nullable
     private Timer timer;
 
-    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
-
     public class Binder extends android.os.Binder {
         public SwapService getService() {
             return SwapService.this;
         }
     }
 
-    @Override
     public void onCreate() {
         super.onCreate();
         startForeground(NOTIFICATION, createNotification());
@@ -362,45 +397,6 @@ public class SwapService extends Service {
         BonjourManager.setVisible(this, getWifiVisibleUserPreference() || getHotspotActivatedUserPreference());
     }
 
-    private void askServerToSwapWithUs(final Repo repo) {
-        compositeDisposable.add(
-                Completable.fromAction(() -> {
-                    String swapBackUri = Utils.getLocalRepoUri(FDroidApp.repo).toString();
-                    HttpURLConnection conn = null;
-                    try {
-                        URL url = new URL(repo.address.replace("/fdroid/repo", "/request-swap"));
-                        conn = (HttpURLConnection) url.openConnection();
-                        conn.setRequestMethod("POST");
-                        conn.setDoInput(true);
-                        conn.setDoOutput(true);
-
-                        try (OutputStream outputStream = conn.getOutputStream();
-                             OutputStreamWriter writer = new OutputStreamWriter(outputStream)) {
-                            writer.write("repo=" + swapBackUri);
-                            writer.flush();
-                        }
-
-                        int responseCode = conn.getResponseCode();
-                        Utils.debugLog(TAG, "Asking server at " + repo.address + " to swap with us in return (by " +
-                                "POSTing to \"/request-swap\" with repo \"" + swapBackUri + "\"): " + responseCode);
-                    } finally {
-                        if (conn != null) {
-                            conn.disconnect();
-                        }
-                    }
-                })
-                        .subscribeOn(Schedulers.io())
-                        .observeOn(AndroidSchedulers.mainThread())
-                        .doOnError(e -> {
-                            Intent intent = new Intent(Downloader.ACTION_INTERRUPTED);
-                            intent.setData(Uri.parse(repo.address));
-                            intent.putExtra(Downloader.EXTRA_ERROR_MESSAGE, e.getLocalizedMessage());
-                            LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
-                        })
-                        .subscribe()
-        );
-    }
-
     /**
      * This is for setting things up for when the {@code SwapService} was
      * started by the user clicking on the initial start button. The things
@@ -424,8 +420,6 @@ public class SwapService extends Service {
 
     @Override
     public void onDestroy() {
-        compositeDisposable.dispose();
-
         Utils.debugLog(TAG, "Destroying service, will disable swapping if required, and unregister listeners.");
         Preferences.get().unregisterLocalRepoHttpsListeners(httpsEnabledListener);
         localBroadcastManager.unregisterReceiver(onWifiChange);

app/src/full/java/org/fdroid/fdroid/nearby/SwapWorkflowActivity.java

@@ -34,18 +34,7 @@ import android.widget.ProgressBar;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import androidx.annotation.LayoutRes;
-import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
-import androidx.annotation.StringRes;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.SearchView;
-import androidx.core.content.ContextCompat;
-import androidx.localbroadcastmanager.content.LocalBroadcastManager;
-
 import com.google.android.material.appbar.MaterialToolbar;
-import com.google.android.material.switchmaterial.SwitchMaterial;
 import com.google.zxing.integration.android.IntentIntegrator;
 import com.google.zxing.integration.android.IntentResult;
 
@@ -65,6 +54,7 @@ import org.fdroid.fdroid.net.BluetoothDownloader;
 import org.fdroid.fdroid.net.Downloader;
 import org.fdroid.fdroid.net.HttpDownloader;
 import org.fdroid.fdroid.qr.CameraCharacteristicsChecker;
+import org.fdroid.fdroid.qr.QrGenAsyncTask;
 import org.fdroid.fdroid.views.main.MainActivity;
 
 import java.util.Date;
@@ -75,8 +65,17 @@ import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
 
+import androidx.annotation.LayoutRes;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.SearchView;
+import com.google.android.material.switchmaterial.SwitchMaterial;
+import androidx.core.content.ContextCompat;
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import cc.mvdan.accesspoint.WifiApControl;
-import io.reactivex.rxjava3.disposables.CompositeDisposable;
 
 import static org.fdroid.fdroid.views.main.MainActivity.ACTION_REQUEST_SWAP;
 
@@ -119,8 +118,6 @@ public class SwapWorkflowActivity extends AppCompatActivity {
     @LayoutRes
     private int currentSwapViewLayoutRes = STEP_INTRO;
 
-    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
-
     public static void requestSwap(Context context, String repo) {
         requestSwap(context, Uri.parse(repo));
     }
@@ -238,7 +235,6 @@ public class SwapWorkflowActivity extends AppCompatActivity {
 
     @Override
     protected void onDestroy() {
-        compositeDisposable.dispose();
         localBroadcastManager.unregisterReceiver(downloaderInterruptedReceiver);
         unbindService(serviceConnection);
         super.onDestroy();
@@ -933,23 +929,18 @@ public class SwapWorkflowActivity extends AppCompatActivity {
         ImageView qrImage = container.findViewById(R.id.wifi_qr_code);
         if (qrUriString != null && qrImage != null) {
             Utils.debugLog(TAG, "Encoded swap URI in QR Code: " + qrUriString);
+            new QrGenAsyncTask(SwapWorkflowActivity.this, R.id.wifi_qr_code).execute(qrUriString);
 
-            compositeDisposable.add(Utils.generateQrBitmap(this, qrUriString)
+            // Replace all blacks with the background blue.
-                    .subscribe(qrBitmap -> {
+            qrImage.setColorFilter(new LightingColorFilter(0xffffffff, ContextCompat.getColor(this,
-                        qrImage.setImageBitmap(qrBitmap);
+                    R.color.swap_blue)));
 
-                        // Replace all blacks with the background blue.
+            final View qrWarningMessage = container.findViewById(R.id.warning_qr_scanner);
-                        qrImage.setColorFilter(new LightingColorFilter(0xffffffff,
+            if (CameraCharacteristicsChecker.getInstance(this).hasAutofocus()) {
-                                ContextCompat.getColor(this, R.color.swap_blue)));
+                qrWarningMessage.setVisibility(View.GONE);
-
+            } else {
-                        final View qrWarningMessage = container.findViewById(R.id.warning_qr_scanner);
+                qrWarningMessage.setVisibility(View.VISIBLE);
-                        if (CameraCharacteristicsChecker.getInstance(this).hasAutofocus()) {
+            }
-                            qrWarningMessage.setVisibility(View.GONE);
-                        } else {
-                            qrWarningMessage.setVisibility(View.VISIBLE);
-                        }
-                    })
-            );
         }
     }
 

app/src/full/java/org/fdroid/fdroid/nearby/WifiStateChangeService.java

@@ -13,10 +13,6 @@ import android.os.Build;
 import android.text.TextUtils;
 import android.util.Log;
 
-import androidx.annotation.Nullable;
-import androidx.core.content.ContextCompat;
-import androidx.localbroadcastmanager.content.LocalBroadcastManager;
-
 import org.apache.commons.net.util.SubnetUtils;
 import org.fdroid.fdroid.BuildConfig;
 import org.fdroid.fdroid.FDroidApp;
@@ -35,8 +31,10 @@ import java.security.cert.Certificate;
 import java.util.Enumeration;
 import java.util.Locale;
 
+import androidx.annotation.Nullable;
+import androidx.core.content.ContextCompat;
+import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import cc.mvdan.accesspoint.WifiApControl;
-import io.reactivex.rxjava3.disposables.CompositeDisposable;
 
 /**
  * Handle state changes to the device's wifi, storing the required bits.
@@ -72,8 +70,6 @@ public class WifiStateChangeService extends IntentService {
     private static int previousWifiState = Integer.MIN_VALUE;
     private static int wifiState;
 
-    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
-
     public WifiStateChangeService() {
         super("WifiStateChangeService");
     }
@@ -86,12 +82,6 @@ public class WifiStateChangeService extends IntentService {
         context.startService(intent);
     }
 
-    @Override
-    public void onDestroy() {
-        compositeDisposable.dispose();
-        super.onDestroy();
-    }
-
     @Override
     protected void onHandleIntent(Intent intent) {
         android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_LOWEST);
@@ -119,7 +109,7 @@ public class WifiStateChangeService extends IntentService {
             }
 
             if (Build.VERSION.SDK_INT < 21 && wifiState == WifiManager.WIFI_STATE_ENABLED) {
-                compositeDisposable.add(UpdateService.scheduleIfStillOnWifi(this).subscribe());
+                UpdateService.scheduleIfStillOnWifi(this);
             }
         }
     }

app/src/main/AndroidManifest.xml

@@ -60,7 +60,7 @@
         android:description="@string/app_description"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@drawable/ic_launcher"
-        android:label="BobStore"
+        android:label="@string/app_name"
         android:networkSecurityConfig="@xml/network_security_config"
         android:supportsRtl="true"
         android:theme="@style/Theme.App">

app/src/main/java/org/fdroid/fdroid/ProgressBufferedInputStream.java

@@ -24,7 +24,7 @@ class ProgressBufferedInputStream extends BufferedInputStream {
     }
 
     @Override
-    public synchronized int read(@NonNull byte[] buffer, int byteOffset, int byteCount) throws IOException {
+    public int read(@NonNull byte[] buffer, int byteOffset, int byteCount) throws IOException {
         if (progressListener != null) {
             currentBytes += byteCount;
             /* don't send every change to keep things efficient.  333333 bytes to keep all

app/src/main/java/org/fdroid/fdroid/UpdateService.java

@@ -30,6 +30,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Process;
 import android.os.SystemClock;
@@ -50,18 +51,15 @@ import org.fdroid.fdroid.installer.InstallManagerService;
 import org.fdroid.fdroid.net.BluetoothDownloader;
 import org.fdroid.fdroid.net.ConnectivityMonitorService;
 
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.concurrent.TimeUnit;
 
 import androidx.annotation.NonNull;
 import androidx.core.app.JobIntentService;
 import androidx.core.app.NotificationCompat;
 import androidx.core.content.ContextCompat;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
-import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
-import io.reactivex.rxjava3.core.Completable;
-import io.reactivex.rxjava3.schedulers.Schedulers;
 
 public class UpdateService extends JobIntentService {
 
@@ -217,30 +215,42 @@ public class UpdateService extends JobIntentService {
      * unlimited networks over metered networks for index updates and auto
      * downloads of app updates. Starting with {@code android-21}, this uses
      * {@link android.app.job.JobScheduler} instead.
-     *
-     * @return a {@link Completable} that schedules the update. If this process is already running,
-     * a {@code Completable} that completes immediately is returned.
      */
-    @NonNull
+    public static void scheduleIfStillOnWifi(Context context) {
-    public static Completable scheduleIfStillOnWifi(Context context) {
         if (Build.VERSION.SDK_INT >= 21) {
             throw new IllegalStateException("This should never be used on android-21 or newer!");
         }
         if (isScheduleIfStillOnWifiRunning || !Preferences.get().isBackgroundDownloadAllowed()) {
-            return Completable.complete();
+            return;
         }
         isScheduleIfStillOnWifiRunning = true;
+        new StillOnWifiAsyncTask(context).execute();
+    }
+
+    private static final class StillOnWifiAsyncTask extends AsyncTask<Void, Void, Void> {
+
+        private final WeakReference<Context> contextWeakReference;
+
+        private StillOnWifiAsyncTask(Context context) {
+            this.contextWeakReference = new WeakReference<>(context);
+        }
+
+        @Override
+        protected Void doInBackground(Void... voids) {
+            Context context = contextWeakReference.get();
+            try {
+                Thread.sleep(120000);
+                if (Preferences.get().isBackgroundDownloadAllowed()) {
+                    Utils.debugLog(TAG, "scheduling update because there is good internet");
+                    schedule(context);
+                }
+            } catch (Throwable e) { // NOPMD
+                Utils.debugLog(TAG, e.getMessage());
+            }
+            isScheduleIfStillOnWifiRunning = false;
+            return null;
+        }
 
-        return Completable.timer(2, TimeUnit.MINUTES)
-                .andThen(Completable.fromAction(() -> {
-                    if (Preferences.get().isBackgroundDownloadAllowed()) {
-                        Utils.debugLog(TAG, "scheduling update because there is good internet");
-                        schedule(context);
-                    }
-                    isScheduleIfStillOnWifiRunning = false;
-                }))
-                .subscribeOn(Schedulers.computation())
-                .observeOn(AndroidSchedulers.mainThread());
     }
 
     public static void stopNow(Context context) {

app/src/main/java/org/fdroid/fdroid/Utils.java

@@ -27,7 +27,6 @@ import android.content.pm.Signature;
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.graphics.Bitmap;
-import android.graphics.Point;
 import android.graphics.Rect;
 import android.net.Uri;
 import android.os.Build;
@@ -45,15 +44,11 @@ import android.text.style.TypefaceSpan;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.util.TypedValue;
-import android.view.Display;
 import android.view.View;
 import android.view.ViewTreeObserver;
 import android.widget.ImageView;
 import android.widget.Toast;
 
-import com.google.zxing.BarcodeFormat;
-import com.google.zxing.encode.Contents;
-import com.google.zxing.encode.QRCodeEncoder;
 import com.nostra13.universalimageloader.core.DisplayImageOptions;
 import com.nostra13.universalimageloader.core.ImageLoader;
 import com.nostra13.universalimageloader.core.assist.ImageScaleType;
@@ -100,11 +95,7 @@ import java.util.regex.Pattern;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
-import androidx.appcompat.app.AppCompatActivity;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
-import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
-import io.reactivex.rxjava3.core.Single;
-import io.reactivex.rxjava3.schedulers.Schedulers;
 
 public final class Utils {
 
@@ -995,27 +986,6 @@ public final class Utils {
         }
     }
 
-    @NonNull
-    public static Single<Bitmap> generateQrBitmap(@NonNull final AppCompatActivity activity,
-                                                  @NonNull final String qrData) {
-        return Single.fromCallable(() -> {
-            Display display = activity.getWindowManager().getDefaultDisplay();
-            Point outSize = new Point();
-            display.getSize(outSize);
-            final int x = outSize.x;
-            final int y = outSize.y;
-            final int qrCodeDimension = Math.min(x, y);
-            debugLog(TAG, "generating QRCode Bitmap of " + qrCodeDimension + "x" + qrCodeDimension);
-            QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(qrData, null,
-                    Contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), qrCodeDimension);
-
-            return qrCodeEncoder.encodeAsBitmap();
-        })
-                .subscribeOn(Schedulers.computation())
-                .observeOn(AndroidSchedulers.mainThread())
-                .doOnError(throwable -> Log.e(TAG, "Could not encode QR as bitmap", throwable));
-    }
-
     /**
      * Keep an instance of this class as an field in an AppCompatActivity for figuring out whether the on
      * screen keyboard is currently visible or not.

app/src/main/java/org/fdroid/fdroid/data/DBHelper.java

@@ -322,16 +322,16 @@ public class DBHelper extends SQLiteOpenHelper {
 
     /**
      * Look for additional, initial repositories from the device's filesystem.
-     * These can be added as part of the ROM ({@code /system} or {@code /product}
+     * These can be added as part of the ROM ({@code /system} or included later
-     * or included later by vendors/OEMs ({@code /vendor}, {@code /odm}, {@code /oem}).
+     * by vendors/OEMs ({@code /vendor}, {@code /odm}, {@code /oem}). These are
-     * These are always added at a lower priority than the repos embedded in the APK via
+     * always added at a lower priority than the repos embedded in the APK via
      * {@code default_repos.xml}.
      * <p>
-     * ROM (System) has the lowest priority, then Product, Vendor, ODM, and OEM.
+     * ROM has the lowest priority, then Vendor, ODM, and OEM.
      */
     private static List<String> loadAdditionalRepos(String packageName) {
         List<String> repoItems = new LinkedList<>();
-        for (String root : Arrays.asList("/system", "/product", "/vendor", "/odm", "/oem")) {
+        for (String root : Arrays.asList("/system", "/vendor", "/odm", "/oem")) {
             File additionalReposFile = new File(root + "/etc/" + packageName + "/additional_repos.xml");
             try {
                 if (additionalReposFile.isFile()) {

app/src/main/java/org/fdroid/fdroid/data/InstalledAppProviderService.java

@@ -31,9 +31,9 @@ import java.util.concurrent.TimeUnit;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.core.app.JobIntentService;
-import io.reactivex.rxjava3.disposables.CompositeDisposable;
+import rx.functions.Action1;
-import io.reactivex.rxjava3.schedulers.Schedulers;
+import rx.schedulers.Schedulers;
-import io.reactivex.rxjava3.subjects.PublishSubject;
+import rx.subjects.PublishSubject;
 
 /**
  * Handles all updates to {@link InstalledAppProvider}, whether checking the contents
@@ -65,15 +65,13 @@ public class InstalledAppProviderService extends JobIntentService {
     private static final String EXTRA_PACKAGE_INFO = "org.fdroid.fdroid.data.extra.PACKAGE_INFO";
 
     /**
-     * This is for notifying the users of this {@link android.content.ContentProvider}
+     * This is for notifing the users of this {@link android.content.ContentProvider}
-     * that the contents have changed. Since {@link Intent}s can come in slow
+     * that the contents has changed.  Since {@link Intent}s can come in slow
      * or fast, and this can trigger a lot of UI updates, the actual
      * notifications are rate limited to one per second.
      */
     private PublishSubject<String> packageChangeNotifier;
 
-    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
-
     @Override
     public void onCreate() {
         super.onCreate();
@@ -83,16 +81,17 @@ public class InstalledAppProviderService extends JobIntentService {
         // only emit an event to the subscriber after it has not received any new events for one second.
         // This ensures that we don't constantly ask our lists of apps to update as we iterate over
         // the list of installed apps and insert them to the database...
-        compositeDisposable.add(
+        packageChangeNotifier
-                packageChangeNotifier
+                .subscribeOn(Schedulers.newThread())
-                        .subscribeOn(Schedulers.newThread())
+                .debounce(3, TimeUnit.SECONDS)
-                        .debounce(3, TimeUnit.SECONDS)
+                .subscribe(new Action1<String>() {
-                        .subscribe(packageName -> {
+                    @Override
-                            Utils.debugLog(TAG, "Notifying content providers to update relevant views.");
+                    public void call(String packageName) {
-                            getContentResolver().notifyChange(AppProvider.getContentUri(), null);
+                        Utils.debugLog(TAG, "Notifying content providers (so they can update the relevant views).");
-                            getContentResolver().notifyChange(ApkProvider.getContentUri(), null);
+                        getContentResolver().notifyChange(AppProvider.getContentUri(), null);
-                        })
+                        getContentResolver().notifyChange(ApkProvider.getContentUri(), null);
-        );
+                    }
+                });
 
         // ...alternatively, this non-debounced version will instantly emit an event about the
         // particular package being updated. This is required so that our AppDetails view can update
@@ -101,18 +100,14 @@ public class InstalledAppProviderService extends JobIntentService {
         // only for changes to specific URIs in the AppProvider. These are triggered when a more
         // general notification (e.g. to AppProvider.getContentUri()) is fired, but not when a
         // sibling such as AppProvider.getHighestPriorityMetadataUri() is fired.
-        compositeDisposable.add(
+        packageChangeNotifier.subscribeOn(Schedulers.newThread())
-                packageChangeNotifier
+                .subscribe(new Action1<String>() {
-                        .subscribeOn(Schedulers.newThread())
+                    @Override
-                        .subscribe(packageName -> getContentResolver()
+                    public void call(String packageName) {
-                                .notifyChange(AppProvider.getHighestPriorityMetadataUri(packageName), null))
+                        getContentResolver()
-        );
+                                .notifyChange(AppProvider.getHighestPriorityMetadataUri(packageName), null);
-    }
+                    }
-
+                });
-    @Override
-    public void onDestroy() {
-        compositeDisposable.dispose();
-        super.onDestroy();
     }
 
     /**
@@ -248,7 +243,12 @@ public class InstalledAppProviderService extends JobIntentService {
     public static File getPathToInstalledApk(PackageInfo packageInfo) {
         File apk = new File(packageInfo.applicationInfo.publicSourceDir);
         if (apk.isDirectory()) {
-            FilenameFilter filter = (dir, name) -> name.endsWith(".apk");
+            FilenameFilter filter = new FilenameFilter() {
+                @Override
+                public boolean accept(File dir, String name) {
+                    return name.endsWith(".apk");
+                }
+            };
             File[] files = apk.listFiles(filter);
             if (files == null) {
                 String msg = packageInfo.packageName + " sourceDir has no APKs: " + apk.getAbsolutePath();

app/src/main/java/org/fdroid/fdroid/installer/FileInstallerActivity.java

@@ -128,7 +128,6 @@ public class FileInstallerActivity extends FragmentActivity {
     @Override
     public void onRequestPermissionsResult(int requestCode,
                                            @NonNull String[] permissions, @NonNull int[] grantResults) {
-        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
         switch (requestCode) {
             case MY_PERMISSIONS_REQUEST_STORAGE:
                 // If request is cancelled, the result arrays are empty.

app/src/main/java/org/fdroid/fdroid/net/Downloader.java

@@ -256,7 +256,7 @@ public abstract class Downloader {
         }
 
         @Override
-        public synchronized void mark(int readlimit) {
+        public void mark(int readlimit) {
             toWrap.mark(readlimit);
         }
 

app/src/main/java/org/fdroid/fdroid/qr/QrGenAsyncTask.java

@@ -0,0 +1,74 @@
+package org.fdroid.fdroid.qr;
+
+import android.annotation.TargetApi;
+import android.graphics.Bitmap;
+import android.graphics.Point;
+import android.os.AsyncTask;
+import android.util.Log;
+import android.view.Display;
+import android.widget.ImageView;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.WriterException;
+import com.google.zxing.encode.Contents;
+import com.google.zxing.encode.QRCodeEncoder;
+
+import org.fdroid.fdroid.Utils;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+public class QrGenAsyncTask extends AsyncTask<String, Void, Void> {
+    private static final String TAG = "QrGenAsyncTask";
+
+    private final AppCompatActivity activity;
+    private final int viewId;
+    private Bitmap qrBitmap;
+
+    public QrGenAsyncTask(AppCompatActivity activity, int viewId) {
+        this.activity = activity;
+        this.viewId = viewId;
+    }
+
+    /*
+     * The method for getting screen dimens changed, so this uses both the
+     * deprecated one and the 13+ one, and supports all Android versions.
+     */
+    @SuppressWarnings("deprecation")
+    @TargetApi(13)
+    @Override
+    protected Void doInBackground(String... s) {
+        String qrData = s[0];
+        Display display = activity.getWindowManager().getDefaultDisplay();
+        Point outSize = new Point();
+        int x, y, qrCodeDimension;
+        display.getSize(outSize);
+        x = outSize.x;
+        y = outSize.y;
+        if (x < y) {
+            qrCodeDimension = x;
+        } else {
+            qrCodeDimension = y;
+        }
+        Utils.debugLog(TAG, "generating QRCode Bitmap of " + qrCodeDimension + "x" + qrCodeDimension);
+        QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(qrData, null,
+                Contents.Type.TEXT, BarcodeFormat.QR_CODE.toString(), qrCodeDimension);
+
+        try {
+            qrBitmap = qrCodeEncoder.encodeAsBitmap();
+        } catch (WriterException e) {
+            Log.e(TAG, "Could not encode QR as bitmap", e);
+        }
+        return null;
+    }
+
+    @Override
+    protected void onPostExecute(Void v) {
+        ImageView qrCodeImageView = (ImageView) activity.findViewById(viewId);
+
+        // If the generation takes too long for whatever reason, then this view, and indeed the entire
+        // activity may not be around any more.
+        if (qrCodeImageView != null) {
+            qrCodeImageView.setImageBitmap(qrBitmap);
+        }
+    }
+}

app/src/main/java/org/fdroid/fdroid/views/ManageReposActivity.java

@@ -19,6 +19,7 @@
 
 package org.fdroid.fdroid.views;
 
+import android.annotation.SuppressLint;
 import android.content.ClipData;
 import android.content.ClipboardManager;
 import android.content.ContentResolver;
@@ -31,13 +32,13 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
+import android.os.AsyncTask;
 import android.os.Build;
 import android.os.Bundle;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
 import android.util.Log;
-import android.util.Pair;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
@@ -49,6 +50,17 @@ import android.widget.ListView;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.appcompat.widget.Toolbar;
+import androidx.core.app.NavUtils;
+import androidx.core.app.TaskStackBuilder;
+import androidx.core.content.ContextCompat;
+import androidx.loader.app.LoaderManager;
+import androidx.loader.content.CursorLoader;
+import androidx.loader.content.Loader;
+
 import com.google.android.material.appbar.MaterialToolbar;
 import com.google.android.material.dialog.MaterialAlertDialogBuilder;
 import com.google.android.material.textfield.TextInputLayout;
@@ -75,22 +87,6 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Locale;
 
-import androidx.annotation.NonNull;
-import androidx.appcompat.app.AlertDialog;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
-import androidx.core.app.NavUtils;
-import androidx.core.app.TaskStackBuilder;
-import androidx.core.content.ContextCompat;
-import androidx.loader.app.LoaderManager;
-import androidx.loader.content.CursorLoader;
-import androidx.loader.content.Loader;
-import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
-import io.reactivex.rxjava3.core.Single;
-import io.reactivex.rxjava3.disposables.CompositeDisposable;
-import io.reactivex.rxjava3.disposables.Disposable;
-import io.reactivex.rxjava3.schedulers.Schedulers;
-
 public class ManageReposActivity extends AppCompatActivity
         implements LoaderManager.LoaderCallbacks<Cursor>, RepoAdapter.EnabledListener {
     private static final String TAG = "ManageReposActivity";
@@ -111,8 +107,6 @@ public class ManageReposActivity extends AppCompatActivity
      */
     private boolean finishAfterAddingRepo;
 
-    private final CompositeDisposable compositeDisposable = new CompositeDisposable();
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         FDroidApp fdroidApp = (FDroidApp) getApplication();
@@ -160,12 +154,6 @@ public class ManageReposActivity extends AppCompatActivity
         });
     }
 
-    @Override
-    protected void onDestroy() {
-        compositeDisposable.dispose();
-        super.onDestroy();
-    }
-
     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         MenuInflater menuInflater = getMenuInflater();
@@ -583,8 +571,10 @@ public class ManageReposActivity extends AppCompatActivity
         /**
          * Adds a new repo to the database.
          */
+        @SuppressLint("StaticFieldLeak")
         private void prepareToCreateNewRepo(final String originalAddress, final String fingerprint,
                                             final String username, final String password) {
+
             final View addRepoForm = addRepoDialog.findViewById(R.id.add_repo_form);
             addRepoForm.setVisibility(View.GONE);
             final View positiveButton = addRepoDialog.getButton(AlertDialog.BUTTON_POSITIVE);
@@ -596,117 +586,153 @@ public class ManageReposActivity extends AppCompatActivity
             final Button skip = addRepoDialog.getButton(AlertDialog.BUTTON_NEGATIVE);
             skip.setText(R.string.skip);
 
-            final int refreshDialog = Integer.MAX_VALUE;
+            final AsyncTask<String, String, String> checker = new AsyncTask<String, String, String>() {
-            final Disposable disposable = Single.fromCallable(() -> {
-                int statusCode = -1;
 
-                if (fingerprintRepoMap.containsKey(fingerprint)) {
+                private int statusCode = -1;
-                    statusCode = refreshDialog;
+                private static final int REFRESH_DIALOG = Integer.MAX_VALUE;
-                    return Pair.create(statusCode, originalAddress);
-                }
 
-                if (originalAddress.startsWith(ContentResolver.SCHEME_CONTENT)
+                @Override
-                        || originalAddress.startsWith(ContentResolver.SCHEME_FILE)) {
+                protected String doInBackground(String... params) {
-                    // TODO check whether there is read access
+                    final String originalAddress = params[0];
-                    return Pair.create(statusCode, originalAddress);
-                }
 
-                final String[] pathsToCheck = {"", "fdroid/repo", "repo"};
+                    if (fingerprintRepoMap.containsKey(fingerprint)) {
-                for (final String path : pathsToCheck) {
+                        statusCode = REFRESH_DIALOG;
-                    Utils.debugLog(TAG, "Check for repo at " + originalAddress + " with suffix '" + path + "'");
+                        return originalAddress;
-                    Uri.Builder builder = Uri.parse(originalAddress).buildUpon().appendEncodedPath(path);
-                    final String addressWithoutIndex = builder.build().toString();
-                    runOnUiThread(() -> textSearching.setText(getString(R.string.repo_searching_address,
-                            addressWithoutIndex)));
-
-                    if (urlRepoMap.containsKey(addressWithoutIndex)) {
-                        statusCode = refreshDialog;
-                        return Pair.create(statusCode, addressWithoutIndex);
                     }
 
-                    final Uri uri = builder.appendPath(IndexUpdater.SIGNED_FILE_NAME).build();
+                    if (originalAddress.startsWith(ContentResolver.SCHEME_CONTENT)
+                            || originalAddress.startsWith(ContentResolver.SCHEME_FILE)) {
+                        // TODO check whether there is read access
+                        return originalAddress;
+                    }
 
-                    try {
+                    final String[] pathsToCheck = {"", "fdroid/repo", "repo"};
-                        final URL url = new URL(uri.toString());
+                    for (final String path : pathsToCheck) {
-                        final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
-                        connection.setRequestMethod("HEAD");
 
-                        statusCode = connection.getResponseCode();
+                        Utils.debugLog(TAG, "Check for repo at " + originalAddress + " with suffix '" + path + "'");
+                        Uri.Builder builder = Uri.parse(originalAddress).buildUpon().appendEncodedPath(path);
+                        final String addressWithoutIndex = builder.build().toString();
+                        publishProgress(addressWithoutIndex);
 
-                        if (statusCode == HttpURLConnection.HTTP_UNAUTHORIZED
+                        if (urlRepoMap.containsKey(addressWithoutIndex)) {
-                                || statusCode == HttpURLConnection.HTTP_OK) {
+                            statusCode = REFRESH_DIALOG;
-                            Utils.debugLog(TAG, "Found F-Droid repo at " + addressWithoutIndex);
+                            return addressWithoutIndex;
-                            return Pair.create(statusCode, addressWithoutIndex);
+                        }
+
+                        final Uri uri = builder.appendPath(IndexUpdater.SIGNED_FILE_NAME).build();
+
+                        try {
+                            if (checkForRepository(uri)) {
+                                Utils.debugLog(TAG, "Found F-Droid repo at " + addressWithoutIndex);
+                                return addressWithoutIndex;
+                            }
+                        } catch (IOException e) {
+                            Log.e(TAG, "Error while searching for repo at " + addressWithoutIndex, e);
+                            return originalAddress;
+                        }
+
+                        if (isCancelled()) {
+                            Utils.debugLog(TAG, "Not checking more repo addresses, because process was skipped.");
+                            break;
                         }
-                    } catch (IOException e) {
-                        Log.e(TAG, "Error while searching for repo at " + addressWithoutIndex, e);
-                        return Pair.create(statusCode, originalAddress);
                     }
+                    return originalAddress;
+
                 }
-                return Pair.create(statusCode, originalAddress);
-            })
-                    .subscribeOn(Schedulers.io())
-                    .observeOn(AndroidSchedulers.mainThread())
-                    .doOnDispose(() -> Utils.debugLog(TAG,
-                            "Not checking more repo addresses, because process was skipped."))
-                    .subscribe(codeAddressPair -> {
-                        final int statusCode = codeAddressPair.first;
-                        final String newAddress = codeAddressPair.second;
 
-                        if (addRepoDialog.isShowing()) {
+                private boolean checkForRepository(Uri indexUri) throws IOException {
-                            if (statusCode == HttpURLConnection.HTTP_UNAUTHORIZED) {
+                    final URL url = new URL(indexUri.toString());
-                                final View view = getLayoutInflater().inflate(R.layout.login, null);
+                    final HttpURLConnection connection = (HttpURLConnection) url.openConnection();
-                                final AlertDialog credentialsDialog = new AlertDialog.Builder(context)
+                    connection.setRequestMethod("HEAD");
-                                        .setView(view).create();
-                                final EditText nameInput = (EditText) view.findViewById(R.id.edit_name);
-                                final EditText passwordInput = (EditText) view.findViewById(R.id.edit_password);
 
-                                if (username != null) {
+                    statusCode = connection.getResponseCode();
-                                    nameInput.setText(username);
-                                }
-                                if (password != null) {
-                                    passwordInput.setText(password);
-                                }
 
-                                credentialsDialog.setTitle(R.string.login_title);
+                    return statusCode == HttpURLConnection.HTTP_UNAUTHORIZED
-                                credentialsDialog.setButton(DialogInterface.BUTTON_NEGATIVE,
+                            || statusCode == HttpURLConnection.HTTP_OK;
-                                        getString(R.string.cancel), (dialog, which) -> {
+                }
+
+                @Override
+                protected void onProgressUpdate(String... values) {
+                    String address = values[0];
+                    textSearching.setText(getString(R.string.repo_searching_address, address));
+                }
+
+                @Override
+                protected void onPostExecute(final String newAddress) {
+
+                    if (addRepoDialog.isShowing()) {
+
+                        if (statusCode == HttpURLConnection.HTTP_UNAUTHORIZED) {
+
+                            final View view = getLayoutInflater().inflate(R.layout.login, null);
+                            final AlertDialog credentialsDialog = new AlertDialog.Builder(context)
+                                    .setView(view).create();
+                            final EditText nameInput = (EditText) view.findViewById(R.id.edit_name);
+                            final EditText passwordInput = (EditText) view.findViewById(R.id.edit_password);
+
+                            if (username != null) {
+                                nameInput.setText(username);
+                            }
+                            if (password != null) {
+                                passwordInput.setText(password);
+                            }
+
+                            credentialsDialog.setTitle(R.string.login_title);
+                            credentialsDialog.setButton(DialogInterface.BUTTON_NEGATIVE,
+                                    getString(R.string.cancel),
+                                    new DialogInterface.OnClickListener() {
+                                        @Override
+                                        public void onClick(DialogInterface dialog, int which) {
                                             dialog.dismiss();
                                             // cancel parent dialog, don't add repo
                                             addRepoDialog.cancel();
-                                        });
+                                        }
+                                    });
 
-                                credentialsDialog.setButton(DialogInterface.BUTTON_POSITIVE,
+                            credentialsDialog.setButton(DialogInterface.BUTTON_POSITIVE,
-                                        getString(R.string.ok),
+                                    getString(R.string.ok),
-                                        (dialog, which) -> createNewRepo(newAddress, fingerprint,
+                                    new DialogInterface.OnClickListener() {
-                                                nameInput.getText().toString(),
+                                        @Override
-                                                passwordInput.getText().toString()));
+                                        public void onClick(DialogInterface dialog, int which) {
+                                            createNewRepo(newAddress, fingerprint,
+                                                    nameInput.getText().toString(),
+                                                    passwordInput.getText().toString());
+                                        }
+                                    });
 
-                                credentialsDialog.show();
+                            credentialsDialog.show();
-                            } else if (statusCode == refreshDialog) {
+
-                                addRepoForm.setVisibility(View.VISIBLE);
+                        } else if (statusCode == REFRESH_DIALOG) {
-                                positiveButton.setVisibility(View.VISIBLE);
+                            addRepoForm.setVisibility(View.VISIBLE);
-                                textSearching.setText("");
+                            positiveButton.setVisibility(View.VISIBLE);
-                                skip.setText(R.string.cancel);
+                            textSearching.setText("");
-                                skip.setOnClickListener(null);
+                            skip.setText(R.string.cancel);
-                                validateRepoDetails(newAddress, fingerprint);
+                            skip.setOnClickListener(null);
-                            } else {
+                            validateRepoDetails(newAddress, fingerprint);
-                                // create repo without username/password
+                        } else {
-                                createNewRepo(newAddress, fingerprint);
+
-                            }
+                            // create repo without username/password
+                            createNewRepo(newAddress, fingerprint);
                         }
-                    });
+                    }
-            compositeDisposable.add(disposable);
+                }
+            };
 
-            skip.setOnClickListener(v -> {
+            skip.setOnClickListener(new View.OnClickListener() {
-                // Still proceed with adding the repo, just don't bother searching for
+                @Override
-                // a better alternative than the one provided.
+                public void onClick(View v) {
-                // The reason for this is that if they are not connected to the internet,
+                    // Still proceed with adding the repo, just don't bother searching for
-                // or their internet is playing up, then you'd have to wait for several
+                    // a better alternative than the one provided.
-                // connection timeouts before being able to proceed.
+                    // The reason for this is that if they are not connected to the internet,
-                createNewRepo(originalAddress, fingerprint);
+                    // or their internet is playing up, then you'd have to wait for several
-                disposable.dispose();
+                    // connection timeouts before being able to proceed.
+
+                    createNewRepo(originalAddress, fingerprint);
+                    checker.cancel(false);
+                }
             });
+
+            checker.execute(originalAddress);
         }
 
         /**

app/src/main/java/org/fdroid/fdroid/views/PreferencesFragment.java

@@ -53,7 +53,6 @@ import org.fdroid.fdroid.work.CleanCacheWorker;
 import org.fdroid.fdroid.work.FDroidMetricsWorker;
 
 import androidx.appcompat.app.AppCompatActivity;
-import androidx.core.app.ActivityCompat;
 import androidx.preference.CheckBoxPreference;
 import androidx.preference.EditTextPreference;
 import androidx.preference.ListPreference;
@@ -292,7 +291,7 @@ public class PreferencesFragment extends PreferenceFragmentCompat
                     AppCompatActivity activity = (AppCompatActivity) getActivity();
                     // Theme will be applied upon activity creation
                     if (activity != null) {
-                        ActivityCompat.recreate(activity);
+                        activity.recreate();
                     }
                 }
                 break;

app/src/main/java/org/fdroid/fdroid/views/RepoDetailsActivity.java

@@ -23,7 +23,6 @@ import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.CompoundButton;
 import android.widget.EditText;
-import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -39,6 +38,7 @@ import org.fdroid.fdroid.Utils;
 import org.fdroid.fdroid.data.Repo;
 import org.fdroid.fdroid.data.RepoProvider;
 import org.fdroid.fdroid.data.Schema.RepoTable;
+import org.fdroid.fdroid.qr.QrGenAsyncTask;
 
 import java.util.Arrays;
 import java.util.HashSet;
@@ -52,7 +52,6 @@ import androidx.core.content.ContextCompat;
 import androidx.localbroadcastmanager.content.LocalBroadcastManager;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
-import io.reactivex.rxjava3.disposables.Disposable;
 
 public class RepoDetailsActivity extends AppCompatActivity {
     private static final String TAG = "RepoDetailsActivity";
@@ -92,8 +91,6 @@ public class RepoDetailsActivity extends AppCompatActivity {
 
     private MirrorAdapter adapterToNotify;
 
-    private Disposable disposable;
-
     /**
      * Help function to make switching between two view states easier.
      * Perhaps there is a better way to do this. I recall that using Adobe
@@ -144,19 +141,7 @@ public class RepoDetailsActivity extends AppCompatActivity {
         Uri uri = Uri.parse(repo.address);
         uri = uri.buildUpon().appendQueryParameter("fingerprint", repo.fingerprint).build();
         String qrUriString = uri.toString();
-        disposable = Utils.generateQrBitmap(this, qrUriString)
+        new QrGenAsyncTask(this, R.id.qr_code).execute(qrUriString);
-                .subscribe(bitmap -> {
-                    final ImageView qrCode = findViewById(R.id.qr_code);
-                    if (qrCode != null) {
-                        qrCode.setImageBitmap(bitmap);
-                    }
-                });
-    }
-
-    @Override
-    protected void onDestroy() {
-        disposable.dispose();
-        super.onDestroy();
     }
 
     @TargetApi(14)

app/src/main/java/org/fdroid/fdroid/views/apps/AppListActivity.java

@@ -266,7 +266,6 @@ public class AppListActivity extends AppCompatActivity implements LoaderManager.
     public void onSearchTermsChanged(@Nullable String category, @NonNull String searchTerms) {
         this.category = category;
         this.searchTerms = searchTerms;
-        appView.scrollToPosition(0);
         getSupportLoaderManager().restartLoader(0, null, this);
         if (TextUtils.isEmpty(searchTerms)) {
             removeSavedSearchSettings(this, SEARCH_TERMS_KEY);

app/src/main/res/values/colors.xml

@@ -34,6 +34,4 @@
 
     <color name="perms_costs_money">#fff4511e</color>
 
-    <color name="immersive_sys_ui">#33000000</color>
-
 </resources>

app/src/main/res/values/default_repos.xml

@@ -4,25 +4,88 @@
     <string-array name="default_repos">
 
         <!-- name -->
-        <item>BoBTV</item>
+        <item>F-Droid Archive</item>
         <!-- address -->
-        <item>http://vps.k-world.me.uk:8088</item>
+        <item>https://f-droid.org/archive</item>
         <!-- description -->
-        <item>The BobTV Repo
+        <item>The archive repository of the F-Droid client. This contains older versions of
+            applications from the main repository.
         </item>
         <!-- version -->
-        <item>1</item>
+        <item>13</item>
         <!-- enabled -->
-        <item>1</item>
+        <item>0</item>
         <!-- priority -->
         <item>1</item>
         <!-- push requests -->
         <item>ignore</item>
         <!-- pubkey -->
         <item>
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         </item>
 
+        <!-- name -->
+        <item>F-Droid</item>
+        <!-- address -->
+        <item>https://f-droid.org/repo</item>
+        <!-- description -->
+        <item>The official F-Droid Free Software repository. Everything in this repository is always built from the source code.
+        </item>
+        <!-- version -->
+        <item>13</item>
+        <!-- enabled -->
+        <item>1</item>
+        <!-- priority -->
+        <item>2</item>
+        <!-- push requests -->
+        <item>ignore</item>
+        <!-- pubkey -->
+        <item>
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+        </item>
+
+        <!-- name -->
+        <item>Guardian Project Archive</item>
+        <!-- address -->
+        <item>https://guardianproject.info/fdroid/archive</item>
+        <!-- description -->
+        <item>The official repository of The Guardian Project apps for use with F-Droid client. This
+            contains older versions of applications from the main repository.
+        </item>
+        <!-- version -->
+        <item>13</item>
+        <!-- enabled -->
+        <item>0</item>
+        <!-- priority -->
+        <item>3</item>
+        <!-- push requests -->
+        <item>ignore</item>
+        <!-- pubkey -->
+        <item>
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+        </item>
+
+        <!-- name -->
+        <item>Guardian Project</item>
+        <!-- address -->
+        <item>https://guardianproject.info/fdroid/repo</item>
+        <!-- description -->
+        <item>The official app repository of The Guardian Project. Applications in this repository
+            are official binaries build by the original application developers and signed by the
+            same key as the APKs that are released in the Google Play store.
+        </item>
+        <!-- version -->
+        <item>13</item>
+        <!-- enabled -->
+        <item>0</item>
+        <!-- priority -->
+        <item>4</item>
+        <!-- push requests -->
+        <item>ignore</item>
+        <!-- pubkey -->
+        <item>
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+        </item>
 
     </string-array>
 

app/src/main/res/values/themes.xml

@@ -69,9 +69,6 @@
         <item name="bottomNavigationStyle">@style/Widget.MaterialComponents.BottomNavigationView.PrimarySurface</item>
 
         <item name="screenshotPlaceholderIconColor">#e8e8e8</item>
-
-        <!--Platform attributes-->
-        <item name="android:statusBarColor">@color/immersive_sys_ui</item>
     </style>
 
     <!-- light app theme with accent colors following roughly android design guidelines -->

build.gradle

@@ -5,7 +5,7 @@ buildscript {
         jcenter() // download from jCenter as last resort https://blog.autsoft.hu/a-confusing-dependency
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:4.2.1'
+        classpath 'com.android.tools.build:gradle:3.6.3'
     }
 }
 allprojects {

gradle/wrapper/gradle-wrapper.properties

@@ -3,5 +3,5 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.4.1-bin.zip
-#distributionSha256Sum=e58cdff0cee6d9b422dcd08ebeb3177bc44eaa09bd9a2e838ff74c408fe1cbcd
+distributionSha256Sum=e58cdff0cee6d9b422dcd08ebeb3177bc44eaa09bd9a2e838ff74c408fe1cbcd