Move first batch of preferences code to :ui:preferences (#7010)

18 files changed, 1691 insertions, 0 deletions

diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MasterSwitchPreference.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MasterSwitchPreference.java
new file mode 100644
index 000000000..cab3d3fc3
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MasterSwitchPreference.java
@@ -0,0 +1,42 @@
+package de.danoeh.antennapod.ui.preferences.preference;
+
+import android.content.Context;
+import android.graphics.Typeface;
+import androidx.preference.SwitchPreferenceCompat;
+import androidx.preference.PreferenceViewHolder;
+import android.util.AttributeSet;
+import android.widget.TextView;
+
+import de.danoeh.antennapod.ui.common.ThemeUtils;
+import de.danoeh.antennapod.ui.preferences.R;
+
+public class MasterSwitchPreference extends SwitchPreferenceCompat {
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+    }
+
+    public MasterSwitchPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MasterSwitchPreference(Context context) {
+        super(context);
+    }
+
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+
+        holder.itemView.setBackgroundColor(ThemeUtils.getColorFromAttr(getContext(), R.attr.colorSurfaceVariant));
+        TextView title = (TextView) holder.findViewById(android.R.id.title);
+        if (title != null) {
+            title.setTypeface(title.getTypeface(), Typeface.BOLD);
+        }
+    }
+}
\ No newline at end of file
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialListPreference.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialListPreference.java
new file mode 100644
index 000000000..a1264c569
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialListPreference.java
@@ -0,0 +1,43 @@
+package de.danoeh.antennapod.ui.preferences.preference;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import androidx.preference.ListPreference;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+
+public class MaterialListPreference extends ListPreference {
+
+    public MaterialListPreference(Context context) {
+        super(context);
+    }
+
+    public MaterialListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onClick() {
+        MaterialAlertDialogBuilder builder = new MaterialAlertDialogBuilder(getContext());
+        builder.setTitle(getTitle());
+        builder.setIcon(getDialogIcon());
+        builder.setNegativeButton(getNegativeButtonText(), null);
+
+        CharSequence[] values = getEntryValues();
+        int selected = -1;
+        for (int i = 0; i < values.length; i++) {
+            if (values[i].toString().equals(getValue())) {
+                selected = i;
+            }
+        }
+        builder.setSingleChoiceItems(getEntries(), selected, (dialog, which) -> {
+            dialog.dismiss();
+            if (which >= 0 && getEntryValues() != null) {
+                String value = getEntryValues()[which].toString();
+                if (callChangeListener(value)) {
+                    setValue(value);
+                }
+            }
+        });
+        builder.show();
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialMultiSelectListPreference.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialMultiSelectListPreference.java
new file mode 100644
index 000000000..1cf1ee170
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/MaterialMultiSelectListPreference.java
@@ -0,0 +1,47 @@
+package de.danoeh.antennapod.ui.preferences.preference;
+
+import android.content.Context;
+import android.content.DialogInterface;
+import android.util.AttributeSet;
+import androidx.preference.MultiSelectListPreference;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class MaterialMultiSelectListPreference extends MultiSelectListPreference {
+
+    public MaterialMultiSelectListPreference(Context context) {
+        super(context);
+    }
+
+    public MaterialMultiSelectListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected void onClick() {
+        MaterialAlertDialogBuilder builder = new MaterialAlertDialogBuilder(getContext());
+        builder.setTitle(getTitle());
+        builder.setIcon(getDialogIcon());
+        builder.setNegativeButton(getNegativeButtonText(), null);
+
+        boolean[] selected = new boolean[getEntries().length];
+        CharSequence[] values = getEntryValues();
+        for (int i = 0; i < values.length; i++) {
+            selected[i] = getValues().contains(values[i].toString());
+        }
+        builder.setMultiChoiceItems(getEntries(), selected,
+                (DialogInterface dialog, int which, boolean isChecked) -> selected[which] = isChecked);
+        builder.setPositiveButton(android.R.string.ok, (dialog, which) -> {
+            Set<String> selectedValues = new HashSet<>();
+            for (int i = 0; i < values.length; i++) {
+                if (selected[i]) {
+                    selectedValues.add(getEntryValues()[i].toString());
+                }
+            }
+            setValues(selectedValues);
+        });
+        builder.show();
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/ThemePreference.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/ThemePreference.java
new file mode 100644
index 000000000..9fdf591c5
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/preference/ThemePreference.java
@@ -0,0 +1,53 @@
+package de.danoeh.antennapod.ui.preferences.preference;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import androidx.cardview.widget.CardView;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceViewHolder;
+import com.google.android.material.elevation.SurfaceColors;
+import de.danoeh.antennapod.storage.preferences.UserPreferences;
+import de.danoeh.antennapod.ui.preferences.R;
+import de.danoeh.antennapod.ui.preferences.databinding.ThemePreferenceBinding;
+
+public class ThemePreference extends Preference {
+    ThemePreferenceBinding viewBinding;
+
+    public ThemePreference(Context context) {
+        super(context);
+        setLayoutResource(R.layout.theme_preference);
+    }
+
+    public ThemePreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        setLayoutResource(R.layout.theme_preference);
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+        viewBinding = ThemePreferenceBinding.bind(holder.itemView);
+        updateUi();
+    }
+
+    void updateThemeCard(CardView card, UserPreferences.ThemePreference theme) {
+        float density = getContext().getResources().getDisplayMetrics().density;
+        int surfaceColor = SurfaceColors.getColorForElevation(getContext(), 1 * density);
+        int surfaceColorActive = SurfaceColors.getColorForElevation(getContext(), 32 * density);
+        UserPreferences.ThemePreference activeTheme = UserPreferences.getTheme();
+        card.setCardBackgroundColor(theme == activeTheme ? surfaceColorActive : surfaceColor);
+        card.setOnClickListener(v -> {
+            UserPreferences.setTheme(theme);
+            if (getOnPreferenceChangeListener() != null) {
+                getOnPreferenceChangeListener().onPreferenceChange(this, UserPreferences.getTheme());
+            }
+            updateUi();
+        });
+    }
+
+    void updateUi() {
+        updateThemeCard(viewBinding.themeSystemCard, UserPreferences.ThemePreference.SYSTEM);
+        updateThemeCard(viewBinding.themeLightCard, UserPreferences.ThemePreference.LIGHT);
+        updateThemeCard(viewBinding.themeDarkCard, UserPreferences.ThemePreference.DARK);
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/AutoDownloadPreferencesFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/AutoDownloadPreferencesFragment.java
new file mode 100644
index 000000000..7c0c3ed4c
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/AutoDownloadPreferencesFragment.java
@@ -0,0 +1,202 @@
+package de.danoeh.antennapod.ui.preferences.screen;
+
+import android.annotation.SuppressLint;
+import android.app.Activity;
+import android.content.Context;
+import android.content.res.Resources;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
+import android.os.Build;
+import android.os.Bundle;
+import android.util.Log;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.preference.CheckBoxPreference;
+import androidx.preference.ListPreference;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceFragmentCompat;
+import androidx.preference.PreferenceScreen;
+import de.danoeh.antennapod.storage.preferences.UserPreferences;
+import de.danoeh.antennapod.ui.preferences.R;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+public class AutoDownloadPreferencesFragment extends PreferenceFragmentCompat {
+    private static final String TAG = "AutoDnldPrefFragment";
+
+    private CheckBoxPreference[] selectedNetworks;
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        addPreferencesFromResource(R.xml.preferences_autodownload);
+
+        setupAutoDownloadScreen();
+        buildAutodownloadSelectedNetworksPreference();
+        setSelectedNetworksEnabled(UserPreferences.isEnableAutodownloadWifiFilter());
+        buildEpisodeCleanupPreference();
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(R.string.pref_automatic_download_title);
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        checkAutodownloadItemVisibility(UserPreferences.isEnableAutodownload());
+    }
+
+    private void setupAutoDownloadScreen() {
+        findPreference(UserPreferences.PREF_ENABLE_AUTODL).setOnPreferenceChangeListener(
+                (preference, newValue) -> {
+                    if (newValue instanceof Boolean) {
+                        checkAutodownloadItemVisibility((Boolean) newValue);
+                    }
+                    return true;
+                });
+        if (Build.VERSION.SDK_INT >= 29) {
+            findPreference(UserPreferences.PREF_ENABLE_AUTODL_WIFI_FILTER).setVisible(false);
+        }
+        findPreference(UserPreferences.PREF_ENABLE_AUTODL_WIFI_FILTER)
+                .setOnPreferenceChangeListener(
+                        (preference, newValue) -> {
+                            if (newValue instanceof Boolean) {
+                                setSelectedNetworksEnabled((Boolean) newValue);
+                                return true;
+                            } else {
+                                return false;
+                            }
+                        }
+                );
+    }
+
+    private void checkAutodownloadItemVisibility(boolean autoDownload) {
+        findPreference(UserPreferences.PREF_EPISODE_CACHE_SIZE).setEnabled(autoDownload);
+        findPreference(UserPreferences.PREF_ENABLE_AUTODL_ON_BATTERY).setEnabled(autoDownload);
+        findPreference(UserPreferences.PREF_ENABLE_AUTODL_WIFI_FILTER).setEnabled(autoDownload);
+        findPreference(UserPreferences.PREF_EPISODE_CLEANUP).setEnabled(autoDownload);
+        setSelectedNetworksEnabled(autoDownload && UserPreferences.isEnableAutodownloadWifiFilter());
+    }
+
+    private static String blankIfNull(String val) {
+        return val == null ? "" : val;
+    }
+
+    @SuppressLint("MissingPermission") // getConfiguredNetworks needs location permission starting with API 29
+    private void buildAutodownloadSelectedNetworksPreference() {
+        if (Build.VERSION.SDK_INT >= 29) {
+            return;
+        }
+
+        final Activity activity = getActivity();
+
+        if (selectedNetworks != null) {
+            clearAutodownloadSelectedNetworsPreference();
+        }
+        // get configured networks
+        WifiManager wifiservice = (WifiManager) activity.getApplicationContext().getSystemService(Context.WIFI_SERVICE);
+        List<WifiConfiguration> networks = wifiservice.getConfiguredNetworks();
+
+        if (networks == null) {
+            Log.e(TAG, "Couldn't get list of configure Wi-Fi networks");
+            return;
+        }
+        Collections.sort(networks, (x, y) ->
+                blankIfNull(x.SSID).compareToIgnoreCase(blankIfNull(y.SSID)));
+        selectedNetworks = new CheckBoxPreference[networks.size()];
+        List<String> prefValues = Arrays.asList(UserPreferences
+                .getAutodownloadSelectedNetworks());
+        PreferenceScreen prefScreen = getPreferenceScreen();
+        Preference.OnPreferenceClickListener clickListener = preference -> {
+            if (preference instanceof CheckBoxPreference) {
+                String key = preference.getKey();
+                List<String> prefValuesList = new ArrayList<>(
+                        Arrays.asList(UserPreferences
+                                .getAutodownloadSelectedNetworks())
+                );
+                boolean newValue = ((CheckBoxPreference) preference)
+                        .isChecked();
+                Log.d(TAG, "Selected network " + key + ". New state: " + newValue);
+
+                int index = prefValuesList.indexOf(key);
+                if (index >= 0 && !newValue) {
+                    // remove network
+                    prefValuesList.remove(index);
+                } else if (index < 0 && newValue) {
+                    prefValuesList.add(key);
+                }
+
+                UserPreferences.setAutodownloadSelectedNetworks(prefValuesList.toArray(new String[0]));
+                return true;
+            } else {
+                return false;
+            }
+        };
+        // create preference for each known network. attach listener and set
+        // value
+        for (int i = 0; i < networks.size(); i++) {
+            WifiConfiguration config = networks.get(i);
+
+            CheckBoxPreference pref = new CheckBoxPreference(activity);
+            String key = Integer.toString(config.networkId);
+            pref.setTitle(config.SSID);
+            pref.setKey(key);
+            pref.setOnPreferenceClickListener(clickListener);
+            pref.setPersistent(false);
+            pref.setChecked(prefValues.contains(key));
+            selectedNetworks[i] = pref;
+            prefScreen.addPreference(pref);
+        }
+    }
+
+    private void clearAutodownloadSelectedNetworsPreference() {
+        if (selectedNetworks != null) {
+            PreferenceScreen prefScreen = getPreferenceScreen();
+
+            for (CheckBoxPreference network : selectedNetworks) {
+                if (network != null) {
+                    prefScreen.removePreference(network);
+                }
+            }
+        }
+    }
+
+    private void buildEpisodeCleanupPreference() {
+        final Resources res = getActivity().getResources();
+
+        ListPreference pref = findPreference(UserPreferences.PREF_EPISODE_CLEANUP);
+        String[] values = res.getStringArray(
+                R.array.episode_cleanup_values);
+        String[] entries = new String[values.length];
+        for (int x = 0; x < values.length; x++) {
+            int v = Integer.parseInt(values[x]);
+            if (v == UserPreferences.EPISODE_CLEANUP_EXCEPT_FAVORITE) {
+                entries[x] =  res.getString(R.string.episode_cleanup_except_favorite_removal);
+            } else if (v == UserPreferences.EPISODE_CLEANUP_QUEUE) {
+                entries[x] = res.getString(R.string.episode_cleanup_queue_removal);
+            } else if (v == UserPreferences.EPISODE_CLEANUP_NULL){
+                entries[x] = res.getString(R.string.episode_cleanup_never);
+            } else if (v == 0) {
+                entries[x] = res.getString(R.string.episode_cleanup_after_listening);
+            } else if (v > 0 && v < 24) {
+                entries[x] = res.getQuantityString(R.plurals.episode_cleanup_hours_after_listening, v, v);
+            } else {
+                int numDays = v / 24; // assume underlying value will be NOT fraction of days, e.g., 36 (hours)
+                entries[x] = res.getQuantityString(R.plurals.episode_cleanup_days_after_listening, numDays, numDays);
+            }
+        }
+        pref.setEntries(entries);
+    }
+
+    private void setSelectedNetworksEnabled(boolean b) {
+        if (selectedNetworks != null) {
+            for (Preference p : selectedNetworks) {
+                p.setEnabled(b);
+            }
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/NotificationPreferencesFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/NotificationPreferencesFragment.java
new file mode 100644
index 000000000..221ea5da1
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/NotificationPreferencesFragment.java
@@ -0,0 +1,28 @@
+package de.danoeh.antennapod.ui.preferences.screen;
+
+import android.os.Bundle;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.preference.PreferenceFragmentCompat;
+import de.danoeh.antennapod.core.sync.SynchronizationSettings;
+import de.danoeh.antennapod.ui.preferences.R;
+
+public class NotificationPreferencesFragment extends PreferenceFragmentCompat {
+
+    private static final String PREF_GPODNET_NOTIFICATIONS = "pref_gpodnet_notifications";
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        addPreferencesFromResource(R.xml.preferences_notifications);
+        setUpScreen();
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(R.string.notification_pref_fragment);
+    }
+
+    private void setUpScreen() {
+        findPreference(PREF_GPODNET_NOTIFICATIONS).setEnabled(SynchronizationSettings.isProviderConnected());
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/ContributorsPagerFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/ContributorsPagerFragment.java
new file mode 100644
index 000000000..912d09880
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/ContributorsPagerFragment.java
@@ -0,0 +1,87 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import androidx.fragment.app.Fragment;
+import androidx.viewpager2.adapter.FragmentStateAdapter;
+import androidx.viewpager2.widget.ViewPager2;
+import com.google.android.material.tabs.TabLayout;
+import com.google.android.material.tabs.TabLayoutMediator;
+import de.danoeh.antennapod.ui.preferences.R;
+
+/**
+ * Displays the 'about->Contributors' pager screen.
+ */
+public class ContributorsPagerFragment extends Fragment {
+    private static final int POS_DEVELOPERS = 0;
+    private static final int POS_TRANSLATORS = 1;
+    private static final int POS_SPECIAL_THANKS = 2;
+    private static final int TOTAL_COUNT = 3;
+
+    @Override
+    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container,
+                             Bundle savedInstanceState) {
+        super.onCreateView(inflater, container, savedInstanceState);
+
+        View rootView = inflater.inflate(R.layout.pager_fragment, container, false);
+        ViewPager2 viewPager = rootView.findViewById(R.id.viewpager);
+        viewPager.setAdapter(new StatisticsPagerAdapter(this));
+        // Give the TabLayout the ViewPager
+        TabLayout tabLayout = rootView.findViewById(R.id.sliding_tabs);
+        new TabLayoutMediator(tabLayout, viewPager, (tab, position) -> {
+            switch (position) {
+                case POS_DEVELOPERS:
+                    tab.setText(R.string.developers);
+                    break;
+                case POS_TRANSLATORS:
+                    tab.setText(R.string.translators);
+                    break;
+                case POS_SPECIAL_THANKS:
+                    tab.setText(R.string.special_thanks);
+                    break;
+                default:
+                    break;
+            }
+        }).attach();
+
+        rootView.findViewById(R.id.toolbar).setVisibility(View.GONE);
+
+        return rootView;
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(R.string.contributors);
+    }
+
+    public static class StatisticsPagerAdapter extends FragmentStateAdapter {
+
+        StatisticsPagerAdapter(@NonNull Fragment fragment) {
+            super(fragment);
+        }
+
+        @NonNull
+        @Override
+        public Fragment createFragment(int position) {
+            switch (position) {
+                case POS_TRANSLATORS:
+                    return new TranslatorsFragment();
+                case POS_SPECIAL_THANKS:
+                    return new SpecialThanksFragment();
+                default:
+                case POS_DEVELOPERS:
+                    return new DevelopersFragment();
+            }
+        }
+
+        @Override
+        public int getItemCount() {
+            return TOTAL_COUNT;
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/DevelopersFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/DevelopersFragment.java
new file mode 100644
index 000000000..de5a21bc0
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/DevelopersFragment.java
@@ -0,0 +1,56 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.ListFragment;
+import io.reactivex.Single;
+import io.reactivex.SingleOnSubscribe;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.schedulers.Schedulers;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+public class DevelopersFragment extends ListFragment {
+    private Disposable developersLoader;
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        getListView().setDivider(null);
+        getListView().setSelector(android.R.color.transparent);
+
+        developersLoader = Single.create((SingleOnSubscribe<ArrayList<SimpleIconListAdapter.ListItem>>) emitter -> {
+            ArrayList<SimpleIconListAdapter.ListItem> developers = new ArrayList<>();
+            BufferedReader reader = new BufferedReader(new InputStreamReader(
+                    getContext().getAssets().open("developers.csv"), "UTF-8"));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                String[] info = line.split(";");
+                developers.add(new SimpleIconListAdapter.ListItem(info[0], info[2],
+                        "https://avatars2.githubusercontent.com/u/" + info[1] + "?s=60&v=4"));
+            }
+            emitter.onSuccess(developers);
+        })
+        .subscribeOn(Schedulers.io())
+        .observeOn(AndroidSchedulers.mainThread())
+        .subscribe(
+                developers -> setListAdapter(new SimpleIconListAdapter<>(getContext(), developers)),
+                error -> Toast.makeText(getContext(), error.getMessage(), Toast.LENGTH_LONG).show()
+        );
+
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (developersLoader != null) {
+            developersLoader.dispose();
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/LicensesFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/LicensesFragment.java
new file mode 100644
index 000000000..85badcefc
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/LicensesFragment.java
@@ -0,0 +1,125 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.os.Bundle;
+import android.view.View;
+import android.widget.ListView;
+import android.widget.Toast;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import androidx.fragment.app.ListFragment;
+import de.danoeh.antennapod.core.util.IntentUtils;
+import de.danoeh.antennapod.ui.preferences.R;
+import io.reactivex.Single;
+import io.reactivex.SingleOnSubscribe;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.schedulers.Schedulers;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.NodeList;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+public class LicensesFragment extends ListFragment {
+    private Disposable licensesLoader;
+    private final ArrayList<LicenseItem> licenses = new ArrayList<>();
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        getListView().setDivider(null);
+
+        licensesLoader = Single.create((SingleOnSubscribe<ArrayList<LicenseItem>>) emitter -> {
+            licenses.clear();
+            InputStream stream = getContext().getAssets().open("licenses.xml");
+            DocumentBuilder docBuilder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+            NodeList libraryList = docBuilder.parse(stream).getElementsByTagName("library");
+            for (int i = 0; i < libraryList.getLength(); i++) {
+                NamedNodeMap lib = libraryList.item(i).getAttributes();
+                licenses.add(new LicenseItem(
+                        lib.getNamedItem("name").getTextContent(),
+                        String.format("By %s, %s license",
+                                lib.getNamedItem("author").getTextContent(),
+                                lib.getNamedItem("license").getTextContent()),
+                        null,
+                        lib.getNamedItem("website").getTextContent(),
+                        lib.getNamedItem("licenseText").getTextContent()));
+            }
+            emitter.onSuccess(licenses);
+        })
+        .subscribeOn(Schedulers.io())
+        .observeOn(AndroidSchedulers.mainThread())
+        .subscribe(
+                developers -> setListAdapter(new SimpleIconListAdapter<LicenseItem>(getContext(), developers)),
+                error -> Toast.makeText(getContext(), error.getMessage(), Toast.LENGTH_LONG).show()
+        );
+
+    }
+
+    private static class LicenseItem extends SimpleIconListAdapter.ListItem {
+        final String licenseUrl;
+        final String licenseTextFile;
+
+        LicenseItem(String title, String subtitle, String imageUrl, String licenseUrl, String licenseTextFile) {
+            super(title, subtitle, imageUrl);
+            this.licenseUrl = licenseUrl;
+            this.licenseTextFile = licenseTextFile;
+        }
+    }
+
+    @Override
+    public void onListItemClick(@NonNull ListView l, @NonNull View v, int position, long id) {
+        super.onListItemClick(l, v, position, id);
+
+        LicenseItem item = licenses.get(position);
+        CharSequence[] items = {"View website", "View license"};
+        new MaterialAlertDialogBuilder(getContext())
+                .setTitle(item.title)
+                .setItems(items, (dialog, which) -> {
+                    if (which == 0) {
+                        IntentUtils.openInBrowser(getContext(), item.licenseUrl);
+                    } else if (which == 1) {
+                        showLicenseText(item.licenseTextFile);
+                    }
+                }).show();
+    }
+
+    private void showLicenseText(String licenseTextFile) {
+        try {
+            BufferedReader reader = new BufferedReader(new InputStreamReader(
+                    getContext().getAssets().open(licenseTextFile), "UTF-8"));
+            StringBuilder licenseText = new StringBuilder();
+            String line;
+            while ((line = reader.readLine()) != null) {
+                licenseText.append(line).append("\n");
+            }
+
+            new MaterialAlertDialogBuilder(getContext())
+                    .setMessage(licenseText)
+                    .show();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (licensesLoader != null) {
+            licensesLoader.dispose();
+        }
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(R.string.licenses);
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SimpleIconListAdapter.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SimpleIconListAdapter.java
new file mode 100644
index 000000000..a63b54e5a
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SimpleIconListAdapter.java
@@ -0,0 +1,59 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.content.Context;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.ImageView;
+import android.widget.TextView;
+import com.bumptech.glide.Glide;
+import com.bumptech.glide.load.engine.DiskCacheStrategy;
+import com.bumptech.glide.request.RequestOptions;
+import de.danoeh.antennapod.ui.preferences.R;
+
+import java.util.List;
+
+/**
+ * Displays a list of items that have a subtitle and an icon.
+ */
+public class SimpleIconListAdapter<T extends SimpleIconListAdapter.ListItem> extends ArrayAdapter<T> {
+    private final Context context;
+    private final List<T> listItems;
+
+    public SimpleIconListAdapter(Context context, List<T> listItems) {
+        super(context, R.layout.simple_icon_list_item, listItems);
+        this.context = context;
+        this.listItems = listItems;
+    }
+
+    @Override
+    public View getView(int position, View view, ViewGroup parent) {
+        if (view == null) {
+            view = View.inflate(context, R.layout.simple_icon_list_item, null);
+        }
+
+        ListItem item = listItems.get(position);
+        ((TextView) view.findViewById(R.id.title)).setText(item.title);
+        ((TextView) view.findViewById(R.id.subtitle)).setText(item.subtitle);
+        Glide.with(context)
+                .load(item.imageUrl)
+                .apply(new RequestOptions()
+                        .diskCacheStrategy(DiskCacheStrategy.NONE)
+                        .fitCenter()
+                        .dontAnimate())
+                .into(((ImageView) view.findViewById(R.id.icon)));
+        return view;
+    }
+
+    public static class ListItem {
+        public final String title;
+        public final String subtitle;
+        public final String imageUrl;
+
+        public ListItem(String title, String subtitle, String imageUrl) {
+            this.title = title;
+            this.subtitle = subtitle;
+            this.imageUrl = imageUrl;
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SpecialThanksFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SpecialThanksFragment.java
new file mode 100644
index 000000000..7e9860036
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/SpecialThanksFragment.java
@@ -0,0 +1,55 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.ListFragment;
+import io.reactivex.Single;
+import io.reactivex.SingleOnSubscribe;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.schedulers.Schedulers;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+public class SpecialThanksFragment extends ListFragment {
+    private Disposable translatorsLoader;
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        getListView().setDivider(null);
+        getListView().setSelector(android.R.color.transparent);
+
+        translatorsLoader = Single.create((SingleOnSubscribe<ArrayList<SimpleIconListAdapter.ListItem>>) emitter -> {
+            ArrayList<SimpleIconListAdapter.ListItem> translators = new ArrayList<>();
+            BufferedReader reader = new BufferedReader(new InputStreamReader(
+                    getContext().getAssets().open("special_thanks.csv"), "UTF-8"));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                String[] info = line.split(";");
+                translators.add(new SimpleIconListAdapter.ListItem(info[0], info[1], info[2]));
+            }
+            emitter.onSuccess(translators);
+        })
+        .subscribeOn(Schedulers.io())
+        .observeOn(AndroidSchedulers.mainThread())
+        .subscribe(
+                translators -> setListAdapter(new SimpleIconListAdapter<>(getContext(), translators)),
+                error -> Toast.makeText(getContext(), error.getMessage(), Toast.LENGTH_LONG).show()
+        );
+
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (translatorsLoader != null) {
+            translatorsLoader.dispose();
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/TranslatorsFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/TranslatorsFragment.java
new file mode 100644
index 000000000..3d2079fce
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/about/TranslatorsFragment.java
@@ -0,0 +1,55 @@
+package de.danoeh.antennapod.ui.preferences.screen.about;
+
+import android.os.Bundle;
+import android.view.View;
+import android.widget.Toast;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.ListFragment;
+import io.reactivex.Single;
+import io.reactivex.SingleOnSubscribe;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.disposables.Disposable;
+import io.reactivex.schedulers.Schedulers;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+
+public class TranslatorsFragment extends ListFragment {
+    private Disposable translatorsLoader;
+
+    @Override
+    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
+        super.onViewCreated(view, savedInstanceState);
+        getListView().setDivider(null);
+        getListView().setSelector(android.R.color.transparent);
+
+        translatorsLoader = Single.create((SingleOnSubscribe<ArrayList<SimpleIconListAdapter.ListItem>>) emitter -> {
+            ArrayList<SimpleIconListAdapter.ListItem> translators = new ArrayList<>();
+            BufferedReader reader = new BufferedReader(new InputStreamReader(
+                    getContext().getAssets().open("translators.csv"), "UTF-8"));
+            String line;
+            while ((line = reader.readLine()) != null) {
+                String[] info = line.split(";");
+                translators.add(new SimpleIconListAdapter.ListItem(info[0], info[1], null));
+            }
+            emitter.onSuccess(translators);
+        })
+        .subscribeOn(Schedulers.io())
+        .observeOn(AndroidSchedulers.mainThread())
+        .subscribe(
+                translators -> setListAdapter(new SimpleIconListAdapter<>(getContext(), translators)),
+                error -> Toast.makeText(getContext(), error.getMessage(), Toast.LENGTH_LONG).show()
+        );
+
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        if (translatorsLoader != null) {
+            translatorsLoader.dispose();
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/ChooseDataFolderDialog.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/ChooseDataFolderDialog.java
new file mode 100644
index 000000000..b43866cc0
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/ChooseDataFolderDialog.java
@@ -0,0 +1,36 @@
+package de.danoeh.antennapod.ui.preferences.screen.downloads;
+
+import android.content.Context;
+
+import android.view.View;
+import androidx.appcompat.app.AlertDialog;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import androidx.core.util.Consumer;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import de.danoeh.antennapod.ui.preferences.R;
+
+public class ChooseDataFolderDialog {
+
+    public static void showDialog(final Context context, Consumer<String> handlerFunc) {
+
+        View content = View.inflate(context, R.layout.choose_data_folder_dialog, null);
+        AlertDialog dialog = new MaterialAlertDialogBuilder(context)
+                .setView(content)
+                .setTitle(R.string.choose_data_directory)
+                .setMessage(R.string.choose_data_directory_message)
+                .setNegativeButton(R.string.cancel_label, null)
+                .create();
+        ((RecyclerView) content.findViewById(R.id.recyclerView)).setLayoutManager(new LinearLayoutManager(context));
+
+        DataFolderAdapter adapter = new DataFolderAdapter(context, path -> {
+            dialog.dismiss();
+            handlerFunc.accept(path);
+        });
+        ((RecyclerView) content.findViewById(R.id.recyclerView)).setAdapter(adapter);
+
+        if (adapter.getItemCount() != 0) {
+            dialog.show();
+        }
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/DataFolderAdapter.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/DataFolderAdapter.java
new file mode 100644
index 000000000..bd6a75503
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/downloads/DataFolderAdapter.java
@@ -0,0 +1,139 @@
+package de.danoeh.antennapod.ui.preferences.screen.downloads;
+
+import android.content.Context;
+import android.text.format.Formatter;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ProgressBar;
+import android.widget.RadioButton;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.core.util.Consumer;
+import androidx.recyclerview.widget.RecyclerView;
+import de.danoeh.antennapod.storage.preferences.UserPreferences;
+import de.danoeh.antennapod.core.util.StorageUtils;
+import de.danoeh.antennapod.ui.preferences.R;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
+
+public class DataFolderAdapter extends RecyclerView.Adapter<DataFolderAdapter.ViewHolder> {
+    private final Consumer<String> selectionHandler;
+    private final String currentPath;
+    private final List<StoragePath> entries;
+    private final String freeSpaceString;
+
+    public DataFolderAdapter(Context context, @NonNull Consumer<String> selectionHandler) {
+        this.entries = getStorageEntries(context);
+        this.currentPath = getCurrentPath();
+        this.selectionHandler = selectionHandler;
+        this.freeSpaceString = context.getString(R.string.choose_data_directory_available_space);
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
+        View entryView = inflater.inflate(R.layout.choose_data_folder_dialog_entry, parent, false);
+        return new ViewHolder(entryView);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+        StoragePath storagePath = entries.get(position);
+        Context context = holder.root.getContext();
+        String freeSpace = Formatter.formatShortFileSize(context, storagePath.getAvailableSpace());
+        String totalSpace = Formatter.formatShortFileSize(context, storagePath.getTotalSpace());
+
+        holder.path.setText(storagePath.getShortPath());
+        holder.size.setText(String.format(freeSpaceString, freeSpace, totalSpace));
+        holder.progressBar.setProgress(storagePath.getUsagePercentage());
+        View.OnClickListener selectListener = v -> selectionHandler.accept(storagePath.getFullPath());
+        holder.root.setOnClickListener(selectListener);
+        holder.radioButton.setOnClickListener(selectListener);
+
+        if (storagePath.getFullPath().equals(currentPath)) {
+            holder.radioButton.toggle();
+        }
+    }
+
+    @Override
+    public int getItemCount() {
+        return entries.size();
+    }
+
+    private String getCurrentPath() {
+        File dataFolder = UserPreferences.getDataFolder(null);
+        if (dataFolder != null) {
+            return dataFolder.getAbsolutePath();
+        }
+        return null;
+    }
+
+    private List<StoragePath> getStorageEntries(Context context) {
+        File[] mediaDirs = context.getExternalFilesDirs(null);
+        final List<StoragePath> entries = new ArrayList<>(mediaDirs.length);
+        for (File dir : mediaDirs) {
+            if (!isWritable(dir)) {
+                continue;
+            }
+            entries.add(new StoragePath(dir.getAbsolutePath()));
+        }
+        if (entries.isEmpty() && isWritable(context.getFilesDir())) {
+            entries.add(new StoragePath(context.getFilesDir().getAbsolutePath()));
+        }
+        return entries;
+    }
+
+    private boolean isWritable(File dir) {
+        return dir != null && dir.exists() && dir.canRead() && dir.canWrite();
+    }
+
+    static class ViewHolder extends RecyclerView.ViewHolder {
+        private final View root;
+        private final TextView path;
+        private final TextView size;
+        private final RadioButton radioButton;
+        private final ProgressBar progressBar;
+
+        ViewHolder(View itemView) {
+            super(itemView);
+            root = itemView.findViewById(R.id.root);
+            path = itemView.findViewById(R.id.path);
+            size = itemView.findViewById(R.id.size);
+            radioButton = itemView.findViewById(R.id.radio_button);
+            progressBar = itemView.findViewById(R.id.used_space);
+        }
+    }
+
+    static class StoragePath {
+        private final String path;
+
+        StoragePath(String path) {
+            this.path = path;
+        }
+
+        String getShortPath() {
+            int prefixIndex = path.indexOf("Android");
+            return (prefixIndex > 0) ? path.substring(0, prefixIndex) : path;
+        }
+
+        String getFullPath() {
+            return this.path;
+        }
+
+        long getAvailableSpace() {
+            return StorageUtils.getFreeSpaceAvailable(path);
+        }
+
+        long getTotalSpace() {
+            return StorageUtils.getTotalSpaceAvailable(path);
+        }
+
+        int getUsagePercentage() {
+            return 100 - (int) (100 * getAvailableSpace() / (float) getTotalSpace());
+        }
+    }
+}
\ No newline at end of file
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/AuthenticationDialog.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/AuthenticationDialog.java
new file mode 100644
index 000000000..a91afe78d
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/AuthenticationDialog.java
@@ -0,0 +1,54 @@
+package de.danoeh.antennapod.ui.preferences.screen.synchronization;
+
+import android.content.Context;
+import android.text.method.HideReturnsTransformationMethod;
+import android.text.method.PasswordTransformationMethod;
+import android.view.LayoutInflater;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import de.danoeh.antennapod.ui.preferences.R;
+import de.danoeh.antennapod.ui.preferences.databinding.AuthenticationDialogBinding;
+
+/**
+ * Displays a dialog with a username and password text field and an optional checkbox to save username and preferences.
+ */
+public abstract class AuthenticationDialog extends MaterialAlertDialogBuilder {
+    boolean passwordHidden = true;
+
+    public AuthenticationDialog(Context context, int titleRes, boolean enableUsernameField,
+                                String usernameInitialValue, String passwordInitialValue) {
+        super(context);
+        setTitle(titleRes);
+        AuthenticationDialogBinding viewBinding = AuthenticationDialogBinding.inflate(LayoutInflater.from(context));
+        setView(viewBinding.getRoot());
+
+        viewBinding.usernameEditText.setEnabled(enableUsernameField);
+        if (usernameInitialValue != null) {
+            viewBinding.usernameEditText.setText(usernameInitialValue);
+        }
+        if (passwordInitialValue != null) {
+            viewBinding.passwordEditText.setText(passwordInitialValue);
+        }
+        viewBinding.showPasswordButton.setOnClickListener(v -> {
+            if (passwordHidden) {
+                viewBinding.passwordEditText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
+                viewBinding.showPasswordButton.setAlpha(1.0f);
+            } else {
+                viewBinding.passwordEditText.setTransformationMethod(PasswordTransformationMethod.getInstance());
+                viewBinding.showPasswordButton.setAlpha(0.6f);
+            }
+            passwordHidden = !passwordHidden;
+        });
+
+        setOnCancelListener(dialog -> onCancelled());
+        setNegativeButton(R.string.cancel_label, (dialog, which) -> onCancelled());
+        setPositiveButton(R.string.confirm_label, (dialog, which)
+                -> onConfirmed(viewBinding.usernameEditText.getText().toString(),
+                        viewBinding.passwordEditText.getText().toString()));
+    }
+
+    protected void onCancelled() {
+
+    }
+
+    protected abstract void onConfirmed(String username, String password);
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/GpodderAuthenticationFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/GpodderAuthenticationFragment.java
new file mode 100644
index 000000000..d28355dad
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/GpodderAuthenticationFragment.java
@@ -0,0 +1,279 @@
+package de.danoeh.antennapod.ui.preferences.screen.synchronization;
+
+import android.app.Dialog;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.view.View;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputMethodManager;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.LinearLayout;
+import android.widget.ProgressBar;
+import android.widget.TextView;
+import android.widget.ViewFlipper;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import androidx.fragment.app.DialogFragment;
+import com.google.android.material.button.MaterialButton;
+import de.danoeh.antennapod.net.common.AntennapodHttpClient;
+import de.danoeh.antennapod.core.sync.SyncService;
+import de.danoeh.antennapod.core.sync.SynchronizationCredentials;
+import de.danoeh.antennapod.core.sync.SynchronizationProviderViewData;
+import de.danoeh.antennapod.core.sync.SynchronizationSettings;
+import de.danoeh.antennapod.core.util.FileNameGenerator;
+import de.danoeh.antennapod.net.sync.gpoddernet.GpodnetService;
+import de.danoeh.antennapod.net.sync.gpoddernet.model.GpodnetDevice;
+import de.danoeh.antennapod.ui.preferences.R;
+import io.reactivex.Completable;
+import io.reactivex.Observable;
+import io.reactivex.android.schedulers.AndroidSchedulers;
+import io.reactivex.schedulers.Schedulers;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Guides the user through the authentication process.
+ */
+public class GpodderAuthenticationFragment extends DialogFragment {
+    public static final String TAG = "GpodnetAuthActivity";
+
+    private ViewFlipper viewFlipper;
+
+    private static final int STEP_DEFAULT = -1;
+    private static final int STEP_HOSTNAME = 0;
+    private static final int STEP_LOGIN = 1;
+    private static final int STEP_DEVICE = 2;
+    private static final int STEP_FINISH = 3;
+
+    private int currentStep = -1;
+
+    private GpodnetService service;
+    private volatile String username;
+    private volatile String password;
+    private volatile GpodnetDevice selectedDevice;
+    private List<GpodnetDevice> devices;
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+        MaterialAlertDialogBuilder dialog = new MaterialAlertDialogBuilder(getContext());
+        dialog.setTitle(R.string.gpodnetauth_login_butLabel);
+        dialog.setNegativeButton(R.string.cancel_label, null);
+        dialog.setCancelable(false);
+        this.setCancelable(false);
+
+        View root = View.inflate(getContext(), R.layout.gpodnetauth_dialog, null);
+        viewFlipper = root.findViewById(R.id.viewflipper);
+        advance();
+        dialog.setView(root);
+
+        return dialog.create();
+    }
+
+    private void setupHostView(View view) {
+        final Button selectHost = view.findViewById(R.id.chooseHostButton);
+        final EditText serverUrlText = view.findViewById(R.id.serverUrlText);
+        selectHost.setOnClickListener(v -> {
+            if (serverUrlText.getText().length() == 0) {
+                return;
+            }
+            SynchronizationCredentials.clear(getContext());
+            SynchronizationCredentials.setHosturl(serverUrlText.getText().toString());
+            service = new GpodnetService(AntennapodHttpClient.getHttpClient(),
+                    SynchronizationCredentials.getHosturl(), SynchronizationCredentials.getDeviceID(),
+                    SynchronizationCredentials.getUsername(), SynchronizationCredentials.getPassword());
+            getDialog().setTitle(SynchronizationCredentials.getHosturl());
+            advance();
+        });
+    }
+
+    private void setupLoginView(View view) {
+        final EditText username = view.findViewById(R.id.etxtUsername);
+        final EditText password = view.findViewById(R.id.etxtPassword);
+        final Button login = view.findViewById(R.id.butLogin);
+        final TextView txtvError = view.findViewById(R.id.credentialsError);
+        final ProgressBar progressBar = view.findViewById(R.id.progBarLogin);
+        final TextView createAccountWarning = view.findViewById(R.id.createAccountWarning);
+
+        if (SynchronizationCredentials.getHosturl().startsWith("http://")) {
+            createAccountWarning.setVisibility(View.VISIBLE);
+        }
+        password.setOnEditorActionListener((v, actionID, event) ->
+                actionID == EditorInfo.IME_ACTION_GO && login.performClick());
+
+        login.setOnClickListener(v -> {
+            final String usernameStr = username.getText().toString();
+            final String passwordStr = password.getText().toString();
+
+            if (usernameHasUnwantedChars(usernameStr)) {
+                txtvError.setText(R.string.gpodnetsync_username_characters_error);
+                txtvError.setVisibility(View.VISIBLE);
+                return;
+            }
+
+            login.setEnabled(false);
+            progressBar.setVisibility(View.VISIBLE);
+            txtvError.setVisibility(View.GONE);
+            InputMethodManager inputManager = (InputMethodManager) getContext()
+                    .getSystemService(Context.INPUT_METHOD_SERVICE);
+            inputManager.hideSoftInputFromWindow(login.getWindowToken(), InputMethodManager.HIDE_NOT_ALWAYS);
+
+            Completable.fromAction(() -> {
+                service.setCredentials(usernameStr, passwordStr);
+                service.login();
+                devices = service.getDevices();
+                GpodderAuthenticationFragment.this.username = usernameStr;
+                GpodderAuthenticationFragment.this.password = passwordStr;
+            })
+                    .subscribeOn(Schedulers.io())
+                    .observeOn(AndroidSchedulers.mainThread())
+                    .subscribe(() -> {
+                        login.setEnabled(true);
+                        progressBar.setVisibility(View.GONE);
+                        advance();
+                    }, error -> {
+                            login.setEnabled(true);
+                            progressBar.setVisibility(View.GONE);
+                            txtvError.setText(error.getCause().getMessage());
+                            txtvError.setVisibility(View.VISIBLE);
+                        });
+
+        });
+    }
+
+    private void setupDeviceView(View view) {
+        final EditText deviceName = view.findViewById(R.id.deviceName);
+        final LinearLayout devicesContainer = view.findViewById(R.id.devicesContainer);
+        deviceName.setText(generateDeviceName());
+
+        MaterialButton createDeviceButton = view.findViewById(R.id.createDeviceButton);
+        createDeviceButton.setOnClickListener(v -> createDevice(view));
+
+        for (GpodnetDevice device : devices) {
+            View row = View.inflate(getContext(), R.layout.gpodnetauth_device_row, null);
+            Button selectDeviceButton = row.findViewById(R.id.selectDeviceButton);
+            selectDeviceButton.setOnClickListener(v -> {
+                selectedDevice = device;
+                advance();
+            });
+            selectDeviceButton.setText(device.getCaption());
+            devicesContainer.addView(row);
+        }
+    }
+
+    private void createDevice(View view) {
+        final EditText deviceName = view.findViewById(R.id.deviceName);
+        final TextView txtvError = view.findViewById(R.id.deviceSelectError);
+        final ProgressBar progBarCreateDevice = view.findViewById(R.id.progbarCreateDevice);
+
+        String deviceNameStr = deviceName.getText().toString();
+        if (isDeviceInList(deviceNameStr)) {
+            return;
+        }
+        progBarCreateDevice.setVisibility(View.VISIBLE);
+        txtvError.setVisibility(View.GONE);
+        deviceName.setEnabled(false);
+
+        Observable.fromCallable(() -> {
+            String deviceId = generateDeviceId(deviceNameStr);
+            service.configureDevice(deviceId, deviceNameStr, GpodnetDevice.DeviceType.MOBILE);
+            return new GpodnetDevice(deviceId, deviceNameStr, GpodnetDevice.DeviceType.MOBILE.toString(), 0);
+        })
+                .subscribeOn(Schedulers.io())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(device -> {
+                    progBarCreateDevice.setVisibility(View.GONE);
+                    selectedDevice = device;
+                    advance();
+                }, error -> {
+                        deviceName.setEnabled(true);
+                        progBarCreateDevice.setVisibility(View.GONE);
+                        txtvError.setText(error.getMessage());
+                        txtvError.setVisibility(View.VISIBLE);
+                    });
+    }
+
+    private String generateDeviceName() {
+        String baseName = getString(R.string.gpodnetauth_device_name_default, Build.MODEL);
+        String name = baseName;
+        int num = 1;
+        while (isDeviceInList(name)) {
+            name = baseName + " (" + num + ")";
+            num++;
+        }
+        return name;
+    }
+
+    private String generateDeviceId(String name) {
+        // devices names must be of a certain form:
+        // https://gpoddernet.readthedocs.org/en/latest/api/reference/general.html#devices
+        return FileNameGenerator.generateFileName(name).replaceAll("\\W", "_").toLowerCase(Locale.US);
+    }
+
+    private boolean isDeviceInList(String name) {
+        if (devices == null) {
+            return false;
+        }
+        String id = generateDeviceId(name);
+        for (GpodnetDevice device : devices) {
+            if (device.getId().equals(id) || device.getCaption().equals(name)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private void setupFinishView(View view) {
+        final Button sync = view.findViewById(R.id.butSyncNow);
+
+        sync.setOnClickListener(v -> {
+            dismiss();
+            SyncService.sync(getContext());
+        });
+    }
+
+    private void advance() {
+        if (currentStep < STEP_FINISH) {
+            View view = viewFlipper.getChildAt(currentStep + 1);
+            if (currentStep == STEP_DEFAULT) {
+                setupHostView(view);
+            } else if (currentStep == STEP_HOSTNAME) {
+                setupLoginView(view);
+            } else if (currentStep == STEP_LOGIN) {
+                if (username == null || password == null) {
+                    throw new IllegalStateException("Username and password must not be null here");
+                } else {
+                    setupDeviceView(view);
+                }
+            } else if (currentStep == STEP_DEVICE) {
+                if (selectedDevice == null) {
+                    throw new IllegalStateException("Device must not be null here");
+                } else {
+                    SynchronizationSettings.setSelectedSyncProvider(SynchronizationProviderViewData.GPODDER_NET);
+                    SynchronizationCredentials.setUsername(username);
+                    SynchronizationCredentials.setPassword(password);
+                    SynchronizationCredentials.setDeviceID(selectedDevice.getId());
+                    setupFinishView(view);
+                }
+            }
+            if (currentStep != STEP_DEFAULT) {
+                viewFlipper.showNext();
+            }
+            currentStep++;
+        } else {
+            dismiss();
+        }
+    }
+
+    private boolean usernameHasUnwantedChars(String username) {
+        Pattern special = Pattern.compile("[!@#$%&*()+=|<>?{}\\[\\]~]");
+        Matcher containsUnwantedChars = special.matcher(username);
+        return containsUnwantedChars.find();
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/NextcloudAuthenticationFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/NextcloudAuthenticationFragment.java
new file mode 100644
index 000000000..b73ee2453
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/NextcloudAuthenticationFragment.java
@@ -0,0 +1,111 @@
+package de.danoeh.antennapod.ui.preferences.screen.synchronization;
+
+import android.app.Dialog;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.view.View;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import androidx.fragment.app.DialogFragment;
+import de.danoeh.antennapod.net.common.AntennapodHttpClient;
+import de.danoeh.antennapod.core.sync.SyncService;
+import de.danoeh.antennapod.core.sync.SynchronizationCredentials;
+import de.danoeh.antennapod.core.sync.SynchronizationProviderViewData;
+import de.danoeh.antennapod.core.sync.SynchronizationSettings;
+import de.danoeh.antennapod.net.sync.nextcloud.NextcloudLoginFlow;
+import de.danoeh.antennapod.ui.preferences.R;
+import de.danoeh.antennapod.ui.preferences.databinding.NextcloudAuthDialogBinding;
+
+/**
+ * Guides the user through the authentication process.
+ */
+public class NextcloudAuthenticationFragment extends DialogFragment
+        implements NextcloudLoginFlow.AuthenticationCallback {
+    public static final String TAG = "NextcloudAuthenticationFragment";
+    private static final String EXTRA_LOGIN_FLOW = "LoginFlow";
+    private NextcloudAuthDialogBinding viewBinding;
+    private NextcloudLoginFlow nextcloudLoginFlow;
+    private boolean shouldDismiss = false;
+
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
+        MaterialAlertDialogBuilder dialog = new MaterialAlertDialogBuilder(getContext());
+        dialog.setTitle(R.string.gpodnetauth_login_butLabel);
+        dialog.setNegativeButton(R.string.cancel_label, null);
+        dialog.setCancelable(false);
+        this.setCancelable(false);
+
+        viewBinding = NextcloudAuthDialogBinding.inflate(getLayoutInflater());
+        dialog.setView(viewBinding.getRoot());
+
+        viewBinding.chooseHostButton.setOnClickListener(v -> {
+            nextcloudLoginFlow = new NextcloudLoginFlow(AntennapodHttpClient.getHttpClient(),
+                    viewBinding.serverUrlText.getText().toString(), getContext(), this);
+            startLoginFlow();
+        });
+        if (savedInstanceState != null && savedInstanceState.getStringArrayList(EXTRA_LOGIN_FLOW) != null) {
+            nextcloudLoginFlow = NextcloudLoginFlow.fromInstanceState(AntennapodHttpClient.getHttpClient(),
+                    getContext(), this, savedInstanceState.getStringArrayList(EXTRA_LOGIN_FLOW));
+            startLoginFlow();
+        }
+        return dialog.create();
+    }
+
+    private void startLoginFlow() {
+        viewBinding.errorText.setVisibility(View.GONE);
+        viewBinding.chooseHostButton.setVisibility(View.GONE);
+        viewBinding.loginProgressContainer.setVisibility(View.VISIBLE);
+        viewBinding.serverUrlText.setEnabled(false);
+        nextcloudLoginFlow.start();
+    }
+
+    @Override
+    public void onSaveInstanceState(@NonNull Bundle outState) {
+        super.onSaveInstanceState(outState);
+        if (nextcloudLoginFlow != null) {
+            outState.putStringArrayList(EXTRA_LOGIN_FLOW, nextcloudLoginFlow.saveInstanceState());
+        }
+    }
+
+    @Override
+    public void onDismiss(@NonNull DialogInterface dialog) {
+        super.onDismiss(dialog);
+        if (nextcloudLoginFlow != null) {
+            nextcloudLoginFlow.cancel();
+        }
+    }
+
+    @Override
+    public void onResume() {
+        super.onResume();
+        if (shouldDismiss) {
+            dismiss();
+        }
+    }
+
+    @Override
+    public void onNextcloudAuthenticated(String server, String username, String password) {
+        SynchronizationSettings.setSelectedSyncProvider(SynchronizationProviderViewData.NEXTCLOUD_GPODDER);
+        SynchronizationCredentials.clear(getContext());
+        SynchronizationCredentials.setPassword(password);
+        SynchronizationCredentials.setHosturl(server);
+        SynchronizationCredentials.setUsername(username);
+        SyncService.fullSync(getContext());
+        if (isResumed()) {
+            dismiss();
+        } else {
+            shouldDismiss = true;
+        }
+    }
+
+    @Override
+    public void onNextcloudAuthError(String errorMessage) {
+        viewBinding.loginProgressContainer.setVisibility(View.GONE);
+        viewBinding.errorText.setVisibility(View.VISIBLE);
+        viewBinding.errorText.setText(errorMessage);
+        viewBinding.chooseHostButton.setVisibility(View.VISIBLE);
+        viewBinding.serverUrlText.setEnabled(true);
+    }
+}
diff --git a/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/SynchronizationPreferencesFragment.java b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/SynchronizationPreferencesFragment.java
new file mode 100644
index 000000000..3c6461272
--- /dev/null
+++ b/ui/preferences/src/main/java/de/danoeh/antennapod/ui/preferences/screen/synchronization/SynchronizationPreferencesFragment.java
@@ -0,0 +1,220 @@
+package de.danoeh.antennapod.ui.preferences.screen.synchronization;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.text.Spanned;
+import android.text.format.DateUtils;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ArrayAdapter;
+import android.widget.ImageView;
+import android.widget.ListAdapter;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AppCompatActivity;
+import com.google.android.material.dialog.MaterialAlertDialogBuilder;
+import androidx.core.text.HtmlCompat;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceFragmentCompat;
+
+import com.google.android.material.snackbar.Snackbar;
+
+import de.danoeh.antennapod.ui.preferences.R;
+import org.greenrobot.eventbus.EventBus;
+import org.greenrobot.eventbus.Subscribe;
+import org.greenrobot.eventbus.ThreadMode;
+
+import de.danoeh.antennapod.event.SyncServiceEvent;
+import de.danoeh.antennapod.core.sync.SynchronizationCredentials;
+import de.danoeh.antennapod.core.sync.SyncService;
+import de.danoeh.antennapod.core.sync.SynchronizationProviderViewData;
+import de.danoeh.antennapod.core.sync.SynchronizationSettings;
+
+public class SynchronizationPreferencesFragment extends PreferenceFragmentCompat {
+    private static final String PREFERENCE_SYNCHRONIZATION_DESCRIPTION = "preference_synchronization_description";
+    private static final String PREFERENCE_GPODNET_SETLOGIN_INFORMATION = "pref_gpodnet_setlogin_information";
+    private static final String PREFERENCE_SYNC = "pref_synchronization_sync";
+    private static final String PREFERENCE_FORCE_FULL_SYNC = "pref_synchronization_force_full_sync";
+    private static final String PREFERENCE_LOGOUT = "pref_synchronization_logout";
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        addPreferencesFromResource(R.xml.preferences_synchronization);
+        setupScreen();
+        updateScreen();
+    }
+
+    @Override
+    public void onStart() {
+        super.onStart();
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setTitle(R.string.synchronization_pref);
+        updateScreen();
+        EventBus.getDefault().register(this);
+    }
+
+    @Override
+    public void onStop() {
+        super.onStop();
+        EventBus.getDefault().unregister(this);
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setSubtitle("");
+    }
+
+    @Subscribe(threadMode = ThreadMode.MAIN, sticky = true)
+    public void syncStatusChanged(SyncServiceEvent event) {
+        if (!SynchronizationSettings.isProviderConnected()) {
+            return;
+        }
+        updateScreen();
+        if (event.getMessageResId() == R.string.sync_status_error
+                || event.getMessageResId() == R.string.sync_status_success) {
+            updateLastSyncReport(SynchronizationSettings.isLastSyncSuccessful(),
+                    SynchronizationSettings.getLastSyncAttempt());
+        } else {
+            ((AppCompatActivity) getActivity()).getSupportActionBar().setSubtitle(event.getMessageResId());
+        }
+    }
+
+    private void setupScreen() {
+        final Activity activity = getActivity();
+        findPreference(PREFERENCE_GPODNET_SETLOGIN_INFORMATION)
+                .setOnPreferenceClickListener(preference -> {
+                    AuthenticationDialog dialog = new AuthenticationDialog(activity,
+                            R.string.pref_gpodnet_setlogin_information_title,
+                            false, SynchronizationCredentials.getUsername(), null) {
+                        @Override
+                        protected void onConfirmed(String username, String password) {
+                            SynchronizationCredentials.setPassword(password);
+                        }
+                    };
+                    dialog.show();
+                    return true;
+                });
+        findPreference(PREFERENCE_SYNC).setOnPreferenceClickListener(preference -> {
+            SyncService.syncImmediately(getActivity().getApplicationContext());
+            return true;
+        });
+        findPreference(PREFERENCE_FORCE_FULL_SYNC).setOnPreferenceClickListener(preference -> {
+            SyncService.fullSync(getContext());
+            return true;
+        });
+        findPreference(PREFERENCE_LOGOUT).setOnPreferenceClickListener(preference -> {
+            SynchronizationCredentials.clear(getContext());
+            Snackbar.make(getView(), R.string.pref_synchronization_logout_toast, Snackbar.LENGTH_LONG).show();
+            SynchronizationSettings.setSelectedSyncProvider(null);
+            updateScreen();
+            return true;
+        });
+    }
+
+    private void updateScreen() {
+        final boolean loggedIn = SynchronizationSettings.isProviderConnected();
+        Preference preferenceHeader = findPreference(PREFERENCE_SYNCHRONIZATION_DESCRIPTION);
+        if (loggedIn) {
+            SynchronizationProviderViewData selectedProvider =
+                    SynchronizationProviderViewData.fromIdentifier(getSelectedSyncProviderKey());
+            preferenceHeader.setTitle("");
+            preferenceHeader.setSummary(selectedProvider.getSummaryResource());
+            preferenceHeader.setIcon(selectedProvider.getIconResource());
+            preferenceHeader.setOnPreferenceClickListener(null);
+        } else {
+            preferenceHeader.setTitle(R.string.synchronization_choose_title);
+            preferenceHeader.setSummary(R.string.synchronization_summary_unchoosen);
+            preferenceHeader.setIcon(R.drawable.ic_cloud);
+            preferenceHeader.setOnPreferenceClickListener((preference) -> {
+                chooseProviderAndLogin();
+                return true;
+            });
+        }
+
+        Preference gpodnetSetLoginPreference = findPreference(PREFERENCE_GPODNET_SETLOGIN_INFORMATION);
+        gpodnetSetLoginPreference.setVisible(isProviderSelected(SynchronizationProviderViewData.GPODDER_NET));
+        gpodnetSetLoginPreference.setEnabled(loggedIn);
+        findPreference(PREFERENCE_SYNC).setEnabled(loggedIn);
+        findPreference(PREFERENCE_FORCE_FULL_SYNC).setEnabled(loggedIn);
+        findPreference(PREFERENCE_LOGOUT).setEnabled(loggedIn);
+        if (loggedIn) {
+            String summary = getString(R.string.synchronization_login_status,
+                    SynchronizationCredentials.getUsername(), SynchronizationCredentials.getHosturl());
+            Spanned formattedSummary = HtmlCompat.fromHtml(summary, HtmlCompat.FROM_HTML_MODE_LEGACY);
+            findPreference(PREFERENCE_LOGOUT).setSummary(formattedSummary);
+            updateLastSyncReport(SynchronizationSettings.isLastSyncSuccessful(),
+                    SynchronizationSettings.getLastSyncAttempt());
+        } else {
+            findPreference(PREFERENCE_LOGOUT).setSummary(null);
+            ((AppCompatActivity) getActivity()).getSupportActionBar().setSubtitle(null);
+        }
+    }
+
+    private void chooseProviderAndLogin() {
+        MaterialAlertDialogBuilder builder = new MaterialAlertDialogBuilder(getContext());
+        builder.setTitle(R.string.dialog_choose_sync_service_title);
+
+        SynchronizationProviderViewData[] providers = SynchronizationProviderViewData.values();
+        ListAdapter adapter = new ArrayAdapter<SynchronizationProviderViewData>(
+                getContext(), R.layout.alertdialog_sync_provider_chooser, providers) {
+
+            ViewHolder holder;
+
+            class ViewHolder {
+                ImageView icon;
+                TextView title;
+            }
+
+            public View getView(int position, View convertView, ViewGroup parent) {
+                final LayoutInflater inflater = LayoutInflater.from(getContext());
+                if (convertView == null) {
+                    convertView = inflater.inflate(
+                            R.layout.alertdialog_sync_provider_chooser, null);
+
+                    holder = new ViewHolder();
+                    holder.icon = (ImageView) convertView.findViewById(R.id.icon);
+                    holder.title = (TextView) convertView.findViewById(R.id.title);
+                    convertView.setTag(holder);
+                } else {
+                    holder = (ViewHolder) convertView.getTag();
+                }
+                SynchronizationProviderViewData synchronizationProviderViewData = getItem(position);
+                holder.title.setText(synchronizationProviderViewData.getSummaryResource());
+                holder.icon.setImageResource(synchronizationProviderViewData.getIconResource());
+                return convertView;
+            }
+        };
+
+        builder.setAdapter(adapter, (dialog, which) -> {
+            switch (providers[which]) {
+                case GPODDER_NET:
+                    new GpodderAuthenticationFragment()
+                            .show(getChildFragmentManager(), GpodderAuthenticationFragment.TAG);
+                    break;
+                case NEXTCLOUD_GPODDER:
+                    new NextcloudAuthenticationFragment()
+                            .show(getChildFragmentManager(), NextcloudAuthenticationFragment.TAG);
+                    break;
+                default:
+                    break;
+            }
+            updateScreen();
+        });
+
+        builder.show();
+    }
+
+    private boolean isProviderSelected(@NonNull SynchronizationProviderViewData provider) {
+        String selectedSyncProviderKey = getSelectedSyncProviderKey();
+        return provider.getIdentifier().equals(selectedSyncProviderKey);
+    }
+
+    private String getSelectedSyncProviderKey() {
+        return SynchronizationSettings.getSelectedSyncProviderKey();
+    }
+
+    private void updateLastSyncReport(boolean successful, long lastTime) {
+        String status = String.format("%1$s (%2$s)", getString(successful
+                        ? R.string.gpodnetsync_pref_report_successful : R.string.gpodnetsync_pref_report_failed),
+                DateUtils.getRelativeDateTimeString(getContext(),
+                        lastTime, DateUtils.MINUTE_IN_MILLIS, DateUtils.WEEK_IN_MILLIS, DateUtils.FORMAT_SHOW_TIME));
+        ((AppCompatActivity) getActivity()).getSupportActionBar().setSubtitle(status);
+    }
+}