Made debug settings searchable (debug only)

* Consolidated main-setttings into a single file
* Debug settings are only enabled in the DEBUG build
* Moved LeakCanary (debug) specific stuff into a small class that's only shipped with the debug build
* Other minor fixes

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

@@ -0,0 +1,101 @@
+package org.schabi.newpipe.settings;
+
+import android.content.Intent;
+import android.os.Bundle;
+
+import androidx.preference.Preference;
+
+import org.schabi.newpipe.R;
+import org.schabi.newpipe.error.ErrorInfo;
+import org.schabi.newpipe.error.ErrorUtil;
+import org.schabi.newpipe.error.UserAction;
+import org.schabi.newpipe.util.PicassoHelper;
+
+import java.util.Optional;
+
+public class DebugSettingsFragment extends BasePreferenceFragment {
+    @Override
+    public void onCreatePreferences(final Bundle savedInstanceState, final String rootKey) {
+        addPreferencesFromResourceRegistry();
+
+        final Preference allowHeapDumpingPreference
+                = findPreference(getString(R.string.allow_heap_dumping_key));
+        final Preference showMemoryLeaksPreference
+                = findPreference(getString(R.string.show_memory_leaks_key));
+        final Preference showImageIndicatorsPreference
+                = findPreference(getString(R.string.show_image_indicators_key));
+        final Preference crashTheAppPreference
+                = findPreference(getString(R.string.crash_the_app_key));
+        final Preference showErrorSnackbarPreference
+                = findPreference(getString(R.string.show_error_snackbar_key));
+        final Preference createErrorNotificationPreference
+                = findPreference(getString(R.string.create_error_notification_key));
+
+        assert allowHeapDumpingPreference != null;
+        assert showMemoryLeaksPreference != null;
+        assert showImageIndicatorsPreference != null;
+        assert crashTheAppPreference != null;
+        assert showErrorSnackbarPreference != null;
+        assert createErrorNotificationPreference != null;
+
+        final Optional<DebugSettingsBVLeakCanaryAPI> optPDLeakCanary = getBVLeakCanary();
+
+        allowHeapDumpingPreference.setEnabled(optPDLeakCanary.isPresent());
+        showMemoryLeaksPreference.setEnabled(optPDLeakCanary.isPresent());
+
+        if (optPDLeakCanary.isPresent()) {
+            final DebugSettingsBVLeakCanaryAPI pdLeakCanary = optPDLeakCanary.get();
+
+            showMemoryLeaksPreference.setOnPreferenceClickListener(preference -> {
+                startActivity(pdLeakCanary.getNewLeakDisplayActivityIntent());
+                return true;
+            });
+        } else {
+            allowHeapDumpingPreference.setSummary(R.string.leak_canary_not_available);
+            showMemoryLeaksPreference.setSummary(R.string.leak_canary_not_available);
+        }
+
+        showImageIndicatorsPreference.setOnPreferenceChangeListener((preference, newValue) -> {
+            PicassoHelper.setIndicatorsEnabled((Boolean) newValue);
+            return true;
+        });
+
+        crashTheAppPreference.setOnPreferenceClickListener(preference -> {
+            throw new RuntimeException();
+        });
+
+        showErrorSnackbarPreference.setOnPreferenceClickListener(preference -> {
+            ErrorUtil.showUiErrorSnackbar(DebugSettingsFragment.this,
+                    "Dummy", new RuntimeException("Dummy"));
+            return true;
+        });
+
+        createErrorNotificationPreference.setOnPreferenceClickListener(preference -> {
+            ErrorUtil.createNotification(requireContext(),
+                    new ErrorInfo(new RuntimeException("Dummy"), UserAction.UI_ERROR, "Dummy"));
+            return true;
+        });
+    }
+
+    private Optional<DebugSettingsBVLeakCanaryAPI> getBVLeakCanary() {
+        try {
+            // Try to find the implementation of the LeakCanary API
+            return Optional.of((DebugSettingsBVLeakCanaryAPI)
+                    Class.forName(DebugSettingsBVLeakCanaryAPI.IMPL_CLASS).newInstance());
+        } catch (final ClassNotFoundException
+                | IllegalAccessException | java.lang.InstantiationException e) {
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Build variant dependent leak canary API for this fragment.
+     * Why is LeakCanary not used directly? Because it can't be assured
+     */
+    public interface DebugSettingsBVLeakCanaryAPI {
+        String IMPL_CLASS =
+                "org.schabi.newpipe.settings.DebugSettingsBVLeakCanary";
+
+        Intent getNewLeakDisplayActivityIntent();
+    }
+}

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

@@ -6,7 +6,6 @@ import android.view.MenuInflater;
 import android.view.MenuItem;
 
 import androidx.annotation.NonNull;
-import androidx.preference.Preference;
 
 import org.schabi.newpipe.App;
 import org.schabi.newpipe.CheckForNewAppVersion;
@@ -26,12 +25,17 @@ public class MainSettingsFragment extends BasePreferenceFragment {
 
         // Check if the app is updatable
         if (!CheckForNewAppVersion.isReleaseApk(App.getApp())) {
-            final Preference update
-                    = findPreference(getString(R.string.update_pref_screen_key));
-            getPreferenceScreen().removePreference(update);
+            getPreferenceScreen().removePreference(
+                    findPreference(getString(R.string.update_pref_screen_key)));
 
             defaultPreferences.edit().putBoolean(getString(R.string.update_app_key), false).apply();
         }
+
+        // Hide debug preferences in RELEASE build variant
+        if (!DEBUG) {
+            getPreferenceScreen().removePreference(
+                    findPreference(getString(R.string.debug_pref_screen_key)));
+        }
     }
 
     @Override

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

@@ -217,6 +217,13 @@ public class SettingsActivity extends AppCompatActivity implements
                     .getEntryByPreferencesResId(R.xml.update_settings)
                     .setSearchable(false);
         }
+
+        // Hide debug preferences in RELEASE build variant
+        if (DEBUG) {
+            SettingsResourceRegistry.getInstance()
+                    .getEntryByPreferencesResId(R.xml.debug_settings)
+                    .setSearchable(true);
+        }
     }
 
     public void setMenuSearchItem(final MenuItem menuSearchItem) {

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

@@ -1,7 +1,6 @@
 package org.schabi.newpipe.settings;
 
 import androidx.annotation.NonNull;
-import androidx.annotation.Nullable;
 import androidx.annotation.XmlRes;
 import androidx.fragment.app.Fragment;
 
@@ -34,6 +33,7 @@ public final class SettingsResourceRegistry {
 
         add(AppearanceSettingsFragment.class, R.xml.appearance_settings);
         add(ContentSettingsFragment.class, R.xml.content_settings);
+        add(DebugSettingsFragment.class, R.xml.debug_settings).setSearchable(false);
         add(DownloadSettingsFragment.class, R.xml.download_settings);
         add(HistorySettingsFragment.class, R.xml.history_settings);
         add(NotificationSettingsFragment.class, R.xml.notification_settings);
@@ -51,7 +51,6 @@ public final class SettingsResourceRegistry {
         return entry;
     }
 
-    @Nullable
     public SettingRegistryEntry getEntryByFragmentClass(
             final Class<? extends Fragment> fragmentClass
     ) {
@@ -62,7 +61,6 @@ public final class SettingsResourceRegistry {
                 .orElse(null);
     }
 
-    @Nullable
     public SettingRegistryEntry getEntryByPreferencesResId(@XmlRes final int preferencesResId) {
         return registeredEntries.stream()
                 .filter(e -> Objects.equals(e.getPreferencesResId(), preferencesResId))
@@ -78,7 +76,6 @@ public final class SettingsResourceRegistry {
         return entry.getPreferencesResId();
     }
 
-    @Nullable
     public Class<? extends Fragment> getFragmentClass(@XmlRes final int preferencesResId) {
         final SettingRegistryEntry entry = getEntryByPreferencesResId(preferencesResId);
         if (entry == null) {