diff --git a/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java b/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java index bd2c7f9a6..045cc5f21 100644 --- a/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java +++ b/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java @@ -16,6 +16,7 @@ import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.TextView; import androidx.annotation.NonNull; +import androidx.annotation.Nullable; import androidx.annotation.UiThread; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; @@ -51,7 +52,6 @@ import de.danoeh.antennapod.core.syndication.handler.UnsupportedFeedtypeExceptio import de.danoeh.antennapod.core.util.DownloadError; import de.danoeh.antennapod.core.util.FileNameGenerator; import de.danoeh.antennapod.core.util.IntentUtils; -import de.danoeh.antennapod.core.util.Optional; import de.danoeh.antennapod.core.util.StorageUtils; import de.danoeh.antennapod.core.util.URLChecker; import de.danoeh.antennapod.core.util.playback.RemoteMedia; @@ -60,9 +60,11 @@ import de.danoeh.antennapod.core.util.syndication.HtmlToPlainText; import de.danoeh.antennapod.databinding.OnlinefeedviewActivityBinding; import de.danoeh.antennapod.dialog.AuthenticationDialog; import de.danoeh.antennapod.discovery.PodcastSearcherRegistry; +import io.reactivex.Maybe; import io.reactivex.Observable; import io.reactivex.android.schedulers.AndroidSchedulers; import io.reactivex.disposables.Disposable; +import io.reactivex.observers.DisposableMaybeObserver; import io.reactivex.schedulers.Schedulers; import org.apache.commons.lang3.StringUtils; import org.greenrobot.eventbus.EventBus; @@ -321,34 +323,48 @@ public class OnlineFeedViewActivity extends AppCompatActivity { } Log.d(TAG, "Parsing feed"); - parser = Observable.fromCallable(this::doParseFeed) + parser = Maybe.fromCallable(this::doParseFeed) .subscribeOn(Schedulers.computation()) .observeOn(AndroidSchedulers.mainThread()) - .subscribe(optionalResult -> { - if(optionalResult.isPresent()) { - FeedHandlerResult result = optionalResult.get(); + .subscribeWith(new DisposableMaybeObserver() { + @Override + public void onSuccess(@NonNull FeedHandlerResult result) { beforeShowFeedInformation(result.feed); showFeedInformation(result.feed, result.alternateFeedUrls); } - }, error -> { - String errorMsg = DownloadError.ERROR_PARSER_EXCEPTION.getErrorString( - OnlineFeedViewActivity.this) + " (" + error.getMessage() + ")"; - showErrorDialog(errorMsg); - Log.d(TAG, "Feed parser exception: " + Log.getStackTraceString(error)); + + @Override + public void onComplete() { + // Ignore null result: We showed the discovery dialog. + } + + @Override + public void onError(@NonNull Throwable error) { + String errorMsg = DownloadError.ERROR_PARSER_EXCEPTION.getErrorString( + OnlineFeedViewActivity.this) + " (" + error.getMessage() + ")"; + showErrorDialog(errorMsg); + Log.d(TAG, "Feed parser exception: " + Log.getStackTraceString(error)); + } }); } - @NonNull - private Optional doParseFeed() throws Exception { + /** + * Try to parse the feed. + * @return The FeedHandlerResult if successful. + * Null if unsuccessful but we started another attempt. + * @throws Exception If unsuccessful but we do not know a resolution. + */ + @Nullable + private FeedHandlerResult doParseFeed() throws Exception { FeedHandler handler = new FeedHandler(); try { - return Optional.of(handler.parseFeed(feed)); + return handler.parseFeed(feed); } catch (UnsupportedFeedtypeException e) { Log.d(TAG, "Unsupported feed type detected"); if ("html".equalsIgnoreCase(e.getRootElement())) { boolean dialogShown = showFeedDiscoveryDialog(new File(feed.getFile_url()), feed.getDownload_url()); if (dialogShown) { - return Optional.empty(); + return null; // Should not display an error message } else { Log.d(TAG, "Supplied feed is an HTML web page that has no references to any feed"); throw e; diff --git a/app/src/main/java/de/danoeh/antennapod/fragment/FeedItemlistFragment.java b/app/src/main/java/de/danoeh/antennapod/fragment/FeedItemlistFragment.java index c86fdc070..6be532887 100644 --- a/app/src/main/java/de/danoeh/antennapod/fragment/FeedItemlistFragment.java +++ b/app/src/main/java/de/danoeh/antennapod/fragment/FeedItemlistFragment.java @@ -56,7 +56,6 @@ import de.danoeh.antennapod.core.storage.DownloadRequestException; import de.danoeh.antennapod.core.storage.DownloadRequester; import de.danoeh.antennapod.core.util.FeedItemPermutors; import de.danoeh.antennapod.core.util.FeedItemUtil; -import de.danoeh.antennapod.core.util.Optional; import de.danoeh.antennapod.ui.common.ThemeUtils; import de.danoeh.antennapod.core.util.gui.MoreContentListFooterUtil; import de.danoeh.antennapod.dialog.EpisodesApplyActionFragment; @@ -549,15 +548,21 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem disposable = Observable.fromCallable(this::loadData) .subscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) - .subscribe(result -> { - feed = result.orElse(null); - refreshHeaderView(); - displayList(); - }, error -> Log.e(TAG, Log.getStackTraceString(error))); + .subscribe( + result -> { + feed = result; + refreshHeaderView(); + displayList(); + }, error -> { + feed = null; + refreshHeaderView(); + displayList(); + Log.e(TAG, Log.getStackTraceString(error)); + }); } - @NonNull - private Optional loadData() { + @Nullable + private Feed loadData() { Feed feed = DBReader.getFeed(feedID); if (feed != null && feed.getItemFilter() != null) { DBReader.loadAdditionalFeedItemListData(feed.getItems()); @@ -569,7 +574,7 @@ public class FeedItemlistFragment extends Fragment implements AdapterView.OnItem FeedItemPermutors.getPermutor(feed.getSortOrder()).reorder(feedItems); feed.setItems(feedItems); } - return Optional.ofNullable(feed); + return feed; } private static class FeedItemListAdapter extends EpisodeItemListAdapter { diff --git a/core/src/main/java/de/danoeh/antennapod/core/util/Optional.java b/core/src/main/java/de/danoeh/antennapod/core/util/Optional.java deleted file mode 100644 index 37f12c01c..000000000 --- a/core/src/main/java/de/danoeh/antennapod/core/util/Optional.java +++ /dev/null @@ -1,213 +0,0 @@ -/* - * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. Oracle designates this - * particular file as subject to the "Classpath" exception as provided - * by Oracle in the LICENSE file that accompanied this code. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - */ -package de.danoeh.antennapod.core.util; - -import java.util.NoSuchElementException; -import java.util.Objects; - -// AntennaPod's stripped-down version of Java/Android platform's java.util.Optional -// so that it can be used on lower API level (API level 14) - -// Android-changed: removed ValueBased paragraph. -/** - * A container object which may or may not contain a non-null value. - * If a value is present, {@code isPresent()} will return {@code true} and - * {@code get()} will return the value. - * - *

Additional methods that depend on the presence or absence of a contained - * value are provided, such as {@link #orElse(java.lang.Object) orElse()} - * (return a default value if value not present) and - * {@link #ifPresent(java.util.function.Consumer) ifPresent()} (execute a block - * of code if the value is present). - * - * @since 1.8 - */ -public final class Optional { - /** - * Common instance for {@code empty()}. - */ - private static final Optional EMPTY = new Optional<>(); - - /** - * If non-null, the value; if null, indicates no value is present - */ - private final T value; - - /** - * Constructs an empty instance. - * - * @implNote Generally only one empty instance, {@link Optional#EMPTY}, - * should exist per VM. - */ - private Optional() { - this.value = null; - } - - /** - * Returns an empty {@code Optional} instance. No value is present for this - * Optional. - * - * @apiNote Though it may be tempting to do so, avoid testing if an object - * is empty by comparing with {@code ==} against instances returned by - * {@code Option.empty()}. There is no guarantee that it is a singleton. - * Instead, use {@link #isPresent()}. - * - * @param Type of the non-existent value - * @return an empty {@code Optional} - */ - public static Optional empty() { - @SuppressWarnings("unchecked") - Optional t = (Optional) EMPTY; - return t; - } - - /** - * Constructs an instance with the value present. - * - * @param value the non-null value to be present - * @throws NullPointerException if value is null - */ - private Optional(T value) { - this.value = Objects.requireNonNull(value); - } - - /** - * Returns an {@code Optional} with the specified present non-null value. - * - * @param the class of the value - * @param value the value to be present, which must be non-null - * @return an {@code Optional} with the value present - * @throws NullPointerException if value is null - */ - public static Optional of(T value) { - return new Optional<>(value); - } - - /** - * Returns an {@code Optional} describing the specified value, if non-null, - * otherwise returns an empty {@code Optional}. - * - * @param the class of the value - * @param value the possibly-null value to describe - * @return an {@code Optional} with a present value if the specified value - * is non-null, otherwise an empty {@code Optional} - */ - public static Optional ofNullable(T value) { - return value == null ? empty() : of(value); - } - - /** - * If a value is present in this {@code Optional}, returns the value, - * otherwise throws {@code NoSuchElementException}. - * - * @return the non-null value held by this {@code Optional} - * @throws NoSuchElementException if there is no value present - * - * @see Optional#isPresent() - */ - public T get() { - if (value == null) { - throw new NoSuchElementException("No value present"); - } - return value; - } - - /** - * Return {@code true} if there is a value present, otherwise {@code false}. - * - * @return {@code true} if there is a value present, otherwise {@code false} - */ - public boolean isPresent() { - return value != null; - } - - - /** - * Return the value if present, otherwise return {@code other}. - * - * @param other the value to be returned if there is no value present, may - * be null - * @return the value, if present, otherwise {@code other} - */ - public T orElse(T other) { - return value != null ? value : other; - } - - /** - * Indicates whether some other object is "equal to" this Optional. The - * other object is considered equal if: - *

    - *
  • it is also an {@code Optional} and; - *
  • both instances have no value present or; - *
  • the present values are "equal to" each other via {@code equals()}. - *
- * - * @param obj an object to be tested for equality - * @return {code true} if the other object is "equal to" this object - * otherwise {@code false} - */ - @Override - public boolean equals(Object obj) { - if (this == obj) { - return true; - } - - if (!(obj instanceof Optional)) { - return false; - } - - Optional other = (Optional) obj; - return (value == other.value) || (value != null && value.equals(other.value)); - } - - /** - * Returns the hash code value of the present value, if any, or 0 (zero) if - * no value is present. - * - * @return hash code value of the present value or 0 if no value is present - */ - @Override - public int hashCode() { - return value != null ? value.hashCode() : 0; - } - - /** - * Returns a non-empty string representation of this Optional suitable for - * debugging. The exact presentation format is unspecified and may vary - * between implementations and versions. - * - * @implSpec If a value is present the result must include its string - * representation in the result. Empty and present Optionals must be - * unambiguously differentiable. - * - * @return the string representation of this instance - */ - @Override - public String toString() { - return value != null - ? String.format("Optional[%s]", value) - : "Optional.empty"; - } -}