Use RxAndroid instead of AsyncTask and Thread

1 files changed, 359 insertions, 208 deletions

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 3ab384012..13d5e7acf 100644
--- a/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java
+++ b/app/src/main/java/de/danoeh/antennapod/activity/OnlineFeedViewActivity.java
@@ -4,18 +4,32 @@ import android.app.AlertDialog;
 import android.app.Dialog;
 import android.content.Context;
 import android.content.DialogInterface;
-import android.content.DialogInterface.OnCancelListener;
 import android.content.Intent;
 import android.os.Bundle;
+import android.os.Looper;
+import android.support.v4.app.NavUtils;
 import android.support.v7.app.ActionBarActivity;
 import android.util.Log;
+import android.view.LayoutInflater;
+import android.view.MenuItem;
+import android.view.View;
+import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.ImageView;
 import android.widget.LinearLayout;
+import android.widget.ListView;
 import android.widget.ProgressBar;
 import android.widget.RelativeLayout;
+import android.widget.Spinner;
+import android.widget.TextView;
+
+import com.bumptech.glide.Glide;
 
 import org.apache.commons.lang3.StringUtils;
-import org.xml.sax.SAXException;
+import org.jsoup.Jsoup;
+import org.jsoup.examples.HtmlToPlainText;
+import org.jsoup.nodes.Document;
 
 import java.io.File;
 import java.io.IOException;
@@ -24,16 +38,22 @@ import java.util.Date;
 import java.util.List;
 import java.util.Map;
 
-import javax.xml.parsers.ParserConfigurationException;
-
 import de.danoeh.antennapod.R;
+import de.danoeh.antennapod.adapter.FeedItemlistDescriptionAdapter;
+import de.danoeh.antennapod.core.dialog.DownloadRequestErrorDialogCreator;
+import de.danoeh.antennapod.core.feed.EventDistributor;
 import de.danoeh.antennapod.core.feed.Feed;
+import de.danoeh.antennapod.core.feed.FeedItem;
 import de.danoeh.antennapod.core.feed.FeedPreferences;
+import de.danoeh.antennapod.core.glide.ApGlideSettings;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.service.download.DownloadRequest;
 import de.danoeh.antennapod.core.service.download.DownloadStatus;
 import de.danoeh.antennapod.core.service.download.Downloader;
 import de.danoeh.antennapod.core.service.download.HttpDownloader;
+import de.danoeh.antennapod.core.storage.DBReader;
+import de.danoeh.antennapod.core.storage.DownloadRequestException;
+import de.danoeh.antennapod.core.storage.DownloadRequester;
 import de.danoeh.antennapod.core.syndication.handler.FeedHandler;
 import de.danoeh.antennapod.core.syndication.handler.FeedHandlerResult;
 import de.danoeh.antennapod.core.syndication.handler.UnsupportedFeedtypeException;
@@ -43,6 +63,11 @@ import de.danoeh.antennapod.core.util.StorageUtils;
 import de.danoeh.antennapod.core.util.URLChecker;
 import de.danoeh.antennapod.core.util.syndication.FeedDiscoverer;
 import de.danoeh.antennapod.dialog.AuthenticationDialog;
+import rx.Observable;
+import rx.Subscriber;
+import rx.Subscription;
+import rx.android.schedulers.AndroidSchedulers;
+import rx.schedulers.Schedulers;
 
 /**
  * Downloads a feed from a feed URL and parses it. Subclasses can display the
@@ -52,27 +77,57 @@ import de.danoeh.antennapod.dialog.AuthenticationDialog;
  * If the feed cannot be downloaded or parsed, an error dialog will be displayed
  * and the activity will finish as soon as the error dialog is closed.
  */
-public abstract class OnlineFeedViewActivity extends ActionBarActivity {
+public class OnlineFeedViewActivity extends ActionBarActivity {
+
     private static final String TAG = "OnlineFeedViewActivity";
+
     public static final String ARG_FEEDURL = "arg.feedurl";
 
-    /**
-     * Optional argument: specify a title for the actionbar.
-     */
+    // Optional argument: specify a title for the actionbar.
     public static final String ARG_TITLE = "title";
 
+    private static final int EVENTS = EventDistributor.DOWNLOAD_HANDLED | EventDistributor.DOWNLOAD_QUEUED | EventDistributor.FEED_LIST_UPDATE;
+
     public static final int RESULT_ERROR = 2;
 
+    private volatile List<Feed> feeds;
     private Feed feed;
-    private Map<String, String> alternateFeedUrls;
+    private String selectedDownloadUrl;
     private Downloader downloader;
 
     private boolean isPaused;
 
+    private Dialog dialog;
+
+    private Button subscribeButton;
+
+    private Subscription download;
+    private Subscription parser;
+    private Subscription updater;
+
+    private EventDistributor.EventListener listener = new EventDistributor.EventListener() {
+        @Override
+        public void update(EventDistributor eventDistributor, Integer arg) {
+            if ((arg & EventDistributor.FEED_LIST_UPDATE) != 0) {
+                updater = Observable.defer(() -> Observable.just(DBReader.getFeedList(OnlineFeedViewActivity.this)))
+                        .subscribeOn(Schedulers.newThread())
+                        .observeOn(AndroidSchedulers.mainThread())
+                        .subscribe(feeds -> {
+                                    OnlineFeedViewActivity.this.feeds = feeds;
+                                    setSubscribeButtonState(feed);
+                                }
+                        );
+            } else if ((arg & EVENTS) != 0) {
+                setSubscribeButtonState(feed);
+            }
+        }
+    };
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         setTheme(UserPreferences.getTheme());
         super.onCreate(savedInstanceState);
+        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
 
         if (getIntent() != null && getIntent().hasExtra(ARG_TITLE)) {
             getSupportActionBar().setTitle(getIntent().getStringExtra(ARG_TITLE));
@@ -87,7 +142,6 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
                 || StringUtils.equals(getIntent().getAction(), Intent.ACTION_VIEW)) {
             feedUrl = (StringUtils.equals(getIntent().getAction(), Intent.ACTION_SEND))
                     ? getIntent().getStringExtra(Intent.EXTRA_TEXT) : getIntent().getDataString();
-
             getSupportActionBar().setTitle(R.string.add_new_feed_label);
         } else {
             throw new IllegalArgumentException("Activity must be started with feedurl argument!");
@@ -102,16 +156,63 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
         }
     }
 
+    /**
+     * Displays a progress indicator.
+     */
+    private void setLoadingLayout() {
+        RelativeLayout rl = new RelativeLayout(this);
+        RelativeLayout.LayoutParams rlLayoutParams = new RelativeLayout.LayoutParams(
+                LinearLayout.LayoutParams.MATCH_PARENT,
+                LinearLayout.LayoutParams.MATCH_PARENT);
+
+        ProgressBar pb = new ProgressBar(this);
+        pb.setIndeterminate(true);
+        RelativeLayout.LayoutParams pbLayoutParams = new RelativeLayout.LayoutParams(
+                LinearLayout.LayoutParams.WRAP_CONTENT,
+                LinearLayout.LayoutParams.WRAP_CONTENT);
+        pbLayoutParams.addRule(RelativeLayout.CENTER_IN_PARENT);
+        rl.addView(pb, pbLayoutParams);
+        addContentView(rl, rlLayoutParams);
+    }
+
     @Override
     protected void onResume() {
         super.onResume();
         isPaused = false;
+        EventDistributor.getInstance().register(listener);
+
     }
 
     @Override
     protected void onPause() {
         super.onPause();
         isPaused = true;
+        EventDistributor.getInstance().unregister(listener);
+    }
+
+    @Override
+    protected void onStop() {
+        super.onStop();
+        if (downloader != null && !downloader.isFinished()) {
+            downloader.cancel();
+        }
+        if(dialog != null && dialog.isShowing()) {
+            dialog.dismiss();
+        }
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        if(updater != null) {
+            updater.unsubscribe();
+        }
+        if(download != null) {
+            download.unsubscribe();
+        }
+        if(parser != null) {
+            parser.unsubscribe();
+        }
     }
 
     @Override
@@ -123,14 +224,6 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
         }
     }
 
-    @Override
-    protected void onStop() {
-        super.onStop();
-        if (downloader != null && !downloader.isFinished()) {
-            downloader.cancel();
-        }
-    }
-
     private void resetIntent(String url, String title) {
         Intent intent = new Intent();
         intent.putExtra(ARG_FEEDURL, url);
@@ -138,41 +231,19 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
         setIntent(intent);
     }
 
-
-    private void onDownloadCompleted(final Downloader downloader) {
-        runOnUiThread(new Runnable() {
-
-            @Override
-            public void run() {
-                Log.d(TAG, "Download was completed");
-                DownloadStatus status = downloader.getResult();
-                if (status != null) {
-                    if (!status.isCancelled()) {
-                        if (status.isSuccessful()) {
-                            parseFeed();
-                        } else if (status.getReason() == DownloadError.ERROR_UNAUTHORIZED) {
-                            if (!isFinishing() && !isPaused) {
-                                Dialog dialog = new FeedViewAuthenticationDialog(OnlineFeedViewActivity.this,
-                                        R.string.authentication_notification_title, downloader.getDownloadRequest().getSource());
-                                dialog.show();
-                            }
-                        } else {
-                            String errorMsg = status.getReason().getErrorString(
-                                    OnlineFeedViewActivity.this);
-                            if (errorMsg != null
-                                    && status.getReasonDetailed() != null) {
-                                errorMsg += " (" + status.getReasonDetailed() + ")";
-                            }
-                            showErrorDialog(errorMsg);
-                        }
-                    }
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case android.R.id.home:
+                Intent destIntent = new Intent(this, MainActivity.class);
+                if (NavUtils.shouldUpRecreateTask(this, destIntent)) {
+                    startActivity(destIntent);
                 } else {
-                    Log.wtf(TAG, "DownloadStatus returned by Downloader was null");
-                    finish();
+                    NavUtils.navigateUpFromSameTask(this);
                 }
-            }
-        });
-
+                return true;
+        }
+        return super.onOptionsItemSelected(item);
     }
 
     private void startFeedDownload(String url, String username, String password) {
@@ -186,133 +257,226 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
                 FileNameGenerator.generateFileName(feed.getDownload_url())).toString();
         feed.setFile_url(fileUrl);
         final DownloadRequest request = new DownloadRequest(feed.getFile_url(),
-                feed.getDownload_url(), "OnlineFeed", 0, Feed.FEEDFILETYPE_FEED, username, password, true, null);
-        downloader = new HttpDownloader(request);
-        new Thread() {
-            @Override
-            public void run() {
-                loadData();
-                downloader.call();
-                onDownloadCompleted(downloader);
-            }
-        }.start();
-
-
-    }
+                feed.getDownload_url(), "OnlineFeed", 0, Feed.FEEDFILETYPE_FEED, username, password,
+                true, null);
 
-    /**
-     * Displays a progress indicator.
-     */
-    private void setLoadingLayout() {
-        RelativeLayout rl = new RelativeLayout(this);
-        RelativeLayout.LayoutParams rlLayoutParams = new RelativeLayout.LayoutParams(
-                LinearLayout.LayoutParams.MATCH_PARENT,
-                LinearLayout.LayoutParams.MATCH_PARENT);
-
-        ProgressBar pb = new ProgressBar(this);
-        pb.setIndeterminate(true);
-        RelativeLayout.LayoutParams pbLayoutParams = new RelativeLayout.LayoutParams(
-                LinearLayout.LayoutParams.WRAP_CONTENT,
-                LinearLayout.LayoutParams.WRAP_CONTENT);
-        pbLayoutParams.addRule(RelativeLayout.CENTER_IN_PARENT);
-        rl.addView(pb, pbLayoutParams);
-        addContentView(rl, rlLayoutParams);
+        download = Observable.create(new Observable.OnSubscribe<DownloadStatus>() {
+                    @Override
+                    public void call(Subscriber<? super DownloadStatus> subscriber) {
+                        feeds = DBReader.getFeedList(OnlineFeedViewActivity.this);
+                        downloader = new HttpDownloader(request);
+                        downloader.call();
+                        Log.d(TAG, "Download was completed");
+                        subscriber.onNext(downloader.getResult());
+                        subscriber.onCompleted();
+                    }
+                })
+                .subscribeOn(Schedulers.newThread())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(status -> {
+                    if (status != null) {
+                        if (!status.isCancelled()) {
+                            if (status.isSuccessful()) {
+                                parseFeed();
+                            } else if (status.getReason() == DownloadError.ERROR_UNAUTHORIZED) {
+                                if (!isFinishing() && !isPaused) {
+                                    dialog = new FeedViewAuthenticationDialog(OnlineFeedViewActivity.this,
+                                            R.string.authentication_notification_title, downloader.getDownloadRequest().getSource());
+                                    dialog.show();
+                                }
+                            } else {
+                                String errorMsg = status.getReason().getErrorString(OnlineFeedViewActivity.this);
+                                if (errorMsg != null && status.getReasonDetailed() != null) {
+                                    errorMsg += " (" + status.getReasonDetailed() + ")";
+                                }
+                                showErrorDialog(errorMsg);
+                            }
+                        }
+                    } else {
+                        Log.wtf(TAG, "DownloadStatus returned by Downloader was null");
+                        finish();
+                    }
+                });
     }
 
     private void parseFeed() {
         if (feed == null || feed.getFile_url() == null && feed.isDownloaded()) {
-            throw new IllegalStateException(
-                    "feed must be non-null and downloaded when parseFeed is called");
+            throw new IllegalStateException("feed must be non-null and downloaded when parseFeed is called");
         }
-
         Log.d(TAG, "Parsing feed");
 
-        Thread thread = new Thread() {
-
+        parser = Observable.create(new Observable.OnSubscribe<FeedHandlerResult>() {
             @Override
-            public void run() {
-                String reasonDetailed = "";
-                boolean successful = false;
-                FeedHandler handler = new FeedHandler();
-                try {
-                    FeedHandlerResult result = handler.parseFeed(feed);
-                    feed = result.feed;
-                    alternateFeedUrls = result.alternateFeedUrls;
-                    successful = true;
-                } catch (SAXException e) {
-                    e.printStackTrace();
-                    reasonDetailed = e.getMessage();
-                } catch (IOException e) {
-                    e.printStackTrace();
-                    reasonDetailed = e.getMessage();
-                } catch (ParserConfigurationException e) {
-                    e.printStackTrace();
-                    reasonDetailed = e.getMessage();
-                } catch (UnsupportedFeedtypeException e) {
-                    Log.d(TAG, "Unsupported feed type detected");
-                    if (StringUtils.equalsIgnoreCase("html", e.getRootElement())) {
-                        if (showFeedDiscoveryDialog(new File(feed.getFile_url()), feed.getDownload_url())) {
-                            return;
+            public void call(Subscriber<? super FeedHandlerResult> subscriber) {
+                        FeedHandler handler = new FeedHandler();
+                        try {
+                            FeedHandlerResult result = handler.parseFeed(feed);
+                            subscriber.onNext(result);
+                        } catch (UnsupportedFeedtypeException e) {
+                            Log.d(TAG, "Unsupported feed type detected");
+                            if (StringUtils.equalsIgnoreCase("html", e.getRootElement())) {
+                                showFeedDiscoveryDialog(new File(feed.getFile_url()), feed.getDownload_url());
+                            } else {
+                                subscriber.onError(e);
+                            }
+                        } catch (Exception e) {
+                            subscriber.onError(e);
+                        } finally {
+                            boolean rc = new File(feed.getFile_url()).delete();
+                            Log.d(TAG, "Deleted feed source file. Result: " + rc);
+                            subscriber.onCompleted();
                         }
-                    } else {
-                        e.printStackTrace();
-                        reasonDetailed = e.getMessage();
                     }
-                } finally {
-                    boolean rc = new File(feed.getFile_url()).delete();
-                    Log.d(TAG, "Deleted feed source file. Result: " + rc);
-                }
-
-                if (successful) {
-                    beforeShowFeedInformation(feed, alternateFeedUrls);
-                    runOnUiThread(new Runnable() {
-                        @Override
-                        public void run() {
-                            showFeedInformation(feed, alternateFeedUrls);
-                        }
-                    });
-                } else {
-                    final String errorMsg =
-                            DownloadError.ERROR_PARSER_EXCEPTION.getErrorString(
-                                    OnlineFeedViewActivity.this)
-                                    + " (" + reasonDetailed + ")";
-                    runOnUiThread(new Runnable() {
-
-                        @Override
-                        public void run() {
-                            showErrorDialog(errorMsg);
-                        }
-                    });
-                }
-            }
-        };
-        thread.start();
-    }
-
-    /**
-     * Can be used to load data asynchronously.
-     */
-    protected void loadData() {
-
+                })
+                .subscribeOn(Schedulers.newThread())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(result -> {
+                    beforeShowFeedInformation(result.feed);
+                    showFeedInformation(result.feed, result.alternateFeedUrls);
+                }, error -> {
+                    String errorMsg = DownloadError.ERROR_PARSER_EXCEPTION.getErrorString(
+                            OnlineFeedViewActivity.this) + " (" + error.getMessage() + ")";
+                    showErrorDialog(errorMsg);
+                });
     }
 
     /**
      * Called after the feed has been downloaded and parsed and before showFeedInformation is called.
      * This method is executed on a background thread
      */
-    protected void beforeShowFeedInformation(Feed feed, Map<String, String> alternateFeedUrls) {
-
+    private void beforeShowFeedInformation(Feed feed) {
+        // remove HTML tags from descriptions
+        Log.d(TAG, "Removing HTML from shownotes");
+        if (feed.getItems() != null) {
+            HtmlToPlainText formatter = new HtmlToPlainText();
+            for (FeedItem item : feed.getItems()) {
+                if (item.getDescription() != null) {
+                    Document description = Jsoup.parse(item.getDescription());
+                    item.setDescription(StringUtils.trim(formatter.getPlainText(description)));
+                }
+            }
+        }
     }
 
     /**
      * Called when feed parsed successfully.
      * This method is executed on the GUI thread.
      */
-    protected void showFeedInformation(Feed feed, Map<String, String> alternateFeedUrls) {
+    private void showFeedInformation(final Feed feed, Map<String, String> alternateFeedUrls) {
+        setContentView(R.layout.listview_activity);
+
+        this.feed = feed;
+        this.selectedDownloadUrl = feed.getDownload_url();
+        EventDistributor.getInstance().register(listener);
+        ListView listView = (ListView) findViewById(R.id.listview);
+        LayoutInflater inflater = (LayoutInflater)
+                getSystemService(Context.LAYOUT_INFLATER_SERVICE);
+        View header = inflater.inflate(R.layout.onlinefeedview_header, listView, false);
+        listView.addHeaderView(header);
+
+        listView.setAdapter(new FeedItemlistDescriptionAdapter(this, 0, feed.getItems()));
+
+        ImageView cover = (ImageView) header.findViewById(R.id.imgvCover);
+        TextView title = (TextView) header.findViewById(R.id.txtvTitle);
+        TextView author = (TextView) header.findViewById(R.id.txtvAuthor);
+        TextView description = (TextView) header.findViewById(R.id.txtvDescription);
+        Spinner spAlternateUrls = (Spinner) header.findViewById(R.id.spinnerAlternateUrls);
+
+        subscribeButton = (Button) header.findViewById(R.id.butSubscribe);
+
+        if (feed.getImage() != null && StringUtils.isNotBlank(feed.getImage().getDownload_url())) {
+            Glide.with(this)
+                    .load(feed.getImage().getDownload_url())
+                    .placeholder(R.color.light_gray)
+                    .error(R.color.light_gray)
+                    .diskCacheStrategy(ApGlideSettings.AP_DISK_CACHE_STRATEGY)
+                    .fitCenter()
+                    .dontAnimate()
+                    .into(cover);
+        }
+
+        title.setText(feed.getTitle());
+        author.setText(feed.getAuthor());
+        description.setText(feed.getDescription());
+
+        subscribeButton.setOnClickListener(v -> {
+            try {
+                Feed f = new Feed(selectedDownloadUrl, new Date(0), feed.getTitle());
+                f.setPreferences(feed.getPreferences());
+                this.feed = f;
+
+                DownloadRequester.getInstance().downloadFeed(this, f);
+            } catch (DownloadRequestException e) {
+                e.printStackTrace();
+                DownloadRequestErrorDialogCreator.newRequestErrorDialog(OnlineFeedViewActivity.this,
+                        e.getMessage());
+            }
+            setSubscribeButtonState(feed);
+        });
+
+        if (alternateFeedUrls.isEmpty()) {
+            spAlternateUrls.setVisibility(View.GONE);
+        } else {
+            spAlternateUrls.setVisibility(View.VISIBLE);
+
+            final List<String> alternateUrlsList = new ArrayList<>();
+            final List<String> alternateUrlsTitleList = new ArrayList<>();
+
+            alternateUrlsList.add(feed.getDownload_url());
+            alternateUrlsTitleList.add(feed.getTitle());
 
+
+            alternateUrlsList.addAll(alternateFeedUrls.keySet());
+            for (String url : alternateFeedUrls.keySet()) {
+                alternateUrlsTitleList.add(alternateFeedUrls.get(url));
+            }
+            ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_item, alternateUrlsTitleList);
+            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+            spAlternateUrls.setAdapter(adapter);
+            spAlternateUrls.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+                @Override
+                public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+                    selectedDownloadUrl = alternateUrlsList.get(position);
+                }
+
+                @Override
+                public void onNothingSelected(AdapterView<?> parent) {
+
+                }
+            });
+        }
+        setSubscribeButtonState(feed);
+    }
+
+    private void setSubscribeButtonState(Feed feed) {
+        if (subscribeButton != null && feed != null) {
+            if (DownloadRequester.getInstance().isDownloadingFile(feed.getDownload_url())) {
+                subscribeButton.setEnabled(false);
+                subscribeButton.setText(R.string.downloading_label);
+            } else if (feedInFeedlist(feed)) {
+                subscribeButton.setEnabled(false);
+                subscribeButton.setText(R.string.subscribed_label);
+            } else {
+                subscribeButton.setEnabled(true);
+                subscribeButton.setText(R.string.subscribe_label);
+            }
+        }
+    }
+
+    private boolean feedInFeedlist(Feed feed) {
+        if (feeds == null || feed == null) {
+            return false;
+        }
+        for (Feed f : feeds) {
+            if (f.getIdentifyingValue().equals(feed.getIdentifyingValue())) {
+                return true;
+            }
+        }
+        return false;
     }
 
     private void showErrorDialog(String errorMsg) {
+        assert(Looper.myLooper() == Looper.getMainLooper()); // run on UI thread
         if (!isFinishing() && !isPaused) {
             AlertDialog.Builder builder = new AlertDialog.Builder(this);
             builder.setTitle(R.string.error_label);
@@ -322,85 +486,71 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
                 builder.setMessage(R.string.error_msg_prefix);
             }
             builder.setNeutralButton(android.R.string.ok,
-                    new DialogInterface.OnClickListener() {
-
-                        @Override
-                        public void onClick(DialogInterface dialog, int which) {
-                            dialog.cancel();
-                        }
+                    (dialog, which) -> {
+                        dialog.cancel();
                     }
             );
-            builder.setOnCancelListener(new OnCancelListener() {
-                @Override
-                public void onCancel(DialogInterface dialog) {
-                    setResult(RESULT_ERROR);
-                    finish();
-                }
+            builder.setOnCancelListener(dialog -> {
+                setResult(RESULT_ERROR);
+                finish();
             });
-            builder.show();
+            if(dialog != null && dialog.isShowing()) {
+                dialog.dismiss();
+            }
+            dialog = builder.show();
         }
     }
 
-    private boolean showFeedDiscoveryDialog(File feedFile, String baseUrl) {
+    private void showFeedDiscoveryDialog(File feedFile, String baseUrl) {
         FeedDiscoverer fd = new FeedDiscoverer();
         final Map<String, String> urlsMap;
         try {
             urlsMap = fd.findLinks(feedFile, baseUrl);
             if (urlsMap == null || urlsMap.isEmpty()) {
-                return false;
+                return;
             }
         } catch (IOException e) {
             e.printStackTrace();
-            return false;
+            return;
         }
 
-        runOnUiThread(new Runnable() {
-            @Override
-            public void run() {
-                if (isPaused || isFinishing()) {
-                    return;
-                }
+        if (isPaused || isFinishing()) {
+            return;
+        }
 
-                final List<String> titles = new ArrayList<String>();
-                final List<String> urls = new ArrayList<String>();
+        final List<String> titles = new ArrayList<>();
+        final List<String> urls = new ArrayList<>();
 
-                urls.addAll(urlsMap.keySet());
-                for (String url : urls) {
-                    titles.add(urlsMap.get(url));
-                }
+        urls.addAll(urlsMap.keySet());
+        for (String url : urls) {
+            titles.add(urlsMap.get(url));
+        }
 
-                final ArrayAdapter<String> adapter = new ArrayAdapter<String>(OnlineFeedViewActivity.this, R.layout.ellipsize_start_listitem, R.id.txtvTitle, titles);
-                DialogInterface.OnClickListener onClickListener = new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialog, int which) {
-                        String selectedUrl = urls.get(which);
-                        dialog.dismiss();
-                        resetIntent(selectedUrl, titles.get(which));
-                        FeedPreferences prefs = feed.getPreferences();
-                        if(prefs != null) {
-                            startFeedDownload(selectedUrl, prefs.getUsername(), prefs.getPassword());
-                        } else {
-                            startFeedDownload(selectedUrl, null, null);
-                        }
-                    }
-                };
-
-                AlertDialog.Builder ab = new AlertDialog.Builder(OnlineFeedViewActivity.this)
-                        .setTitle(R.string.feeds_label)
-                        .setCancelable(true)
-                        .setOnCancelListener(new OnCancelListener() {
-                            @Override
-                            public void onCancel(DialogInterface dialog) {
-                                finish();
-                            }
-                        })
-                        .setAdapter(adapter, onClickListener);
-                ab.show();
+        final ArrayAdapter<String> adapter = new ArrayAdapter<>(OnlineFeedViewActivity.this, R.layout.ellipsize_start_listitem, R.id.txtvTitle, titles);
+        DialogInterface.OnClickListener onClickListener = (dialog, which) -> {
+            String selectedUrl = urls.get(which);
+            dialog.dismiss();
+            resetIntent(selectedUrl, titles.get(which));
+            FeedPreferences prefs = feed.getPreferences();
+            if(prefs != null) {
+                startFeedDownload(selectedUrl, prefs.getUsername(), prefs.getPassword());
+            } else {
+                startFeedDownload(selectedUrl, null, null);
             }
-        });
+        };
 
+        AlertDialog.Builder ab = new AlertDialog.Builder(OnlineFeedViewActivity.this)
+                .setTitle(R.string.feeds_label)
+                .setCancelable(true)
+                .setOnCancelListener(dialog -> finish())
+                .setAdapter(adapter, onClickListener);
 
-        return true;
+        runOnUiThread(() -> {
+            if(dialog != null && dialog.isShowing()) {
+                dialog.dismiss();
+            }
+            dialog = ab.show();
+        });
     }
 
     private class FeedViewAuthenticationDialog extends AuthenticationDialog {
@@ -423,4 +573,5 @@ public abstract class OnlineFeedViewActivity extends ActionBarActivity {
             startFeedDownload(feedUrl, username, password);
         }
     }
+
 }