Refactor OPML export from asynctask to observable

4 files changed, 112 insertions, 124 deletions

diff --git a/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivity.java b/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivity.java
index 61765d6b7..dd932814f 100644
--- a/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivity.java
+++ b/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivity.java
@@ -26,11 +26,9 @@ import de.danoeh.antennapod.preferences.PreferenceController;
  */
 public class PreferenceActivity extends AppCompatActivity {
 
+    private static WeakReference<PreferenceActivity> instance;
     private PreferenceController preferenceController;
     private MainFragment prefFragment;
-    private static WeakReference<PreferenceActivity> instance;
-
-
     private final PreferenceController.PreferenceUI preferenceUI = new PreferenceController.PreferenceUI() {
         @TargetApi(Build.VERSION_CODES.HONEYCOMB)
         @Override
@@ -128,5 +126,14 @@ public class PreferenceActivity extends AppCompatActivity {
             }
             super.onPause();
         }
+
+        @Override
+        public void onStop() {
+            PreferenceActivity activity = instance.get();
+            if(activity != null && activity.preferenceController != null) {
+                activity.preferenceController.onStop();
+            }
+            super.onStop();
+        }
     }
 }
diff --git a/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivityGingerbread.java b/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivityGingerbread.java
index 4af988ea0..390bec15c 100644
--- a/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivityGingerbread.java
+++ b/app/src/main/java/de/danoeh/antennapod/activity/PreferenceActivityGingerbread.java
@@ -18,9 +18,6 @@ import de.danoeh.antennapod.preferences.PreferenceController;
  */
 public class PreferenceActivityGingerbread extends android.preference.PreferenceActivity {
     private static final String TAG = "PreferenceActivity";
-
-    private PreferenceController preferenceController;
-
     private final PreferenceController.PreferenceUI preferenceUI = new PreferenceController.PreferenceUI() {
 
         @SuppressWarnings("deprecation")
@@ -34,6 +31,7 @@ public class PreferenceActivityGingerbread extends android.preference.Preference
             return PreferenceActivityGingerbread.this;
         }
     };
+    private PreferenceController preferenceController;
 
     @SuppressLint("NewApi")
     @SuppressWarnings("deprecation")
@@ -61,6 +59,12 @@ public class PreferenceActivityGingerbread extends android.preference.Preference
     }
 
     @Override
+    protected void onStop() {
+        preferenceController.onStop();
+        super.onStop();
+    }
+
+    @Override
     protected void onApplyThemeResource(Theme theme, int resid, boolean first) {
         theme.applyStyle(UserPreferences.getTheme(), true);
     }
diff --git a/app/src/main/java/de/danoeh/antennapod/asynctask/OpmlExportWorker.java b/app/src/main/java/de/danoeh/antennapod/asynctask/OpmlExportWorker.java
index 13abb26ea..8f866f4ff 100644
--- a/app/src/main/java/de/danoeh/antennapod/asynctask/OpmlExportWorker.java
+++ b/app/src/main/java/de/danoeh/antennapod/asynctask/OpmlExportWorker.java
@@ -1,12 +1,5 @@
 package de.danoeh.antennapod.asynctask;
 
-import android.annotation.SuppressLint;
-import android.app.ProgressDialog;
-import android.content.Context;
-import android.content.Intent;
-import android.net.Uri;
-import android.os.AsyncTask;
-import android.support.v7.app.AlertDialog;
 import android.util.Log;
 
 import java.io.File;
@@ -14,109 +7,55 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 
-import de.danoeh.antennapod.core.R;
 import de.danoeh.antennapod.core.opml.OpmlWriter;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
 import de.danoeh.antennapod.core.storage.DBReader;
 import de.danoeh.antennapod.core.util.LangUtils;
+import rx.Observable;
 
 /**
  * Writes an OPML file into the export directory in the background.
  */
-public class OpmlExportWorker extends AsyncTask<Void, Void, Void> {
+public class OpmlExportWorker {
+
+    public static final String EXPORT_DIR = "export/";
     private static final String TAG = "OpmlExportWorker";
     private static final String DEFAULT_OUTPUT_NAME = "antennapod-feeds.opml";
-    public static final String EXPORT_DIR = "export/";
-
-    private Context context;
     private File output;
 
-    private ProgressDialog progDialog;
-    private Exception exception;
-
-    public OpmlExportWorker(Context context, File output) {
-        this.context = context;
-        this.output = output;
+    public OpmlExportWorker() {
+        this(new File(UserPreferences.getDataFolder(EXPORT_DIR), DEFAULT_OUTPUT_NAME));
     }
 
-    public OpmlExportWorker(Context context) {
-        this.context = context;
+    public OpmlExportWorker(File output) {
+        this.output = output;
     }
 
-    @Override
-    protected Void doInBackground(Void... params) {
-        OpmlWriter opmlWriter = new OpmlWriter();
-        if (output == null) {
-            output = new File(
-                    UserPreferences.getDataFolder(EXPORT_DIR),
-                    DEFAULT_OUTPUT_NAME);
-            if (output.exists()) {
-                Log.w(TAG, "Overwriting previously exported file.");
-                output.delete();
-            }
+    public Observable<File> exportObservable() {
+        if (output.exists()) {
+            Log.w(TAG, "Overwriting previously exported file.");
+            output.delete();
         }
-        OutputStreamWriter writer = null;
-        try {
-            writer = new OutputStreamWriter(new FileOutputStream(output), LangUtils.UTF_8);
-            opmlWriter.writeDocument(DBReader.getFeedList(), writer);
-        } catch (IOException e) {
-            e.printStackTrace();
-            exception = e;
-        } finally {
-            if (writer != null) {
-                try {
-                    writer.close();
-                } catch (IOException ioe) {
-                    exception = ioe;
+        OpmlWriter opmlWriter = new OpmlWriter();
+        return Observable.create(subscriber -> {
+            OutputStreamWriter writer = null;
+            try {
+                writer = new OutputStreamWriter(new FileOutputStream(output), LangUtils.UTF_8);
+                opmlWriter.writeDocument(DBReader.getFeedList(), writer);
+                subscriber.onNext(output);
+            } catch (IOException e) {
+                subscriber.onError(e);
+            } finally {
+                if (writer != null) {
+                    try {
+                        writer.close();
+                    } catch (IOException e) {
+                        subscriber.onError(e);
+                    }
                 }
+                subscriber.onCompleted();
             }
-        }
-        return null;
-    }
-
-    @Override
-    protected void onPostExecute(Void result) {
-        progDialog.dismiss();
-        AlertDialog.Builder alert = new AlertDialog.Builder(context)
-                .setNeutralButton(android.R.string.ok,
-                        (dialog, which) -> dialog.dismiss());
-        if (exception != null) {
-            alert.setTitle(R.string.export_error_label);
-            alert.setMessage(exception.getMessage());
-        } else {
-            alert.setTitle(R.string.opml_export_success_title);
-            alert.setMessage(context
-                    .getString(R.string.opml_export_success_sum)
-                    + output.toString())
-                    .setPositiveButton(R.string.send_label, (dialog, which) -> {
-                        Uri outputUri = Uri.fromFile(output);
-                        Intent sendIntent = new Intent(Intent.ACTION_SEND);
-                        sendIntent.putExtra(Intent.EXTRA_SUBJECT,
-                                context.getResources().getText(R.string.opml_export_label));
-                        sendIntent.putExtra(Intent.EXTRA_STREAM, outputUri);
-                        sendIntent.setType("text/plain");
-                        context.startActivity(Intent.createChooser(sendIntent,
-                                context.getResources().getText(R.string.send_label)));
-                    });
-        }
-        alert.create().show();
-    }
-
-    @Override
-    protected void onPreExecute() {
-        progDialog = new ProgressDialog(context);
-        progDialog.setMessage(context.getString(R.string.exporting_label));
-        progDialog.setIndeterminate(true);
-        progDialog.show();
-    }
-
-    @SuppressLint("NewApi")
-    public void executeAsync() {
-        if (android.os.Build.VERSION.SDK_INT > android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
-            executeOnExecutor(THREAD_POOL_EXECUTOR);
-        } else {
-            execute();
-        }
+        });
     }
 
 }
diff --git a/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceController.java b/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceController.java
index 85eaafcad..3e5095a62 100644
--- a/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceController.java
+++ b/app/src/main/java/de/danoeh/antennapod/preferences/PreferenceController.java
@@ -3,6 +3,7 @@ package de.danoeh.antennapod.preferences;
 import android.Manifest;
 import android.annotation.SuppressLint;
 import android.app.Activity;
+import android.app.ProgressDialog;
 import android.app.TimePickerDialog;
 import android.content.ActivityNotFoundException;
 import android.content.Context;
@@ -66,6 +67,10 @@ import de.danoeh.antennapod.dialog.AutoFlattrPreferenceDialog;
 import de.danoeh.antennapod.dialog.GpodnetSetHostnameDialog;
 import de.danoeh.antennapod.dialog.ProxyDialog;
 import de.danoeh.antennapod.dialog.VariableSpeedDialog;
+import rx.Observable;
+import rx.Subscription;
+import rx.android.schedulers.AndroidSchedulers;
+import rx.schedulers.Schedulers;
 
 /**
  * Sets up a preference UI that lets the user change user preferences.
@@ -97,32 +102,11 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
     private static final String PREF_KNOWN_ISSUES = "prefKnownIssues";
     private static final String PREF_FAQ = "prefFaq";
     private static final String PREF_SEND_CRASH_REPORT = "prefSendCrashReport";
-
-    private final PreferenceUI ui;
-
-    private CheckBoxPreference[] selectedNetworks;
-
     private static final String[] EXTERNAL_STORAGE_PERMISSIONS = {
             Manifest.permission.READ_EXTERNAL_STORAGE,
             Manifest.permission.WRITE_EXTERNAL_STORAGE };
     private static final int PERMISSION_REQUEST_EXTERNAL_STORAGE = 41;
-
-    public PreferenceController(PreferenceUI ui) {
-        this.ui = ui;
-        PreferenceManager.getDefaultSharedPreferences(ui.getActivity().getApplicationContext())
-            .registerOnSharedPreferenceChangeListener(this);
-    }
-
-    @Override
-    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
-        if(key.equals(UserPreferences.PREF_SONIC)) {
-            CheckBoxPreference prefSonic = (CheckBoxPreference) ui.findPreference(UserPreferences.PREF_SONIC);
-            if(prefSonic != null) {
-                prefSonic.setChecked(sharedPreferences.getBoolean(UserPreferences.PREF_SONIC, false));
-            }
-        }
-    }
-
+    private final PreferenceUI ui;
     private final SharedPreferences.OnSharedPreferenceChangeListener gpoddernetListener =
             (sharedPreferences, key) -> {
                 if (GpodnetPreferences.PREF_LAST_SYNC_ATTEMPT_TIMESTAMP.equals(key)) {
@@ -130,6 +114,14 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
                             GpodnetPreferences.getLastSyncAttemptTimestamp());
                 }
             };
+    private CheckBoxPreference[] selectedNetworks;
+    private Subscription subscription;
+
+    public PreferenceController(PreferenceUI ui) {
+        this.ui = ui;
+        PreferenceManager.getDefaultSharedPreferences(ui.getActivity().getApplicationContext())
+            .registerOnSharedPreferenceChangeListener(this);
+    }
 
     /**
      * Returns the preference activity that should be used on this device.
@@ -144,6 +136,16 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
         }
     }
 
+    @Override
+    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
+        if(key.equals(UserPreferences.PREF_SONIC)) {
+            CheckBoxPreference prefSonic = (CheckBoxPreference) ui.findPreference(UserPreferences.PREF_SONIC);
+            if(prefSonic != null) {
+                prefSonic.setChecked(sharedPreferences.getBoolean(UserPreferences.PREF_SONIC, false));
+            }
+        }
+    }
+
     public void onCreate() {
         final Activity activity = ui.getActivity();
 
@@ -179,11 +181,7 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
                 }
         );
         ui.findPreference(PreferenceController.PREF_OPML_EXPORT).setOnPreferenceClickListener(
-                preference -> {
-                    new OpmlExportWorker(activity).executeAsync();
-                    return true;
-                }
-        );
+                preference -> exportOpml());
         ui.findPreference(PreferenceController.PREF_CHOOSE_DATA_DIR).setOnPreferenceClickListener(
                 preference -> {
                     if (Build.VERSION_CODES.KITKAT <= Build.VERSION.SDK_INT &&
@@ -440,6 +438,40 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
         setSelectedNetworksEnabled(UserPreferences.isEnableAutodownloadWifiFilter());
     }
 
+    private boolean exportOpml() {
+        Context context = ui.getActivity();
+        final ProgressDialog progressDialog = new ProgressDialog(context);
+        progressDialog.setMessage(context.getString(R.string.exporting_label));
+        progressDialog.setIndeterminate(true);
+        progressDialog.show();
+        final AlertDialog.Builder alert = new AlertDialog.Builder(context)
+                .setNeutralButton(android.R.string.ok, (dialog, which) -> dialog.dismiss());
+        Observable<File> observable = new OpmlExportWorker().exportObservable();
+        subscription = observable.subscribeOn(Schedulers.newThread())
+                .observeOn(AndroidSchedulers.mainThread())
+                .subscribe(output -> {
+                    alert.setTitle(R.string.opml_export_success_title);
+                    String message = context.getString(R.string.opml_export_success_sum) + output.toString();
+                    alert.setMessage(message);
+                    alert.setPositiveButton(R.string.send_label, (dialog, which) -> {
+                        Uri outputUri = Uri.fromFile(output);
+                        Intent sendIntent = new Intent(Intent.ACTION_SEND);
+                        sendIntent.putExtra(Intent.EXTRA_SUBJECT,
+                                context.getResources().getText(R.string.opml_export_label));
+                        sendIntent.putExtra(Intent.EXTRA_STREAM, outputUri);
+                        sendIntent.setType("text/plain");
+                        context.startActivity(Intent.createChooser(sendIntent,
+                                context.getResources().getText(R.string.send_label)));
+                    });
+                    alert.create().show();
+                }, error -> {
+                    alert.setTitle(R.string.export_error_label);
+                    alert.setMessage(error.getMessage());
+                    alert.show();
+                }, () -> progressDialog.dismiss());
+        return true;
+    }
+
     private void openInBrowser(String url) {
         try {
             Intent myIntent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
@@ -464,6 +496,12 @@ public class PreferenceController implements SharedPreferences.OnSharedPreferenc
         GpodnetPreferences.unregisterOnSharedPreferenceChangeListener(gpoddernetListener);
     }
 
+    public void onStop() {
+        if(subscription != null) {
+            subscription.unsubscribe();
+        }
+    }
+
     @SuppressLint("NewApi")
     public void onActivityResult(int requestCode, int resultCode, Intent data) {
         if (resultCode == Activity.RESULT_OK &&