add reset extSD card folder dialog

app/src/main/AndroidManifest.xml

@@ -76,10 +76,6 @@
             android:name=".about.AboutActivity"
             android:label="@string/title_activity_about"/>
 
-        <activity
-            android:name=".history.HistoryActivity"
-            android:label="@string/title_activity_history"/>
-
         <service android:name=".local.subscription.services.SubscriptionsImportService"/>
         <service android:name=".local.subscription.services.SubscriptionsExportService"/>
 
@@ -122,6 +118,7 @@
         <activity
             android:name=".ReCaptchaActivity"
             android:label="@string/reCaptchaActivity"/>
+        <activity android:name=".download.ExtSDDownloadFailedActivity" />
 
         <provider
             android:name="android.support.v4.content.FileProvider"

app/src/main/java/org/schabi/newpipe/download/ExtSDDownloadFailedActivity.java

@@ -0,0 +1,40 @@
+package org.schabi.newpipe.download;
+
+import android.app.AlertDialog;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.support.annotation.Nullable;
+import android.support.v7.app.AppCompatActivity;
+
+import org.schabi.newpipe.R;
+import org.schabi.newpipe.settings.NewPipeSettings;
+import org.schabi.newpipe.util.ServiceHelper;
+import org.schabi.newpipe.util.ThemeHelper;
+
+public class ExtSDDownloadFailedActivity extends AppCompatActivity {
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        ThemeHelper.setTheme(this, ServiceHelper.getSelectedServiceId(this));
+    }
+
+    @Override
+    protected void onStart() {
+        super.onStart();
+        new AlertDialog.Builder(this)
+                .setTitle(R.string.download_to_sdcard_error_title)
+                .setMessage(R.string.download_to_sdcard_error_message)
+                .setPositiveButton(R.string.yes, (DialogInterface dialogInterface, int i) -> {
+
+                    NewPipeSettings.resetDownloadFolders(this);
+                    finish();
+                })
+                .setNegativeButton(R.string.cancel, (DialogInterface dialogInterface, int i) -> {
+
+                    dialogInterface.dismiss();
+                    finish();
+                })
+                .create()
+                .show();
+    }
+}

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

@@ -107,4 +107,17 @@ public class NewPipeSettings {
     private static File getFolder(String defaultDirectoryName) {
         return new File(Environment.getExternalStorageDirectory(), defaultDirectoryName);
     }
+
+    public static void resetDownloadFolders(Context context) {
+        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
+        resetDownloadFolder(prefs, context.getString(R.string.download_path_audio_key), Environment.DIRECTORY_MUSIC);
+        resetDownloadFolder(prefs, context.getString(R.string.download_path_key), Environment.DIRECTORY_MOVIES);
+    }
+
+    private static void resetDownloadFolder(SharedPreferences prefs, String key, String defaultDirectoryName) {
+        final File folder = getFolder(defaultDirectoryName);
+        SharedPreferences.Editor spEditor = prefs.edit();
+        spEditor.putString(key, new File(folder, "NewPipe").getAbsolutePath());
+        spEditor.apply();
+    }
 }

app/src/main/java/us/shandian/giga/get/DownloadManagerImpl.java

@@ -1,10 +1,22 @@
 package us.shandian.giga.get;
 
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.content.SharedPreferences;
+import android.os.Handler;
+import android.preference.PreferenceManager;
 import android.support.annotation.Nullable;
 import android.util.Log;
 
+import org.schabi.newpipe.R;
+import org.schabi.newpipe.download.ExtSDDownloadFailedActivity;
+import org.schabi.newpipe.settings.NewPipeSettings;
+
 import java.io.File;
 import java.io.FilenameFilter;
+import java.io.IOException;
 import java.io.RandomAccessFile;
 import java.net.HttpURLConnection;
 import java.net.URL;
@@ -23,7 +35,8 @@ public class DownloadManagerImpl implements DownloadManager {
     private static final String TAG = DownloadManagerImpl.class.getSimpleName();
     private final DownloadDataSource mDownloadDataSource;
 
-    private final ArrayList<DownloadMission> mMissions = new ArrayList<DownloadMission>();
+    private final ArrayList<DownloadMission> mMissions = new ArrayList<>();
+    private final Context context;
 
     /**
      * Create a new instance
@@ -33,6 +46,13 @@ public class DownloadManagerImpl implements DownloadManager {
      */
     public DownloadManagerImpl(Collection<String> searchLocations, DownloadDataSource downloadDataSource) {
         mDownloadDataSource = downloadDataSource;
+        this.context = null;
+        loadMissions(searchLocations);
+    }
+
+    public DownloadManagerImpl(Collection<String> searchLocations, DownloadDataSource downloadDataSource, Context context) {
+        mDownloadDataSource = downloadDataSource;
+        this.context = context;
         loadMissions(searchLocations);
     }
 
@@ -277,10 +297,12 @@ public class DownloadManagerImpl implements DownloadManager {
     }
 
     private class Initializer extends Thread {
-        private DownloadMission mission;
+        private final DownloadMission mission;
+        private final Handler handler;
 
         public Initializer(DownloadMission mission) {
             this.mission = mission;
+            this.handler = new Handler();
         }
 
         @Override
@@ -335,6 +357,13 @@ public class DownloadManagerImpl implements DownloadManager {
                 af.close();
 
                 mission.start();
+            } catch (IOException ie) {
+                if(context == null) throw new RuntimeException(ie);
+
+                if(ie.getMessage().contains("Permission denied")) {
+                    handler.post(() ->
+                        context.startActivity(new Intent(context, ExtSDDownloadFailedActivity.class)));
+                } else throw new RuntimeException(ie);
             } catch (Exception e) {
                 // TODO Notify
                 throw new RuntimeException(e);

app/src/main/java/us/shandian/giga/service/DownloadManagerService.java

@@ -81,7 +81,7 @@ public class DownloadManagerService extends Service {
             ArrayList<String> paths = new ArrayList<>(2);
             paths.add(NewPipeSettings.getVideoDownloadPath(this));
             paths.add(NewPipeSettings.getAudioDownloadPath(this));
-            mManager = new DownloadManagerImpl(paths, mDataSource);
+            mManager = new DownloadManagerImpl(paths, mDataSource, this);
             if (DEBUG) {
                 Log.d(TAG, "mManager == null");
                 Log.d(TAG, "Download directory: " + paths);

app/src/main/res/values/strings.xml

@@ -170,6 +170,8 @@
     <string name="search_history_deleted">Search history deleted.</string>
     <!-- error strings -->
     <string name="general_error">Error</string>
+    <string name="download_to_sdcard_error_title">External storage not available.</string>
+    <string name="download_to_sdcard_error_message">Download to external SD Card is not possible yet. Should the download place be reseted?</string>
     <string name="network_error">Network error</string>
     <string name="could_not_load_thumbnails">Could not load all thumbnails</string>
     <string name="youtube_signature_decryption_error">Could not decrypt video URL signature</string>