Added Content Country selection setting. This changes the SearchEngine interface slightly. Still need a reliable test to prove whether YouTube is serving different search results based on the country code passed in the search query.

app/src/main/java/org/schabi/newpipe/ActionBarHandler.java

@@ -321,7 +321,7 @@ public class ActionBarHandler {
                         }
                     });
             builder.create().show();
-            Log.d(TAG, "Either no Streaming player for audio was installed, or something importand crashed:");
+            Log.d(TAG, "Either no Streaming player for audio was installed, or something important crashed:");
             e.printStackTrace();
         }
     }

app/src/main/java/org/schabi/newpipe/SearchEngine.java

@@ -31,5 +31,6 @@ public interface SearchEngine {
         public Vector<VideoInfoItem> resultList = new Vector<>();
     }
 
-    Result search(String query, int page);
+    //Result search(String query, int page);
+    Result search(String query, int page, String contentCountry);
 }

app/src/main/java/org/schabi/newpipe/VideoItemListFragment.java

@@ -1,10 +1,12 @@
 package org.schabi.newpipe;
 
 import android.content.Context;
+import android.content.SharedPreferences;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.Bundle;
 import android.os.Handler;
+import android.preference.PreferenceManager;
 import android.support.v4.app.ListFragment;
 import android.util.Log;
 import android.view.View;
@@ -90,7 +92,11 @@ public class VideoItemListFragment extends ListFragment {
         @Override
         public void run() {
             try {
-                SearchEngine.Result result = engine.search(query, page);
+                SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getContext());
+                String contentCountryKey = getContext().getString(R.string.contentCountry);
+                String contentCountry = sp.getString(contentCountryKey, "");
+                SearchEngine.Result result = engine.search(query, page, contentCountry);
+                Log.i(TAG, "countryCode passed:\""+contentCountry+"\"");
                 if(run) {
                     h.post(new ResultRunnable(result, requestId));
                 }

app/src/main/java/org/schabi/newpipe/youtube/YoutubeSearchEngine.java

@@ -1,6 +1,7 @@
 package org.schabi.newpipe.youtube;
 
 import android.net.Uri;
+import android.preference.PreferenceManager;
 import android.util.Log;
 
 import org.jsoup.Jsoup;
@@ -38,7 +39,8 @@ public class YoutubeSearchEngine implements SearchEngine {
     private static final String TAG = YoutubeSearchEngine.class.toString();
 
     @Override
-    public Result search(String query, int page) {
+    public Result search(String query, int page, String countryCode) {
+        //String contentCountry = PreferenceManager.getDefaultSharedPreferences(this).getString(getString(R.string., "");
         Uri.Builder builder = new Uri.Builder();
         builder.scheme("https")
                 .authority("www.youtube.com")
@@ -46,6 +48,18 @@ public class YoutubeSearchEngine implements SearchEngine {
                 .appendQueryParameter("search_query", query)
                 .appendQueryParameter("page", Integer.toString(page))
                 .appendQueryParameter("filters", "video");
+
+        //if we've been passed a valid, non-empty country code, append it to the URL
+        if(countryCode.length() > 0) {
+            if(countryCode.length() == 2) {
+                builder.appendQueryParameter("gl", countryCode);
+                builder.appendQueryParameter("persist_gl", "1");
+                Log.i(TAG, "URI: \""+builder+"\"");
+            }
+            else {
+                Log.e(TAG, "invalid country code passed to search(): \""+countryCode+"\"");
+            }
+        }
         String url = builder.build().toString();
 
         String site = Downloader.download(url);
@@ -115,4 +129,5 @@ public class YoutubeSearchEngine implements SearchEngine {
         }
         return result;
     }
+
 }

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

@@ -24,4 +24,183 @@
     </string-array>
     <string name="defaultAudioFormat">m4a</string>
     <string name="showNextVideo">show_next_video</string>
+    <string name="contentCountry">content_country</string>
+    <!-- TODO: scrape these programmatically, then store in a local cache -->
+    <!-- alternatively, load these from some local android data store -->
+    <string-array name="countryCodes">
+        <item></item><!--NONE-->
+        <item>US</item>
+        <item>DZ</item>
+        <item>AR</item>
+        <item>AU</item>
+        <item>AT</item>
+        <item>AZ</item>
+        <item>BH</item>
+        <item>BY</item>
+        <item>BE</item>
+        <item>BA</item>
+        <item>BR</item>
+        <item>BG</item>
+        <item>CA</item>
+        <item>CL</item>
+        <item>CO</item>
+        <item>HR</item>
+        <item>CZ</item>
+        <item>DK</item>
+        <item>EG</item>
+        <item>EE</item>
+        <item>FI</item>
+        <item>FR</item>
+        <item>GE</item>
+        <item>DE</item>
+        <item>GH</item>
+        <item>GR</item>
+        <item>HK</item>
+        <item>HU</item>
+        <item>IS</item>
+        <item>IN</item>
+        <item>ID</item>
+        <item>IE</item>
+        <item>IL</item>
+        <item>IT</item>
+        <item>JP</item>
+        <item>JO</item>
+        <item>KZ</item>
+        <item>KE</item>
+        <item>KW</item>
+        <item>LV</item>
+        <item>LB</item>
+        <item>LY</item>
+        <item>LT</item>
+        <item>LU</item>
+        <item>MK</item>
+        <item>MY</item>
+        <item>MX</item>
+        <item>ME</item>
+        <item>MA</item>
+        <item>NL</item>
+        <item>NZ</item>
+        <item>NG</item>
+        <item>NO</item>
+        <item>OM</item>
+        <item>PE</item>
+        <item>PH</item>
+        <item>PL</item>
+        <item>PT</item>
+        <item>PR</item>
+        <item>QA</item>
+        <item>RO</item>
+        <item>RU</item>
+        <item>SA</item>
+        <item>SN</item>
+        <item>RS</item>
+        <item>SG</item>
+        <item>SK</item>
+        <item>SI</item>
+        <item>ZA</item>
+        <item>KR</item>
+        <item>ES</item>
+        <item>SE</item>
+        <item>CH</item>
+        <item>TW</item>
+        <item>TZ</item>
+        <item>TH</item>
+        <item>TN</item>
+        <item>TR</item>
+        <item>UG</item>
+        <item>UA</item>
+        <item>AE</item>
+        <item>GB</item>
+        <item>VN</item>
+        <item>YE</item>
+        <item>ZW</item>
+    </string-array>
+    <string-array name="countryNames">
+        <item>(None)</item>
+        <item>Worldwide (USA)</item>
+        <item>Algeria</item>
+        <item>Argentina</item>
+        <item>Australia</item>
+        <item>Austria</item>
+        <item>Azerbaijan</item>
+        <item>Bahrain</item>
+        <item>Belarus</item>
+        <item>Belgium</item>
+        <item>Bosnia and Herzegovina</item>
+        <item>Brazil</item>
+        <item>Bulgaria</item>
+        <item>Canada</item>
+        <item>Chile</item>
+        <item>Colombia</item>
+        <item>Croatia</item>
+        <item>Czech Republic</item>
+        <item>Denmark</item>
+        <item>Egypt</item>
+        <item>Estonia</item>
+        <item>Finland</item>
+        <item>France</item>
+        <item>Georgia</item>
+        <item>Germany</item>
+        <item>Ghana</item>
+        <item>Greece</item>
+        <item>Hong Kong</item>
+        <item>Hungary</item>
+        <item>Iceland</item>
+        <item>India</item>
+        <item>Indonesia</item>
+        <item>Ireland</item>
+        <item>Israel</item>
+        <item>Italy</item>
+        <item>Japan</item>
+        <item>Jordan</item>
+        <item>Kazakhstan</item>
+        <item>Kenya</item>
+        <item>Kuwait</item>
+        <item>Latvia</item>
+        <item>Lebanon</item>
+        <item>Libya</item>
+        <item>Lithuania</item>
+        <item>Luxembourg</item>
+        <item>Macedonia</item>
+        <item>Malaysia</item>
+        <item>Mexico</item>
+        <item>Montenegro</item>
+        <item>Morocco</item>
+        <item>Netherlands</item>
+        <item>New Zealand</item>
+        <item>Nigeria</item>
+        <item>Norway</item>
+        <item>Oman</item>
+        <item>Peru</item>
+        <item>Philippines</item>
+        <item>Poland</item>
+        <item>Portugal</item>
+        <item>Puerto Rico</item>
+        <item>Qatar</item>
+        <item>Romania</item>
+        <item>Russia</item>
+        <item>Saudi Arabia</item>
+        <item>Senegal</item>
+        <item>Serbia</item>
+        <item>Singapore</item>
+        <item>Slovakia</item>
+        <item>Slovenia</item>
+        <item>South Africa</item>
+        <item>South Korea</item>
+        <item>Spain</item>
+        <item>Sweden</item>
+        <item>Switzerland</item>
+        <item>Taiwan</item>
+        <item>Tanzania</item>
+        <item>Thailand</item>
+        <item>Tunisia</item>
+        <item>Turkey</item>
+        <item>Uganda</item>
+        <item>Ukraine</item>
+        <item>United Arab Emirates</item>
+        <item>United Kingdom</item>
+        <item>Vietnam</item>
+        <item>Yemen</item>
+        <item>Zimbabwe</item>
+    </string-array>
 </resources>

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

@@ -49,4 +49,5 @@
     <string name="showNextVideoTitle">Show \"Next video\" item.</string>
     <string name="urlNotSupportedText">Url not Supported.</string>
     <string name="showSimilarVideosButtonText">Similar Videos</string>
+    <string name="contentCountryTitle">Video Content Country</string>
 </resources>

app/src/main/res/xml/settings_screen.xml

@@ -51,4 +51,10 @@
         android:title="@string/showNextVideoTitle"
         android:defaultValue="true" />
 
+    <ListPreference
+        android:key="@string/contentCountry"
+        android:title="@string/contentCountryTitle"
+        android:entries="@array/countryNames"
+        android:entryValues="@array/countryCodes"
+        android:defaultValue="" /> <!-- default will include no country code in URL-->
 </PreferenceScreen>