implement support for article sorting modes instead of previous preference options

org.fox.ttrss/src/main/java/org/fox/ttrss/ArticlePager.java

@@ -233,7 +233,7 @@ public class ArticlePager extends Fragment {
 				put("view_mode", m_activity.getViewMode());
 				put("skip", String.valueOf(fskip));
 				put("include_nested", "true");
-				put("order_by", m_prefs.getBoolean("oldest_first", false) ? "date_reverse" : "");
+				put("order_by", m_activity.getSortMode());
 				
 				if (feed.is_cat) put("is_cat", "true");
 				

org.fox.ttrss/src/main/java/org/fox/ttrss/FeedsActivity.java

@@ -2,6 +2,9 @@ package org.fox.ttrss;
 
 
 import android.annotation.SuppressLint;
+import android.app.AlertDialog;
+import android.app.Dialog;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.SharedPreferences;
 import android.os.Bundle;
@@ -297,10 +300,58 @@ public class FeedsActivity extends OnlineActivity implements HeadlinesEventListe
             //getSupportFragmentManager().popBackStack();
 			return true;
         case R.id.headlines_toggle_sort_order:
-            SharedPreferences.Editor editor = m_prefs.edit();
+            Dialog dialog = new Dialog(this);
-            editor.putBoolean("oldest_first", !m_prefs.getBoolean("oldest_first", false));
+
-            editor.commit();
+            String sortMode = getSortMode();
+
+            int selectedIndex = 0;
+
+            if (sortMode.equals("feed_dates")) {
+                selectedIndex = 1;
+            } else if (sortMode.equals("date_reverse")) {
+                selectedIndex = 2;
+            } else if (sortMode.equals("title")) {
+                selectedIndex = 3;
+            }
+
+            AlertDialog.Builder builder = new AlertDialog.Builder(this)
+                    .setTitle(getString(R.string.headlines_sort_articles_title))
+                    .setSingleChoiceItems(
+                            new String[] {
+                                    getString(R.string.headlines_sort_default),
+                                    getString(R.string.headlines_sort_newest_first),
+                                    getString(R.string.headlines_sort_oldest_first),
+                                    getString(R.string.headlines_sort_title)
+                            },
+                            selectedIndex, new DialogInterface.OnClickListener() {
+                                @Override
+                                public void onClick(DialogInterface dialog,
+                                                    int which) {
+                                    Log.d(TAG, "which:" + which);
+
+                                    switch (which) {
+                                        case 0:
+                                            setSortMode("default");
+                                            break;
+                                        case 1:
+                                            setSortMode("feed_dates");
+                                            break;
+                                        case 2:
+                                            setSortMode("date_reverse");
+                                            break;
+                                        case 3:
+                                            setSortMode("title");
+                                            break;
+                                    }
+                                    dialog.cancel();
+
                                     refresh();
+                                }
+                            });
+
+            dialog = builder.create();
+            dialog.show();
+
             return true;
         case R.id.show_feeds:
 			setUnreadOnly(!getUnreadOnly());

org.fox.ttrss/src/main/java/org/fox/ttrss/HeadlinesFragment.java

@@ -541,7 +541,7 @@ public class HeadlinesFragment extends Fragment implements OnItemClickListener,
 					put("offset", String.valueOf(0));
 					put("skip", String.valueOf(fskip));
 					put("include_nested", "true");
-					put("order_by", m_prefs.getBoolean("oldest_first", false) ? "date_reverse" : "");
+					put("order_by", m_activity.getSortMode());
 					
 					if (isCat) put("is_cat", "true");
 

org.fox.ttrss/src/main/java/org/fox/ttrss/OnlineActivity.java

@@ -1723,6 +1723,18 @@ public class OnlineActivity extends CommonActivity {
 
 	}
 
+    public String getSortMode() {
+        return m_prefs.getString("headlines_sort_mode", "default");
+    }
+
+    public void setSortMode(String sortMode) {
+        Log.d(TAG, "setSortMode:" + sortMode);
+
+        SharedPreferences.Editor editor = m_prefs.edit();
+        editor.putString("headlines_sort_mode", sortMode);
+        editor.commit();
+    }
+
     public void setViewMode(String viewMode) {
 		SharedPreferences.Editor editor = m_prefs.edit();
 		editor.putString("view_mode", viewMode);

org.fox.ttrss/src/main/java/org/fox/ttrss/offline/OfflineActivity.java

@@ -824,6 +824,16 @@ public class OfflineActivity extends CommonActivity {
 		editor.commit();
 	}
 
+    /* public String getSortMode() {
+        return m_prefs.getString("headlines_sort_mode", "default");
+    }
+
+    public void setSortMode(String sortMode) {
+        SharedPreferences.Editor editor = m_prefs.edit();
+        editor.putString("headlines_sort_mode", sortMode);
+        editor.commit();
+    } */
+
 	public String getViewMode() {		
 		return m_prefs.getString("offline_view_mode", "adaptive");
 	}

org.fox.ttrss/src/main/res/values/strings.xml

@@ -244,5 +244,10 @@
     <string name="error_loading_image">Error loading image.</string>
     <string name="open_parent">Open parent</string>
     <string name="toggle_sort_order">Toggle oldest first</string>
+    <string name="headlines_sort_default">Default</string>
+    <string name="headlines_sort_newest_first">Newest first</string>
+    <string name="headlines_sort_oldest_first">Oldest first</string>
+    <string name="headlines_sort_title">Title</string>
+    <string name="headlines_sort_articles_title">Sort articles</string>
 
 </resources>

org.fox.ttrss/src/main/res/xml/preferences.xml

@@ -104,11 +104,6 @@
             android:summary="@string/pref_headlines_full_content_long"
             android:title="@string/pref_headlines_full_content" /> -->
         
-        <CheckBoxPreference
-            android:defaultValue="false"
-            android:key="oldest_first"
-            android:summary="@string/requires_api5"
-            android:title="@string/offline_oldest_first" />
         <CheckBoxPreference
             android:defaultValue="false"
             android:key="headlines_mark_read_scroll"
@@ -171,10 +166,6 @@
             android:key="offline_image_cache_enabled"
             android:summary="@string/offline_image_cache_enabled_summary"
             android:title="@string/offline_image_cache_enabled" />
-        <CheckBoxPreference
-            android:defaultValue="false"
-            android:key="offline_oldest_first"
-            android:title="@string/offline_oldest_first" />
     </PreferenceCategory>
     <PreferenceCategory android:title="@string/debugging" >
         <CheckBoxPreference