Feeds/categories can be sorted by "item" counts/alphabetically + sorting is dynamic for feeds/categories.

src/core/feedsmodelstandardcategory.cpp

@@ -31,6 +31,17 @@ QVariant FeedsModelStandardCategory::data(int column, int role) const {
         return QVariant();
       }
 
+    case Qt::EditRole:
+      if (column == FDS_MODEL_TITLE_INDEX) {
+        return m_title;
+      }
+      else if (column == FDS_MODEL_COUNTS_INDEX) {
+        return countOfUnreadMessages();
+      }
+      else {
+        return QVariant();
+      }
+
     case Qt::DisplayRole:
       if (column == FDS_MODEL_TITLE_INDEX) {
         return QString("%1%2").arg(m_title, "-C");

src/core/feedsmodelstandardfeed.cpp

@@ -80,6 +80,20 @@ QVariant FeedsModelStandardFeed::data(int column, int role) const {
       else if (column == FDS_MODEL_COUNTS_INDEX) {
         return QString("(%1)").arg(QString::number(countOfUnreadMessages()));
       }
+      else {
+        return QVariant();
+      }
+
+    case Qt::EditRole:
+      if (column == FDS_MODEL_TITLE_INDEX) {
+        return m_title;
+      }
+      else if (column == FDS_MODEL_COUNTS_INDEX) {
+        return countOfUnreadMessages();
+      }
+      else {
+        return QVariant();
+      }
 
     case Qt::DecorationRole:
       return column == FDS_MODEL_TITLE_INDEX ?

src/core/feedsproxymodel.cpp

@@ -3,6 +3,7 @@
 #include "core/feedsmodelcategory.h"
 #include "core/feedsmodelfeed.h"
 #include "core/feedsmodelrootitem.h"
+#include "core/defs.h"
 
 
 FeedsProxyModel::FeedsProxyModel(QObject *parent)
@@ -37,12 +38,20 @@ bool FeedsProxyModel::lessThan(const QModelIndex &left,
     // NOTE: Here we want to accomplish that ALL
     // categories are queued one after another and all
     // feeds are queued one after another too.
-    // Moreover, sort everything alphabetically.
+    // Moreover, sort everything alphabetically or
+    // by item counts, depending on the sort column.
 
     if (left_item->kind() == right_item->kind()) {
       // Both items are feeds or both items are categories.
+      if (left.column() == FDS_MODEL_COUNTS_INDEX) {
+        // User wants to sort according to counts.
+        return left_item->countOfUnreadMessages() < right_item->countOfUnreadMessages();
+      }
+      else {
+        // In other cases, sort by title.
         return left_item->title() < right_item->title();
       }
+    }
     else if (left_item->kind() == FeedsModelRootItem::Feed) {
       // Left item is feed, right item is category.
       return false;

src/core/messagesmodel.cpp

@@ -418,10 +418,6 @@ bool MessagesModel::setBatchMessagesRead(const QModelIndexList &messages, int re
   }
 }
 
-bool MessagesModel::switchAllMessageImportance() {
-  return false;
-}
-
 bool MessagesModel::setAllMessagesDeleted(int deleted) {
   QSqlDatabase db_handle = database();
 

src/core/messagesmodel.h

@@ -70,7 +70,6 @@ class MessagesModel : public QSqlTableModel {
     // of many messages via DIRECT SQL calls.
     // List of loaded feed ids is used for WHERE clause.
     // Model is reset after one of these methods is applied.
-    bool switchAllMessageImportance();
     bool setAllMessagesDeleted(int deleted);
     bool setAllMessagesRead(int read);
 

src/gui/messagesview.h

@@ -30,16 +30,19 @@ class MessagesView : public QTreeView {
     void openSelectedSourceMessagesInternally();
     void openSelectedMessagesInternally();
 
+    // Works with SELECTED messages only.
     void setSelectedMessagesReadStatus(int read);
     void markSelectedMessagesRead();
     void markSelectedMessagesUnread();
     void deleteSelectedMessages();
     void switchSelectedMessagesImportance();
 
+    // Sets ALL (unfiltered) messages read.
     void setAllMessagesReadStatus(int read);
     void setAllMessagesRead();
     void setAllMessagesUnread();
 
+    // Sets ALL (unfiltered) messages deleted.
     void setAllMessagesDeleteStatus(int deleted);
     void setAllMessagesDeleted();