diff --git a/CMakeLists.txt b/CMakeLists.txt
index d7ceafa71..5df6a68e5 100755
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -255,6 +255,7 @@ set(APP_SOURCES
   src/gui/messagesview.cpp
   src/gui/statusbar.cpp
   src/gui/iconfactory.cpp
+  src/gui/formcategorydetails.cpp
 
   # CORE sources.
   src/core/debugging.cpp
@@ -316,6 +317,7 @@ set(APP_HEADERS
   src/gui/feedsview.h
   src/gui/messagesview.h
   src/gui/statusbar.h
+  src/gui/formcategorydetails.h
 
   # CORE headers.
   src/core/settings.h
diff --git a/src/core/feedsmodel.cpp b/src/core/feedsmodel.cpp
index 75947b081..eefa4c89d 100644
--- a/src/core/feedsmodel.cpp
+++ b/src/core/feedsmodel.cpp
@@ -294,12 +294,25 @@ QList<FeedsModelFeed*> FeedsModel::feedsForIndex(const QModelIndex &index) {
   return getFeeds(item);
 }
 
-bool FeedsModel::isUnequal(FeedsModelFeed *lhs, FeedsModelFeed *rhs) {
-  return !isEqual(lhs, rhs);
-}
+QList<FeedsModelFeed*> FeedsModel::feedsForIndexes(const QModelIndexList &indexes) {
+  QList<FeedsModelFeed*> feeds;
 
-bool FeedsModel::isEqual(FeedsModelFeed *lhs, FeedsModelFeed *rhs) {
-  return lhs->id() == rhs->id();
+  // Get selected feeds for each index.
+  foreach (const QModelIndex &index, indexes) {
+    feeds.append(feedsForIndex(index));
+  }
+
+  // Now we obtained all feeds from corresponding indexes.
+  if (indexes.size() != feeds.size()) {
+    // Selection contains duplicate feeds (for
+    // example situation where feed and its parent category are both
+    // selected). So, remove duplicates from the list.
+    qSort(feeds.begin(), feeds.end(), FeedsModelRootItem::lessThan);
+    feeds.erase(std::unique(feeds.begin(), feeds.end(), FeedsModelRootItem::isEqual),
+                feeds.end());
+  }
+
+  return feeds;
 }
 
 bool FeedsModel::markFeedsRead(const QList<FeedsModelFeed*> &feeds,
@@ -370,28 +383,6 @@ bool FeedsModel::markFeedsDeleted(const QList<FeedsModelFeed *> &feeds,
   }
 }
 
-
-QList<FeedsModelFeed*> FeedsModel::feedsForIndexes(const QModelIndexList &indexes) {
-  QList<FeedsModelFeed*> feeds;
-
-  // Get selected feeds for each index.
-  foreach (const QModelIndex &index, indexes) {
-    feeds.append(feedsForIndex(index));
-  }
-
-  // Now we obtained all feeds from corresponding indexes.
-  if (indexes.size() != feeds.size()) {
-    // Selection contains duplicate feeds (for
-    // example situation where feed and its parent category are both
-    // selected). So, remove duplicates from the list.
-    qSort(feeds.begin(), feeds.end(), isUnequal);
-    feeds.erase(std::unique(feeds.begin(), feeds.end(), isEqual),
-                feeds.end());
-  }
-
-  return feeds;
-}
-
 QHash<int, FeedsModelCategory*> FeedsModel::getAllCategories() {
   return getCategories(m_rootItem);
 }
diff --git a/src/core/feedsmodel.h b/src/core/feedsmodel.h
index f5a144174..52fe8fd4c 100644
--- a/src/core/feedsmodel.h
+++ b/src/core/feedsmodel.h
@@ -54,10 +54,6 @@ class FeedsModel : public QAbstractItemModel {
     // Returns feeds contained within single index.
     QList<FeedsModelFeed*> feedsForIndex(const QModelIndex &index);
 
-    // Equality "operators" used for identifying duplicate feeds.
-    static bool isUnequal(FeedsModelFeed *lhs, FeedsModelFeed *rhs);
-    static bool isEqual(FeedsModelFeed *lhs, FeedsModelFeed *rhs);
-
   public slots:
     bool markFeedsRead(const QList<FeedsModelFeed*> &feeds, int read);
     bool markFeedsDeleted(const QList<FeedsModelFeed*> &feeds, int deleted);
diff --git a/src/core/feedsmodelrootitem.cpp b/src/core/feedsmodelrootitem.cpp
index 488077b5e..4644e32c3 100755
--- a/src/core/feedsmodelrootitem.cpp
+++ b/src/core/feedsmodelrootitem.cpp
@@ -98,3 +98,18 @@ QList<FeedsModelRootItem *> FeedsModelRootItem::childItems() const {
 void FeedsModelRootItem::clearChilds() {
   m_childItems.clear();
 }
+
+bool FeedsModelRootItem::isEqual(FeedsModelRootItem *lhs,
+                                 FeedsModelRootItem *rhs) {
+  return (lhs->kind() == rhs->kind()) && (lhs->id() == rhs->id());
+}
+
+bool FeedsModelRootItem::lessThan(FeedsModelRootItem *lhs,
+                                  FeedsModelRootItem *rhs) {
+  if (lhs->kind() == rhs->kind()) {
+    return lhs->id() < rhs->id();
+  }
+  else {
+    return false;
+  }
+}
diff --git a/src/core/feedsmodelrootitem.h b/src/core/feedsmodelrootitem.h
index 2e7bdf059..fdb1046f5 100755
--- a/src/core/feedsmodelrootitem.h
+++ b/src/core/feedsmodelrootitem.h
@@ -54,6 +54,10 @@ class FeedsModelRootItem {
     // Removes all childs from this item.
     void clearChilds();
 
+    // Compares two model items.
+    static bool isEqual(FeedsModelRootItem *lhs, FeedsModelRootItem *rhs);
+    static bool lessThan(FeedsModelRootItem *lhs, FeedsModelRootItem *rhs);
+
   protected:
     Kind m_kind;
     QString m_title;
diff --git a/src/gui/feedmessageviewer.cpp b/src/gui/feedmessageviewer.cpp
index 47807c664..8ca418f76 100644
--- a/src/gui/feedmessageviewer.cpp
+++ b/src/gui/feedmessageviewer.cpp
@@ -185,6 +185,8 @@ void FeedMessageViewer::createConnections() {
           SIGNAL(triggered()), this, SLOT(updateSelectedFeeds()));
   connect(FormMain::getInstance()->m_ui->m_actionUpdateAllFeeds,
           SIGNAL(triggered()), this, SLOT(updateAllFeeds()));
+  connect(FormMain::getInstance()->m_ui->m_actionAddNewCategory,
+          SIGNAL(triggered()), m_feedsView, SLOT(addNewCategory()));
 }
 
 void FeedMessageViewer::initialize() {
diff --git a/src/gui/feedsview.cpp b/src/gui/feedsview.cpp
index a433555d3..1b5e996bd 100644
--- a/src/gui/feedsview.cpp
+++ b/src/gui/feedsview.cpp
@@ -6,10 +6,12 @@
 #include "core/feedsproxymodel.h"
 #include "core/feedsmodelrootitem.h"
 #include "gui/formmain.h"
+#include "gui/formcategorydetails.h"
 
 #include <QMenu>
 #include <QHeaderView>
 #include <QContextMenuEvent>
+#include <QPointer>
 
 
 FeedsView::FeedsView(QWidget *parent) : QTreeView(parent), m_contextMenu(NULL) {
@@ -51,6 +53,18 @@ void FeedsView::clearSelectedFeeds() {
   setSelectedFeedsClearStatus(1);
 }
 
+void FeedsView::addNewCategory() {
+  QPointer<FormCategoryDetails> form_pointer = new FormCategoryDetails(this);
+
+  if (form_pointer.data()->exec() == QDialog::Accepted) {
+    // User submitted some new category.
+
+
+  }
+
+  delete form_pointer.data();
+}
+
 void FeedsView::markSelectedFeedsReadStatus(int read) {
   m_sourceModel->markFeedsRead(selectedFeeds(), read);
   updateCountsOfSelectedFeeds(false);
diff --git a/src/gui/feedsview.h b/src/gui/feedsview.h
index 37367ae85..f49f56b47 100644
--- a/src/gui/feedsview.h
+++ b/src/gui/feedsview.h
@@ -33,6 +33,9 @@ class FeedsView : public QTreeView {
     void setSelectedFeedsClearStatus(int clear);
     void clearSelectedFeeds();
 
+    // Category operators.
+    void addNewCategory();
+
     // Reloads counts for selected feeds.
     void updateCountsOfSelectedFeeds(bool update_total_too = true);
 
diff --git a/src/gui/formcategorydetails.cpp b/src/gui/formcategorydetails.cpp
new file mode 100644
index 000000000..ffa4ed019
--- /dev/null
+++ b/src/gui/formcategorydetails.cpp
@@ -0,0 +1,25 @@
+#include "gui/formcategorydetails.h"
+
+#include "gui/iconthemefactory.h"
+#include "gui/feedsview.h"
+
+
+FormCategoryDetails::FormCategoryDetails(FeedsView *parent)
+  : QDialog(parent) {
+  // Set flags and attributes.
+  setWindowFlags(Qt::MSWindowsFixedSizeDialogHint | Qt::Dialog);
+  setWindowIcon(IconThemeFactory::getInstance()->fromTheme("document-new"));
+}
+
+FormCategoryDetails::FormCategoryDetails(FeedsModelCategory *category,
+                                         FeedsView *parent)
+  :QDialog(parent) {
+  // Set flags and attributes.
+  setWindowFlags(Qt::MSWindowsFixedSizeDialogHint | Qt::Dialog);
+  setWindowIcon(IconThemeFactory::getInstance()->fromTheme("document-new"));
+
+}
+
+FormCategoryDetails::~FormCategoryDetails() {
+  qDebug("Destroying FormCategoryDetails instance.");
+}
diff --git a/src/gui/formcategorydetails.h b/src/gui/formcategorydetails.h
new file mode 100644
index 000000000..527e13e02
--- /dev/null
+++ b/src/gui/formcategorydetails.h
@@ -0,0 +1,31 @@
+#ifndef FORMCATEGORYDETAILS_H
+#define FORMCATEGORYDETAILS_H
+
+#include <QDialog>
+
+
+class FeedsModelCategory;
+class FeedsView;
+
+class FormCategoryDetails : public QDialog {
+    Q_OBJECT
+
+  public:
+    // Constructors and destructors.
+    // This constructor is supposed to create new categories.
+    explicit FormCategoryDetails(FeedsView *parent = 0);
+
+    // This constructor is supposed to edit existing categories.
+    explicit FormCategoryDetails(FeedsModelCategory *category,
+                                 FeedsView *parent = 0);
+
+    // Destructor.
+    virtual ~FormCategoryDetails();
+
+  signals:
+
+  public slots:
+
+};
+
+#endif // FORMCATEGORYDETAILS_H