diff --git a/src/vlistwidget.cpp b/src/vlistwidget.cpp
index c5d93a66..11a6a047 100644
--- a/src/vlistwidget.cpp
+++ b/src/vlistwidget.cpp
@@ -1,19 +1,28 @@
 #include "vlistwidget.h"
+
 #include <QVBoxLayout>
 #include <QKeyEvent>
 #include <QCoreApplication>
 #include <QDebug>
 #include <QLabel>
+
+#include "vlineedit.h"
 #include "utils/vutils.h"
 
 const QString searchPrefix("Search for: ");
+
 //TODO: make the style configuable
 const QString c_searchKeyStyle("border:none; background:#eaeaea; color:%1;");
+
 const QString c_colorNotMatch("#fd676b");
+
 const QString c_colorMatch("grey");
 
-VListWidget::VListWidget(QWidget *parent):QListWidget(parent), m_isInSearch(false),
-    m_curItemIdx(-1), m_curItem(nullptr)
+VListWidget::VListWidget(QWidget *parent)
+        : QListWidget(parent),
+          m_isInSearch(false),
+          m_curItemIdx(-1),
+          m_curItem(nullptr)
 {
     m_label = new QLabel(searchPrefix, this);
     //TODO: make the style configuable
@@ -122,13 +131,15 @@ void VListWidget::keyPressEvent(QKeyEvent *p_event)
     }
 }
 
-void VListWidget::enterSearchMode() {
+void VListWidget::enterSearchMode()
+{
     m_label->show();
     m_searchKey->show();
     setSelectionMode(QAbstractItemView::SingleSelection);
 }
 
-void VListWidget::exitSearchMode(bool restoreSelection) {
+void VListWidget::exitSearchMode(bool restoreSelection)
+{
     m_searchKey->clear();
     m_label->hide();
     m_searchKey->hide();
@@ -138,8 +149,8 @@ void VListWidget::exitSearchMode(bool restoreSelection) {
     }
 }
 
-
-void VListWidget::refresh() {
+void VListWidget::refresh()
+{
     m_isInSearch = false;
     m_hitItems = findItems("", Qt::MatchContains);
     m_hitCount = m_hitItems.count();
@@ -160,7 +171,8 @@ void VListWidget::refresh() {
     }
 }
 
-void VListWidget::clear() {
+void VListWidget::clear()
+{
     QListWidget::clear();
     m_hitCount = 0;
     m_hitItems.clear();
@@ -170,7 +182,8 @@ void VListWidget::clear() {
     exitSearchMode();
 }
 
-void VListWidget::selectItem(QListWidgetItem *item) {
+void VListWidget::selectItem(QListWidgetItem *item)
+{
     if (item) {
         for(const auto& it : selectedItems()) {
             it->setSelected(false);
diff --git a/src/vlistwidget.h b/src/vlistwidget.h
index f7c72afb..c7df808e 100644
--- a/src/vlistwidget.h
+++ b/src/vlistwidget.h
@@ -2,22 +2,27 @@
 #define VLISTWIDGET_H
 
 #include <QListWidget>
-#include <QLineEdit>
 #include <QPainter>
 #include <QStyleOptionViewItem>
 #include <QModelIndex>
 #include <QItemDelegate>
-#include "vlineedit.h"
 #include <QDebug>
 #include <QLabel>
 
+class VLineEdit;
+
 class VItemDelegate : public QItemDelegate
 {
 public:
-    explicit VItemDelegate(QObject *parent = Q_NULLPTR):QItemDelegate(parent), m_searchKey() {
+    explicit VItemDelegate(QObject *parent = Q_NULLPTR)
+        : QItemDelegate(parent), m_searchKey()
+    {
     }
 
-    void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const {
+    void paint(QPainter *painter,
+               const QStyleOptionViewItem &option,
+               const QModelIndex &index) const Q_DECL_OVERRIDE
+    {
         painter->save();
         QPainter::CompositionMode oldCompMode = painter->compositionMode();
         // set background color
@@ -28,6 +33,7 @@ public:
         } else {
             // use default brush
         }
+
         painter->drawRect(option.rect);
 
         Qt::GlobalColor hitPenColor = Qt::blue;
@@ -39,7 +45,8 @@ public:
         if (value.isValid()) {
             QString text = value.toString();
             int idx;
-            bool isHit = !m_searchKey.isEmpty() && (idx=text.indexOf(m_searchKey, 0, Qt::CaseInsensitive)) != -1;
+            bool isHit = !m_searchKey.isEmpty()
+                         && (idx = text.indexOf(m_searchKey, 0, Qt::CaseInsensitive)) != -1;
             if (isHit) {
                 qDebug() << QString("highlight: %1 (with: %2)").arg(text).arg(m_searchKey);
                 // split the text by the search key
@@ -63,7 +70,13 @@ public:
         painter->restore();
     }
 
-    void drawText(QPainter *painter, Qt::GlobalColor penColor, QRectF& rect, int flags, QString text, QRectF& boundRect) const {
+    void drawText(QPainter *painter,
+                  Qt::GlobalColor penColor,
+                  QRectF& rect,
+                  int flags,
+                  QString text,
+                  QRectF& boundRect) const
+    {
         if (!text.isEmpty()) {
             painter->setPen(QPen(penColor));
             painter->drawText(rect, flags, text, &boundRect);
@@ -71,7 +84,8 @@ public:
         }
     }
 
-    void setSearchKey(const QString& key) {
+    void setSearchKey(const QString& key)
+    {
         m_searchKey = key;
     }
 
@@ -83,16 +97,23 @@ class VListWidget : public QListWidget
 {
 public:
     explicit VListWidget(QWidget *parent = Q_NULLPTR);
-    void keyPressEvent(QKeyEvent *event);
+
     void selectItem(QListWidgetItem *item);
+
     void exitSearchMode(bool restoreSelection=true);
+
     void enterSearchMode();
+
     void refresh();
 
-public Q_SLOTS:
-    void handleSearchKeyChanged(const QString& updatedText);
+public slots:
     void clear();
 
+private slots:
+    void handleSearchKeyChanged(const QString& updatedText);
+
+protected:
+    void keyPressEvent(QKeyEvent *p_event) Q_DECL_OVERRIDE;
 
 private:
     QLabel *m_label;
@@ -100,10 +121,19 @@ private:
     bool m_isInSearch;
 
     VItemDelegate* m_delegateObj;
-    QList<QListWidgetItem*> m_hitItems; // items that are matched by the search key
-    int m_hitCount; // how many items are matched, if no search key or key is empty string, all items are matched
-    int m_curItemIdx; // current selected item index
-    QListWidgetItem* m_curItem; // current selected item
+
+    // Items that are matched by the search key.
+    QList<QListWidgetItem*> m_hitItems;
+
+    // How many items are matched, if no search key or key is empty string,
+    // all items are matched.
+    int m_hitCount;
+
+    // Current selected item index.
+    int m_curItemIdx;
+
+    // Current selected item.
+    QListWidgetItem* m_curItem;
 };
 
 #endif // VLISTWIDGET_H