Utils: Un-export TreeViewComboBoxView

It's only used as QTreeView in user code.

Change-Id: I1db77e6a5acc6b6feec914a025c403e74cb6cef2
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/libs/utils/treeviewcombobox.cpp

@@ -5,21 +5,23 @@
 
 #include <QWheelEvent>
 
-using namespace Utils;
+namespace Utils {
 
-TreeViewComboBoxView::TreeViewComboBoxView(QWidget *parent)
-    : QTreeView(parent)
+class TreeViewComboBoxView final : public QTreeView
 {
+public:
+    TreeViewComboBoxView()
+    {
         // TODO: Disable the root for all items (with a custom delegate?)
         setRootIsDecorated(false);
-}
+    }
 
-void TreeViewComboBoxView::adjustWidth(int width)
-{
+    void adjustWidth(int width)
+    {
         setMaximumWidth(width);
         setMinimumWidth(qMin(qMax(sizeHintForColumn(0), minimumSizeHint().width()), width));
-}
-
+    }
+};
 
 TreeViewComboBox::TreeViewComboBox(QWidget *parent)
     : QComboBox(parent)
@@ -135,7 +137,9 @@ void TreeViewComboBox::hidePopup()
         QComboBox::hidePopup();
 }
 
-TreeViewComboBoxView *TreeViewComboBox::view() const
+QTreeView *TreeViewComboBox::view() const
 {
     return m_view;
 }
+
+} // Utils

src/libs/utils/treeviewcombobox.h

@@ -10,13 +10,6 @@
 
 namespace Utils {
 
-class QTCREATOR_UTILS_EXPORT TreeViewComboBoxView : public QTreeView
-{
-public:
-    TreeViewComboBoxView(QWidget *parent = nullptr);
-    void adjustWidth(int width);
-};
-
 class QTCREATOR_UTILS_EXPORT TreeViewComboBox : public QComboBox
 {
 public:
@@ -29,14 +22,15 @@ public:
     void showPopup() override;
     void hidePopup() override;
 
-    TreeViewComboBoxView *view() const;
+    QTreeView *view() const;
 
 private:
     QModelIndex indexBelow(QModelIndex index);
     QModelIndex indexAbove(QModelIndex index);
     QModelIndex lastIndex(const QModelIndex &index);
 
-    TreeViewComboBoxView *m_view;
+    class TreeViewComboBoxView *m_view;
     bool m_skipNextHide = false;
 };
-}
+
+} // Utils