Get rid of QtGetScrollBarsContainer() from wxWindow API under wxQt

Because It is simpler to initialize (the inherited) m_qtContainer member
directly in derived classes during construction process, and make the API
a little bit cleaner.

include/wx/qt/frame.h

@@ -51,7 +51,6 @@ public:
     virtual void RemoveChild( wxWindowBase *child ) override;
 
     QMainWindow *GetQMainWindow() const;
-    virtual QAbstractScrollArea *QtGetScrollBarsContainer() const override;
 
 protected:
     virtual wxPoint GetClientAreaOrigin() const override;

include/wx/qt/listbox.h

@@ -87,8 +87,6 @@ protected:
 
     virtual int DoListHitTest(const wxPoint& point) const override;
 
-    virtual QAbstractScrollArea *QtGetScrollBarsContainer() const override;
-
 #if wxUSE_CHECKLISTBOX
     bool       m_hasCheckBoxes;
 #endif // wxUSE_CHECKLISTBOX

include/wx/qt/textctrl.h

@@ -93,8 +93,6 @@ protected:
     virtual bool DoLoadFile(const wxString& file, int fileType) override;
     virtual bool DoSaveFile(const wxString& file, int fileType) override;
 
-    virtual QAbstractScrollArea *QtGetScrollBarsContainer() const override;
-
     // From wxTextEntry:
     virtual wxWindow *GetEditableWindow() override { return this; }
 

include/wx/qt/window.h

@@ -181,8 +181,6 @@ public:
     virtual void QtHandleShortcut ( int command );
 #endif // wxUSE_ACCEL
 
-    virtual QAbstractScrollArea *QtGetScrollBarsContainer() const;
-
 #if wxUSE_TOOLTIPS
     // applies tooltip to the widget.
     virtual void QtApplyToolTip(const wxString& text);
@@ -228,11 +226,13 @@ protected:
     // itself.
     virtual QWidget* QtGetParentWidget() const { return GetHandle(); }
 
-    QWidget *m_qtWindow;
+    QWidget             *m_qtWindow;
+    QAbstractScrollArea *m_qtContainer;  // either nullptr or the same as m_qtWindow pointer
+                                         // if m_qtWindow derives from QAbstractScrollArea,
+                                         // e.g. QListWidget and QTextEdit.
 
 private:
     void Init();
-    QAbstractScrollArea *m_qtContainer;  // either nullptr or the same as m_qtWindow pointer
 
     // Return the viewport of m_qtContainer, if it's used, or just m_qtWindow.
     //

src/qt/frame.cpp

@@ -209,11 +209,6 @@ void wxFrame::RemoveChild( wxWindowBase *child )
     wxFrameBase::RemoveChild( child );
 }
 
-QAbstractScrollArea *wxFrame::QtGetScrollBarsContainer() const
-{
-    return nullptr;
-}
-
 // get the origin of the client area in the client coordinates
 // excluding any menubar and toolbar if any.
 wxPoint wxFrame::GetClientAreaOrigin() const

src/qt/listbox.cpp

@@ -178,6 +178,7 @@ void wxListBox::DoCreate(wxWindow* parent, long style)
     Init();
 
     m_qtWindow =
+    m_qtContainer =
     m_qtListWidget = new wxQtListWidget( parent, this );
 
     if ( style & wxLB_SORT )
@@ -368,11 +369,6 @@ void wxListBox::QtSendEvent(wxEventType evtType, int rowIndex, bool selected)
     SendEvent(evtType, rowIndex, selected);
 }
 
-QAbstractScrollArea *wxListBox::QtGetScrollBarsContainer() const
-{
-    return static_cast<QAbstractScrollArea*>(m_qtListWidget);
-}
-
 void wxListBox::UnSelectAll()
 {
     Q_FOREACH(QListWidgetItem* l, m_qtListWidget->selectedItems())

src/qt/textctrl.cpp

@@ -676,6 +676,9 @@ bool wxTextCtrl::Create(wxWindow *parent,
 
     m_qtEdit->SetStyleFlags(style);
 
+    m_qtWindow =
+    m_qtContainer = m_qtEdit->ScrollBarsContainer();
+
     if ( QtCreateControl( parent, id, pos, size, style, validator, name ) )
     {
         // set the initial text value without sending the event:
@@ -910,8 +913,3 @@ QWidget *wxTextCtrl::GetHandle() const
 {
     return (QWidget *) m_qtEdit->GetHandle();
 }
-
-QAbstractScrollArea *wxTextCtrl::QtGetScrollBarsContainer() const
-{
-    return m_qtEdit->ScrollBarsContainer();
-}

src/qt/window.cpp

@@ -443,8 +443,8 @@ void wxWindowQt::AddChild( wxWindowBase *child )
 {
     // Make sure all children are children of the inner scroll area widget (if any):
 
-    if ( QtGetScrollBarsContainer() )
-        QtReparent( child->GetHandle(), QtGetScrollBarsContainer()->viewport() );
+    if ( m_qtContainer )
+        QtReparent( child->GetHandle(), m_qtContainer->viewport() );
 
     wxWindowBase::AddChild( child );
 }
@@ -548,9 +548,9 @@ void wxWindowQt::Update()
 {
     wxLogTrace(TRACE_QT_WINDOW, wxT("wxWindow::Update %s"), GetName());
     // send the paint event to the inner widget in scroll areas:
-    if ( QtGetScrollBarsContainer() )
+    if ( m_qtContainer )
     {
-        QtGetScrollBarsContainer()->viewport()->repaint();
+        m_qtContainer->viewport()->repaint();
     } else {
         GetHandle()->repaint();
     }
@@ -561,9 +561,9 @@ void wxWindowQt::Refresh( bool WXUNUSED( eraseBackground ), const wxRect *rect )
     QWidget *widget;
 
     // get the inner widget in scroll areas:
-    if ( QtGetScrollBarsContainer() )
+    if ( m_qtContainer )
     {
-        widget = QtGetScrollBarsContainer()->viewport();
+        widget = m_qtContainer->viewport();
     } else {
         widget = GetHandle();
     }
@@ -701,15 +701,14 @@ QWidget *wxWindowQt::QtGetClientWidget() const
 /* Returns a scrollbar for the given orientation */
 QScrollBar *wxWindowQt::QtGetScrollBar( int orientation ) const
 {
-    QAbstractScrollArea *scrollArea = QtGetScrollBarsContainer();
-    wxCHECK_MSG( scrollArea, nullptr, "Window without scrolling area" );
+    wxCHECK_MSG( m_qtContainer, nullptr, "Window without scrolling area" );
 
     if ( orientation == wxHORIZONTAL )
     {
-        return scrollArea->horizontalScrollBar();
+        return m_qtContainer->horizontalScrollBar();
     }
 
-    return scrollArea->verticalScrollBar();
+    return m_qtContainer->verticalScrollBar();
 }
 
 
@@ -780,8 +779,8 @@ void wxWindowQt::ScrollWindow( int dx, int dy, const wxRect *rect )
 {
     // check if this is a scroll area (scroll only inner viewport)
     QWidget *widget;
-    if ( QtGetScrollBarsContainer() )
-        widget = QtGetScrollBarsContainer()->viewport();
+    if ( m_qtContainer )
+        widget = m_qtContainer->viewport();
     else
         widget = GetHandle();
     // scroll the widget or the specified rect (not children)
@@ -1166,8 +1165,8 @@ bool wxWindowQt::QtSetBackgroundStyle()
 {
     QWidget *widget;
     // if it is a scroll area, don't make transparent (invisible) scroll bars:
-    if ( QtGetScrollBarsContainer() )
-        widget = QtGetScrollBarsContainer()->viewport();
+    if ( m_qtContainer )
+        widget = m_qtContainer->viewport();
     else
         widget = GetHandle();
     // check if the control is created (wxGTK requires calling it before):
@@ -1283,8 +1282,8 @@ bool wxWindowQt::QtHandlePaintEvent ( QWidget *handler, QPaintEvent *event )
      * for the client area (the scrolled part). Events for the whole window
      * (including scrollbars and maybe status or menu bars are handled by Qt */
 
-    if ( (QtGetScrollBarsContainer() &&
-          QtGetScrollBarsContainer() != handler) || handler != GetHandle() )
+    if ( (m_qtContainer &&
+          m_qtContainer != handler) || handler != GetHandle() )
     {
         return false;
     }
@@ -1294,10 +1293,10 @@ bool wxWindowQt::QtHandlePaintEvent ( QWidget *handler, QPaintEvent *event )
 
     // Prepare the Qt painter for wxWindowDC:
     bool ok = false;
-    if ( QtGetScrollBarsContainer() )
+    if ( m_qtContainer )
     {
         // QScrollArea can only draw in the viewport:
-        ok = m_qtPainter->begin( QtGetScrollBarsContainer()->viewport() );
+        ok = m_qtPainter->begin( m_qtContainer->viewport() );
     }
     if ( !ok )
     {
@@ -1774,11 +1773,6 @@ QWidget *wxWindowQt::GetHandle() const
     return m_qtWindow;
 }
 
-QAbstractScrollArea *wxWindowQt::QtGetScrollBarsContainer() const
-{
-    return m_qtContainer;
-}
-
 void wxWindowQt::QtSetPicture( QPicture* pict )
 {
     m_qtPicture.reset(pict);