Introduced wxDCPenChanger and wxDCBrushChanger.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39269 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dc.h

@@ -1,5 +1,5 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        dc.h
+// Name:        wx/dc.h
 // Purpose:     wxDC class
 // Author:      Vadim Zeitlin
 // Modified by:
@@ -868,6 +868,68 @@ private:
     DECLARE_NO_COPY_CLASS(wxDCTextColourChanger)
 };
 
+// ----------------------------------------------------------------------------
+// helper class: you can use it to temporarily change the DC pen and
+// restore it automatically when the object goes out of scope
+// ----------------------------------------------------------------------------
+
+class WXDLLEXPORT wxDCPenChanger
+{
+public:
+    wxDCPenChanger(wxDC& dc) : m_dc(dc), m_penOld() { }
+
+    ~wxDCPenChanger()
+    {
+        if ( m_penOld.Ok() )
+            m_dc.SetPen(m_penOld);
+    }
+
+    void Set(const wxPen& pen)
+    {
+        if ( !m_penOld.Ok() )
+            m_penOld = m_dc.GetPen();
+        m_dc.SetPen(pen);
+    }
+
+private:
+    wxDC& m_dc;
+
+    wxPen m_penOld;
+
+    DECLARE_NO_COPY_CLASS(wxDCPenChanger)
+};
+
+// ----------------------------------------------------------------------------
+// helper class: you can use it to temporarily change the DC brush and
+// restore it automatically when the object goes out of scope
+// ----------------------------------------------------------------------------
+
+class WXDLLEXPORT wxDCBrushChanger
+{
+public:
+    wxDCBrushChanger(wxDC& dc) : m_dc(dc), m_brushOld() { }
+
+    ~wxDCBrushChanger()
+    {
+        if ( m_brushOld.Ok() )
+            m_dc.SetBrush(m_brushOld);
+    }
+
+    void Set(const wxBrush& brush)
+    {
+        if ( !m_brushOld.Ok() )
+            m_brushOld = m_dc.GetBrush();
+        m_dc.SetBrush(brush);
+    }
+
+private:
+    wxDC& m_dc;
+
+    wxBrush m_brushOld;
+
+    DECLARE_NO_COPY_CLASS(wxDCBrushChanger)
+};
+
 // ----------------------------------------------------------------------------
 // another small helper class: sets the clipping region in its ctor and
 // destroys it in the dtor

src/generic/renderg.cpp

@@ -232,12 +232,13 @@ wxRendererGeneric::DrawTreeItemButton(wxWindow * WXUNUSED(win),
                                       int flags)
 {
     // store settings
-    wxPen pen(dc.GetPen());
-    wxBrush brush(dc.GetBrush());
+    wxDCPenChanger penChanger(dc);
+    wxDCBrushChanger brushChanger(dc);
 
     // white background
-    dc.SetPen(*wxGREY_PEN);
-    dc.SetBrush(*wxWHITE_BRUSH);
+    penChanger.Set(*wxGREY_PEN);
+    brushChanger.Set(*wxWHITE_BRUSH);
+
     dc.DrawRectangle(rect);
 
     // black lines
@@ -257,9 +258,6 @@ wxRendererGeneric::DrawTreeItemButton(wxWindow * WXUNUSED(win),
         dc.DrawLine(xMiddle, yMiddle - halfHeight,
                     xMiddle, yMiddle + halfHeight + 1);
     }
-
-    dc.SetPen(pen);
-    dc.SetBrush(brush);
 }
 
 // ----------------------------------------------------------------------------