Resolve GCC's 'type-punned pointer will break strict-aliasing rules' warning by break...

[wxWidgets.git] / include / wx / dc.h

diff --git a/include/wx/dc.h b/include/wx/dc.h
index 1fd9da829b5c1a2912131772ba6f074df75cffa7..82f4848adf17d3b93427d37c88e2e7e574aaba12 100644 (file)
--- a/include/wx/dc.h
+++ b/include/wx/dc.h
@@ -104,19 +104,14 @@ enum wxFloodFillStyle
     wxFLOOD_BORDER
 };
 
-//  Mapping modes (same values as used by Windows, don't change)
+//  Mapping modes
 enum wxMappingMode
 {
     wxMM_TEXT = 1,
+    wxMM_METRIC,
     wxMM_LOMETRIC,
-    wxMM_HIMETRIC,
-    wxMM_LOENGLISH,
-    wxMM_HIENGLISH,
     wxMM_TWIPS,
-    wxMM_ISOTROPIC,
-    wxMM_ANISOTROPIC,
-    wxMM_POINTS,
-    wxMM_METRIC
+    wxMM_POINTS
 };
 
 #if WXWIN_COMPATIBILITY_2_8
@@ -373,7 +368,7 @@ public:
     // logical functions
 
     virtual void SetLogicalFunction(wxRasterOperationMode function) = 0;
-    virtual wxRasterOperationMode GetLogicalFunction() const 
+    virtual wxRasterOperationMode GetLogicalFunction() const
                                       { return m_logicalFunction; }
 
     // text measurement
@@ -707,6 +702,9 @@ private:
 class WXDLLIMPEXP_CORE wxDC : public wxObject
 {
 public:
+    // copy attributes (font, colours and writing direction) from another DC
+    void CopyAttributes(const wxDC& dc);
+
     virtual ~wxDC() { delete m_pimpl; }
 
     wxDCImpl *GetImpl()
@@ -1134,7 +1132,7 @@ public:
 
     bool Blit(wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height,
               wxDC *source, wxCoord xsrc, wxCoord ysrc,
-              wxRasterOperationMode rop = wxCOPY, bool useMask = false, 
+              wxRasterOperationMode rop = wxCOPY, bool useMask = false,
               wxCoord xsrcMask = wxDefaultCoord, wxCoord ysrcMask = wxDefaultCoord)
     {
         return m_pimpl->DoBlit(xdest, ydest, width, height,
@@ -1142,7 +1140,7 @@ public:
     }
     bool Blit(const wxPoint& destPt, const wxSize& sz,
               wxDC *source, const wxPoint& srcPt,
-              wxRasterOperationMode rop = wxCOPY, bool useMask = false, 
+              wxRasterOperationMode rop = wxCOPY, bool useMask = false,
               const wxPoint& srcPtMask = wxDefaultPosition)
     {
         return m_pimpl->DoBlit(destPt.x, destPt.y, sz.x, sz.y,
@@ -1162,7 +1160,7 @@ public:
     }
     bool StretchBlit(const wxPoint& dstPt, const wxSize& dstSize,
                      wxDC *source, const wxPoint& srcPt, const wxSize& srcSize,
-                     wxRasterOperationMode rop = wxCOPY, bool useMask = false, 
+                     wxRasterOperationMode rop = wxCOPY, bool useMask = false,
                      const wxPoint& srcMaskPt = wxDefaultPosition)
     {
         return m_pimpl->DoStretchBlit(dstPt.x, dstPt.y, dstSize.x, dstSize.y,
@@ -1201,7 +1199,50 @@ public:
 #endif  // WXWIN_COMPATIBILITY_2_8
 
 #ifdef __WXMSW__
+    // GetHDC() is the simplest way to retrieve an HDC From a wxDC but only
+    // works if this wxDC is GDI-based and fails for GDI+ contexts (and
+    // anything else without HDC, e.g. wxPostScriptDC)
     WXHDC GetHDC() const;
+
+    // don't use these methods manually, use GetTempHDC() instead
+    virtual WXHDC AcquireHDC() { return GetHDC(); }
+    virtual void ReleaseHDC(WXHDC WXUNUSED(hdc)) { }
+
+    // helper class holding the result of GetTempHDC() with std::auto_ptr<>-like
+    // semantics, i.e. it is moved when copied
+    class TempHDC
+    {
+    public:
+        TempHDC(wxDC& dc)
+            : m_dc(dc),
+              m_hdc(dc.AcquireHDC())
+        {
+        }
+
+        TempHDC(const TempHDC& thdc)
+            : m_dc(thdc.m_dc),
+              m_hdc(thdc.m_hdc)
+        {
+            const_cast<TempHDC&>(thdc).m_hdc = 0;
+        }
+
+        ~TempHDC()
+        {
+            if ( m_hdc )
+                m_dc.ReleaseHDC(m_hdc);
+        }
+
+        WXHDC GetHDC() const { return m_hdc; }
+
+    private:
+        wxDC& m_dc;
+        WXHDC m_hdc;
+
+        wxDECLARE_NO_ASSIGN_CLASS(TempHDC);
+    };
+
+    // GetTempHDC() also works for wxGCDC (but still not for wxPostScriptDC &c)
+    TempHDC GetTempHDC() { return TempHDC(*this); }
 #endif // __WXMSW__
 
 protected:
@@ -1212,7 +1253,7 @@ protected:
 
 private:
     DECLARE_ABSTRACT_CLASS(wxDC)
-    DECLARE_NO_COPY_CLASS(wxDC)
+    wxDECLARE_NO_COPY_CLASS(wxDC);
 };
 
 // ----------------------------------------------------------------------------
@@ -1248,7 +1289,7 @@ private:
 
     wxColour m_colFgOld;
 
-    DECLARE_NO_COPY_CLASS(wxDCTextColourChanger)
+    wxDECLARE_NO_COPY_CLASS(wxDCTextColourChanger);
 };
 
 // ----------------------------------------------------------------------------
@@ -1275,7 +1316,7 @@ private:
 
     wxPen m_penOld;
 
-    DECLARE_NO_COPY_CLASS(wxDCPenChanger)
+    wxDECLARE_NO_COPY_CLASS(wxDCPenChanger);
 };
 
 // ----------------------------------------------------------------------------
@@ -1302,7 +1343,7 @@ private:
 
     wxBrush m_brushOld;
 
-    DECLARE_NO_COPY_CLASS(wxDCBrushChanger)
+    wxDECLARE_NO_COPY_CLASS(wxDCBrushChanger);
 };
 
 // ----------------------------------------------------------------------------
@@ -1325,7 +1366,7 @@ public:
 private:
     wxDC& m_dc;
 
-    DECLARE_NO_COPY_CLASS(wxDCClipper)
+    wxDECLARE_NO_COPY_CLASS(wxDCClipper);
 };
 
 // ----------------------------------------------------------------------------
@@ -1336,8 +1377,21 @@ private:
 class WXDLLIMPEXP_CORE wxDCFontChanger
 {
 public:
-    wxDCFontChanger(wxDC& dc, const wxFont& font) : m_dc(dc), m_fontOld(dc.GetFont())
+    wxDCFontChanger(wxDC& dc)
+        : m_dc(dc), m_fontOld()
+    {
+    }
+
+    wxDCFontChanger(wxDC& dc, const wxFont& font)
+        : m_dc(dc), m_fontOld(dc.GetFont())
+    {
+        m_dc.SetFont(font);
+    }
+
+    void Set(const wxFont& font)
     {
+        if ( !m_fontOld.Ok() )
+            m_fontOld = m_dc.GetFont();
         m_dc.SetFont(font);
     }
 
@@ -1352,7 +1406,7 @@ private:
 
     wxFont m_fontOld;
 
-    DECLARE_NO_COPY_CLASS(wxDCFontChanger)
+    wxDECLARE_NO_COPY_CLASS(wxDCFontChanger);
 };