Adding wxDC::GetHandle for wxOSX-cocoa and wxOSX-carbon

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72224 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/dc.h

@@ -283,6 +283,8 @@ public:
         return NULL;
     }
 
+    virtual void* GetHandle() const = 0;
+    
     // query dimension, colour deps, resolution
 
     virtual void DoGetSize(int *width, int *height) const = 0;
@@ -787,6 +789,9 @@ public:
     wxWindow *GetWindow() const
         { return m_pimpl->GetWindow(); }
 
+    void *GetHandle() const
+        { return m_pimpl->GetHandle(); }
+
     bool IsOk() const
         { return m_pimpl && m_pimpl->IsOk(); }
 

include/wx/dcgraph.h

@@ -109,6 +109,8 @@ public:
     wxGraphicsContext* GetGraphicsContext() const { return m_graphicContext; }
     virtual void SetGraphicsContext( wxGraphicsContext* ctx );
 
+    virtual void* GetHandle() const;
+
     // the true implementations
     virtual bool DoFloodFill(wxCoord x, wxCoord y, const wxColour& col,
                              wxFloodFillStyle style = wxFLOOD_SURFACE);

include/wx/dcmirror.h

@@ -66,6 +66,9 @@ public:
     virtual void SetLogicalFunction(wxRasterOperationMode function)
         { m_dc.SetLogicalFunction(function); }
 
+    virtual void* GetHandle() const
+        { return m_dc.GetHandle(); }
+
 protected:
     // returns x and y if not mirroring or y and x if mirroring
     wxCoord GetX(wxCoord x, wxCoord y) const { return m_mirror ? y : x; }

include/wx/dcsvg.h

@@ -96,6 +96,8 @@ public:
     virtual void SetFont(const wxFont& font);
     virtual void SetPen(const wxPen& pen);
 
+    virtual void* GetHandle() const { return NULL; }
+
 private:
    virtual bool DoGetPixel(wxCoord, wxCoord, wxColour *) const
    {

include/wx/generic/dcpsg.h

@@ -94,6 +94,8 @@ public:
     virtual int GetResolution() const;
     virtual wxRect GetPaperRect() const;
 
+    virtual void* GetHandle() const { return NULL; }
+    
 protected:
     bool DoFloodFill(wxCoord x1, wxCoord y1, const wxColour &col,
                      wxFloodFillStyle style = wxFLOOD_SURFACE);

interface/wx/dc.h

@@ -1535,6 +1535,22 @@ public:
     //@}
 
 
+    /**
+       Returns a value that can be used as a handle to the native drawing
+       context, if this wxDC has something that could be thought of in that
+       way.  (Not all of them do.)
+
+       For example, on Windows the return value is an HDC, on OSX it is a
+       CGContextRef and on wxGTK it will be a GdkDrawable.  If the DC is a
+       wxGCDC then the return value will be the value returned from
+       wxGraphicsContext::GetNativeContext.  A value of NULL is returned if
+       the DC does not have anything that fits the handle concept.
+       
+       @since 2.9.5
+     */
+    void* GetHandle() const;
+    
+
     void SetLogicalScale(double x, double y);
     void GetLogicalScale(double *x, double *y) const;
     void SetLogicalOrigin(wxCoord x, wxCoord y);

src/common/dcgraph.cpp

@@ -433,6 +433,16 @@ void wxGCDCImpl::ComputeScaleAndOrigin()
     }
 }
 
+void* wxGCDCImpl::GetHandle() const
+{
+    void* cgctx = NULL;
+    wxGraphicsContext* gc = GetGraphicsContext();
+    if (gc) {
+        cgctx = gc->GetNativeContext();
+    }
+    return cgctx;
+}
+
 void wxGCDCImpl::SetPalette( const wxPalette& WXUNUSED(palette) )
 {