Add wxEnhMetaFile::Detach().

Allow getting the handle from this class, this is useful if it needs to be
passed to some other library, for example.

Closes #15706.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76117 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/enhmeta.h

@@ -52,13 +52,21 @@ public:
     // this method
     bool SetClipboard(int width = 0, int height = 0);
 
+    // Detach the HENHMETAFILE from this object, i.e. don't delete the handle
+    // in the dtor -- the caller is now responsible for doing this, e.g. using
+    // Free() method below.
+    WXHANDLE Detach() { WXHANDLE h = m_hMF; m_hMF = 0; return h; }
+
+    // Destroy the given HENHMETAFILE object.
+    static void Free(WXHANDLE handle);
+
     // implementation
     WXHANDLE GetHENHMETAFILE() const { return m_hMF; }
     void SetHENHMETAFILE(WXHANDLE hMF) { Free(); m_hMF = hMF; }
 
 protected:
     void Init();
-    void Free();
+    void Free() { Free(m_hMF); }
     void Assign(const wxEnhMetaFile& mf);
 
     // we don't use these functions (but probably should) but have to implement