+// the same as ScreenHDC but for memory DCs: creates the HDC in ctor and
+// destroys it in dtor
+class MemoryHDC
+{
+public:
+ MemoryHDC() { m_hdc = ::CreateCompatibleDC(NULL); }
+ ~MemoryHDC() { ::DeleteObject(m_hdc); }
+
+ operator HDC() const { return m_hdc; }
+
+private:
+ HDC m_hdc;
+};
+
+// a class which selects a GDI object into a DC in its ctor and deselects in
+// dtor
+class SelectInHDC
+{
+public:
+ SelectInHDC(HDC hdc, HGDIOBJ hgdiobj) : m_hdc(hdc)
+ { m_hgdiobj = ::SelectObject(hdc, hgdiobj); }
+
+ ~SelectInHDC() { ::SelectObject(m_hdc, m_hgdiobj); }
+
+ // return true if the object was successfully selected
+ operator bool() const { return m_hgdiobj != 0; }
+
+private:
+ HDC m_hdc;
+ HGDIOBJ m_hgdiobj;
+};
+