wxMemoryDC::wxMemoryDC()
{
- m_hDC = (WXHDC) ::CreateCompatibleDC((HDC) NULL);
- m_ok = (m_hDC != 0);
- m_bOwnsDC = TRUE;
-
- SetBrush(*wxWHITE_BRUSH);
- SetPen(*wxBLACK_PEN);
+ CreateCompatible(NULL);
- // the background mode is only used for text background and is set in
- // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
- ::SetBkMode( GetHdc(), TRANSPARENT );
+ Init();
}
-wxMemoryDC::wxMemoryDC(wxDC *old_dc)
+wxMemoryDC::wxMemoryDC(wxDC *dc)
{
- old_dc->BeginDrawing();
+ wxCHECK_RET( dc, _T("NULL dc in wxMemoryDC ctor") );
+
+ dc->BeginDrawing();
- m_hDC = (WXHDC) ::CreateCompatibleDC(GetHdcOf(*old_dc));
- m_ok = (m_hDC != 0);
+ CreateCompatible(dc);
- old_dc->EndDrawing();
+ dc->EndDrawing();
- SetBrush(*wxWHITE_BRUSH);
- SetPen(*wxBLACK_PEN);
+ Init();
+}
+
+void wxMemoryDC::Init()
+{
+ if ( m_ok )
+ {
+ SetBrush(*wxWHITE_BRUSH);
+ SetPen(*wxBLACK_PEN);
- // the background mode is only used for text background and is set in
- // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
- ::SetBkMode( GetHdc(), TRANSPARENT );
+ // the background mode is only used for text background and is set in
+ // DrawText() to OPAQUE as required, otherwise always TRANSPARENT
+ ::SetBkMode( GetHdc(), TRANSPARENT );
+ }
}
-wxMemoryDC::~wxMemoryDC()
+bool wxMemoryDC::CreateCompatible(wxDC *dc)
{
+ m_hDC = (WXHDC)::CreateCompatibleDC(dc ? GetHdcOf(*dc) : NULL);
+
+ // as we created the DC, we must delete it in the dtor
+ m_bOwnsDC = TRUE;
+
+ m_ok = m_hDC != 0;
+
+ return m_ok;
}
void wxMemoryDC::SelectObject(const wxBitmap& bitmap)