Doc tweaks

[wxWidgets.git] / src / msw / dcmemory.cpp

diff --git a/src/msw/dcmemory.cpp b/src/msw/dcmemory.cpp
index cb5a8a8abcd9a32c4e9d6e9e2b325f2e1813cbb2..744f2ae65a3c46dd335ca597a6d719713d508258 100644 (file)
--- a/src/msw/dcmemory.cpp
+++ b/src/msw/dcmemory.cpp
@@ -53,37 +53,47 @@ IMPLEMENT_DYNAMIC_CLASS(wxMemoryDC, wxDC)
 
 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)