make code dealing with wxUSE_IDLEMENUUPDATES a bit more clear and avoid warning due...

[wxWidgets.git] / src / common / dcbase.cpp

diff --git a/src/common/dcbase.cpp b/src/common/dcbase.cpp
index 168ea59a211720df41edfed4e8374575006c04eb..206c1662dd45854e93365d1023774efd783034ec 100644 (file)
--- a/src/common/dcbase.cpp
+++ b/src/common/dcbase.cpp
@@ -157,9 +157,19 @@ wxDCImpl* wxNativeDCFactory::CreateMemoryDC( wxMemoryDC *owner )
     return new wxMemoryDCImpl( owner );
 }
 
-wxDCImpl* wxNativeDCFactory::CreateMemoryDC( wxMemoryDC *owner, wxBitmap &bitmap )
+wxDCImpl* wxNativeDCFactory::CreateMemoryDC(wxMemoryDC *owner, wxBitmap& bitmap)
 {
-    return new wxMemoryDCImpl( owner, bitmap );
+    // the bitmap may be modified when it's selected into a memory DC so make
+    // sure changing this bitmap doesn't affect any other shallow copies of it
+    // (see wxMemoryDC::SelectObject())
+    //
+    // notice that we don't provide any ctor equivalent to SelectObjectAsSource
+    // method because this should be rarely needed and easy to work around by
+    // using the default ctor and calling SelectObjectAsSource itself
+    if ( bitmap.IsOk() )
+        bitmap.UnShare();
+
+    return new wxMemoryDCImpl(owner, bitmap);
 }
 
 wxDCImpl* wxNativeDCFactory::CreateMemoryDC( wxMemoryDC *owner, wxDC *dc )
@@ -1638,3 +1648,15 @@ void wxDCImpl::CalculateEllipticPoints( wxPointList* points,
 } // CalculateEllipticPoints
 
 #endif // __WXWINCE__
+
+float wxDCImpl::GetFontPointSizeAdjustment(float dpi)
+{
+    // wxMSW has long-standing bug where wxFont point size is interpreted as
+    // "pixel size corresponding to given point size *on screen*". In other
+    // words, on a typical 600dpi printer and a typical 96dpi screen, fonts
+    // are ~6 times smaller when printing. Unfortunately, this bug is so severe
+    // that *all* printing code has to account for it and consequently, other
+    // ports need to emulate this bug too:
+    const wxSize screenPPI = wxGetDisplayPPI();
+    return float(screenPPI.y) / dpi;
+}