initialize wx{Client,Paint,Window}DC with fonts/colours of its window

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54324 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/dc.h

@@ -13,7 +13,7 @@
     A wxDC is a @e "device context" onto which graphics and text can be drawn.
     It is intended to represent different output devices and offers a common
     abstract API for drawing on any of them.
-    
+
     wxWidgets offers an alternative drawing API based on the modern drawing
     backends GDI+, CoreGraphics and Cairo. See wxGraphicsContext, wxGraphicsRenderer
     and related classes. There is also a wxGCDC linking the APIs by offering
@@ -21,7 +21,11 @@
 
     wxDC is an abstract base class and cannot be created directly.
     Use wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or
-    wxPrinterDC.
+    wxPrinterDC. Notice that device contexts which are associated with windows
+    (i.e. wxClientDC, wxWindowDC and wxPaintDC) use the window font and colours
+    by default (starting with wxWidgets 2.9.0) but the other device context
+    classes use system-default values so you always must set the appropriate
+    fonts and colours before using them.
 
     In addition to the versions of the methods documented below, there
     are also versions which accept single wxPoint parameter instead

interface/dcclient.h

@@ -26,6 +26,9 @@
     To draw on the whole window including decorations, construct a wxWindowDC
     object (Windows only).
 
+    A wxPaintDC object is initialized to use the same font and colours as the
+    window it is associated with.
+
     @library{wxcore}
     @category{dc}
 
@@ -57,6 +60,9 @@ public:
     To draw on the whole window including decorations, construct a wxWindowDC
     object (Windows only).
 
+    A wxClientDC object is initialized to use the same font and colours as the
+    window it is associated with.
+
     @library{wxcore}
     @category{dc}
 
@@ -87,6 +93,9 @@ public:
     To draw on the client area of a window from outside an EVT_PAINT() handler,
     construct a wxClientDC object.
 
+    A wxWindowDC object is initialized to use the same font and colours as the
+    window it is associated with.
+
     @library{wxcore}
     @category{dc}