Fix harmless warning about using wxCONTROL_CHECKED in ternary operator.

Add wxCONTROL_NONE which is just a symbolic name for 0 and use it in the code
to avoid g++ 4.8 warnings about mixing enum and int in conditional expression.

Closes #16242.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76484 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/renderer.h

@@ -52,6 +52,7 @@ class WXDLLIMPEXP_FWD_CORE wxWindow;
 // control state flags used in wxRenderer and wxColourScheme
 enum
 {
+    wxCONTROL_NONE       = 0x00000000,  // absence of any other flags
     wxCONTROL_DISABLED   = 0x00000001,  // control is disabled
     wxCONTROL_FOCUSED    = 0x00000002,  // currently has keyboard focus
     wxCONTROL_PRESSED    = 0x00000004,  // (button) is pressed

interface/wx/renderer.h

@@ -12,6 +12,13 @@
 */
 enum
 {
+    /**
+        Default state, no special flags.
+
+        @since 3.1.0
+     */
+    wxCONTROL_NONE       = 0x00000000,
+
     /** Control is disabled. */
     wxCONTROL_DISABLED   = 0x00000001,
 

src/msw/radiobut.cpp

@@ -322,7 +322,7 @@ void wxRadioButton::MSWOnButtonResetOwnerDrawn()
 
 int wxRadioButton::MSWGetButtonCheckedFlag() const
 {
-    return m_isChecked ? wxCONTROL_CHECKED : 0;
+    return m_isChecked ? wxCONTROL_CHECKED : wxCONTROL_NONE;
 }
 
 void wxRadioButton::MSWDrawButtonBitmap(wxDC& dc, const wxRect& rect, int flags)