Adjust the font size when DPI of window changes

include/wx/font.h

@@ -501,6 +501,13 @@ public:
     // account as well.
     static int GetNumericWeightOf(wxFontWeight weight);
 
+    // Some ports need to modify the font object when the DPI of the window it
+    // is used with changes, this function can be used to do it.
+    //
+    // Currently it is only used in wxMSW and is not considered to be part of
+    // wxWidgets public API.
+    virtual void WXAdjustToPPI(const wxSize& WXUNUSED(ppi)) { }
+
     // this doesn't do anything and is kept for compatibility only
 #if WXWIN_COMPATIBILITY_2_8
     wxDEPRECATED_INLINE(void SetNoAntiAliasing(bool no = true), wxUnusedVar(no);)

include/wx/msw/font.h

@@ -120,6 +120,8 @@ public:
 
     virtual bool IsFixedWidth() const wxOVERRIDE;
 
+    virtual void WXAdjustToPPI(const wxSize& ppi) wxOVERRIDE;
+
     wxDEPRECATED_MSG("use wxFONT{FAMILY,STYLE,WEIGHT}_XXX constants ie: wxFONTFAMILY_SWISS, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_BOLD")
     wxFont(int size,
            int family,

include/wx/msw/window.h

@@ -592,6 +592,11 @@ public:
     void MSWUpdateOnDPIChange(const wxSize& oldDPI, const wxSize& newDPI);
 
 protected:
+    // Called from MSWUpdateOnDPIChange() specifically to update the control
+    // font, as this may need to be done differently for some specific native
+    // controls. The default version updates m_font of this window.
+    virtual void MSWUpdateFontOnDPIChange(const wxSize& newDPI);
+
     // this allows you to implement standard control borders without
     // repeating the code in different classes that are not derived from
     // wxControl