Remove redundant code from wxStatusBarMac

Remove a lot of Mac-specific code from wxStatusBarMac in favour of using
shared wxStatusBarGeneric:

- Now that wxFRAME_EX_METAL aka NSWindowStyleMaskTexturedBackground
  doesn’t affect text placement, there’s no reason for customized
  DrawFieldText(). As a side effect of this removal, ellipsizing fields
  is now supported.

- Remove customized DoUpdateStatusText() code that is no longer needed.

See https://github.com/wxWidgets/wxWidgets/pull/2160#pullrequestreview-563916013

include/wx/generic/statusbr.h

@@ -70,7 +70,7 @@ protected:
     void OnSysColourChanged(wxSysColourChangedEvent& event);
 
 protected:
-
+    virtual int GetEffectiveFieldStyle(int i) const { return m_panes[i].GetStyle(); }
     virtual void DrawFieldText(wxDC& dc, const wxRect& rc, int i, int textHeight);
     virtual void DrawField(wxDC& dc, int i, int textHeight);
 

include/wx/osx/statusbr.h

@@ -31,9 +31,7 @@ public:
     void OnPaint(wxPaintEvent& event);
 
 protected:
-    virtual void DrawFieldText(wxDC& dc, const wxRect& rc, int i, int textHeight) wxOVERRIDE;
-    virtual void DrawField(wxDC& dc, int i, int textHeight) wxOVERRIDE;
-    virtual void DoUpdateStatusText(int number = 0) wxOVERRIDE;
+    virtual int GetEffectiveFieldStyle(int WXUNUSED(i)) const wxOVERRIDE { return wxSB_NORMAL; }
 
     virtual void InitColours() wxOVERRIDE;
 

src/generic/statusbr.cpp

@@ -265,9 +265,11 @@ void wxStatusBarGeneric::DrawFieldText(wxDC& dc, const wxRect& rect, int i, int
         SetEllipsizedFlag(i, text != GetStatusText(i));
     }
 
-#if defined( __WXGTK__ ) || defined(__WXMAC__)
+#if defined( __WXGTK__ )
     xpos++;
     ypos++;
+#elif defined(__WXMAC__)
+    xpos++;
 #endif
 
     // draw the text
@@ -285,7 +287,7 @@ void wxStatusBarGeneric::DrawField(wxDC& dc, int i, int textHeight)
     if (rect.GetWidth() <= 0)
         return;     // happens when the status bar is shrunk in a very small area!
 
-    int style = m_panes[i].GetStyle();
+    int style = GetEffectiveFieldStyle(i);
     if (style == wxSB_RAISED || style == wxSB_SUNKEN)
     {
         // Draw border

src/osx/carbon/statbrma.cpp

@@ -97,51 +97,6 @@ void wxStatusBarMac::InitColours()
     }
 }
 
-void wxStatusBarMac::DrawFieldText(wxDC& dc, const wxRect& rect, int i, int textHeight)
-{
-    int w, h;
-    GetSize( &w , &h );
-
-    wxString text(GetStatusText( i ));
-
-    int xpos = rect.x + wxFIELD_TEXT_MARGIN + 1;
-    int ypos = 2 + (rect.height - textHeight) / 2;
-
-    if ( MacGetTopLevelWindow()->GetExtraStyle() & wxFRAME_EX_METAL )
-        ypos++;
-
-    dc.SetClippingRegion(rect.x, 0, rect.width, h);
-    dc.DrawText(text, xpos, ypos);
-    dc.DestroyClippingRegion();
-}
-
-void wxStatusBarMac::DrawField(wxDC& dc, int i, int textHeight)
-{
-    wxRect rect;
-    GetFieldRect(i, rect);
-
-    DrawFieldText(dc, rect, i, textHeight);
-}
-
-void wxStatusBarMac::DoUpdateStatusText(int number)
-{
-    wxRect rect;
-    GetFieldRect(number, rect);
-
-    int w, h;
-    GetSize( &w, &h );
-
-    rect.y = 0;
-    rect.height = h ;
-
-    Refresh( true, &rect );
-    // we should have to force the update here
-    // TODO Remove if no regressions occur
-#if 0
-    Update();
-#endif
-}
-
 void wxStatusBarMac::OnPaint(wxPaintEvent& WXUNUSED(event))
 {
     wxPaintDC dc(this);