adding magnification API into the wxWindow classes for best retina support

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74247 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/cocoa/private.h

@@ -247,6 +247,8 @@ public :
 
     virtual void WindowToScreen( int *x, int *y );
 
+    virtual double GetMagnificationFactor() const;
+
     virtual bool IsActive();
 
     virtual void SetModified(bool modified);

include/wx/osx/core/private.h

@@ -874,6 +874,8 @@ public :
 
     virtual void WindowToScreen( int *x, int *y ) = 0;
     
+    virtual double GetMagnificationFactor() const { return 1.0; }
+
     virtual bool IsActive() = 0;
 
     wxNonOwnedWindow*   GetWXPeer() { return m_wxPeer; }

include/wx/osx/nonownedwnd.h

@@ -66,6 +66,8 @@ public:
 
     virtual wxPoint GetClientAreaOrigin() const;
     
+    virtual double GetMagnificationFactor() const;
+
     // implement base class pure virtuals
 
     virtual bool SetTransparent(wxByte alpha);

include/wx/osx/window.h

@@ -98,6 +98,8 @@ public:
     virtual int GetCharHeight() const;
     virtual int GetCharWidth() const;
     
+    virtual double GetMagnificationFactor() const;
+
 public:
     virtual void SetScrollbar( int orient, int pos, int thumbVisible,
                                int range, bool refresh = true );

include/wx/window.h

@@ -521,6 +521,11 @@ public:
         return wxSize( wxMax( client.x, best.x ), wxMax( client.y, best.y ) );
     }
 
+    // returns the magnification of the backing store of this window
+    // eg 2.0 for a window on a retina screen
+    virtual double GetMagnificationFactor() const
+    { return 1.0; }
+    
     // return the size of the left/right and top/bottom borders in x and y
     // components of the result respectively
     virtual wxSize GetWindowBorderSize() const;

src/osx/cocoa/nonownedwnd.mm

@@ -1035,6 +1035,11 @@ void wxNonOwnedWindowCocoaImpl::WindowToScreen( int *x, int *y )
         *y = p.y;
 }
 
+double wxNonOwnedWindowCocoaImpl::GetMagnificationFactor() const
+{
+    return [m_macWindow backingScaleFactor];
+}
+
 bool wxNonOwnedWindowCocoaImpl::IsActive()
 {
     return [m_macWindow isKeyWindow];

src/osx/nonownedwnd_osx.cpp

@@ -478,6 +478,11 @@ void wxNonOwnedWindow::DoGetClientSize( int *width, int *height ) const
        *height = h ;
 }
 
+double wxNonOwnedWindow::GetMagnificationFactor() const
+{
+    return m_nowpeer->GetMagnificationFactor();
+}
+
 void wxNonOwnedWindow::WindowWasPainted()
 {
     s_lastFlush = clock();

src/osx/window_osx.cpp

@@ -877,6 +877,13 @@ void wxWindowMac::DoGetClientSize( int *x, int *y ) const
        *y = hh;
 }
 
+double wxWindowMac::GetMagnificationFactor() const
+{
+    wxNonOwnedWindow* tlw = MacGetTopLevelWindow() ;
+    wxCHECK_MSG( tlw , 1.0, wxT("TopLevel Window missing") ) ;
+    return tlw->GetMagnificationFactor();    
+}
+
 bool wxWindowMac::SetCursor(const wxCursor& cursor)
 {
     if (m_cursor.IsSameAs(cursor))