Merge branch 'display-funcs'

Implement all global functions in terms of wxDisplay and add
wxDisplay::GetPPI().

See https://github.com/wxWidgets/wxWidgets/pull/963

include/wx/display.h

@@ -11,6 +11,7 @@
 #define _WX_DISPLAY_H_BASE_
 
 #include "wx/defs.h"
+#include "wx/gdicmn.h"      // wxSize
 
 // NB: no #if wxUSE_DISPLAY here, the display geometry part of this class (but
 //     not the video mode stuff) is always available but if wxUSE_DISPLAY == 0
@@ -74,6 +75,12 @@ public:
     // get the client area of the display, i.e. without taskbars and such
     wxRect GetClientArea() const;
 
+    // get the depth, i.e. number of bits per pixel (0 if unknown)
+    int GetDepth() const;
+
+    // get the resolution of this monitor in pixels per inch
+    wxSize GetPPI() const;
+
     // name may be empty
     wxString GetName() const;
 

include/wx/gdicmn.h

@@ -1080,6 +1080,9 @@ extern WXDLLIMPEXP_DATA_CORE(const wxPoint) wxDefaultPosition;
 extern void WXDLLIMPEXP_CORE wxInitializeStockLists();
 extern void WXDLLIMPEXP_CORE wxDeleteStockLists();
 
+// Note: all the display-related functions here exist for compatibility only,
+// please use wxDisplay class in the new code
+
 // is the display colour (or monochrome)?
 extern bool WXDLLIMPEXP_CORE wxColourDisplay();
 

include/wx/private/display.h

@@ -78,6 +78,18 @@ public:
     // return the area of the display available for normal windows
     virtual wxRect GetClientArea() const { return GetGeometry(); }
 
+    // return the depth or 0 if unknown
+    virtual int GetDepth() const = 0;
+
+    // return the resolution of the display, uses GetSizeMM() by default but
+    // can be also overridden directly
+    virtual wxSize GetPPI() const;
+
+    // return the physical size of the display or (0, 0) if unknown: this is
+    // only used by GetPPI() implementation in the base class, so if GetPPI()
+    // is overridden, this one doesn't have to be implemented
+    virtual wxSize GetSizeMM() const { return wxSize(0, 0); }
+
     // return the name (may be empty)
     virtual wxString GetName() const { return wxString(); }