Add System Colour screen to drawing sample.

This adds an additional screen to the drawing sample showing all available wxSystemColour values. It makes sense for testing these values but also provides a convenient overview of available colours for the library user.

samples/drawing/drawing.cpp

@@ -38,6 +38,7 @@
 #include "wx/graphics.h"
 #include "wx/filename.h"
 #include "wx/metafile.h"
+#include "wx/settings.h"
 
 // ----------------------------------------------------------------------------
 // resources
@@ -149,6 +150,7 @@ protected:
     void DrawSplines(wxDC& dc);
     void DrawDefault(wxDC& dc);
     void DrawGradients(wxDC& dc);
+    void DrawSystemColours(wxDC& dc);
 
     void DrawRegionsHelper(wxDC& dc, wxCoord x, bool firstTime);
 
@@ -301,6 +303,7 @@ enum
 #if wxUSE_GRAPHICS_CONTEXT
     File_ShowGraphics,
 #endif
+    File_ShowSystemColours,
     File_ShowGradients,
     MenuShow_Last = File_ShowGradients,
 
@@ -1548,6 +1551,47 @@ void MyCanvas::DrawGradients(wxDC& dc)
 #endif // wxUSE_GRAPHICS_CONTEXT
 }
 
+void MyCanvas::DrawSystemColours(wxDC& dc)
+{
+    wxSize textSize = dc.GetTextExtent("#WWWWgy");
+    int lineHeight = textSize.GetHeight();
+    wxRect r(textSize.GetWidth() + 10, 10, 100, lineHeight);
+
+    dc.SetPen(*wxTRANSPARENT_PEN);
+
+    static const char* sysColNames[] = {
+        "wxSYS_COLOUR_SCROLLBAR", "wxSYS_COLOUR_DESKTOP", "wxSYS_COLOUR_ACTIVECAPTION",
+        "wxSYS_COLOUR_INACTIVECAPTION", "wxSYS_COLOUR_MENU", "wxSYS_COLOUR_WINDOW",
+        "wxSYS_COLOUR_WINDOWFRAME", "wxSYS_COLOUR_MENUTEXT", "wxSYS_COLOUR_WINDOWTEXT",
+        "wxSYS_COLOUR_CAPTIONTEXT", "wxSYS_COLOUR_ACTIVEBORDER", "wxSYS_COLOUR_INACTIVEBORDER",
+        "wxSYS_COLOUR_APPWORKSPACE", "wxSYS_COLOUR_HIGHLIGHT", "wxSYS_COLOUR_HIGHLIGHTTEXT",
+        "wxSYS_COLOUR_BTNFACE", "wxSYS_COLOUR_BTNSHADOW", "wxSYS_COLOUR_GRAYTEXT",
+        "wxSYS_COLOUR_BTNTEXT", "wxSYS_COLOUR_INACTIVECAPTIONTEXT", "wxSYS_COLOUR_BTNHIGHLIGHT",
+        "wxSYS_COLOUR_3DDKSHADOW", "wxSYS_COLOUR_3DLIGHT", "wxSYS_COLOUR_INFOTEXT",
+        "wxSYS_COLOUR_INFOBK", "wxSYS_COLOUR_LISTBOX", "wxSYS_COLOUR_HOTLIGHT",
+        "wxSYS_COLOUR_GRADIENTACTIVECAPTION", "wxSYS_COLOUR_GRADIENTINACTIVECAPTION",
+        "wxSYS_COLOUR_MENUHILIGHT", "wxSYS_COLOUR_MENUBAR", "wxSYS_COLOUR_LISTBOXTEXT",
+        "wxSYS_COLOUR_LISTBOXHIGHLIGHTTEXT"
+    };
+
+    for (int i = wxSYS_COLOUR_SCROLLBAR; i < wxSYS_COLOUR_MAX; i++)
+    {
+        wxSystemColour sysColour = (wxSystemColour)i;
+
+        wxString colourName = sysColNames[sysColour];
+
+        wxColour c = wxSystemSettings::GetColour(sysColour);
+        dc.DrawText(c.GetAsString(wxC2S_HTML_SYNTAX), 10, r.y);
+
+        dc.SetBrush(wxBrush(c));
+        dc.DrawRectangle(r);
+        
+        dc.DrawText(colourName, r.GetRight() + 10, r.y);
+
+        r.y += lineHeight + 4;
+    }
+}
+
 void MyCanvas::DrawRegions(wxDC& dc)
 {
     dc.DrawText(wxT("You should see a red rect partly covered by a cyan one ")
@@ -1746,6 +1790,10 @@ void MyCanvas::Draw(wxDC& pdc)
         case File_ShowGradients:
             DrawGradients(dc);
             break;
+            
+        case File_ShowSystemColours:
+            DrawSystemColours(dc);
+            break;
 
         default:
             break;
@@ -1901,6 +1949,7 @@ MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 #if wxUSE_GRAPHICS_CONTEXT
     menuScreen->Append(File_ShowGraphics, wxT("&Graphics screen"));
 #endif
+    menuScreen->Append(File_ShowSystemColours, wxT("System &colours"));
 
     wxMenu *menuFile = new wxMenu;
 #if wxUSE_GRAPHICS_CONTEXT