include/wx/compositewin.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/compositewin.h
   3 // Purpose:     wxCompositeWindow<> declaration
   4 // Author:      Vadim Zeitlin
   5 // Created:     2011-01-02
   6 // RCS-ID:      $Id: wxhead.h,v 1.12 2010-04-22 12:44:51 zeitlin Exp $
   7 // Copyright:   (c) 2011 Vadim Zeitlin <vadim@wxwidgets.org>
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_COMPOSITEWIN_H_
  12 #define _WX_COMPOSITEWIN_H_
  13
  14 #include "wx/window.h"
  15
  16 // NB: This is an experimental and, as for now, undocumented class used only by
  17 //     wxWidgets itself internally. Don't use it in your code until its API is
  18 //     officially stabilized unless you are ready to change it with the next
  19 //     wxWidgets release.
  20
  21 // FIXME-VC6: This compiler can't compile DoSetForAllParts() template function,
  22 // it can't determine whether the deduced type should be "T" or "const T&". And
  23 // without this function wxCompositeWindow is pretty useless so simply disable
  24 // this code for it, this does mean that setting colours/fonts/... for
  25 // composite controls won't work in the library compiled with it but so far
  26 // this only affects the generic wxDatePickerCtrl which is not used by default
  27 // under MSW anyhow so it doesn't seem to be worth it to spend time and uglify
  28 // the code to fix it.
  29 #ifndef __VISUALC6__
  30
  31 // ----------------------------------------------------------------------------
  32 // wxCompositeWindow is a helper for implementing composite windows: to define
  33 // a class using subwindows, simply inherit from it specialized with the real
  34 // base class name and implement GetCompositeWindowParts() pure virtual method.
  35 // ----------------------------------------------------------------------------
  36
  37 // The template parameter W must be a wxWindow-derived class.
  38 template <class W>
  39 class wxCompositeWindow : public W
  40 {
  41 public:
  42     typedef W BaseWindowClass;
  43
  44     // Default ctor doesn't do anything.
  45     wxCompositeWindow() { }
  46
  47     // Override all wxWindow methods which must be forwarded to the composite
  48     // window parts.
  49
  50     // Attribute setters group.
  51     //
  52     // NB: Unfortunately we can't factor out the call for the setter itself
  53     //     into DoSetForAllParts() because we can't call the function passed to
  54     //     it non-virtually and we need to do this to avoid infinite recursion,
  55     //     so we work around this by calling the method of this object itself
  56     //     manually in each function.
  57     virtual bool SetForegroundColour(const wxColour& colour)
  58     {
  59         if ( !BaseWindowClass::SetForegroundColour(colour) )
  60             return false;
  61
  62         DoSetForAllParts(&wxWindowBase::SetForegroundColour, colour);
  63
  64         return true;
  65     }
  66
  67     virtual bool SetBackgroundColour(const wxColour& colour)
  68     {
  69         if ( !BaseWindowClass::SetBackgroundColour(colour) )
  70             return false;
  71
  72         DoSetForAllParts(&wxWindowBase::SetBackgroundColour, colour);
  73
  74         return true;
  75     }
  76
  77     virtual bool SetFont(const wxFont& font)
  78     {
  79         if ( !BaseWindowClass::SetFont(font) )
  80             return false;
  81
  82         DoSetForAllParts(&wxWindowBase::SetFont, font);
  83
  84         return true;
  85     }
  86
  87     virtual bool SetCursor(const wxCursor& cursor)
  88     {
  89         if ( !BaseWindowClass::SetCursor(cursor) )
  90             return false;
  91
  92         DoSetForAllParts(&wxWindowBase::SetCursor, cursor);
  93
  94         return true;
  95     }
  96
  97 private:
  98     // Must be implemented by the derived class to return all children to which
  99     // the public methods we override should forward to.
 100     virtual wxWindowList GetCompositeWindowParts() const = 0;
 101
 102     template <class T>
 103     void DoSetForAllParts(bool (wxWindowBase::*func)(const T&), const T& arg)
 104     {
 105         // Simply call the setters for all parts of this composite window.
 106         const wxWindowList parts = GetCompositeWindowParts();
 107         for ( wxWindowList::const_iterator i = parts.begin();
 108               i != parts.end();
 109               ++i )
 110         {
 111             wxWindow * const child = *i;
 112
 113             // Allow NULL elements in the list, this makes the code of derived
 114             // composite controls which may have optionally shown children
 115             // simpler and it doesn't cost us much here.
 116             if ( child )
 117                 (child->*func)(arg);
 118         }
 119     }
 120
 121     wxDECLARE_NO_COPY_TEMPLATE_CLASS(wxCompositeWindow, W);
 122 };
 123
 124 #else // __VISUALC6__
 125
 126 template <class W>
 127 class wxCompositeWindow : public W
 128 {
 129 };
 130
 131 #endif // !__VISUALC6__/__VISUALC6__
 132
 133 #endif // _WX_COMPOSITEWIN_H_