1. wxPaintDC reuse now seems to actually work instead of leading to mysterious

bugs (but I still don't know why should we have it at all)
2. wxMenuItem initializes m_bChecked variable - thanks Purify
3. don't try to delete the brush which couldn't be created in app.cpp


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2724 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/dcclient.h

@@ -6,59 +6,77 @@
 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Copyright:   (c) Julian Smart and Markus Holzem
-// Licence:   	wxWindows license
+// Licence:     wxWindows license
 /////////////////////////////////////////////////////////////////////////////
 
 #ifndef _WX_DCCLIENT_H_
 #define _WX_DCCLIENT_H_
 
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
 #ifdef __GNUG__
-#pragma interface "dcclient.h"
+    #pragma interface "dcclient.h"
 #endif
 
 #include "wx/dc.h"
 
-class WXDLLEXPORT wxWindowDC: public wxDC
+// ----------------------------------------------------------------------------
+// array types
+// ----------------------------------------------------------------------------
+
+// this one if used by wxPaintDC only
+struct WXDLLEXPORT wxPaintDCInfo;
+WX_DECLARE_OBJARRAY(wxPaintDCInfo, wxArrayDCInfo);
+
+// ----------------------------------------------------------------------------
+// DC classes
+// ----------------------------------------------------------------------------
+
+class WXDLLEXPORT wxWindowDC : public wxDC
 {
-  DECLARE_DYNAMIC_CLASS(wxWindowDC)
+    DECLARE_DYNAMIC_CLASS(wxWindowDC)
 
- public:
+public:
-  wxWindowDC(void);
+    wxWindowDC();
 
-  // Create a DC corresponding to a canvas
+    // Create a DC corresponding to the whole window
-  wxWindowDC(wxWindow *win);
+    wxWindowDC(wxWindow *win);
 
-  ~wxWindowDC(void);
+    virtual ~wxWindowDC();
 };
 
-class WXDLLEXPORT wxClientDC: public wxWindowDC
+class WXDLLEXPORT wxClientDC : public wxWindowDC
 {
-  DECLARE_DYNAMIC_CLASS(wxClientDC)
+    DECLARE_DYNAMIC_CLASS(wxClientDC)
 
- public:
+public:
-  wxClientDC(void);
+    wxClientDC();
 
-  // Create a DC corresponding to a canvas
+    // Create a DC corresponding to the client area of the window
-  wxClientDC(wxWindow *win);
+    wxClientDC(wxWindow *win);
 
-  ~wxClientDC(void);
+    virtual ~wxClientDC();
 };
 
-class WXDLLEXPORT wxPaintDC: public wxWindowDC
+class WXDLLEXPORT wxPaintDC : public wxWindowDC
 {
-  DECLARE_DYNAMIC_CLASS(wxPaintDC)
+    DECLARE_DYNAMIC_CLASS(wxPaintDC)
 
- public:
+public:
-  wxPaintDC(void);
+    wxPaintDC();
 
-  // Create a DC corresponding to a canvas
+    // Create a DC corresponding for painting the window in OnPaint()
-  wxPaintDC(wxWindow *win);
+    wxPaintDC(wxWindow *win);
 
-  ~wxPaintDC(void);
+    virtual ~wxPaintDC();
 
- protected:
+protected:
-    static WXHDC ms_PaintHDC;
+    static wxArrayDCInfo ms_cache;
-    static size_t  ms_PaintCount;
+
+    // find the entry for this DC in the cache (keyed by the window)
+    wxPaintDCInfo *FindInCache(size_t *index = NULL) const;
 };
 
 #endif

src/msw/app.cpp

@@ -234,8 +234,12 @@ bool wxApp::Initialize()
     LOGBRUSH lb;
     lb.lbStyle = BS_PATTERN;
     lb.lbHatch = (int)LoadBitmap( wxhInstance, "wxDISABLE_BUTTON_BITMAP" );
-    wxDisableButtonBrush = ::CreateBrushIndirect( & lb );
+    if ( lb.lbHatch )
-    ::DeleteObject( (HGDIOBJ)lb.lbHatch );
+    {
+        wxDisableButtonBrush = ::CreateBrushIndirect( & lb );
+        ::DeleteObject( (HGDIOBJ)lb.lbHatch );
+    }
+    //else: wxWindows resources are probably not linked in
 
 #if wxUSE_PENWINDOWS
     wxRegisterPenWin();

src/msw/dc.cpp

@@ -639,7 +639,6 @@ void wxDC::DoDrawBitmap( const wxBitmap &bmp, long x, long y, bool useMask )
         HBITMAP hbitmap = (HBITMAP) bmp.GetHBITMAP( );
         ::SelectObject( memdc, hbitmap );
         ::BitBlt( cdc, x, y, bmp.GetWidth(), bmp.GetHeight(), memdc, 0, 0, SRCCOPY);
-        ::SelectObject( memdc, 0 );
         ::DeleteDC( memdc );
     }
     else

src/msw/dcclient.cpp

@@ -36,6 +36,28 @@
 
 #include "wx/dcclient.h"
 
+// ----------------------------------------------------------------------------
+// array/list types
+// ----------------------------------------------------------------------------
+
+struct WXDLLEXPORT wxPaintDCInfo
+{
+    wxPaintDCInfo(wxWindow *win, wxDC *dc)
+    {
+        hwnd = win->GetHWND();
+        hdc = dc->GetHDC();
+        count = 1;
+    }
+
+    WXHWND    hwnd;       // window for this DC
+    WXHDC     hdc;        // the DC handle
+    size_t    count;      // usage count
+};
+
+#include "wx/arrimpl.cpp"
+
+WX_DEFINE_OBJARRAY(wxArrayDCInfo);
+
 // ----------------------------------------------------------------------------
 // macros
 // ----------------------------------------------------------------------------
@@ -127,59 +149,94 @@ wxClientDC::~wxClientDC()
 // wxPaintDC
 // ----------------------------------------------------------------------------
 
-// TODO (VZ) I have still some doubts about this hack and I still think that we
+// VZ: initial implementation (by JACS) only remembered the last wxPaintDC
-//           should store pairs of (hwnd, hdc) and not just the DC - what if
+//     created and tried to reuse - this was supposed to take care of a
-//           BeginPaint() was called on other window? It seems to work like
+//     situation when a derived class OnPaint() calls base class OnPaint()
-//           this, but to be sure about it we'd need to store hwnd too...
+//     because in this case ::BeginPaint() shouldn't be called second time.
+//
+//     I'm not sure how useful this is, however we must remember the HWND
+//     associated with the last HDC as well - otherwise we may (and will!) try
+//     to reuse the HDC for another HWND which is a nice recipe for disaster.
+//
+//     So we store a list of windows for which we already have the DC and not
+//     just one single hDC. This seems to work, but I'm really not sure about
+//     the usefullness of the whole idea - IMHO it's much better to not call
+//     base class OnPaint() at all, or, if we realyl want to allow it, add a
+//     "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
+//     !NULL instead of creating a new DC.
 
-WXHDC  wxPaintDC::ms_PaintHDC = 0;
+wxArrayDCInfo wxPaintDC::ms_cache;
-size_t wxPaintDC::ms_PaintCount = 0; // count of ms_PaintHDC usage
 
 wxPaintDC::wxPaintDC()
 {
-  m_canvas = NULL;
+    m_canvas = NULL;
+    m_hDC = 0;
 }
 
 wxPaintDC::wxPaintDC(wxWindow *canvas)
 {
-  wxCHECK_RET( canvas, "NULL canvas in wxPaintDC ctor" );
+    wxCHECK_RET( canvas, "NULL canvas in wxPaintDC ctor" );
-  
+
 #ifdef __WXDEBUG__
-  wxCHECK_RET( g_isPainting, _T("wxPaintDC may be created only in EVT_PAINT handler!") );
+    if ( !g_isPainting )
-#endif
+    {
+        wxFAIL_MSG( _T("wxPaintDC may be created only in EVT_PAINT handler!") );
 
-  m_canvas = canvas;
+        return;
+    }
+#endif // __WXDEBUG__
 
-  // Don't call Begin/EndPaint if it's already been called: for example, if
+    m_canvas = canvas;
-  // calling a base class OnPaint.
-  if ( ms_PaintCount > 0 ) {
-    // it means that we've already called BeginPaint and so we must just
-    // reuse the same HDC (BeginPaint shouldn't be called more than once)
-    wxASSERT( ms_PaintHDC );
 
-    m_hDC = ms_PaintHDC;
+    // do we have a DC for this window in the cache?
-    ms_PaintCount++;
+    wxPaintDCInfo *info = FindInCache();
-  }
+    if ( info )
-  else {
+    {
-    ms_PaintHDC =
+        m_hDC = info->hdc;
-    m_hDC = (WXHDC)::BeginPaint((HWND)m_canvas->GetHWND(), &g_paintStruct);
+        info->count++;
-    ms_PaintCount = 1;
+    }
-    m_hDCCount++;
+    else // not in cache, create a new one
-  }
+    {
+        m_hDC = (WXHDC)::BeginPaint(GetWinHwnd(m_canvas), &g_paintStruct);
+        ms_cache.Add(new wxPaintDCInfo(m_canvas, this));
+    }
 
-  SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
+    SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
 }
 
 wxPaintDC::~wxPaintDC()
 {
-  if ( m_hDC ) {
+    if ( m_hDC )
-    if ( !--ms_PaintCount ) {
+    {
-      ::EndPaint((HWND)m_canvas->GetHWND(), &g_paintStruct);
+        size_t index;
-      m_hDCCount--;
+        wxPaintDCInfo *info = FindInCache(&index);
-      m_hDC = (WXHDC) NULL;
+
-      ms_PaintHDC = (WXHDC) NULL;
+        wxCHECK_RET( info, _T("existing DC should have a cache entry") );
+
+        if ( !--info->count )
+        {
+            ::EndPaint(GetWinHwnd(m_canvas), &g_paintStruct);
+
+            ms_cache.Remove(index);
+        }
+        //else: cached DC entry is still in use
     }
-    //else: ms_PaintHDC still in use
-  }
 }
 
+wxPaintDCInfo *wxPaintDC::FindInCache(size_t *index) const
+{
+    wxPaintDCInfo *info = NULL;
+    size_t nCache = ms_cache.GetCount();
+    for ( size_t n = 0; n < nCache; n++ )
+    {
+        info = &ms_cache[n];
+        if ( info->hwnd == m_canvas->GetHWND() )
+        {
+            if ( index )
+                *index = n;
+            break;
+        }
+    }
+
+    return info;
+}

src/msw/menuitem.cpp

@@ -105,6 +105,7 @@ wxMenuItem::wxMenuItem(wxMenu *pParentMenu, int id,
     m_pParentMenu = pParentMenu;
     m_pSubMenu    = pSubMenu;
     m_bEnabled    = TRUE;
+    m_bChecked    = FALSE;
     m_idItem      = id;
 }