// Created: 01/02/97
// RCS-ID: $Id$
// Copyright: (c) Julian Smart and Markus Holzem
-// Licence: wxWindows licence
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
+// ===========================================================================
+// declarations
+// ===========================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+
#ifdef __GNUG__
-#pragma implementation "dcclient.h"
+ #pragma implementation "dcclient.h"
#endif
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
-#pragma hdrstop
+ #pragma hdrstop
#endif
-#ifndef WX_PRECOMP
-#endif
+#include "wx/string.h"
+#include "wx/log.h"
+#include "wx/window.h"
+
+#include "wx/msw/private.h"
#include "wx/dcclient.h"
-#include "wx/log.h"
-#include <windows.h>
+// ----------------------------------------------------------------------------
+// array/list types
+// ----------------------------------------------------------------------------
-#if !USE_SHARED_LIBRARY
-IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
-IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
-IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)
-#endif
+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
+// ----------------------------------------------------------------------------
+
+ IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
+ IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
+ IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)
-/*
- * wxWindowDC
- */
+// ----------------------------------------------------------------------------
+// global variables
+// ----------------------------------------------------------------------------
-wxWindowDC::wxWindowDC(void)
+static PAINTSTRUCT g_paintStruct;
+
+#ifdef __WXDEBUG__
+ // a global variable which we check to verify that wxPaintDC are only
+ // created in resopnse to WM_PAINT message - doing this from elsewhere is a
+ // common programming error among wxWindows programmers and might lead to
+ // very subtle and difficult to debug refresh/repaint bugs.
+ int g_isPainting = 0;
+#endif // __WXDEBUG__
+
+// ===========================================================================
+// implementation
+// ===========================================================================
+
+// ----------------------------------------------------------------------------
+// wxWindowDC
+// ----------------------------------------------------------------------------
+
+wxWindowDC::wxWindowDC()
{
m_canvas = NULL;
}
wxWindowDC::wxWindowDC(wxWindow *the_canvas)
{
m_canvas = the_canvas;
-// m_hDC = (WXHDC) ::GetDCEx((HWND) the_canvas->GetHWND(), NULL, DCX_WINDOW);
- m_hDC = (WXHDC) ::GetWindowDC((HWND) the_canvas->GetHWND() );
- m_hDCCount ++;
+ m_hDC = (WXHDC) ::GetWindowDC(GetWinHwnd(the_canvas) );
+ m_hDCCount++;
SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
}
-wxWindowDC::~wxWindowDC(void)
+wxWindowDC::~wxWindowDC()
{
if (m_canvas && m_hDC)
{
SelectOldObjects(m_hDC);
- ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
- m_hDC = 0;
+ if ( !::ReleaseDC(GetWinHwnd(m_canvas), GetHdc()) )
+ {
+ wxLogLastError(wxT("ReleaseDC"));
+ }
+
+ m_hDC = 0;
}
- m_hDCCount --;
+
+ m_hDCCount--;
}
-/*
- * wxClientDC
- */
+// ----------------------------------------------------------------------------
+// wxClientDC
+// ----------------------------------------------------------------------------
-wxClientDC::wxClientDC(void)
+wxClientDC::wxClientDC()
{
m_canvas = NULL;
}
wxClientDC::wxClientDC(wxWindow *the_canvas)
{
m_canvas = the_canvas;
-// BeginDrawing();
- m_hDC = (WXHDC) ::GetDC((HWND) the_canvas->GetHWND());
+ m_hDC = (WXHDC) ::GetDC(GetWinHwnd(the_canvas));
+
+ // the background mode is only used for text background
+ // and is set in DrawText() to OPAQUE as required, other-
+ // wise always TRANSPARENT, RR
+ ::SetBkMode( GetHdc(), TRANSPARENT );
SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
}
-wxClientDC::~wxClientDC(void)
+wxClientDC::~wxClientDC()
{
-// EndDrawing();
-
- if (m_canvas && (HDC) m_hDC)
+ if ( m_canvas && GetHdc() )
{
SelectOldObjects(m_hDC);
- ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
- m_hDC = 0;
+ ::ReleaseDC(GetWinHwnd(m_canvas), GetHdc());
+ m_hDC = 0;
}
}
-/*
- * wxPaintDC
- */
+// ----------------------------------------------------------------------------
+// wxPaintDC
+// ----------------------------------------------------------------------------
-wxPaintDC::wxPaintDC(void)
+// VZ: initial implementation (by JACS) only remembered the last wxPaintDC
+// created and tried to reuse - this was supposed to take care of a
+// situation when a derived class OnPaint() calls base class OnPaint()
+// 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 really want to allow it, add a
+// "wxPaintDC *" parameter to wxPaintEvent which should be used if it's
+// !NULL instead of creating a new DC.
+
+wxArrayDCInfo wxPaintDC::ms_cache;
+
+wxPaintDC::wxPaintDC()
{
- m_canvas = NULL;
+ m_canvas = NULL;
+ m_hDC = 0;
}
-static PAINTSTRUCT g_paintStruct;
+wxPaintDC::wxPaintDC(wxWindow *canvas)
+{
+ wxCHECK_RET( canvas, wxT("NULL canvas in wxPaintDC ctor") );
-// Don't call Begin/EndPaint if it's already been called:
-// for example, if calling a base class OnPaint.
+#ifdef __WXDEBUG__
+ if ( g_isPainting <= 0 )
+ {
+ wxFAIL_MSG( wxT("wxPaintDC may be created only in EVT_PAINT handler!") );
-WXHDC wxPaintDC::ms_PaintHDC = 0;
-size_t wxPaintDC::ms_PaintCount = 0; // count of ms_PaintHDC usage
+ return;
+ }
+#endif // __WXDEBUG__
-wxPaintDC::wxPaintDC(wxWindow *canvas)
-{
- wxCHECK_RET( canvas, "NULL canvas in wxPaintDC ctor" );
+ m_canvas = canvas;
- m_canvas = canvas;
- 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 );
+ // do we have a DC for this window in the cache?
+ wxPaintDCInfo *info = FindInCache();
+ if ( info )
+ {
+ m_hDC = info->hdc;
+ info->count++;
+ }
+ 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));
+ }
- m_hDC = ms_PaintHDC;
- ms_PaintCount++;
- }
- else {
- ms_PaintHDC =
- m_hDC = (WXHDC)::BeginPaint((HWND)m_canvas->GetHWND(), &g_paintStruct);
- ms_PaintCount = 1;
- m_hDCCount++;
- }
+ // the background mode is only used for text background
+ // and is set in DrawText() to OPAQUE as required, other-
+ // wise always TRANSPARENT, RR
+ ::SetBkMode( GetHdc(), TRANSPARENT );
- SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
+ SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
}
wxPaintDC::~wxPaintDC()
{
- if ( m_hDC ) {
- if ( !--ms_PaintCount ) {
- ::EndPaint((HWND)m_canvas->GetHWND(), &g_paintStruct);
- m_hDCCount--;
- m_hDC = (WXHDC) NULL;
- ms_PaintHDC = (WXHDC) NULL;
+ if ( m_hDC )
+ {
+ SelectOldObjects(m_hDC);
+
+ size_t index;
+ wxPaintDCInfo *info = FindInCache(&index);
+
+ wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
+
+ if ( !--info->count )
+ {
+ ::EndPaint(GetWinHwnd(m_canvas), &g_paintStruct);
+
+ ms_cache.Remove(index);
+
+ // Reduce the number of bogus reports of non-freed memory
+ // at app exit
+ if (ms_cache.IsEmpty())
+ ms_cache.Clear();
+ }
+ //else: cached DC entry is still in use
+
+ // prevent the base class dtor from ReleaseDC()ing it again
+ m_hDC = 0;
}
- 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;
+}
+
+// find the entry for this DC in the cache (keyed by the window)
+WXHDC wxPaintDC::FindDCInCache(wxWindow* win)
+{
+ wxPaintDCInfo *info = NULL;
+ size_t nCache = ms_cache.GetCount();
+ for ( size_t n = 0; n < nCache; n++ )
+ {
+ info = &ms_cache[n];
+ if ( info->hwnd == win->GetHWND() )
+ {
+ return info->hdc;
+ }
+ }
+ return 0;
}
projects / wxWidgets.git / blobdiff