Restored the ability to scroll.

[wxWidgets.git] / src / msw / dcclient.cpp

diff --git a/src/msw/dcclient.cpp b/src/msw/dcclient.cpp
index 8af9d2aad7bd1917c5c1b422430f65b4e69242ae..ea236015d5f00d8995da7560edc939835b6a795b 100644 (file)
--- a/src/msw/dcclient.cpp
+++ b/src/msw/dcclient.cpp
@@ -6,128 +6,256 @@
 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Copyright:   (c) Julian Smart and Markus Holzem
 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Copyright:   (c) Julian Smart and Markus Holzem

-// Licence:    wxWindows licence
+// Licence:     wxWindows licence

 /////////////////////////////////////////////////////////////////////////////
 
 /////////////////////////////////////////////////////////////////////////////
 

+// ===========================================================================
+// declarations
+// ===========================================================================
+
+// ----------------------------------------------------------------------------
+// headers
+// ----------------------------------------------------------------------------
+

 #ifdef __GNUG__
 #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__
 #endif
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifdef __BORLANDC__

-#pragma hdrstop
+    #pragma hdrstop

 #endif
 
 #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/dcclient.h"

-#include "wx/log.h"

 
 

-#include <windows.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
+// ----------------------------------------------------------------------------

 
 #if !USE_SHARED_LIBRARY
 
 #if !USE_SHARED_LIBRARY

-IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxDC)
-IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
-IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxDC)
+    IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
+    IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
+    IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)

 #endif
 
 #endif
 

-wxClientDC::wxClientDC(void)
+// ----------------------------------------------------------------------------
+// global variables
+// ----------------------------------------------------------------------------
+
+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;
 }
 
 {
   m_canvas = NULL;
 }
 

-wxClientDC::wxClientDC(wxWindow *the_canvas)
+wxWindowDC::wxWindowDC(wxWindow *the_canvas)

 {
   m_canvas = the_canvas;
 {
   m_canvas = the_canvas;

-//  BeginDrawing();
-  m_hDC = (WXHDC) ::GetDC((HWND) the_canvas->GetHWND());
+  m_hDC = (WXHDC) ::GetWindowDC(GetWinHwnd(the_canvas) );
+  m_hDCCount++;
+
+  SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));

 }
 
 }
 

-wxClientDC::~wxClientDC(void)
+wxWindowDC::~wxWindowDC()

 {
 {

-//  EndDrawing();
-
-  if (m_canvas && (HDC) m_hDC)
+  if (m_canvas && m_hDC)

   {
     SelectOldObjects(m_hDC);
 
   {
     SelectOldObjects(m_hDC);
 

-    ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
-       m_hDC = 0;
+    if ( !::ReleaseDC(GetWinHwnd(m_canvas), GetHdc()) )
+    {
+        wxLogLastError("ReleaseDC");
+    }
+
+    m_hDC = 0;

   }
   }

+
+  m_hDCCount--;

 }
 
 }
 

-wxWindowDC::wxWindowDC(void)
+// ----------------------------------------------------------------------------
+// wxClientDC
+// ----------------------------------------------------------------------------
+
+wxClientDC::wxClientDC()

 {
   m_canvas = NULL;
 }
 
 {
   m_canvas = NULL;
 }
 

-wxWindowDC::wxWindowDC(wxWindow *the_canvas)
+wxClientDC::wxClientDC(wxWindow *the_canvas)

 {
   m_canvas = 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) ::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));

 }
 
 }
 

-wxWindowDC::~wxWindowDC(void)
+wxClientDC::~wxClientDC()

 {
 {

-  if (m_canvas && m_hDC)
+  if ( m_canvas && GetHdc() )

   {
     SelectOldObjects(m_hDC);
 
   {
     SelectOldObjects(m_hDC);
 

-    ::ReleaseDC((HWND) m_canvas->GetHWND(), (HDC) m_hDC);
-       m_hDC = 0;
+    ::ReleaseDC(GetWinHwnd(m_canvas), GetHdc());
+    m_hDC = 0;

   }
   }

-  m_hDCCount --;

 }
 
 }
 

-wxPaintDC::wxPaintDC(void)
-{
-  m_canvas = NULL;
-}
+// ----------------------------------------------------------------------------
+// wxPaintDC
+// ----------------------------------------------------------------------------

 
 

-static PAINTSTRUCT g_paintStruct;
+// 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.

 
 

-// Don't call Begin/EndPaint if it's already been called:
-// for example, if calling a base class OnPaint.
+wxArrayDCInfo wxPaintDC::ms_cache;

 
 

-WXHDC  wxPaintDC::ms_PaintHDC = 0;
-size_t wxPaintDC::ms_PaintCount = 0; // count of ms_PaintHDC usage
+wxPaintDC::wxPaintDC()
+{
+    m_canvas = NULL;
+    m_hDC = 0;
+}

 
 wxPaintDC::wxPaintDC(wxWindow *canvas)
 {
 
 wxPaintDC::wxPaintDC(wxWindow *canvas)
 {

-  wxCHECK_RET( canvas, "NULL canvas in wxPaintDC ctor" );
+    wxCHECK_RET( canvas, _T("NULL canvas in wxPaintDC ctor") );

 
 

-  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 );
+#ifdef __WXDEBUG__
+    if ( g_isPainting <= 0 )
+    {
+        wxFAIL_MSG( _T("wxPaintDC may be created only in EVT_PAINT handler!") );

 
 

-    m_hDC = ms_PaintHDC;
-    ms_PaintCount++;
-  }
-  else {
-    ms_PaintHDC =
-    m_hDC = (WXHDC)::BeginPaint((HWND)m_canvas->GetHWND(), &g_paintStruct);
-    ms_PaintCount = 1;
-    m_hDCCount++;
-  }
+        return;
+    }
+#endif // __WXDEBUG__
+
+    m_canvas = canvas;
+
+    // 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));
+    }
+
+    // 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));

 }
 
 wxPaintDC::~wxPaintDC()
 {
 }
 
 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, _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
+
+        // 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;
+}