// Author: Julian Smart
// Modified by:
// Created: 01/02/97
-// RCS-ID: $Id$
// Copyright: (c) Julian Smart
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef WX_PRECOMP
#include "wx/string.h"
+ #include "wx/hashmap.h"
#include "wx/log.h"
#include "wx/window.h"
#endif
#include "wx/msw/private.h"
// ----------------------------------------------------------------------------
-// array/list types
+// local data structures
// ----------------------------------------------------------------------------
-struct WXDLLEXPORT wxPaintDCInfo
+// This is a base class for two concrete subclasses below and contains HDC
+// cached for the duration of the WM_PAINT processing together with some
+// bookkeeping information.
+class wxPaintDCInfo
{
- wxPaintDCInfo(wxWindow *win, wxPaintDCImpl *dc)
+public:
+ wxPaintDCInfo(HDC hdc)
+ : m_hdc(hdc)
{
- hwnd = win->GetHWND();
- hdc = dc->GetHDC();
- count = 1;
}
- WXHWND hwnd; // window for this DC
- WXHDC hdc; // the DC handle
- size_t count; // usage count
+ // The derived class must perform some cleanup.
+ virtual ~wxPaintDCInfo() = 0;
+
+ WXHDC GetHDC() const { return (WXHDC)m_hdc; }
+
+protected:
+ const HDC m_hdc;
+
+ wxDECLARE_NO_COPY_CLASS(wxPaintDCInfo);
};
-#include "wx/arrimpl.cpp"
+namespace
+{
-WX_DEFINE_OBJARRAY(wxArrayDCInfo)
+// This subclass contains information for the HDCs we create ourselves, i.e.
+// those for which we call BeginPaint() -- and hence need to call EndPaint().
+class wxPaintDCInfoOur : public wxPaintDCInfo
+{
+public:
+ wxPaintDCInfoOur(wxWindow* win)
+ : wxPaintDCInfo(::BeginPaint(GetHwndOf(win), GetPaintStructPtr(m_ps))),
+ m_hwnd(GetHwndOf(win))
+ {
+ }
-// ----------------------------------------------------------------------------
-// macros
-// ----------------------------------------------------------------------------
+ virtual ~wxPaintDCInfoOur()
+ {
+ ::EndPaint(m_hwnd, &m_ps);
+ }
+
+private:
+ // This helper is only needed in order to call it from the ctor initializer
+ // list.
+ static PAINTSTRUCT* GetPaintStructPtr(PAINTSTRUCT& ps)
+ {
+ wxZeroMemory(ps);
+ return &ps;
+ }
+
+ const HWND m_hwnd;
+ PAINTSTRUCT m_ps;
+
+ wxDECLARE_NO_COPY_CLASS(wxPaintDCInfoOur);
+};
+
+// This subclass contains information for the HDCs we receive from outside, as
+// WPARAM of WM_PAINT itself.
+class wxPaintDCInfoExternal : public wxPaintDCInfo
+{
+public:
+ wxPaintDCInfoExternal(HDC hdc)
+ : wxPaintDCInfo(hdc),
+ m_state(::SaveDC(hdc))
+ {
+ }
+
+ virtual ~wxPaintDCInfoExternal()
+ {
+ ::RestoreDC(m_hdc, m_state);
+ }
+
+private:
+ const int m_state;
+
+ wxDECLARE_NO_COPY_CLASS(wxPaintDCInfoExternal);
+};
+
+// The global map containing HDC to use for the given window. The entries in
+// this map only exist during WM_PAINT processing and are destroyed when it is
+// over.
+//
+// It is needed because in some circumstances it can happen that more than one
+// wxPaintDC is created for the same window during its WM_PAINT handling (and
+// as this can happen implicitly, e.g. by calling a function in some library,
+// this can be quite difficult to find) but we need to reuse the same HDC for
+// all of them because we can't call BeginPaint() more than once. So we cache
+// the first HDC created for the window in this map and then reuse it later if
+// needed. And, of course, remove it from the map when the painting is done.
+WX_DECLARE_HASH_MAP(wxWindow *, wxPaintDCInfo *,
+ wxPointerHash, wxPointerEqual,
+ PaintDCInfos);
+
+PaintDCInfos gs_PaintDCInfos;
+
+} // anonymous namespace
// ----------------------------------------------------------------------------
// global variables
// ----------------------------------------------------------------------------
-static PAINTSTRUCT g_paintStruct;
-
#ifdef wxHAS_PAINT_DEBUG
// a global variable which we check to verify that wxPaintDC are only
// created in response to WM_PAINT message - doing this from elsewhere is a
// wxPaintDCImpl
// ----------------------------------------------------------------------------
-// VZ: initial implementation (by JACS) only remembered the last wxPaintDC
-// created and tried to reuse it - 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.
-
IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)
-wxArrayDCInfo wxPaintDCImpl::ms_cache;
-
wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
wxClientDCImpl( owner )
{
m_window = window;
// 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 = FindDCInCache(m_window);
+ if ( !m_hDC )
{
- m_hDC = (WXHDC)::BeginPaint(GetHwndOf(m_window), &g_paintStruct);
- if (m_hDC)
- ms_cache.Add(new wxPaintDCInfo(m_window, this));
+ // not in cache, create a new one
+ wxPaintDCInfoOur* const info = new wxPaintDCInfoOur(m_window);
+ gs_PaintDCInfos[m_window] = info;
+ m_hDC = info->GetHDC();
}
// Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
if ( m_hDC )
{
SelectOldObjects(m_hDC);
+ m_hDC = 0;
+ }
+}
- size_t index;
- wxPaintDCInfo *info = FindInCache(&index);
-
- wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
- if ( --info->count == 0 )
- {
- ::EndPaint(GetHwndOf(m_window), &g_paintStruct);
+/* static */
+wxPaintDCInfo *wxPaintDCImpl::FindInCache(wxWindow *win)
+{
+ PaintDCInfos::const_iterator it = gs_PaintDCInfos.find( win );
- ms_cache.RemoveAt(index);
+ return it != gs_PaintDCInfos.end() ? it->second : NULL;
+}
- // 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
+/* static */
+WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)
+{
+ wxPaintDCInfo* const info = FindInCache(win);
- // prevent the base class dtor from ReleaseDC()ing it again
- m_hDC = 0;
- }
+ return info ? info->GetHDC() : 0;
}
-wxPaintDCInfo *wxPaintDCImpl::FindInCache(size_t *index) const
+/* static */
+void wxPaintDCImpl::EndPaint(wxWindow *win)
{
- wxPaintDCInfo *info = NULL;
- size_t nCache = ms_cache.GetCount();
- for ( size_t n = 0; n < nCache; n++ )
+ wxPaintDCInfo *info = FindInCache(win);
+ if ( info )
{
- wxPaintDCInfo *info1 = &ms_cache[n];
- if ( info1->hwnd == m_window->GetHWND() )
- {
- info = info1;
- if ( index )
- *index = n;
- break;
- }
+ gs_PaintDCInfos.erase(win);
+ delete info;
}
-
- return info;
}
-// find the entry for this DC in the cache (keyed by the window)
-WXHDC wxPaintDCImpl::FindDCInCache(wxWindow* win)
+wxPaintDCInfo::~wxPaintDCInfo()
{
- size_t nCache = ms_cache.GetCount();
- for ( size_t n = 0; n < nCache; n++ )
- {
- wxPaintDCInfo *info = &ms_cache[n];
- if ( info->hwnd == win->GetHWND() )
- {
- return info->hdc;
- }
- }
- return 0;
}
/*
* wxPaintDCEx
*/
-// TODO: don't duplicate wxPaintDCImpl code here!!
-
class wxPaintDCExImpl: public wxPaintDCImpl
{
public:
wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
~wxPaintDCExImpl();
-
- int m_saveState;
};
wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
: wxPaintDCImpl( owner )
{
- wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
-
- m_saveState = 0;
-
- m_window = window;
-
- wxPaintDCInfo *info = FindInCache();
- if ( info )
- {
- m_hDC = info->hdc;
- info->count++;
- }
- else // not in cache, create a new one
- {
- m_hDC = dc;
- ms_cache.Add(new wxPaintDCInfo(m_window, this));
- m_saveState = SaveDC((HDC) dc);
- }
+ wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
+
+ m_window = window;
+ m_hDC = dc;
}
wxPaintDCExImpl::~wxPaintDCExImpl()
{
- size_t index;
- wxPaintDCInfo *info = FindInCache(&index);
-
- wxCHECK_RET( info, wxT("existing DC should have a cache entry") );
-
- if ( --info->count == 0 )
- {
- RestoreDC((HDC) m_hDC, m_saveState);
- ms_cache.RemoveAt(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;
+ // prevent the base class dtor from ReleaseDC()ing it again
+ m_hDC = 0;
}
-
-
projects / wxWidgets.git / blobdiff