- 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(GetHwndOf(m_canvas), &g_paintStruct);
+
+ 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;
+ }
+}
+
+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;
+ }