X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/c6eba8f8b204b0d722db0007e3e0d5e2d2d20085..d1d7cdff87c64552187e1984d86c8f7a8b94fdb7:/src/msw/dcclient.cpp diff --git a/src/msw/dcclient.cpp b/src/msw/dcclient.cpp index 81dac38ce8..b6b44efe1b 100644 --- a/src/msw/dcclient.cpp +++ b/src/msw/dcclient.cpp @@ -28,11 +28,36 @@ #pragma hdrstop #endif -#include "wx/dcclient.h" +#include "wx/string.h" #include "wx/log.h" +#include "wx/window.h" #include "wx/msw/private.h" +#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 // ---------------------------------------------------------------------------- @@ -54,7 +79,7 @@ static PAINTSTRUCT g_paintStruct; // 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. - extern bool g_isPainting = FALSE; + int g_isPainting = 0; #endif // __WXDEBUG__ // =========================================================================== @@ -85,7 +110,11 @@ wxWindowDC::~wxWindowDC() { SelectOldObjects(m_hDC); - ::ReleaseDC(GetWinHwnd(m_canvas), GetHdc()); + if ( !::ReleaseDC(GetWinHwnd(m_canvas), GetHdc()) ) + { + wxLogLastError("ReleaseDC"); + } + m_hDC = 0; } @@ -124,57 +153,99 @@ wxClientDC::~wxClientDC() // wxPaintDC // ---------------------------------------------------------------------------- -// TODO (VZ) I have still some doubts about this hack and I still think that we -// should store pairs of (hwnd, hdc) and not just the DC - what if -// BeginPaint() was called on other window? It seems to work like -// this, but to be sure about it we'd need to store hwnd too... - -WXHDC wxPaintDC::ms_PaintHDC = 0; -size_t wxPaintDC::ms_PaintCount = 0; // count of ms_PaintHDC usage +// 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; } wxPaintDC::wxPaintDC(wxWindow *canvas) { - wxCHECK_RET( canvas, "NULL canvas in wxPaintDC ctor" ); - wxCHECK_RET( g_isPainting, - _T("wxPaintDC may be created only in EVT_PAINT handler!") ); + wxCHECK_RET( canvas, _T("NULL canvas in wxPaintDC ctor") ); - m_canvas = canvas; +#ifdef __WXDEBUG__ + if ( g_isPainting <= 0 ) + { + wxFAIL_MSG( _T("wxPaintDC may be created only in EVT_PAINT handler!") ); - // Don't call Begin/EndPaint if it's already been called: for example, if - // 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 ); + return; + } +#endif // __WXDEBUG__ - m_hDC = ms_PaintHDC; - ms_PaintCount++; - } - else { - ms_PaintHDC = - m_hDC = (WXHDC)::BeginPaint((HWND)m_canvas->GetHWND(), &g_paintStruct); - ms_PaintCount = 1; - m_hDCCount++; - } + m_canvas = canvas; - SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID)); + // 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)); + } + + 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, _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; +}