Ensure there is valid context for DrawRectangle

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

diff --git a/src/msw/dcclient.cpp b/src/msw/dcclient.cpp
index ca1caadb274323696f5e0b35c198f225656feb17..1da0e015315e0fa29527dfcad63b8271445ba4ed 100644 (file)
--- a/src/msw/dcclient.cpp
+++ b/src/msw/dcclient.cpp
@@ -1,11 +1,11 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        dcclient.cpp
+// Name:        src/msw/dcclient.cpp

 // Purpose:     wxClientDC class
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$
 // Purpose:     wxClientDC class
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$

-// Copyright:   (c) Julian Smart and Markus Holzem
+// Copyright:   (c) Julian Smart

 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 


@@ -17,10 +17,6 @@
 // headers
 // ----------------------------------------------------------------------------
 
 // headers
 // ----------------------------------------------------------------------------
 

-#ifdef __GNUG__
-    #pragma implementation "dcclient.h"
-#endif
-

 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 


@@ -28,237 +24,364 @@
     #pragma hdrstop
 #endif
 
     #pragma hdrstop
 #endif
 

-#include "wx/string.h"
-#include "wx/log.h"
-#include "wx/window.h"
+#include "wx/dcclient.h"
+#include "wx/msw/dcclient.h"

 
 

-#include "wx/msw/private.h"
+#ifndef WX_PRECOMP
+    #include "wx/string.h"
+    #include "wx/hashmap.h"
+    #include "wx/log.h"
+    #include "wx/window.h"
+#endif

 
 

-#include "wx/dcclient.h"
+#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, wxDC *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))
+    {
+    }

 
 

-    IMPLEMENT_DYNAMIC_CLASS(wxWindowDC, wxDC)
-    IMPLEMENT_DYNAMIC_CLASS(wxClientDC, wxWindowDC)
-    IMPLEMENT_DYNAMIC_CLASS(wxPaintDC, wxWindowDC)
+    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
 // ----------------------------------------------------------------------------
 
 
 // ----------------------------------------------------------------------------
 // global variables
 // ----------------------------------------------------------------------------
 

-static PAINTSTRUCT g_paintStruct;
-
-#ifdef __WXDEBUG__
+#ifdef wxHAS_PAINT_DEBUG

     // a global variable which we check to verify that wxPaintDC are only
     // 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
+    // created in response to WM_PAINT message - doing this from elsewhere is a
+    // common programming error among wxWidgets programmers and might lead to

     // very subtle and difficult to debug refresh/repaint bugs.
     int g_isPainting = 0;
     // very subtle and difficult to debug refresh/repaint bugs.
     int g_isPainting = 0;

-#endif // __WXDEBUG__
+#endif // wxHAS_PAINT_DEBUG

 
 // ===========================================================================
 // implementation
 // ===========================================================================
 
 // ----------------------------------------------------------------------------
 
 // ===========================================================================
 // implementation
 // ===========================================================================
 
 // ----------------------------------------------------------------------------

-// wxWindowDC
+// wxMSWWindowDCImpl

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-wxWindowDC::wxWindowDC()
+IMPLEMENT_ABSTRACT_CLASS(wxWindowDCImpl, wxMSWDCImpl)
+
+wxWindowDCImpl::wxWindowDCImpl( wxDC *owner ) :
+   wxMSWDCImpl( owner )

 {
 {

-  m_canvas = NULL;

 }
 
 }
 

-wxWindowDC::wxWindowDC(wxWindow *the_canvas)
+wxWindowDCImpl::wxWindowDCImpl( wxDC *owner, wxWindow *window ) :
+   wxMSWDCImpl( owner )

 {
 {

-  m_canvas = the_canvas;
-  m_hDC = (WXHDC) ::GetWindowDC(GetWinHwnd(the_canvas) );
-  m_hDCCount++;
+    wxCHECK_RET( window, wxT("invalid window in wxWindowDCImpl") );
+
+    m_window = window;
+    m_hDC = (WXHDC) ::GetWindowDC(GetHwndOf(m_window));

 
 

-  SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
+    // m_bOwnsDC was already set to false in the base class ctor, so the DC
+    // will be released (and not deleted) in ~wxDC
+    InitDC();

 }
 
 }
 

-wxWindowDC::~wxWindowDC()
+void wxWindowDCImpl::InitDC()

 {
 {

-  if (m_canvas && m_hDC)
-  {
-    SelectOldObjects(m_hDC);
+    // the background mode is only used for text background and is set in
+    // DrawText() to OPAQUE as required, otherwise always TRANSPARENT,
+    ::SetBkMode(GetHdc(), TRANSPARENT);

 
 

-    if ( !::ReleaseDC(GetWinHwnd(m_canvas), GetHdc()) )
-    {
-        wxLogLastError("ReleaseDC");
-    }
+    // since we are a window dc we need to grab the palette from the window
+#if wxUSE_PALETTE
+    InitializePalette();
+#endif
+}

 
 

-    m_hDC = 0;
-  }
+void wxWindowDCImpl::DoGetSize(int *width, int *height) const
+{
+    wxCHECK_RET( m_window, wxT("wxWindowDCImpl without a window?") );

 
 

-  m_hDCCount--;
+    m_window->GetSize(width, height);

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------

-// wxClientDC
+// wxClientDCImpl

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-wxClientDC::wxClientDC()
+IMPLEMENT_ABSTRACT_CLASS(wxClientDCImpl, wxWindowDCImpl)
+
+wxClientDCImpl::wxClientDCImpl( wxDC *owner ) :
+   wxWindowDCImpl( owner )

 {
 {

-  m_canvas = NULL;

 }
 
 }
 

-wxClientDC::wxClientDC(wxWindow *the_canvas)
+wxClientDCImpl::wxClientDCImpl( wxDC *owner, wxWindow *window ) :
+   wxWindowDCImpl( owner )

 {
 {

-  m_canvas = the_canvas;
-  m_hDC = (WXHDC) ::GetDC(GetWinHwnd(the_canvas));
+    wxCHECK_RET( window, wxT("invalid window in wxClientDCImpl") );

 
 

-  // 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 );
+    m_window = window;
+    m_hDC = (WXHDC)::GetDC(GetHwndOf(window));

 
 

-  SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
+    // m_bOwnsDC was already set to false in the base class ctor, so the DC
+    // will be released (and not deleted) in ~wxDC
+
+    InitDC();

 }
 
 }
 

-wxClientDC::~wxClientDC()
+void wxClientDCImpl::InitDC()

 {
 {

-  if ( m_canvas && GetHdc() )
-  {
-    SelectOldObjects(m_hDC);
+    wxWindowDCImpl::InitDC();
+
+    // in wxUniv build we must manually do some DC adjustments usually
+    // performed by Windows for us
+    //
+    // we also need to take the menu/toolbar manually into account under
+    // Windows CE because they're just another control there, not anything
+    // special as usually under Windows
+#if defined(__WXUNIVERSAL__) || defined(__WXWINCE__)
+    wxPoint ptOrigin = m_window->GetClientAreaOrigin();
+    if ( ptOrigin.x || ptOrigin.y )
+    {
+        // no need to shift DC origin if shift is null
+        SetDeviceOrigin(ptOrigin.x, ptOrigin.y);
+    }

 
 

-    ::ReleaseDC(GetWinHwnd(m_canvas), GetHdc());
-    m_hDC = 0;
-  }
+    // clip the DC to avoid overwriting the non client area
+    wxSize size = m_window->GetClientSize();
+    DoSetClippingRegion(0, 0, size.x, size.y);
+#endif // __WXUNIVERSAL__ || __WXWINCE__
+}
+
+wxClientDCImpl::~wxClientDCImpl()
+{
+}
+
+void wxClientDCImpl::DoGetSize(int *width, int *height) const
+{
+    wxCHECK_RET( m_window, wxT("wxClientDCImpl without a window?") );
+
+    m_window->GetClientSize(width, height);

 }
 
 // ----------------------------------------------------------------------------
 }
 
 // ----------------------------------------------------------------------------

-// wxPaintDC
+// wxPaintDCImpl

 // ----------------------------------------------------------------------------
 
 // ----------------------------------------------------------------------------
 

-// 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;
+IMPLEMENT_ABSTRACT_CLASS(wxPaintDCImpl, wxClientDCImpl)

 
 

-wxPaintDC::wxPaintDC()
+wxPaintDCImpl::wxPaintDCImpl( wxDC *owner ) :
+   wxClientDCImpl( owner )

 {
 {

-    m_canvas = NULL;
-    m_hDC = 0;

 }
 
 }
 

-wxPaintDC::wxPaintDC(wxWindow *canvas)
+wxPaintDCImpl::wxPaintDCImpl( wxDC *owner, wxWindow *window ) :
+   wxClientDCImpl( owner )

 {
 {

-    wxCHECK_RET( canvas, wxT("NULL canvas in wxPaintDC ctor") );
+    wxCHECK_RET( window, wxT("NULL canvas in wxPaintDCImpl ctor") );

 
 

-#ifdef __WXDEBUG__
+#ifdef wxHAS_PAINT_DEBUG

     if ( g_isPainting <= 0 )
     {
     if ( g_isPainting <= 0 )
     {

-        wxFAIL_MSG( wxT("wxPaintDC may be created only in EVT_PAINT handler!") );
+        wxFAIL_MSG( wxT("wxPaintDCImpl may be created only in EVT_PAINT handler!") );

 
         return;
     }
 
         return;
     }

-#endif // __WXDEBUG__
+#endif // wxHAS_PAINT_DEBUG
+
+    // see comments in src/msw/window.cpp where this is defined
+    extern bool wxDidCreatePaintDC;

 
 

-    m_canvas = canvas;
+    wxDidCreatePaintDC = true;
+
+
+    m_window = window;

 
     // do we have a DC for this window in the cache?
 
     // do we have a DC for this window in the cache?

-    wxPaintDCInfo *info = FindInCache();
-    if ( info )
+    m_hDC = FindDCInCache(m_window);
+    if ( !m_hDC )

     {
     {

-        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));
+        // not in cache, create a new one
+        wxPaintDCInfoOur* const info = new wxPaintDCInfoOur(m_window);
+        gs_PaintDCInfos[m_window] = info;
+        m_hDC = info->GetHDC();

     }
 
     }
 

-    // 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 );
+    // Note: at this point m_hDC can be NULL under MicroWindows, when dragging.
+    if (!GetHDC())
+        return;
+
+    // (re)set the DC parameters.
+    InitDC();

 
 

-    SetBackground(wxBrush(m_canvas->GetBackgroundColour(), wxSOLID));
+    // the HDC can have a clipping box (which we didn't set), make sure our
+    // DoGetClippingBox() checks for it
+    m_clipping = true;

 }
 
 }
 

-wxPaintDC::~wxPaintDC()
+wxPaintDCImpl::~wxPaintDCImpl()

 {
     if ( m_hDC )
     {
         SelectOldObjects(m_hDC);
 {
     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 )
-        {
-            ::EndPaint(GetWinHwnd(m_canvas), &g_paintStruct);
+/* static */
+wxPaintDCInfo *wxPaintDCImpl::FindInCache(wxWindow *win)
+{
+    PaintDCInfos::const_iterator it = gs_PaintDCInfos.find( win );

 
 

-            ms_cache.Remove(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 *wxPaintDC::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 )

     {
     {

-        info = &ms_cache[n];
-        if ( info->hwnd == m_canvas->GetHWND() )
-        {
-            if ( index )
-                *index = n;
-            break;
-        }
+        gs_PaintDCInfos.erase(win);
+        delete info;

     }
     }

+}
+
+wxPaintDCInfo::~wxPaintDCInfo()
+{
+}
+
+/*
+ * wxPaintDCEx
+ */
+
+class wxPaintDCExImpl: public wxPaintDCImpl
+{
+public:
+    wxPaintDCExImpl( wxDC *owner, wxWindow *window, WXHDC dc );
+    ~wxPaintDCExImpl();
+};
+
+
+IMPLEMENT_ABSTRACT_CLASS(wxPaintDCEx,wxPaintDC)
+
+wxPaintDCEx::wxPaintDCEx(wxWindow *window, WXHDC dc)
+           : wxPaintDC(new wxPaintDCExImpl(this, window, dc))
+{
+}

 
 

-    return info;
+wxPaintDCExImpl::wxPaintDCExImpl(wxDC *owner, wxWindow *window, WXHDC dc)
+               : wxPaintDCImpl( owner )
+{
+    wxCHECK_RET( dc, wxT("wxPaintDCEx requires an existing device context") );
+
+    m_window = window;
+    m_hDC = dc;
+}
+
+wxPaintDCExImpl::~wxPaintDCExImpl()
+{
+    // prevent the base class dtor from ReleaseDC()ing it again
+    m_hDC = 0;

 }
 }