made it possible to preserve background when using wxBufferedDC (replaces patch 87626...

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@25567 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index 2b5ef0bd096f71c17a7b0a866d17d2b0a9000fa5..37988bef0404d9b66afbe7c765ffd38724a03654 100644 (file)
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -2,7 +2,7 @@
 // Name:        wx/dcbuffer.h
 // Purpose:     wxBufferedDC class
 // Author:      Ron Lee <ron@debian.org>
 // Name:        wx/dcbuffer.h
 // Purpose:     wxBufferedDC class
 // Author:      Ron Lee <ron@debian.org>

-// Modified by:
+// Modified by: Vadim Zeitlin (refactored, added bg preservation)

 // Created:     16/03/02
 // RCS-ID:      $Id$
 // Copyright:   (c) Ron Lee
 // Created:     16/03/02
 // RCS-ID:      $Id$
 // Copyright:   (c) Ron Lee


@@ -13,95 +13,136 @@
 #define _WX_DCBUFFER_H_
 
 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
 #define _WX_DCBUFFER_H_
 
 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)

-#pragma interface "dcbuffer.h"
+    #pragma interface "dcbuffer.h"

 #endif
 
 #include "wx/dcmemory.h"
 #include "wx/dcclient.h"
 
 #endif
 
 #include "wx/dcmemory.h"
 #include "wx/dcclient.h"
 

-
-// ==============================================================
-//   Double buffering helper.
-// --------------------------------------------------------------
-
-class WXDLLIMPEXP_ADV wxBufferedDC : public wxMemoryDC
+// flags for wxBufferedDC ctor/Init()
+enum

 {
 {

-private:
+    // this is more efficient and hence default
+    wxBUFFER_DC_OVERWRITE_BG = 0,

 
 

-        // Without the existence of a wxNullDC, this must be
-        // a pointer, else it could probably be a reference.
+    // preserve the old background: more time consuming
+    wxBUFFER_DC_PRESERVE_BG = 1,

 
 

-    wxDC        *m_dc;
-    wxBitmap    m_buffer;
-
-public:

 
 

-        // Default ctor, must subsequently call Init for
-        // two stage construction.
-
-    wxBufferedDC()
-        : m_dc( 0 )
-    {}
+    // flags used by default
+    wxBUFFER_DC_DEFAULT = wxBUFFER_DC_PRESERVE_BG
+};

 
 

-        // Construct a wxBufferedDC using a user supplied buffer.
+// ----------------------------------------------------------------------------
+// Double buffering helper.
+// ----------------------------------------------------------------------------

 
 

-    wxBufferedDC( wxDC *dc, const wxBitmap &buffer );
+class WXDLLIMPEXP_ADV wxBufferedDC : public wxMemoryDC
+{
+public:
+    // Default ctor, must subsequently call Init for two stage construction.
+    wxBufferedDC() : m_dc( 0 )
+    {
+    }

 
 

-        // Construct a wxBufferedDC with an internal buffer of 'area'
-        // (where area is usually something like the size of the window
-        // being buffered)
+    // Construct a wxBufferedDC using a user supplied buffer.
+    wxBufferedDC(wxDC *dc, const wxBitmap &buffer);

 
 

-    wxBufferedDC( wxDC *dc, const wxSize &area );
+    // Construct a wxBufferedDC with an internal buffer of 'area'
+    // (where area is usually something like the size of the window
+    // being buffered)
+    wxBufferedDC(wxDC *dc, const wxSize &area, int flags = wxBUFFER_DC_DEFAULT);

 
     // default copy ctor ok.
 
 
     // default copy ctor ok.
 

-        // The usually desired  action in the dtor is to blit the buffer.
-
-    ~wxBufferedDC();
+    // The usually desired  action in the dtor is to blit the buffer.
+    virtual ~wxBufferedDC() { if ( m_dc ) UnMask(); }

 
 

-        // These reimplement the actions of the ctors for
-        // two stage creation, but are not used by the ctors
-        // themselves to save a few cpu cycles.
+    // These reimplement the actions of the ctors for two stage creation, but
+    // are not used by the ctors themselves to save a few cpu cycles.
+    void Init(wxDC *dc, const wxBitmap &bitmap);
+    void Init(wxDC *dc, const wxSize &area, int flags = wxBUFFER_DC_DEFAULT);

 
 

-    void Init( wxDC *dc, const wxBitmap &bitmap );
-    void Init( wxDC *dc, const wxSize &area );
+    // Blits the buffer to the dc, and detaches the dc from the buffer (so it
+    // can be effectively used once only).
+    //
+    // Usually called in the dtor or by the dtor of derived classes if the
+    // BufferedDC must blit before the derived class (which may own the dc it's
+    // blitting to) is destroyed.
+    void UnMask();

 
 

-        // Blits the buffer to the dc, and detaches the dc from
-        // the buffer.  Usually called in the dtor or by the dtor
-        // of derived classes if the BufferedDC must blit before
-        // the derived class (which may own the dc it's blitting
-        // to) is destroyed.
+private:
+    // check that the bitmap is valid and use it
+    void UseBuffer()
+    {
+        wxASSERT_MSG( m_buffer.Ok(), _T("invalid bitmap in wxBufferedDC") );
+
+        SelectObject(m_buffer);
+    }
+
+    // preserve the background if necessary
+    void SaveBg(const wxSize& area, int flags)
+    {
+        if ( flags & wxBUFFER_DC_PRESERVE_BG )
+        {
+            Blit(0, 0, area.GetWidth(), area.GetHeight(), m_dc, 0, 0);
+        }
+    }
+
+    // Without the existence of a wxNullDC, this must be
+    // a pointer, else it could probably be a reference.
+    wxDC       *m_dc;

 
 

-    void UnMask();
+    wxBitmap    m_buffer;

 
     DECLARE_NO_COPY_CLASS(wxBufferedDC)
 };
 
 
 
     DECLARE_NO_COPY_CLASS(wxBufferedDC)
 };
 
 

-// ==============================================================
-//   Double buffered PaintDC.
-// --------------------------------------------------------------
+// ----------------------------------------------------------------------------
+// Double buffered PaintDC.
+// ----------------------------------------------------------------------------

 
 // Creates a double buffered wxPaintDC, optionally allowing the
 // user to specify their own buffer to use.
 
 // Creates a double buffered wxPaintDC, optionally allowing the
 // user to specify their own buffer to use.

-

 class WXDLLIMPEXP_ADV wxBufferedPaintDC : public wxBufferedDC
 {
 class WXDLLIMPEXP_ADV wxBufferedPaintDC : public wxBufferedDC
 {

-private:
-
-    wxPaintDC    m_paintdc;
-

 public:
 public:

-
-    wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer = wxNullBitmap );
+    // this ctor creates a bitmap of the size of the window for buffering
+    wxBufferedPaintDC(wxWindow *window, int flags = wxBUFFER_DC_DEFAULT)
+        : wxBufferedDC(&m_paintdc, window->GetClientSize(), flags),
+          m_paintdc(window)
+    {
+        Prepare(window);
+    }
+
+    // the bitmap must be valid here
+    wxBufferedPaintDC(wxWindow *window, const wxBitmap& buffer)
+        : wxBufferedDC(&m_paintdc, buffer)
+    {
+        Prepare(window);
+    }

 
     // default copy ctor ok.
 
 
     // default copy ctor ok.
 

-    ~wxBufferedPaintDC();
+    virtual ~wxBufferedPaintDC()
+    {
+        // We must UnMask here, else by the time the base class
+        // does it, the PaintDC will have already been destroyed.
+        UnMask();
+    }
+
+private:
+    // prepare the underlying DC
+    void Prepare(wxWindow *window)
+    {
+        window->PrepareDC(m_paintdc);
+    }
+
+    wxPaintDC m_paintdc;

 
     DECLARE_NO_COPY_CLASS(wxBufferedPaintDC)
 };
 
 
     DECLARE_NO_COPY_CLASS(wxBufferedPaintDC)
 };
 

-

 #endif  // _WX_DCBUFFER_H_
 
 #endif  // _WX_DCBUFFER_H_
 

diff --git a/src/generic/dcbuffer.cpp b/src/generic/dcbuffer.cpp
index 4467604e2338e1940205ab1b137be14ed54c3694..6e5396a0eec4b85e6daca6c7b08cedf6b8da2ac7 100644 (file)
--- a/src/generic/dcbuffer.cpp
+++ b/src/generic/dcbuffer.cpp
@@ -1,15 +1,14 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        dcbuffer.cpp
+// Name:        generic/dcbuffer.cpp

 // Purpose:     wxBufferedDC class
 // Author:      Ron Lee <ron@debian.org>
 // Purpose:     wxBufferedDC class
 // Author:      Ron Lee <ron@debian.org>

-// Modified by:
+// Modified by: Vadim Zeitlin (refactored, added bg preservation)

 // Created:     16/03/02
 // RCS-ID:      $Id$
 // Copyright:   (c) Ron Lee
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // Created:     16/03/02
 // RCS-ID:      $Id$
 // Copyright:   (c) Ron Lee
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 

-

 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
     #pragma implementation "dcbuffer.h"
 #endif
 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
     #pragma implementation "dcbuffer.h"
 #endif


@@ -21,36 +20,29 @@
 #endif
 
 #ifndef WX_PRECOMP
 #endif
 
 #ifndef WX_PRECOMP

-#include "wx/window.h"
+    #include "wx/window.h"

 #endif
 
 #include "wx/dcbuffer.h"
 
 #endif
 
 #include "wx/dcbuffer.h"
 

+// ----------------------------------------------------------------------------
+// Double buffering helper.
+// ----------------------------------------------------------------------------

 
 

-// ==============================================================
-//   Double buffering helper.
-// --------------------------------------------------------------
-
-wxBufferedDC::wxBufferedDC( wxDC *dc, const wxBitmap &buffer )
-    : m_dc( dc )
-    , m_buffer( buffer )
+wxBufferedDC::wxBufferedDC(wxDC *dc, const wxBitmap& buffer)
+            : m_dc( dc ),
+              m_buffer( buffer )

 {
 {

-    SelectObject( m_buffer );
+    UseBuffer();

 }
 
 }
 

-wxBufferedDC::wxBufferedDC( wxDC *dc, const wxSize &area )
-    : m_dc( dc )
-    , m_buffer( area.GetWidth(), area.GetHeight() )
+wxBufferedDC::wxBufferedDC(wxDC *dc, const wxSize& area, int flags)
+            : m_dc( dc ),
+              m_buffer( area.GetWidth(), area.GetHeight() )

 {
 {

-    SelectObject( m_buffer );
-}
+    UseBuffer();

 
 

-wxBufferedDC::~wxBufferedDC()
-{
-    if( m_dc != 0 )
-    {
-        UnMask();
-    }
+    SaveBg(area, flags);

 }
 
 void wxBufferedDC::Init( wxDC *dc, const wxBitmap &buffer )
 }
 
 void wxBufferedDC::Init( wxDC *dc, const wxBitmap &buffer )


@@ -60,50 +52,23 @@ void wxBufferedDC::Init( wxDC *dc, const wxBitmap &buffer )
 
     m_dc = dc;
     m_buffer = buffer;
 
     m_dc = dc;
     m_buffer = buffer;

-    SelectObject( m_buffer );
+
+    UseBuffer();

 }
 
 }
 

-void wxBufferedDC::Init( wxDC *dc, const wxSize &area )
+void wxBufferedDC::Init(wxDC *dc, const wxSize& area, int flags)

 {
 {

-    wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
-                  _T("wxBufferedDC already initialised") );
+    Init(dc, wxBitmap(area.GetWidth(), area.GetHeight()));

 
 

-    m_dc = dc;
-    m_buffer = wxBitmap( area.GetWidth(), area.GetHeight() );
-    SelectObject( m_buffer );
+    SaveBg(area, flags);

 }
 
 void wxBufferedDC::UnMask()
 {
 }
 
 void wxBufferedDC::UnMask()
 {

-    wxASSERT_MSG( m_dc != 0, _T("No low level DC associated with buffer (anymore)") );
+    wxASSERT_MSG( m_dc != 0,
+                  _T("No underlying DC associated with wxBufferedDC (anymore)") );

 
     m_dc->Blit( 0, 0, m_buffer.GetWidth(), m_buffer.GetHeight(), this, 0, 0 );
 
     m_dc->Blit( 0, 0, m_buffer.GetWidth(), m_buffer.GetHeight(), this, 0, 0 );

-    m_dc = 0;
+    m_dc = NULL;

 }
 
 }
 

-
-// ==============================================================
-//   Double buffered PaintDC.
-// --------------------------------------------------------------
-
-wxBufferedPaintDC::wxBufferedPaintDC( wxWindow *window, const wxBitmap &buffer )
-    : m_paintdc( window )
-{
-    window->PrepareDC( m_paintdc );
-
-    if( buffer != wxNullBitmap )
-        Init( &m_paintdc, buffer );
-    else
-        Init( &m_paintdc, window->GetClientSize() );
-}
-
-wxBufferedPaintDC::~wxBufferedPaintDC()
-{
-        // We must UnMask here, else by the time the base class
-        // does it, the PaintDC will have already been destroyed.
-
-    UnMask();
-}
-
-
-// vi:sts=4:sw=4:et