Further performance optimizations

[wxWidgets.git] / include / wx / dcbuffer.h

diff --git a/include/wx/dcbuffer.h b/include/wx/dcbuffer.h
index b29469ce2ac57b1067ec9c5c393c925ac6831b22..203f7cd1a38c93a7aef6be8c9718a7caf3fe71e2 100644 (file)
--- a/include/wx/dcbuffer.h
+++ b/include/wx/dcbuffer.h
@@ -14,60 +14,86 @@
 
 #include "wx/dcmemory.h"
 #include "wx/dcclient.h"
 
 #include "wx/dcmemory.h"
 #include "wx/dcclient.h"

+#include "wx/window.h"
+
+// Split platforms into two groups - those which have well-working
+// double-buffering by default, and those which do not.
+#if defined(__WXMAC__) || defined(__WXGTK20__) || defined(__WXDFB__)
+    #define wxALWAYS_NATIVE_DOUBLE_BUFFER       1
+#else
+    #define wxALWAYS_NATIVE_DOUBLE_BUFFER       0
+#endif

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

-class WXDLLIMPEXP_ADV wxBufferedDC : public wxMemoryDC
+// Assumes the buffer bitmap covers the entire scrolled window,
+// and prepares the window DC accordingly
+#define wxBUFFER_VIRTUAL_AREA       0x01
+
+// Assumes the buffer bitmap only covers the client area;
+// does not prepare the window DC
+#define wxBUFFER_CLIENT_AREA        0x02
+
+// Set when not using specific buffer bitmap. Note that this
+// is private style and not returned by GetStyle.
+#define wxBUFFER_USES_SHARED_BUFFER 0x04
+
+class WXDLLIMPEXP_CORE wxBufferedDC : public wxMemoryDC

 {
 public:
     // Default ctor, must subsequently call Init for two stage construction.
 {
 public:
     // Default ctor, must subsequently call Init for two stage construction.

-    wxBufferedDC() : m_dc( 0 )
+    wxBufferedDC()
+        : m_dc(NULL),
+          m_buffer(NULL),
+          m_style(0)

     {
     }
 
     // Construct a wxBufferedDC using a user supplied buffer.
     {
     }
 
     // Construct a wxBufferedDC using a user supplied buffer.

-    wxBufferedDC(wxDC *dc, const wxBitmap &buffer)
-        : m_dc( dc ),
-          m_buffer( buffer )
+    wxBufferedDC(wxDC *dc,
+                 wxBitmap& buffer = wxNullBitmap,
+                 int style = wxBUFFER_CLIENT_AREA)
+        : m_dc(NULL), m_buffer(NULL)

     {
     {

-        UseBuffer();
+        Init(dc, buffer, style);

     }
 
     // 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 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)
-        : m_dc( dc ),
-          m_buffer( area.GetWidth(), area.GetHeight() )
+    wxBufferedDC(wxDC *dc, const wxSize& area, int style = wxBUFFER_CLIENT_AREA)
+        : m_dc(NULL), m_buffer(NULL)

     {
     {

-        UseBuffer();
+        Init(dc, area, style);

     }
 
     }
 

-    // default copy ctor ok.
-

     // The usually desired  action in the dtor is to blit the buffer.
     virtual ~wxBufferedDC()
     {
     // The usually desired  action in the dtor is to blit the buffer.
     virtual ~wxBufferedDC()
     {

-        if ( m_dc ) UnMask();
+        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.
-    void Init(wxDC *dc, const wxBitmap &buffer)
+    // These reimplement the actions of the ctors for two stage creation
+    void Init(wxDC *dc,
+              wxBitmap& buffer = wxNullBitmap,
+              int style = wxBUFFER_CLIENT_AREA)

     {
     {

-        wxASSERT_MSG( m_dc == 0 && m_buffer == wxNullBitmap,
-                      _T("wxBufferedDC already initialised") );
-        m_dc = dc;
-        m_buffer = buffer;
+        InitCommon(dc, style);
+
+        m_buffer = &buffer;
+

         UseBuffer();
     }
 
         UseBuffer();
     }
 

-    void Init(wxDC *dc, const wxSize &area)
+    void Init(wxDC *dc, const wxSize &area, int style = wxBUFFER_CLIENT_AREA)

     {
     {

-        Init(dc, wxBitmap(area.GetWidth(), area.GetHeight()));
+        InitCommon(dc, style);
+
+        UseBuffer(area.x, area.y);

     }
 
     // Blits the buffer to the dc, and detaches the dc from the buffer (so it
     }
 
     // Blits the buffer to the dc, and detaches the dc from the buffer (so it


@@ -76,26 +102,29 @@ public:
     // 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.
     // 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()
-    {
-        wxASSERT_MSG( m_dc != 0,
-                      _T("No underlying DC associated with wxBufferedDC (anymore)") );
+    void UnMask();

 
 

-        m_dc->Blit( m_dc->DeviceToLogicalX(0), m_dc->DeviceToLogicalY(0),
-                    m_buffer.GetWidth(), m_buffer.GetHeight(), this,
-                    DeviceToLogicalX(0), DeviceToLogicalY(0) );
-        m_dc = NULL;
-    }
+    // Set and get the style
+    void SetStyle(int style) { m_style = style; }
+    int GetStyle() const { return m_style & ~wxBUFFER_USES_SHARED_BUFFER; }

 
 private:
 
 private:

-    // check that the bitmap is valid and use it
-    void UseBuffer()
+    // common part of Init()s
+    void InitCommon(wxDC *dc, int style)

     {
     {

-        wxASSERT_MSG( m_buffer.Ok(), _T("invalid bitmap in wxBufferedDC") );
+        wxASSERT_MSG( !m_dc, _T("wxBufferedDC already initialised") );
+
+        m_dc = dc;
+        m_style = style;

 
 

-        SelectObject(m_buffer);
+        // inherit the same layout direction as the original DC
+        if (dc && dc->IsOk())
+            SetLayoutDirection(dc->GetLayoutDirection());

     }
 
     }
 

+    // check that the bitmap is valid and use it
+    void UseBuffer(wxCoord w = -1, wxCoord h = -1);
+

     // the underlying DC to which we copy everything drawn on this one in
     // UnMask()
     //
     // the underlying DC to which we copy everything drawn on this one in
     // UnMask()
     //


@@ -103,9 +132,13 @@ private:
     //     could probably be a reference.
     wxDC *m_dc;
 
     //     could probably be a reference.
     wxDC *m_dc;
 

-    // the buffer (selected in this DC)
-    wxBitmap m_buffer;
+    // the buffer (selected in this DC), initially invalid
+    wxBitmap *m_buffer;
+
+    // the buffering style
+    int m_style;

 
 

+    DECLARE_DYNAMIC_CLASS(wxBufferedDC)

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


@@ -116,17 +149,32 @@ private:
 
 // 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_CORE wxBufferedPaintDC : public wxBufferedDC

 {
 public:
 {
 public:

-    // If no bitmap is supplied by the user, a temporary one wil; be created.
-    wxBufferedPaintDC(wxWindow *window, const wxBitmap& buffer = wxNullBitmap)
+    // If no bitmap is supplied by the user, a temporary one will be created.
+    wxBufferedPaintDC(wxWindow *window, wxBitmap& buffer, int style = wxBUFFER_CLIENT_AREA)

         : m_paintdc(window)
     {
         : m_paintdc(window)
     {

-        if( buffer != wxNullBitmap )
-            Init(&m_paintdc, buffer);
+        // If we're buffering the virtual window, scale the paint DC as well
+        if (style & wxBUFFER_VIRTUAL_AREA)
+            window->PrepareDC( m_paintdc );
+
+        if( buffer.IsOk() )
+            Init(&m_paintdc, buffer, style);

         else
         else

-            Init(&m_paintdc, window->GetClientSize());
+            Init(&m_paintdc, GetBufferedSize(window, style), style);
+    }
+
+    // If no bitmap is supplied by the user, a temporary one will be created.
+    wxBufferedPaintDC(wxWindow *window, int style = wxBUFFER_CLIENT_AREA)
+        : m_paintdc(window)
+    {
+        // If we're using the virtual window, scale the paint DC as well
+        if (style & wxBUFFER_VIRTUAL_AREA)
+            window->PrepareDC( m_paintdc );
+
+        Init(&m_paintdc, GetBufferedSize(window, style), style);

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


@@ -138,11 +186,81 @@ public:
         UnMask();
     }
 
         UnMask();
     }
 

+protected:
+    // return the size needed by the buffer: this depends on whether we're
+    // buffering just the currently shown part or the total (scrolled) window
+    static wxSize GetBufferedSize(wxWindow *window, int style)
+    {
+        return style & wxBUFFER_VIRTUAL_AREA ? window->GetVirtualSize()
+                                             : window->GetClientSize();
+    }
+

 private:
     wxPaintDC m_paintdc;
 
 private:
     wxPaintDC m_paintdc;
 

+    DECLARE_ABSTRACT_CLASS(wxBufferedPaintDC)

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

-#endif  // _WX_DCBUFFER_H_

 
 

+
+//
+// wxAutoBufferedPaintDC is a wxPaintDC in toolkits which have double-
+// buffering by default. Otherwise it is a wxBufferedPaintDC. Thus,
+// you can only expect it work with a simple constructor that
+// accepts single wxWindow* argument.
+//
+#if wxALWAYS_NATIVE_DOUBLE_BUFFER
+    #define wxAutoBufferedPaintDCBase           wxPaintDC
+#else
+    #define wxAutoBufferedPaintDCBase           wxBufferedPaintDC
+#endif
+
+
+#ifdef __WXDEBUG__
+
+class WXDLLIMPEXP_CORE wxAutoBufferedPaintDC : public wxAutoBufferedPaintDCBase
+{
+public:
+
+    wxAutoBufferedPaintDC(wxWindow* win)
+        : wxAutoBufferedPaintDCBase(win)
+    {
+        TestWinStyle(win);
+    }
+
+    virtual ~wxAutoBufferedPaintDC() { }
+
+private:
+
+    void TestWinStyle(wxWindow* win)
+    {
+        // Help the user to get the double-buffering working properly.
+        wxASSERT_MSG( win->GetBackgroundStyle() == wxBG_STYLE_CUSTOM,
+                      wxT("In constructor, you need to call SetBackgroundStyle(wxBG_STYLE_CUSTOM), ")
+                      wxT("and also, if needed, paint the background manually in the paint event handler."));
+    }
+
+    DECLARE_NO_COPY_CLASS(wxAutoBufferedPaintDC)
+};
+
+#else // !__WXDEBUG__
+
+// In release builds, just use typedef
+typedef wxAutoBufferedPaintDCBase wxAutoBufferedPaintDC;
+
+#endif
+
+
+// Check if the window is natively double buffered and will return a wxPaintDC
+// if it is, a wxBufferedPaintDC otherwise.  It is the caller's responsibility
+// to delete the wxDC pointer when finished with it.
+inline wxDC* wxAutoBufferedPaintDCFactory(wxWindow* window)
+{
+    if ( window->IsDoubleBuffered() )
+        return new wxPaintDC(window);
+    else
+        return new wxBufferedPaintDC(window);
+}
+
+#endif  // _WX_DCBUFFER_H_