// implementation
// ============================================================================
+IMPLEMENT_DYNAMIC_CLASS(wxBufferedDC,wxMemoryDC)
+IMPLEMENT_ABSTRACT_CLASS(wxBufferedPaintDC,wxBufferedDC)
+
// ----------------------------------------------------------------------------
// wxSharedDCBufferManager: helper class maintaining backing store bitmap
// ----------------------------------------------------------------------------
static wxBitmap* GetBuffer(int w, int h)
{
+ if ( ms_usingSharedBuffer )
+ return new wxBitmap(w, h);
+
if ( !ms_buffer ||
w > ms_buffer->GetWidth() ||
h > ms_buffer->GetHeight() )
{
delete ms_buffer;
+
+ // we must always return a valid bitmap but creating a bitmap of
+ // size 0 would fail, so create a 1*1 bitmap in this case
+ if ( !w )
+ w = 1;
+ if ( !h )
+ h = 1;
+
ms_buffer = new wxBitmap(w, h);
}
+
+ ms_usingSharedBuffer = true;
return ms_buffer;
}
+ static void ReleaseBuffer(wxBitmap* buffer)
+ {
+ if ( buffer == ms_buffer )
+ {
+ wxASSERT_MSG( ms_usingSharedBuffer, wxT("shared buffer already released") );
+ ms_usingSharedBuffer = false;
+ }
+ else
+ {
+ delete buffer;
+ }
+ }
+
private:
static wxBitmap *ms_buffer;
+ static bool ms_usingSharedBuffer;
DECLARE_DYNAMIC_CLASS(wxSharedDCBufferManager)
};
wxBitmap* wxSharedDCBufferManager::ms_buffer = NULL;
+bool wxSharedDCBufferManager::ms_usingSharedBuffer = false;
IMPLEMENT_DYNAMIC_CLASS(wxSharedDCBufferManager, wxModule)
m_dc->GetSize(&w, &h);
m_buffer = wxSharedDCBufferManager::GetBuffer(w, h);
+ m_style |= wxBUFFER_USES_SHARED_BUFFER;
}
SelectObject(*m_buffer);
+
+ // now that the DC is valid we can inherit the attributes (fonts, colours,
+ // layout direction, ...) from the original DC
+ if ( m_dc->IsOk() )
+ CopyAttributes(*m_dc);
}
+void wxBufferedDC::UnMask()
+{
+ wxCHECK_RET( m_dc, wxT("no underlying wxDC?") );
+ wxASSERT_MSG( m_buffer && m_buffer->IsOk(), wxT("invalid backing store") );
+
+ wxCoord x = 0,
+ y = 0;
+
+ if ( m_style & wxBUFFER_CLIENT_AREA )
+ GetDeviceOrigin(&x, &y);
+
+ // avoid blitting too much: if we were created for a bigger bitmap (and
+ // reused for a smaller one later) we should only blit the real bitmap area
+ // and not the full allocated back buffer
+ int widthDC,
+ heightDC;
+
+ m_dc->GetSize(&widthDC, &heightDC);
+
+ int widthBuf = m_buffer->GetWidth(),
+ heightBuf = m_buffer->GetHeight();
+
+ m_dc->Blit(0, 0,
+ wxMin(widthDC, widthBuf), wxMin(heightDC, heightBuf),
+ this,
+ -x, -y);
+ m_dc = NULL;
+
+ if ( m_style & wxBUFFER_USES_SHARED_BUFFER )
+ wxSharedDCBufferManager::ReleaseBuffer(m_buffer);
+}