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);
}
IMPLEMENT_DYNAMIC_CLASS(wxSharedDCBufferManager, wxModule)
-IMPLEMENT_DYNAMIC_CLASS(wxBufferedDC, wxMemoryDC)
-IMPLEMENT_ABSTRACT_CLASS(wxBufferedPaintDC, wxBufferedDC)
-
// ============================================================================
// wxBufferedDC
// ============================================================================
}
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 && m_dc->IsOk() )
+ CopyAttributes(*m_dc);
}
void wxBufferedDC::UnMask()
{
- wxCHECK_RET( m_dc, _T("no underlying wxDC?") );
- wxASSERT_MSG( m_buffer && m_buffer->IsOk(), _T("invalid backing store") );
+ wxCHECK_RET( m_dc, wxT("no underlying wxDC?") );
+ wxASSERT_MSG( m_buffer && m_buffer->IsOk(), wxT("invalid backing store") );
wxCoord x = 0,
y = 0;
+ // Ensure the scale matches the device
+ SetUserScale(1.0, 1.0);
+
if ( m_style & wxBUFFER_CLIENT_AREA )
GetDeviceOrigin(&x, &y);
- m_dc->Blit(0, 0, m_buffer->GetWidth(), m_buffer->GetHeight(),
- this, -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 )