+size_t wxDataViewMainWindow::GetFirstVisibleRow()
+{
+ int x = 0;
+ int y = 0;
+ m_owner->CalcUnscrolledPosition( x, y, &x, &y );
+
+ return y / m_lineHeight;
+}
+
+size_t wxDataViewMainWindow::GetLastVisibleRow()
+{
+ wxSize client_size = GetClientSize();
+ m_owner->CalcUnscrolledPosition( client_size.x, client_size.y, &client_size.x, &client_size.y );
+
+ return wxMin( GetRowCount()-1, ((unsigned)client_size.y/m_lineHeight)+1 );
+}
+
+size_t wxDataViewMainWindow::GetRowCount()