- if (old_y != m_yScrollPosition)
- {
- m_win->SetScrollPos( wxVERTICAL, m_yScrollPosition );
- m_targetWindow->ScrollWindow( 0, (old_y-m_yScrollPosition)*m_yScrollPixelsPerLine,
- GetScrollRect() );
- }
+ if ( new_x == m_xScrollPosition && new_y == m_yScrollPosition )
+ return; // nothing to do, the position didn't change
+
+ // flush all pending repaints before we change m_{x,y}ScrollPosition, as
+ // otherwise invalidated area could be updated incorrectly later when
+ // ScrollWindow() makes sure they're repainted before scrolling them
+ m_targetWindow->Update();
+
+ // update the position and scroll the window now:
+ if (m_xScrollPosition != new_x)
+ {
+ int old_x = m_xScrollPosition;
+ m_xScrollPosition = new_x;
+ m_win->SetScrollPos( wxHORIZONTAL, new_x );
+ m_targetWindow->ScrollWindow( (old_x-new_x)*m_xScrollPixelsPerLine, 0,
+ GetScrollRect() );
+ }
+
+ if (m_yScrollPosition != new_y)
+ {
+ int old_y = m_yScrollPosition;
+ m_yScrollPosition = new_y;
+ m_win->SetScrollPos( wxVERTICAL, new_y );
+ m_targetWindow->ScrollWindow( 0, (old_y-new_y)*m_yScrollPixelsPerLine,
+ GetScrollRect() );