- int w, h;
- GetClientSize(&w, &h);
-
- int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
- int noPositions = (int) ( ((nMaxHeight - h)/(float)m_yScrollPixelsPerLine) + 0.5 );
- if (noPositions < 0)
- noPositions = 0;
-
- if ( (m_yScrollPosition + nScrollInc) < 0 )
- nScrollInc = -m_yScrollPosition; // As -ve as we can go
- else if ( (m_yScrollPosition + nScrollInc) > noPositions )
- nScrollInc = noPositions - m_yScrollPosition; // As +ve as we can go
-
- return nScrollInc;
+ if (m_yScrollPixelsPerLine > 0) {
+ int w, h;
+ GetClientSize(&w, &h);
+
+ int nMaxHeight = m_yScrollLines*m_yScrollPixelsPerLine;
+ int noPositions = (int) ( ((nMaxHeight - h)/(float)m_yScrollPixelsPerLine) + 0.5 );
+ if (noPositions < 0)
+ noPositions = 0;
+
+ if ( (m_yScrollPosition + nScrollInc) < 0 )
+ nScrollInc = -m_yScrollPosition; // As -ve as we can go
+ else if ( (m_yScrollPosition + nScrollInc) > noPositions )
+ nScrollInc = noPositions - m_yScrollPosition; // As +ve as we can go
+ }
+ else
+ Refresh();