WM_USER_VABS

WM_USER_VABS

This message requests table window to scroll vertically by (signed) number of lines specified in lParam. Positive lParam means scrolling forward in data (contents of window moves up), negative - backward. wParam contains number of data lines completely visible in the window (1 if data area is smaller than 1 line). If lParam is 0, message requests to calculate new position of vertical scrollbar.

Standard table window should simply pass this message to Tablefunction.

Owner-drawn window must modify table data but neither redraw nor invalidate the window. If window's appearance remains unchanged and lParam is not 0, window function must return -1. If window supports byte scrolling, it must return (index of topmost line)*MAXTRACK/(total number of lines). If total number of lines is less than or equal to wParam, it returns 0. Otherwise, it must return (index of topmost line)*MAXTRACK/(total number of lines-wParam). As constant MAXTRACK is relatively big, use MulDiv to calculate return value.