Oracle Forms Developer – Form Builder Reference, Volume 1

354
ten_percent NUMBER;
new_x NUMBER;
old_y NUMBER;
BEGIN
/*
** Get the id’s for the View and its corresponding canvas
*/
vw_id := Find_View( viewname );
cn_id := Find_Canvas( viewname );
/*
** Determine the view width and corresponding canvas
** width.
*/
vw_wid := Get_View_Property(vw_id,WIDTH);
cn_wid := Get_Canvas_Property(cn_id,WIDTH);
/*
** Calculate how many units of canvas width are outside of
** view, and determine 10% of that.
*/
ten_percent := 0.10 * (cn_wid - vw_wid);
/*
** Determine at what horizontal position the view
** currently is on the corresponding canvas
*/
vw_x:= Get_View_Property(vw_id,VIEWPORT_X_POS_ON_CANVAS);
/*
** Calculate the new x position of the view on its canvas
** to effect the 10% scroll in the proper direction.
** Closer than ten percent of the distance to the edge
** towards which we are moving, then position the view
** against that edge.
*/
IF direction=’LEFT’ THEN
IF vw_x > ten_percent THEN
new_x := vw_x - ten_percent;
ELSE
new_x := 0;
END IF;
ELSIF direction=’RIGHT’ THEN
IF vw_x < cn_wid - vw_wid - ten_percent THEN
new_x := vw_x + ten_percent;
ELSE
new_x := cn_wid - vw_wid;
END IF;
END IF;
/*
** Scroll the view that much horizontally
*/
old_y := Get_View_Property(vw_id,VIEWPORT_Y_POS_ON_CANVAS);
Scroll_View( vw_id, new_x , old_y );
END;