Method onVScrollBar

gui/table.go:1474–1501

onVScrollBar is called when a vertical scroll bar event is received

(evname string, ev interface{})

// onVScrollBar is called when a vertical scroll bar event is received
func (t *Table) onVScrollBar(evname string, ev interface{}) {

	// Calculates the new first visible line
	pos := t.vscroll.Value()
	maxFirst := t.calcMaxFirst()
	first := int(math.Floor((float64(maxFirst) * pos) + 0.5))

	// Sets the new selected row
	sel := t.rowCursor
	selChange := false
	if sel < first {
		t.rowCursor = first
		selChange = true
	} else {
		lines := first - t.firstRow
		lastRow := t.lastRow + lines
		if sel > lastRow {
			t.rowCursor = lastRow
			selChange = true
		}
	}
	t.scrollBarEvent = true
	t.firstRow = first
	t.recalc()
	if selChange {
		t.Dispatch(OnChange, nil)
	}
}

// calcMaxFirst calculates the maximum index of the first visible row
// such as the remaining rows fits completely inside the table