bool ScrollArea::touchScroll(const QPoint &delta) {
int32 scTop = scrollTop(), scMax = scrollTopMax(), scNew = snap(scTop - delta.y(), 0, scMax);
if (scNew == scTop) return false;
scrollToY(scNew);
return true;
}
void ScrollArea::scrollToY(int toTop, int toBottom) {
myEnsureResized(widget());
myEnsureResized(this);
int toMin = 0, toMax = scrollTopMax();
if (toTop < toMin) {
toTop = toMin;
} else if (toTop > toMax) {
toTop = toMax;
}
bool exact = (toBottom < 0);
int curTop = scrollTop(), curHeight = height(), curBottom = curTop + curHeight, scToTop = toTop;
if (!exact && toTop >= curTop) {
if (toBottom < toTop) toBottom = toTop;
if (toBottom <= curBottom) return;
scToTop = toBottom - curHeight;
if (scToTop > toTop) scToTop = toTop;
if (scToTop == curTop) return;
} else {
scToTop = toTop;
}
verticalScrollBar()->setValue(scToTop);
}