bool scrollInDirection(Frame* frame, FocusDirection direction)
{
ASSERT(frame);
if (frame && canScrollInDirection(frame->document(), direction)) {
int dx = 0;
int dy = 0;
switch (direction) {
case FocusDirectionLeft:
dx = - Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionRight:
dx = Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionUp:
dy = - Scrollbar::pixelsPerLineStep();
break;
case FocusDirectionDown:
dy = Scrollbar::pixelsPerLineStep();
break;
default:
ASSERT_NOT_REACHED();
return false;
}
frame->view()->scrollBy(IntSize(dx, dy));
return true;
}
return false;
}
bool canScrollInDirection(const Node* container, FocusDirection direction)
{
ASSERT(container);
if (isHTMLSelectElement(container))
return false;
if (container->isDocumentNode())
return canScrollInDirection(toDocument(container)->frame(), direction);
if (!isScrollableNode(container))
return false;
switch (direction) {
case FocusDirectionLeft:
return (container->renderer()->style().overflowX() != OHIDDEN && container->renderBox()->scrollLeft() > 0);
case FocusDirectionUp:
return (container->renderer()->style().overflowY() != OHIDDEN && container->renderBox()->scrollTop() > 0);
case FocusDirectionRight:
return (container->renderer()->style().overflowX() != OHIDDEN && container->renderBox()->scrollLeft() + container->renderBox()->clientWidth() < container->renderBox()->scrollWidth());
case FocusDirectionDown:
return (container->renderer()->style().overflowY() != OHIDDEN && container->renderBox()->scrollTop() + container->renderBox()->clientHeight() < container->renderBox()->scrollHeight());
default:
ASSERT_NOT_REACHED();
return false;
}
}
Node* scrollableEnclosingBoxOrParentFrameForNodeInDirection(FocusDirection direction, Node* node)
{
ASSERT(node);
Node* parent = node;
do {
if (parent->isDocumentNode())
parent = static_cast<Document*>(parent)->document()->frame()->ownerElement();
else
parent = parent->parentNode();
} while (parent && !canScrollInDirection(parent, direction) && !parent->isDocumentNode());
return parent;
}
bool canBeScrolledIntoView(FocusDirection direction, const FocusCandidate& candidate)
{
ASSERT(candidate.visibleNode && candidate.isOffscreen);
IntRect candidateRect = candidate.rect;
for (Node* parentNode = candidate.visibleNode->parentNode(); parentNode; parentNode = parentNode->parentNode()) {
IntRect parentRect = nodeRectInAbsoluteCoordinates(parentNode);
if (!candidateRect.intersects(parentRect)) {
if (((direction == FocusDirectionLeft || direction == FocusDirectionRight) && parentNode->renderer()->style()->overflowX() == OHIDDEN)
|| ((direction == FocusDirectionUp || direction == FocusDirectionDown) && parentNode->renderer()->style()->overflowY() == OHIDDEN))
return false;
}
if (parentNode == candidate.enclosingScrollableBox)
return canScrollInDirection(parentNode, direction);
}
return true;
}
bool scrollInDirection(Node* container, FocusDirection direction)
{
ASSERT(container);
if (container->isDocumentNode())
return scrollInDirection(static_cast<Document*>(container)->frame(), direction);
if (!container->renderBox())
return false;
if (canScrollInDirection(container, direction)) {
int dx = 0;
int dy = 0;
switch (direction) {
case FocusDirectionLeft:
dx = - min(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollLeft());
break;
case FocusDirectionRight:
ASSERT(container->renderBox()->scrollWidth() > (container->renderBox()->scrollLeft() + container->renderBox()->clientWidth()));
dx = min(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollWidth() - (container->renderBox()->scrollLeft() + container->renderBox()->clientWidth()));
break;
case FocusDirectionUp:
dy = - min(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollTop());
break;
case FocusDirectionDown:
ASSERT(container->renderBox()->scrollHeight() - (container->renderBox()->scrollTop() + container->renderBox()->clientHeight()));
dy = min(Scrollbar::pixelsPerLineStep(), container->renderBox()->scrollHeight() - (container->renderBox()->scrollTop() + container->renderBox()->clientHeight()));
break;
default:
ASSERT_NOT_REACHED();
return false;
}
container->renderBox()->enclosingLayer()->scrollByRecursively(dx, dy);
return true;
}
return false;
}
