void AutoscrollController::startAutoscrollForSelection(RenderObject* renderer)
{
// We don't want to trigger the autoscroll or the panScroll if it's already active
if (m_autoscrollTimer.isActive())
return;
RenderBox* scrollable = RenderBox::findAutoscrollable(renderer);
if (!scrollable)
return;
m_autoscrollType = AutoscrollForSelection;
m_autoscrollRenderer = scrollable;
startAutoscrollTimer();
}
void AutoscrollController::startPanScrolling(RenderBox* scrollable, const IntPoint& lastKnownMousePosition)
{
// We don't want to trigger the autoscroll or the panScroll if it's already active
if (m_autoscrollTimer.isActive())
return;
m_autoscrollType = AutoscrollForPan;
m_autoscrollRenderer = scrollable;
m_panScrollStartPos = lastKnownMousePosition;
if (FrameView* view = scrollable->frame()->view())
view->addPanScrollIcon(lastKnownMousePosition);
startAutoscrollTimer();
}
void AutoscrollController::updateDragAndDrop(Node* dropTargetNode, const IntPoint& eventPosition, double eventTime)
{
if (!dropTargetNode) {
stopAutoscrollTimer();
return;
}
RenderBox* scrollable = RenderBox::findAutoscrollable(dropTargetNode->renderer());
if (!scrollable) {
stopAutoscrollTimer();
return;
}
Frame& frame = scrollable->frame();
Page* page = frame.page();
if (!page || !page->settings().autoscrollForDragAndDropEnabled()) {
stopAutoscrollTimer();
return;
}
IntSize offset = scrollable->calculateAutoscrollDirection(eventPosition);
if (offset.isZero()) {
stopAutoscrollTimer();
return;
}
m_dragAndDropAutoscrollReferencePosition = eventPosition + offset;
if (m_autoscrollType == NoAutoscroll) {
m_autoscrollType = AutoscrollForDragAndDrop;
m_autoscrollRenderer = scrollable;
m_dragAndDropAutoscrollStartTime = eventTime;
startAutoscrollTimer();
} else if (m_autoscrollRenderer != scrollable) {
m_dragAndDropAutoscrollStartTime = eventTime;
m_autoscrollRenderer = scrollable;
}
}