void ScrollView::startAutoScroll(const Vec2& deltaMove, float timeInSec, bool attenuated)
{
Vec2 adjustedDeltaMove = flattenVectorByDirection(deltaMove);
_autoScrolling = true;
_autoScrollTargetDelta = adjustedDeltaMove;
_autoScrollAttenuate = attenuated;
_autoScrollStartPosition = _innerContainer->getPosition();
_autoScrollTotalTime = timeInSec;
_autoScrollAccumulatedTime = 0;
_autoScrollBraking = false;
_autoScrollBrakingStartPosition = Vec2::ZERO;
// If the destination is also out of boundary of same side, start brake from beginning.
Vec2 currentOutOfBoundary = getHowMuchOutOfBoundary();
if (!fltEqualZero(currentOutOfBoundary))
{
_autoScrollCurrentlyOutOfBoundary = true;
Vec2 afterOutOfBoundary = getHowMuchOutOfBoundary(adjustedDeltaMove);
if(currentOutOfBoundary.x * afterOutOfBoundary.x > 0 || currentOutOfBoundary.y * afterOutOfBoundary.y > 0)
{
_autoScrollBraking = true;
}
}
}
void ScrollView::processInertiaScrolling(float dt)
{
_inertiaScrollElapsedTime += dt;
if(isOutOfBoundaryLeftOrRight() || isOutOfBoundaryTopOrBottom())
{
// If the inner container is out of boundary, shorten the inertia time.
_inertiaScrollElapsedTime += dt * (45000 / INERTIA_DEACCELERATION);
}
float percentage = _inertiaScrollElapsedTime / _inertiaScrollExpectedTime;
if(percentage >= 1)
{
_inertiaScrolling = false;
startBounceBackIfNeeded();
return;
}
percentage = tweenfunc::quartEaseOut(percentage);
Vec2 inertiaVelocity = _inertiaInitiVelocity * (1 - percentage);
Vec2 displacement = inertiaVelocity * dt;
if(!_bounceEnabled)
{
Vec2 outOfBoundary = getHowMuchOutOfBoundary(displacement);
if(outOfBoundary != Vec2::ZERO)
{
// Don't allow to go out of boundary
displacement += outOfBoundary;
_inertiaScrolling = false;
}
}
moveChildren(displacement.x, displacement.y);
}
void ScrollView::moveChildrenToPosition(const Vec2& position)
{
setInnerContainerPosition(position);
Vec2 outOfBoundary = getHowMuchOutOfBoundary(Vec2::ZERO);
updateScrollBar(outOfBoundary);
}
void ScrollView::onSizeChanged()
{
Layout::onSizeChanged();
_topBoundary = _contentSize.height;
_rightBoundary = _contentSize.width;
Size innerSize = _innerContainer->getContentSize();
float orginInnerSizeWidth = innerSize.width;
float orginInnerSizeHeight = innerSize.height;
float innerSizeWidth = MAX(orginInnerSizeWidth, _contentSize.width);
float innerSizeHeight = MAX(orginInnerSizeHeight, _contentSize.height);
_innerContainer->setContentSize(Size(innerSizeWidth, innerSizeHeight));
setInnerContainerPosition(Vec2(0, _contentSize.height - _innerContainer->getContentSize().height));
if (_verticalScrollBar != nullptr)
_verticalScrollBar->onScrolled(getHowMuchOutOfBoundary());
if (_horizontalScrollBar != nullptr)
_horizontalScrollBar->onScrolled(getHowMuchOutOfBoundary());
}
bool ScrollView::isOutOfBoundary(MoveDirection dir)
{
Vec2 outOfBoundary = getHowMuchOutOfBoundary();
switch(dir)
{
case MoveDirection::TOP: return outOfBoundary.y > 0;
case MoveDirection::BOTTOM: return outOfBoundary.y < 0;
case MoveDirection::LEFT: return outOfBoundary.x < 0;
case MoveDirection::RIGHT: return outOfBoundary.x > 0;
}
return false;
}
void ScrollView::processAutoScrolling(float deltaTime)
{
// Make auto scroll shorter if it needs to deaccelerate.
float brakingFactor = (isNecessaryAutoScrollBrake() ? OUT_OF_BOUNDARY_BREAKING_FACTOR : 1);
// Elapsed time
_autoScrollAccumulatedTime += deltaTime * (1 / brakingFactor);
// Calculate the progress percentage
float percentage = MIN(1, _autoScrollAccumulatedTime / _autoScrollTotalTime);
if(_autoScrollAttenuate)
{
// Use quintic(5th degree) polynomial
percentage = tweenfunc::quintEaseOut(percentage);
}
// Calculate the new position
Vec2 newPosition = _autoScrollStartPosition + (_autoScrollTargetDelta * percentage);
bool reachedEnd = std::abs(percentage - 1) <= this->getAutoScrollStopEpsilon();
if (reachedEnd)
{
newPosition = _autoScrollStartPosition + _autoScrollTargetDelta;
}
if(_bounceEnabled)
{
// The new position is adjusted if out of boundary
newPosition = _autoScrollBrakingStartPosition + (newPosition - _autoScrollBrakingStartPosition) * brakingFactor;
}
else
{
// Don't let go out of boundary
Vec2 moveDelta = newPosition - getInnerContainerPosition();
Vec2 outOfBoundary = getHowMuchOutOfBoundary(moveDelta);
if (!fltEqualZero(outOfBoundary))
{
newPosition += outOfBoundary;
reachedEnd = true;
}
}
// Finish auto scroll if it ended
if(reachedEnd)
{
_autoScrolling = false;
dispatchEvent(SCROLLVIEW_EVENT_AUTOSCROLL_ENDED, EventType::AUTOSCROLL_ENDED);
}
moveInnerContainer(newPosition - getInnerContainerPosition(), reachedEnd);
}
void ScrollView::moveInnerContainer(const Vec2& deltaMove, bool canStartBounceBack)
{
Vec2 adjustedMove = flattenVectorByDirection(deltaMove);
setInnerContainerPosition(getInnerContainerPosition() + adjustedMove);
Vec2 outOfBoundary = getHowMuchOutOfBoundary();
updateScrollBar(outOfBoundary);
if(_bounceEnabled && canStartBounceBack)
{
startBounceBackIfNeeded();
}
}
bool ScrollView::startBounceBackIfNeeded()
{
if (!_bounceEnabled)
{
return false;
}
Vec2 bounceBackAmount = getHowMuchOutOfBoundary();
if(fltEqualZero(bounceBackAmount))
{
return false;
}
startAutoScroll(bounceBackAmount, BOUNCE_BACK_DURATION, true);
return true;
}
bool ScrollView::startBounceBackIfNeeded()
{
if (!_bounceEnabled)
{
return false;
}
Vec2 outOfBoundary = getHowMuchOutOfBoundary(Vec2::ZERO);
if(outOfBoundary == Vec2::ZERO)
{
return false;
}
_bouncingBack = true;
startAutoScroll(outOfBoundary, BOUNCE_BACK_DURATION, true);
return true;
}
void ListView::jumpToItem(ssize_t itemIndex, const Vec2& positionRatioInView, const Vec2& itemAnchorPoint)
{
Widget* item = getItem(itemIndex);
if (item == nullptr)
{
return;
}
doLayout();
Vec2 destination = calculateItemDestination(positionRatioInView, item, itemAnchorPoint);
if(!_bounceEnabled)
{
Vec2 delta = destination - getInnerContainerPosition();
Vec2 outOfBoundary = getHowMuchOutOfBoundary(delta);
destination += outOfBoundary;
}
jumpToDestination(destination);
}
void ListView::startAttenuatingAutoScroll(const Vec2& deltaMove, const Vec2& initialVelocity)
{
Vec2 adjustedDeltaMove = deltaMove;
if(!_items.empty() && _magneticType != MagneticType::NONE)
{
adjustedDeltaMove = flattenVectorByDirection(adjustedDeltaMove);
// If the destination is out of boundary, do nothing here. Because it will be handled by bouncing back.
if(getHowMuchOutOfBoundary(adjustedDeltaMove) == Vec2::ZERO)
{
MagneticType magType = _magneticType;
if(magType == MagneticType::BOTH_END)
{
if(_direction == Direction::HORIZONTAL)
{
magType = (adjustedDeltaMove.x > 0 ? MagneticType::LEFT : MagneticType::RIGHT);
}
else if(_direction == Direction::VERTICAL)
{
magType = (adjustedDeltaMove.y > 0 ? MagneticType::BOTTOM : MagneticType::TOP);
}
}
// Adjust the delta move amount according to the magnetic type
Vec2 magneticAnchorPoint = getAnchorPointByMagneticType(magType);
Vec2 magneticPosition = -_innerContainer->getPosition();
magneticPosition.x += getContentSize().width * magneticAnchorPoint.x;
magneticPosition.y += getContentSize().height * magneticAnchorPoint.y;
Widget* pTargetItem = getClosestItemToPosition(magneticPosition - adjustedDeltaMove, magneticAnchorPoint);
Vec2 itemPosition = calculateItemPositionWithAnchor(pTargetItem, magneticAnchorPoint);
adjustedDeltaMove = magneticPosition - itemPosition;
}
}
ScrollView::startAttenuatingAutoScroll(adjustedDeltaMove, initialVelocity);
}
void ScrollView::scrollChildren(const Vec2& deltaMove)
{
Vec2 realMove = deltaMove;
if(_bounceEnabled)
{
// If the position of the inner container is out of the boundary, the offsets should be divided by two.
Vec2 outOfBoundary = getHowMuchOutOfBoundary();
realMove.x *= (outOfBoundary.x == 0 ? 1 : 0.5f);
realMove.y *= (outOfBoundary.y == 0 ? 1 : 0.5f);
}
if(!_bounceEnabled)
{
Vec2 outOfBoundary = getHowMuchOutOfBoundary(realMove);
realMove += outOfBoundary;
}
bool scrolledToLeft = false;
bool scrolledToRight = false;
bool scrolledToTop = false;
bool scrolledToBottom = false;
if (realMove.y > 0.0f) // up
{
float icBottomPos = _innerContainer->getBottomBoundary();
if (icBottomPos + realMove.y >= _bottomBoundary)
{
scrolledToBottom = true;
}
}
else if (realMove.y < 0.0f) // down
{
float icTopPos = _innerContainer->getTopBoundary();
if (icTopPos + realMove.y <= _topBoundary)
{
scrolledToTop = true;
}
}
if (realMove.x < 0.0f) // left
{
float icRightPos = _innerContainer->getRightBoundary();
if (icRightPos + realMove.x <= _rightBoundary)
{
scrolledToRight = true;
}
}
else if (realMove.x > 0.0f) // right
{
float icLeftPos = _innerContainer->getLeftBoundary();
if (icLeftPos + realMove.x >= _leftBoundary)
{
scrolledToLeft = true;
}
}
moveInnerContainer(realMove, false);
if(realMove.x != 0 || realMove.y != 0)
{
processScrollingEvent();
}
if(scrolledToBottom)
{
processScrollEvent(MoveDirection::BOTTOM, false);
}
if(scrolledToTop)
{
processScrollEvent(MoveDirection::TOP, false);
}
if(scrolledToLeft)
{
processScrollEvent(MoveDirection::LEFT, false);
}
if(scrolledToRight)
{
processScrollEvent(MoveDirection::RIGHT, false);
}
}
bool ScrollView::isOutOfBoundary()
{
return !fltEqualZero(getHowMuchOutOfBoundary());
}
bool ScrollView::isOutOfBoundary()
{
return getHowMuchOutOfBoundary() != Vec2::ZERO;
}
