cocos2dx学习之UIListView.cpp

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Copyright (c) 2013-2017 Chukong Technologies Inc.

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#include "ui/UIListView.h"

#include "ui/UIHelper.h"

NS_CC_BEGIN

static const float DEFAULT_TIME_IN_SEC_FOR_SCROLL_TO_ITEM = 1.0f;

namespace ui {

IMPLEMENT_CLASS_GUI_INFO(ListView)

ListView::ListView():

_model(nullptr),

_gravity(Gravity::CENTER_VERTICAL),

_magneticType(MagneticType::NONE),

_magneticAllowedOutOfBoundary(true),

_itemsMargin(0.0f),

_leftPadding(0.0f),

_topPadding(0.0f),

_rightPadding(0.0f),

_bottomPadding(0.0f),

_scrollTime(DEFAULT_TIME_IN_SEC_FOR_SCROLL_TO_ITEM),

_curSelectedIndex(-1),

_innerContainerDoLayoutDirty(true),

_listViewEventListener(nullptr),

_listViewEventSelector(nullptr),

_eventCallback(nullptr)

{

this->setTouchEnabled(true);

}

ListView::~ListView()

{

_listViewEventListener = nullptr;

_listViewEventSelector = nullptr;

_items.clear();

CC_SAFE_RELEASE(_model);

}

ListView* ListView::create()

{

ListView* widget = new (std::nothrow) ListView();

if (widget && widget->init())

{

widget->autorelease();

return widget;

}

CC_SAFE_DELETE(widget);

return nullptr;

}

bool ListView::init()

{

if (ScrollView::init())

{

setDirection(Direction::VERTICAL);

return true;

}

return false;

}

void ListView::setItemModel(Widget *model)

{

if (nullptr == model)

{

CCLOG("Can't set a nullptr to item model!");

return;

}

CC_SAFE_RELEASE_NULL(_model);

_model = model;

CC_SAFE_RETAIN(_model);

}

void ListView::handleReleaseLogic(Touch *touch)

{

ScrollView::handleReleaseLogic(touch);

if(!_autoScrolling)

{

startMagneticScroll();

}

}

void ListView::onItemListChanged()

{

_outOfBoundaryAmountDirty = true;

}

void ListView::updateInnerContainerSize()

{

switch (_direction)

{

case Direction::VERTICAL:

{

size_t length = _items.size();

float totalHeight = (length - 1) * _itemsMargin + (_topPadding + _bottomPadding);

for (auto& item : _items)

{

totalHeight += item->getContentSize().height;

}

float finalWidth = _contentSize.width;

float finalHeight = totalHeight;

setInnerContainerSize(Size(finalWidth, finalHeight));

break;

}

case Direction::HORIZONTAL:

{

size_t length = _items.size();

float totalWidth = (length - 1) * _itemsMargin + (_leftPadding + _rightPadding);

for (auto& item : _items)

{

totalWidth += item->getContentSize().width;

}

float finalWidth = totalWidth;

float finalHeight = _contentSize.height;

setInnerContainerSize(Size(finalWidth, finalHeight));

break;

}

default:

break;

}

}

void ListView::remedyVerticalLayoutParameter(LinearLayoutParameter* layoutParameter, ssize_t itemIndex)

{

CCASSERT(nullptr != layoutParameter, "Layout parameter can't be nullptr!");

switch (_gravity)

{

case Gravity::LEFT:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::LEFT);

break;

case Gravity::RIGHT:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::RIGHT);

break;

case Gravity::CENTER_HORIZONTAL:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::CENTER_HORIZONTAL);

break;

default:

break;

}

if (0 == itemIndex)

{

layoutParameter->setMargin(Margin(_leftPadding, _topPadding, _rightPadding, 0.f));

}

else if (_items.size() - 1 == itemIndex)

{

layoutParameter->setMargin(Margin(_leftPadding, _itemsMargin, _rightPadding, _bottomPadding));

}

else

{

layoutParameter->setMargin(Margin(_leftPadding, _itemsMargin, _rightPadding, 0.0f));

}

}

void ListView::remedyHorizontalLayoutParameter(LinearLayoutParameter* layoutParameter, ssize_t itemIndex)

{

CCASSERT(nullptr != layoutParameter, "Layout parameter can't be nullptr!");

switch (_gravity)

{

case Gravity::TOP:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::TOP);

break;

case Gravity::BOTTOM:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::BOTTOM);

break;

case Gravity::CENTER_VERTICAL:

layoutParameter->setGravity(LinearLayoutParameter::LinearGravity::CENTER_VERTICAL);

break;

default:

break;

}

if (0 == itemIndex)

{

layoutParameter->setMargin(Margin(_leftPadding, _topPadding, 0.f, _bottomPadding));

}

else if (_items.size() == itemIndex)

{

layoutParameter->setMargin(Margin(_itemsMargin, _topPadding, _rightPadding, _bottomPadding));

}

else

{

layoutParameter->setMargin(Margin(_itemsMargin, _topPadding, 0.f, _bottomPadding));

}

}

void ListView::remedyLayoutParameter(Widget *item)

{

CCASSERT(nullptr != item, "ListView Item can't be nullptr!");

LinearLayoutParameter* linearLayoutParameter = (LinearLayoutParameter*)(item->getLayoutParameter());

bool isLayoutParameterExists = true;

if (!linearLayoutParameter)

{

linearLayoutParameter = LinearLayoutParameter::create();

isLayoutParameterExists = false;

}

ssize_t itemIndex = getIndex(item);

switch (_direction)

{

case Direction::VERTICAL:

{

this->remedyVerticalLayoutParameter(linearLayoutParameter, itemIndex);

break;

}

case Direction::HORIZONTAL:

{

this->remedyHorizontalLayoutParameter(linearLayoutParameter, itemIndex);

break;

}

default:

break;

}

if (!isLayoutParameterExists)

{

item->setLayoutParameter(linearLayoutParameter);

}

}

void ListView::pushBackDefaultItem()

{

if (nullptr == _model)

{

return;

}

Widget* newItem = _model->clone();

remedyLayoutParameter(newItem);

addChild(newItem);

requestDoLayout();

}

void ListView::insertDefaultItem(ssize_t index)

{

if (nullptr == _model)

{

return;

}

insertCustomItem(_model->clone(), index);

}

void ListView::pushBackCustomItem(Widget* item)

{

remedyLayoutParameter(item);

addChild(item);

requestDoLayout();

}

void ListView::addChild(cocos2d::Node *child, int zOrder, int tag)

{

ScrollView::addChild(child, zOrder, tag);

Widget* widget = dynamic_cast<Widget*>(child);

if (nullptr != widget)

{

_items.pushBack(widget);

onItemListChanged();

}

}

void ListView::addChild(cocos2d::Node *child)

{

ListView::addChild(child, child->getLocalZOrder(), child->getName());

}

void ListView::addChild(cocos2d::Node *child, int zOrder)

{

ListView::addChild(child, zOrder, child->getName());

}

void ListView::addChild(Node* child, int zOrder, const std::string &name)

{

ScrollView::addChild(child, zOrder, name);

Widget* widget = dynamic_cast<Widget*>(child);

if (nullptr != widget)

{

_items.pushBack(widget);

onItemListChanged();

}

}

void ListView::removeChild(cocos2d::Node *child, bool cleanup)

{

Widget* widget = dynamic_cast<Widget*>(child);

if (nullptr != widget)

{

if (-1 != _curSelectedIndex)

{

auto removedIndex = getIndex(widget);

if (_curSelectedIndex > removedIndex)

{

_curSelectedIndex -= 1;

}

else if (_curSelectedIndex == removedIndex)

{

_curSelectedIndex = -1;

}

}

_items.eraseObject(widget);

onItemListChanged();

}

ScrollView::removeChild(child, cleanup);

requestDoLayout();

}

void ListView::removeAllChildren()

{

this->removeAllChildrenWithCleanup(true);

}

void ListView::removeAllChildrenWithCleanup(bool cleanup)

{

ScrollView::removeAllChildrenWithCleanup(cleanup);

_curSelectedIndex = -1;

_items.clear();

onItemListChanged();

}

void ListView::insertCustomItem(Widget* item, ssize_t index)

{

if (-1 != _curSelectedIndex)

{

if (_curSelectedIndex >= index)

{

_curSelectedIndex += 1;

}

}

_items.insert(index, item);

onItemListChanged();

ScrollView::addChild(item);

remedyLayoutParameter(item);

requestDoLayout();

}

void ListView::removeItem(ssize_t index)

{

Widget* item = getItem(index);

if (nullptr == item)

{

return;

}

removeChild(item, true);

}

void ListView::removeLastItem()

{

removeItem(_items.size() -1);

}

void ListView::removeAllItems()

{

removeAllChildren();

}

Widget* ListView::getItem(ssize_t index) const

{

if (index < 0 || index >= _items.size())

{

return nullptr;

}

return _items.at(index);

}

Vector<Widget*>& ListView::getItems()

{

return _items;

}

ssize_t ListView::getIndex(Widget *item) const

{

if (nullptr == item)

{

return -1;

}

return _items.getIndex(item);

}

void ListView::setGravity(Gravity gravity)

{

if (_gravity == gravity)

{

return;

}

_gravity = gravity;

requestDoLayout();

}

void ListView::setMagneticType(MagneticType magneticType)

{

_magneticType = magneticType;

_outOfBoundaryAmountDirty = true;

startMagneticScroll();

}

ListView::MagneticType ListView::getMagneticType() const

{

return _magneticType;

}

void ListView::setMagneticAllowedOutOfBoundary(bool magneticAllowedOutOfBoundary)

{

_magneticAllowedOutOfBoundary = magneticAllowedOutOfBoundary;

}

bool ListView::getMagneticAllowedOutOfBoundary() const

{

return _magneticAllowedOutOfBoundary;

}

void ListView::setItemsMargin(float margin)

{

if (_itemsMargin == margin)

{

return;

}

_itemsMargin = margin;

requestDoLayout();

}

float ListView::getItemsMargin()const

{

return _itemsMargin;

}

void ListView::setPadding(float l, float t, float r, float b)

{

if (l == _leftPadding && t == _topPadding && r == _rightPadding && b == _bottomPadding)

{

return;

}

_leftPadding = l;

_topPadding = t;

_rightPadding = r;

_bottomPadding = b;

requestDoLayout();

}

void ListView::setLeftPadding(float l)

{

if (l == _leftPadding)

{

return;

}

_leftPadding = l;

requestDoLayout();

}

void ListView::setTopPadding(float t)

{

if (t == _topPadding)

{

return;

}

_topPadding = t;

requestDoLayout();

}

void ListView::setRightPadding(float r)

{

if (r == _rightPadding)

{

return;

}

_rightPadding = r;

requestDoLayout();

}

void ListView::setBottomPadding(float b)

{

if (b == _bottomPadding)

{

return;

}

_bottomPadding = b;

requestDoLayout();

}

float ListView::getLeftPadding() const

{

return _leftPadding;

}

float ListView::getTopPadding() const

{

return _topPadding;

}

float ListView::getRightPadding() const

{

return _rightPadding;

}

float ListView::getBottomPadding() const

{

return _bottomPadding;

}

void ListView::setScrollDuration(float time)

{

if (time >= 0)

_scrollTime = time;

}

float ListView::getScrollDuration() const

{

return _scrollTime;

}

void ListView::setDirection(Direction dir)

{

switch (dir)

{

case Direction::NONE:

case Direction::BOTH:

break;

case Direction::VERTICAL:

setLayoutType(Type::VERTICAL);

break;

case Direction::HORIZONTAL:

setLayoutType(Type::HORIZONTAL);

break;

default:

return;

break;

}

ScrollView::setDirection(dir);

}

void ListView::refreshView()

{

forceDoLayout();

}

void ListView::requestDoLayout()

{

_innerContainerDoLayoutDirty = true;

}

void ListView::doLayout()

{

if(!_innerContainerDoLayoutDirty)

{

return;

}

ssize_t length = _items.size();

for (int i = 0; i < length; ++i)

{

Widget* item = _items.at(i);

item->setLocalZOrder(i);

remedyLayoutParameter(item);

}

updateInnerContainerSize();

_innerContainer->forceDoLayout();

_innerContainerDoLayoutDirty = false;

}

void ListView::addEventListenerListView(Ref *target, SEL_ListViewEvent selector)

{

_listViewEventListener = target;

_listViewEventSelector = selector;

}

void ListView::addEventListener(const ccListViewCallback& callback)

{

_eventCallback = callback;

}

void ListView::selectedItemEvent(TouchEventType event)

{

this->retain();

switch (event)

{

case TouchEventType::BEGAN:

{

if (_listViewEventListener && _listViewEventSelector)

{

(_listViewEventListener->*_listViewEventSelector)(this, LISTVIEW_ONSELECTEDITEM_START);

}

if (_eventCallback) {

_eventCallback(this,EventType::ON_SELECTED_ITEM_START);

}

if (_ccEventCallback)

{

_ccEventCallback(this, static_cast<int>(EventType::ON_SELECTED_ITEM_START));

}

}

break;

default:

{

if (_listViewEventListener && _listViewEventSelector)

{

(_listViewEventListener->*_listViewEventSelector)(this, LISTVIEW_ONSELECTEDITEM_END);

}

if (_eventCallback) {

_eventCallback(this, EventType::ON_SELECTED_ITEM_END);

}

if (_ccEventCallback)

{

_ccEventCallback(this, static_cast<int>(EventType::ON_SELECTED_ITEM_END));

}

}

break;

}

this->release();

}

void ListView::interceptTouchEvent(TouchEventType event, Widget *sender, Touch* touch)

{

ScrollView::interceptTouchEvent(event, sender, touch);

if (!_touchEnabled)

{

return;

}

if (event != TouchEventType::MOVED)

{

Widget* parent = sender;

while (parent)

{

if (parent && (parent->getParent() == _innerContainer))

{

_curSelectedIndex = getIndex(parent);

break;

}

parent = dynamic_cast<Widget*>(parent->getParent());

}

if (sender->isHighlighted()) {

selectedItemEvent(event);

}

}

}

static Vec2 calculateItemPositionWithAnchor(Widget* item, const Vec2& itemAnchorPoint)

{

Vec2 origin(item->getLeftBoundary(), item->getBottomBoundary());

Size size = item->getContentSize();

return origin + Vec2(size.width * itemAnchorPoint.x, size.height * itemAnchorPoint.y);

}

static Widget* findClosestItem(const Vec2& targetPosition, const Vector<Widget*>& items, const Vec2& itemAnchorPoint, ssize_t firstIndex, float distanceFromFirst, ssize_t lastIndex, float distanceFromLast)

{

CCASSERT(firstIndex >= 0 && lastIndex < items.size() && firstIndex <= lastIndex, "");

if (firstIndex == lastIndex)

{

return items.at(firstIndex);

}

if (lastIndex - firstIndex == 1)

{

if (distanceFromFirst <= distanceFromLast)

{

return items.at(firstIndex);

}

else

{

return items.at(lastIndex);

}

}

// Binary search

ssize_t midIndex = (firstIndex + lastIndex) / 2;

Vec2 itemPosition = calculateItemPositionWithAnchor(items.at(midIndex), itemAnchorPoint);

float distanceFromMid = (targetPosition - itemPosition).length();

if (distanceFromFirst <= distanceFromLast)

{

// Left half

return findClosestItem(targetPosition, items, itemAnchorPoint, firstIndex, distanceFromFirst, midIndex, distanceFromMid);

}

else

{

// Right half

return findClosestItem(targetPosition, items, itemAnchorPoint, midIndex, distanceFromMid, lastIndex, distanceFromLast);

}

}

Widget* ListView::getClosestItemToPosition(const Vec2& targetPosition, const Vec2& itemAnchorPoint) const

{

if (_items.empty())

{

return nullptr;

}

// Find the closest item through binary search

ssize_t firstIndex = 0;

Vec2 firstPosition = calculateItemPositionWithAnchor(_items.at(firstIndex), itemAnchorPoint);

float distanceFromFirst = (targetPosition - firstPosition).length();

ssize_t lastIndex = _items.size() - 1;

Vec2 lastPosition = calculateItemPositionWithAnchor(_items.at(lastIndex), itemAnchorPoint);

float distanceFromLast = (targetPosition - lastPosition).length();

return findClosestItem(targetPosition, _items, itemAnchorPoint, firstIndex, distanceFromFirst, lastIndex, distanceFromLast);

}

Widget* ListView::getClosestItemToPositionInCurrentView(const Vec2& positionRatioInView, const Vec2& itemAnchorPoint) const

{

// Calculate the target position

Size contentSize = getContentSize();

Vec2 targetPosition = -_innerContainer->getPosition();

targetPosition.x += contentSize.width * positionRatioInView.x;

targetPosition.y += contentSize.height * positionRatioInView.y;

return getClosestItemToPosition(targetPosition, itemAnchorPoint);

}

Widget* ListView::getCenterItemInCurrentView() const

{

return getClosestItemToPositionInCurrentView(Vec2::ANCHOR_MIDDLE, Vec2::ANCHOR_MIDDLE);

}

Widget* ListView::getLeftmostItemInCurrentView() const

{

if (_direction == Direction::HORIZONTAL)

{

return getClosestItemToPositionInCurrentView(Vec2::ANCHOR_MIDDLE_LEFT, Vec2::ANCHOR_MIDDLE);

}

return nullptr;

}

Widget* ListView::getRightmostItemInCurrentView() const

{

if (_direction == Direction::HORIZONTAL)

{

return getClosestItemToPositionInCurrentView(Vec2::ANCHOR_MIDDLE_RIGHT, Vec2::ANCHOR_MIDDLE);

}

return nullptr;

}

Widget* ListView::getTopmostItemInCurrentView() const

{

if (_direction == Direction::VERTICAL)

{

return getClosestItemToPositionInCurrentView(Vec2::ANCHOR_MIDDLE_TOP, Vec2::ANCHOR_MIDDLE);

}

return nullptr;

}

Widget* ListView::getBottommostItemInCurrentView() const

{

if (_direction == Direction::VERTICAL)

{

return getClosestItemToPositionInCurrentView(Vec2::ANCHOR_MIDDLE_BOTTOM, Vec2::ANCHOR_MIDDLE);

}

return nullptr;

}

void ListView::jumpToBottom()

{

doLayout();

ScrollView::jumpToBottom();

}

void ListView::jumpToTop()

{

doLayout();

ScrollView::jumpToTop();

}

void ListView::jumpToLeft()

{

doLayout();

ScrollView::jumpToLeft();

}

void ListView::jumpToRight()

{

doLayout();

ScrollView::jumpToRight();

}

void ListView::jumpToTopLeft()

{

doLayout();

ScrollView::jumpToTopLeft();

}

void ListView::jumpToTopRight()

{

doLayout();

ScrollView::jumpToTopRight();

}

void ListView::jumpToBottomLeft()

{

doLayout();

ScrollView::jumpToBottomLeft();

}

void ListView::jumpToBottomRight()

{

doLayout();

ScrollView::jumpToBottomRight();

}

void ListView::jumpToPercentVertical(float percent)

{

doLayout();

ScrollView::jumpToPercentVertical(percent);

}

void ListView::jumpToPercentHorizontal(float percent)

{

doLayout();

ScrollView::jumpToPercentHorizontal(percent);

}

void ListView::jumpToPercentBothDirection(const Vec2& percent)

{

doLayout();

ScrollView::jumpToPercentBothDirection(percent);

}

Vec2 ListView::calculateItemDestination(const Vec2& positionRatioInView, Widget* item, const Vec2& itemAnchorPoint)

{

const Size& contentSize = getContentSize();

Vec2 positionInView;

positionInView.x += contentSize.width * positionRatioInView.x;

positionInView.y += contentSize.height * positionRatioInView.y;

Vec2 itemPosition = calculateItemPositionWithAnchor(item, itemAnchorPoint);

return -(itemPosition - positionInView);

}

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::scrollToItem(ssize_t itemIndex, const Vec2& positionRatioInView, const Vec2& itemAnchorPoint)

{

scrollToItem(itemIndex, positionRatioInView, itemAnchorPoint, _scrollTime);

}

void ListView::scrollToItem(ssize_t itemIndex, const Vec2& positionRatioInView, const Vec2& itemAnchorPoint, float timeInSec)

{

Widget* item = getItem(itemIndex);

if (item == nullptr)

{

return;

}

Vec2 destination = calculateItemDestination(positionRatioInView, item, itemAnchorPoint);

startAutoScrollToDestination(destination, timeInSec, true);

}

ssize_t ListView::getCurSelectedIndex() const

{

return _curSelectedIndex;

}

void ListView::setCurSelectedIndex(int itemIndex)

{

Widget* item = getItem(itemIndex);

if (item == nullptr)

{

return;

}

_curSelectedIndex = itemIndex;

this->selectedItemEvent(cocos2d::ui::Widget::TouchEventType::ENDED);

}

void ListView::onSizeChanged()

{

ScrollView::onSizeChanged();

requestDoLayout();

}

std::string ListView::getDescription() const

{

return "ListView";

}

Widget* ListView::createCloneInstance()

{

return ListView::create();

}

void ListView::copyClonedWidgetChildren(Widget* model)

{

auto& arrayItems = static_cast<ListView*>(model)->getItems();

for (auto& item : arrayItems)

{

pushBackCustomItem(item->clone());

}

}

void ListView::copySpecialProperties(Widget *widget)

{

ListView* listViewEx = dynamic_cast<ListView*>(widget);

if (listViewEx)

{

ScrollView::copySpecialProperties(widget);

setItemModel(listViewEx->_model);

setItemsMargin(listViewEx->_itemsMargin);

setGravity(listViewEx->_gravity);

_listViewEventListener = listViewEx->_listViewEventListener;

_listViewEventSelector = listViewEx->_listViewEventSelector;

_eventCallback = listViewEx->_eventCallback;

}

}

Vec2 ListView::getHowMuchOutOfBoundary(const Vec2& addition)

{

if(!_magneticAllowedOutOfBoundary || _items.empty())

{

return ScrollView::getHowMuchOutOfBoundary(addition);

}

else if(_magneticType == MagneticType::NONE || _magneticType == MagneticType::BOTH_END)

{

return ScrollView::getHowMuchOutOfBoundary(addition);

}

else if(addition == Vec2::ZERO && !_outOfBoundaryAmountDirty)

{

return _outOfBoundaryAmount;

}

// If it is allowed to be out of boundary by magnetic, adjust the boundaries according to the magnetic type.

float leftBoundary = _leftBoundary;

float rightBoundary = _rightBoundary;

float topBoundary = _topBoundary;

float bottomBoundary = _bottomBoundary;

{

ssize_t lastItemIndex = _items.size() - 1;

Size contentSize = getContentSize();

Vec2 firstItemAdjustment, lastItemAdjustment;

if(_magneticType == MagneticType::CENTER)

{

firstItemAdjustment = (contentSize - _items.at(0)->getContentSize()) / 2;

lastItemAdjustment = (contentSize - _items.at(lastItemIndex)->getContentSize()) / 2;

}

else if(_magneticType == MagneticType::LEFT)

{

lastItemAdjustment = contentSize - _items.at(lastItemIndex)->getContentSize();

}

else if(_magneticType == MagneticType::RIGHT)

{

firstItemAdjustment = contentSize - _items.at(0)->getContentSize();

}

else if(_magneticType == MagneticType::TOP)

{

lastItemAdjustment = contentSize - _items.at(lastItemIndex)->getContentSize();

}

else if(_magneticType == MagneticType::BOTTOM)

{

firstItemAdjustment = contentSize - _items.at(0)->getContentSize();

}

leftBoundary += firstItemAdjustment.x;

rightBoundary -= lastItemAdjustment.x;

topBoundary -= firstItemAdjustment.y;

bottomBoundary += lastItemAdjustment.y;

}

// Calculate the actual amount

Vec2 outOfBoundaryAmount;

if(_innerContainer->getLeftBoundary() + addition.x > leftBoundary)

{

outOfBoundaryAmount.x = leftBoundary - (_innerContainer->getLeftBoundary() + addition.x);

}

else if(_innerContainer->getRightBoundary() + addition.x < rightBoundary)

{

outOfBoundaryAmount.x = rightBoundary - (_innerContainer->getRightBoundary() + addition.x);

}

if(_innerContainer->getTopBoundary() + addition.y < topBoundary)

{

outOfBoundaryAmount.y = topBoundary - (_innerContainer->getTopBoundary() + addition.y);

}

else if(_innerContainer->getBottomBoundary() + addition.y > bottomBoundary)

{

outOfBoundaryAmount.y = bottomBoundary - (_innerContainer->getBottomBoundary() + addition.y);

}

if(addition == Vec2::ZERO)

{

_outOfBoundaryAmount = outOfBoundaryAmount;

_outOfBoundaryAmountDirty = false;

}

return outOfBoundaryAmount;

}

static Vec2 getAnchorPointByMagneticType(ListView::MagneticType magneticType)

{

switch(magneticType)

{

case ListView::MagneticType::NONE: return Vec2::ZERO;

case ListView::MagneticType::BOTH_END: return Vec2::ANCHOR_TOP_LEFT;

case ListView::MagneticType::CENTER: return Vec2::ANCHOR_MIDDLE;

case ListView::MagneticType::LEFT: return Vec2::ANCHOR_MIDDLE_LEFT;

case ListView::MagneticType::RIGHT: return Vec2::ANCHOR_MIDDLE_RIGHT;

case ListView::MagneticType::TOP: return Vec2::ANCHOR_MIDDLE_TOP;

case ListView::MagneticType::BOTTOM: return Vec2::ANCHOR_MIDDLE_BOTTOM;

}

return Vec2::ZERO;

}

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 ListView::startMagneticScroll()

{

if(_items.empty() || _magneticType == MagneticType::NONE)

{

return;

}

// Find the closest item

Vec2 magneticAnchorPoint = getAnchorPointByMagneticType(_magneticType);

Vec2 magneticPosition = -_innerContainer->getPosition();

magneticPosition.x += getContentSize().width * magneticAnchorPoint.x;

magneticPosition.y += getContentSize().height * magneticAnchorPoint.y;

Widget* pTargetItem = getClosestItemToPosition(magneticPosition, magneticAnchorPoint);

scrollToItem(getIndex(pTargetItem), magneticAnchorPoint, magneticAnchorPoint);

}

}

NS_CC_END

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