本文主要是介绍循环的pageview,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
在平常偶尔能看到一些前辈的优秀的代码,但是一直苦于没有地方保存,之后我就把它放到这里保存着
cocos2dx 循环翻页的pageview。
引擎中提供的pageview没有循环的功能,这个类实现了循环,而且即使更新,也就是不预先创建大量的页面,这样稍微节省点内存资源。下面是代码。
头文件:
#ifndef __CyclePageView_H__
#define __CyclePageView_H__
#include "ui/UIPageView.h"
NS_CC_BEGINnamespace ui {//
class CCyclePageView : public PageView
{
public:static CCyclePageView* create(); void SetPageSize(ssize_t size);void scrollToPage(ssize_t idx) ; void CopyProp(PageView* pPageView);Layout* GetCurPage(){ return m_pCurLayout;}void addPageChangedListener(const std::function<void(Layout*, size_t)> callback){ m_callback = callback; }protected:virtual bool onTouchBegan(Touch *touch, Event *unusedEvent) override;virtual bool scrollPages(Vec2 touchOffset) override;virtual void handleMoveLogic(Touch *touch) override;virtual void handleReleaseLogic(Touch *touch) override;void movePages(Vec2 offset);void updateAllPagesSize();void updateAllPagesPosition();virtual void doLayout() override;void UpdateShowLayout(ssize_t nCurIdx, Layout* layout, bool isForceCallBack=false);CCyclePageView();~CCyclePageView();Layout* m_pLeftLayout;Layout* m_pRightLayout;Layout* m_pCurLayout;ssize_t m_nPageSize;std::function<void(Layout*,size_t)> m_callback;
};}
NS_CC_END
#endif // __CyclePageView_H__
cpp文件:
<pre name="code" class="cpp">#include "CyclePageView.h" NS_CC_BEGINnamespace ui {CCyclePageView* CCyclePageView::create()
{CCyclePageView* widget = new (std::nothrow) CCyclePageView();if (widget && widget->init()){widget->autorelease();return widget;}CC_SAFE_DELETE(widget);return nullptr;
}CCyclePageView::CCyclePageView() :m_pLeftLayout(nullptr), m_pRightLayout(nullptr),m_pCurLayout(nullptr), m_callback(nullptr), m_nPageSize(0)
{_touchEnabled = false;_isAutoScrolling = false;_curPageIdx = 0;
}
CCyclePageView::~CCyclePageView()
{
}void CCyclePageView::SetPageSize(ssize_t size)
{if (!m_pCurLayout){m_pCurLayout = Layout::create();m_pCurLayout->setContentSize(getContentSize());addChild(m_pCurLayout);}if (!m_pRightLayout){m_pRightLayout = Layout::create();m_pRightLayout->setContentSize(getContentSize());addChild(m_pRightLayout);}if (!m_pLeftLayout){m_pLeftLayout = Layout::create();m_pLeftLayout->setContentSize(getContentSize());addChild(m_pLeftLayout);}m_nPageSize = size;
}void CCyclePageView::scrollToPage(ssize_t idx)
{if (_direction == Direction::HORIZONTAL){_autoScrollDistance = (_curPageIdx - idx)*getContentSize().width;if (m_pCurLayout){_autoScrollDistance -= m_pCurLayout->getPositionX();}if (_autoScrollDistance > 0){_autoScrollDirection = AutoScrollDirection::RIGHT;_touchMoveDirection = TouchDirection::RIGHT;UpdateShowLayout(_curPageIdx - 1, m_pRightLayout);}else{_autoScrollDirection = AutoScrollDirection::LEFT;_touchMoveDirection = TouchDirection::LEFT;UpdateShowLayout(_curPageIdx + 1, m_pLeftLayout);}}else if (_direction == Direction::VERTICAL){_autoScrollDistance = (_curPageIdx - idx)*getContentSize().height;if (m_pCurLayout){_autoScrollDistance -= m_pCurLayout->getPositionY();}if (_autoScrollDistance > 0){_autoScrollDirection = AutoScrollDirection::DOWN;_touchMoveDirection = TouchDirection::DOWN;UpdateShowLayout(_curPageIdx - 1, m_pRightLayout);}else{_autoScrollDirection = AutoScrollDirection::UP;_touchMoveDirection = TouchDirection::UP;UpdateShowLayout(_curPageIdx + 1, m_pLeftLayout);}}_autoScrollSpeed = fabs(_autoScrollDistance) / 0.2f;if (_autoScrollDistance>0.000001f || _autoScrollDistance<-0.000001f){_isAutoScrolling = true;}UpdateShowLayout(_curPageIdx, m_pCurLayout,true);
}bool CCyclePageView::scrollPages(Vec2 touchOffset)
{if (m_nPageSize <= 0){return false;}movePages(touchOffset);return true;
}void CCyclePageView::movePages(Vec2 offset)
{if (!m_pCurLayout || !m_pRightLayout || !m_pLeftLayout){return;}m_pCurLayout->setPosition(m_pCurLayout->getPosition() + offset);m_pRightLayout->setPosition(m_pRightLayout->getPosition() + offset);m_pLeftLayout->setPosition(m_pLeftLayout->getPosition() + offset);Size size = getContentSize();switch (_touchMoveDirection){case TouchDirection::LEFT: // left if (m_pCurLayout->getPositionX()<-size.width*0.75){Layout* newRight = m_pLeftLayout;newRight->setPositionX(m_pRightLayout->getPositionX() + size.width);m_pLeftLayout = m_pCurLayout;m_pCurLayout = m_pRightLayout;m_pRightLayout = newRight;++_curPageIdx;UpdateShowLayout(_curPageIdx, m_pCurLayout,true);}break;case TouchDirection::RIGHT: // right if (m_pCurLayout->getPositionX()>size.width*0.75){Layout* newLeft = m_pRightLayout;newLeft->setPositionX(m_pLeftLayout->getPositionX() - size.width);m_pRightLayout = m_pCurLayout;m_pCurLayout = m_pLeftLayout;m_pLeftLayout = newLeft;--_curPageIdx;UpdateShowLayout(_curPageIdx, m_pCurLayout, true);}break;case TouchDirection::UP:if (m_pCurLayout->getPositionY()>size.width*0.75){Layout* newLeft = m_pRightLayout;newLeft->setPositionX(m_pLeftLayout->getPositionX() - size.height);m_pRightLayout = m_pCurLayout;m_pCurLayout = m_pLeftLayout;m_pLeftLayout = newLeft;--_curPageIdx;UpdateShowLayout(_curPageIdx, m_pCurLayout, true);}break;case TouchDirection::DOWN:if (m_pCurLayout->getPositionY()<-size.height*0.75){Layout* newRight = m_pLeftLayout;newRight->setPositionX(m_pRightLayout->getPositionX() + size.height);m_pLeftLayout = m_pCurLayout;m_pCurLayout = m_pRightLayout;m_pRightLayout = newRight;++_curPageIdx;UpdateShowLayout(_curPageIdx, m_pCurLayout, true);}break;default:break;}if (_curPageIdx<0){_curPageIdx = m_nPageSize-1;}if (_curPageIdx >= m_nPageSize){_curPageIdx = 0;}
}void CCyclePageView::doLayout()
{if (!_doLayoutDirty){return;}updateAllPagesPosition();updateAllPagesSize();//updateBoundaryPages();_doLayoutDirty = false;
}
void CCyclePageView::updateAllPagesSize()
{Size selfSize = getContentSize();if (!m_pCurLayout || !m_pRightLayout || !m_pLeftLayout){return;}m_pCurLayout->setContentSize(selfSize);m_pRightLayout->setContentSize(selfSize);m_pLeftLayout->setContentSize(selfSize);
}void CCyclePageView::updateAllPagesPosition()
{ // If the layout is dirty, don't trigger auto scroll_isAutoScrolling = false;if (!m_pCurLayout || !m_pRightLayout || !m_pLeftLayout){return;}Size size = getContentSize();m_pCurLayout->setPosition(Vec2::ZERO);if (_direction == Direction::HORIZONTAL){m_pRightLayout->setPositionX(size.width);m_pLeftLayout->setPositionX(-size.width);}else if (_direction == Direction::VERTICAL){m_pRightLayout->setPositionY(size.height);m_pLeftLayout->setPositionY(-size.height);}
}void CCyclePageView::CopyProp(PageView* pPageView)
{if (pPageView){this->copyProperties(pPageView);this->copyClonedWidgetChildren(pPageView);this->copySpecialProperties(pPageView);}
}
bool CCyclePageView::onTouchBegan(Touch *touch, Event *unusedEvent)
{return PageView::onTouchBegan(touch, unusedEvent);
}void CCyclePageView::handleMoveLogic(Touch *touch)
{PageView::handleMoveLogic(touch);UpdateShowLayout(_curPageIdx, m_pCurLayout);switch (_touchMoveDirection){case TouchDirection::LEFT: // left UpdateShowLayout(_curPageIdx+1, m_pRightLayout);break;case TouchDirection::RIGHT: // right UpdateShowLayout(_curPageIdx- 1, m_pLeftLayout);break;case TouchDirection::UP:UpdateShowLayout(_curPageIdx - 1, m_pLeftLayout);break;case TouchDirection::DOWN:UpdateShowLayout(_curPageIdx + 1, m_pRightLayout);break;default:break;}
}
void CCyclePageView::UpdateShowLayout(ssize_t nCurIdx, Layout* layout,bool isForceCallBack)
{if (nCurIdx<0){nCurIdx = m_nPageSize - 1;}if (nCurIdx >= m_nPageSize){nCurIdx = 0;}if (layout && (isForceCallBack || layout->getTag() != nCurIdx)){ layout->setTag(nCurIdx);if (m_callback){m_callback(layout,nCurIdx);}}
}void CCyclePageView::handleReleaseLogic(Touch *touch)
{if (m_nPageSize <= 0){return;}if (m_pCurLayout){Vec2 curPagePos = m_pCurLayout->getPosition();auto contentSize = getContentSize();float moveBoundray = 0.0f;float scrollDistance;if (_direction == Direction::HORIZONTAL){curPagePos.y = 0;moveBoundray = curPagePos.x;scrollDistance = contentSize.width / 2.0;}else if (_direction == Direction::VERTICAL){curPagePos.x = 0;moveBoundray = curPagePos.y;scrollDistance = contentSize.height / 2.0;}if (!_usingCustomScrollThreshold){_customScrollThreshold = scrollDistance;}float boundary = _customScrollThreshold;if (_direction == Direction::HORIZONTAL){if (moveBoundray <= -boundary){scrollToPage(_curPageIdx + 1);}else if (moveBoundray >= boundary){scrollToPage(_curPageIdx - 1);}else{scrollToPage(_curPageIdx);}}else if (_direction == Direction::VERTICAL){if (moveBoundray >= boundary){scrollToPage(_curPageIdx + 1);}else if (moveBoundray <= -boundary){scrollToPage(_curPageIdx - 1);}else{scrollToPage(_curPageIdx);}}}
}
}
NS_CC_END
</pre><pre name="code" class="cpp">
很好理解,直接放到引擎的ui里面,直接用就是了。如果js要用,那还要自己手动绑定,这个按照引擎绑定照着做就行。来源地址:
https://github.com/mydishes/cocos2dx-Ex/tree/master/CyclePageView。
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