CCScrollableLayer.cpp

/****************************************************************************
Copyright (c) 2012-2013 Igor Zavorotkin <ivzave@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
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#include "cocoa/CCSet.h"
#include "touch_dispatcher/CCTouchHandler.h"
#include "CCDirector.h"

#include "CCCommonExtended.h"
#include "CCGeometryExtended.h"
#include "CCNodeExtended.h"

#include "CCScrollableLayer.h"

USING_NS_CC;

const float kCCScrollableLayerScrollShift = 5.0f;

const int kCCScrollableLayerBindingRight = 1;
const int kCCScrollableLayerBindingUpper = 2;

CCScrollableLayer* CCScrollableLayer::create(const CCSize& tWindowSize, const CCSize& tLayerSize, CCScrollableLayerBinding eBinding)
{
	CCScrollableLayer* pRet = new CCScrollableLayer();

	return pRet->init(tWindowSize, tLayerSize, eBinding) ? (CCScrollableLayer*)pRet->autorelease() : (delete pRet, pRet = NULL);
}

CCScrollableLayer::CCScrollableLayer() :
		m_eBinding(kCCScrollableLayerBindingBottomLeft),
		m_bScrolling(false)
{
}

bool CCScrollableLayer::init(const CCSize& tWindowSize, const CCSize& tLayerSize, CCScrollableLayerBinding eBinding)
{
	do
	{
		CCEnsureElseBreak(CCLayer::init());

		m_eBinding = eBinding;
		CCSize tBinding(eBinding & kCCScrollableLayerBindingRight,
				(eBinding & kCCScrollableLayerBindingUpper) >> 1);

		CCSize tShiftSize(cczSub(tLayerSize, tWindowSize));

		// TODO find better formula
		//m_tMinShift = binding * min(dx, 0)
		//m_tMaxShift = max(dx, binding * dx)

		m_tMinShift = cczNormalizeTo(
				cczDenormalizeTo(tBinding, cczMin(tShiftSize, CCSizeZero)),
				tWindowSize);
		m_tMaxShift = cczNormalizeTo(
				cczMax(tShiftSize, cczDenormalizeTo(tBinding, tShiftSize)),
				tWindowSize);

		setContentSize(tWindowSize);
		setTouchEnabled(true);
		ignoreAnchorPointForPosition(false);
		setShift(tBinding);

		return true;
	} while (false);

	return false;
}

void CCScrollableLayer::setShift(const CCSize& tShift)
{
	setAnchorPoint(ccpShift(
			ccp(0.5f, 0.5f),
			cczAdd(m_tMinShift, cczDenormalizeTo(tShift, cczSub(m_tMaxShift, m_tMinShift)))));
}

void CCScrollableLayer::setLayerSize(const CCSize& tSize)
{
	CCSize tBinding(m_eBinding & kCCScrollableLayerBindingRight,
			(m_eBinding & kCCScrollableLayerBindingUpper) >> 1);

	CCSize tShiftSize(cczSub(tSize, getContentSize()));

	CCSize tOldMaxShift(m_tMaxShift);

	m_tMinShift = cczNormalizeTo(
			cczDenormalizeTo(tBinding, cczMin(tShiftSize, CCSizeZero)),
			getContentSize());

	m_tMaxShift = cczNormalizeTo(
			cczMax(tShiftSize, cczDenormalizeTo(tBinding, tShiftSize)),
			getContentSize());

	CCSize tPreserveShift(cczSub(
			m_tMaxShift,
			tOldMaxShift));

	setAnchorPoint(ccpShift(
			getAnchorPoint(),
			cczDenormalizeTo(tBinding, tPreserveShift)));
}

void CCScrollableLayer::registerWithTouchDispatcher()
{
	CCDirector::sharedDirector()->getTouchDispatcher()->addTargetedDelegate(this, kCCScrollableLayerTouchPriority, false);
}

bool CCScrollableLayer::ccTouchBegan(CCTouch* pTouch, CCEvent* pEvent)
{
	CC_UNUSED_PARAM(pEvent);

	do
	{
		CC_BREAK_IF_NOT(CCNodeIsVisibleRecursive(this));

		CCPoint tTouchPoint(convertTouchToNodeSpaceAR(pTouch));

		CC_BREAK_IF_NOT(CCRectMakeWithCenterAndSize(CCPointZero, getContentSize()).containsPoint(tTouchPoint));
		m_tBeginTouchPoint = tTouchPoint;

		return true;
	} while (false);

	return false;
}

void CCScrollableLayer::ccTouchMoved(CCTouch* pTouch, CCEvent* pEvent)
{
	CC_UNUSED_PARAM(pEvent);

	CCPoint tTouchPoint(convertTouchToNodeSpaceAR(pTouch));
	CCPoint tPrevTouchPoint(convertToNodeSpaceAR(pTouch->getPreviousLocation()));

	CCSize tShift(cczClamp(
			cczAdd(
					cczNormalizeTo(ccpDiff(tPrevTouchPoint, tTouchPoint), getContentSize()),
					ccpDiff(getAnchorPoint(), ccp(0.5f, 0.5f))),
			m_tMinShift,
			m_tMaxShift));

	if (!m_bScrolling && cczLength(ccpDiff(m_tBeginTouchPoint, tPrevTouchPoint)) >= kCCScrollableLayerScrollShift)
	{
		m_bScrolling = true;
		// TODO find workaround instead of HACK
		CCSet* pSet = new CCSet();
		pSet->addObject(pTouch);
		CCTouchDispatcher* pTouchDispatcher = CCDirector::sharedDirector()->getTouchDispatcher();
		CCTargetedTouchHandler* pHandler = (CCTargetedTouchHandler*)pTouchDispatcher->findHandler(this);
		pHandler->getClaimedTouches()->removeObject(pTouch);
		pTouchDispatcher->touchesCancelled(pSet, NULL);
		pHandler->getClaimedTouches()->addObject(pTouch);
		delete pSet;
	}

	if (m_bScrolling)
	{
		setAnchorPoint(ccpShift(ccp(0.5f, 0.5f), tShift));
	}
}

void CCScrollableLayer::ccTouchEnded(CCTouch* pTouch, CCEvent* pEvent)
{
	CC_UNUSED_PARAM(pTouch);
	CC_UNUSED_PARAM(pEvent);

	// TODO kinetic scrolling here

	m_bScrolling = false;
}

void CCScrollableLayer::ccTouchCancelled(CCTouch* pTouch, CCEvent* pEvent)
{
	CC_UNUSED_PARAM(pTouch);
	CC_UNUSED_PARAM(pEvent);

	m_bScrolling = false;
}