CCScrollView not bouncing off the bottom

cocos2d-x C++
#1

Hi!

Im using cocos2dx 2.2.4 and i have an issue with CCScrollView
The thing is: when i swipe it from bottom to top - it perfectly bounces off the top.
But then i swipe it from top to bottom - it does not, the content of scroll view just goes downwards as long as i swipe it and in the end disappears from the visible area of scrollview.

What to do??

Here is how i initialize scrollview:

CCScrollView* scrollView = CCScrollView::create( background->getContentSize() );
scrollView->setTouchPriority( kCCMenuHandlerPriority );
scrollView->setDirection( kCCScrollViewDirectionVertical );
background->addChild( scrollView );
    
CCScale9Sprite* testPlaceholder = CCScale9Sprite::create( "whitepixel.png", CCRect( 0, 0, scrollView->getViewSize().width, scrollView->getViewSize().height ) );
testPlaceholder->setColor( ccBLUE );
scrollView->addChild( testPlaceholder );

background is just a CCScale9Sprite, with size 500x500

In the mean time CCTableView which use CCScrollView works just as i need it: it bounces off both top and bottom edges, but i can’t find whats the difference between my using CCScrollView and CCTableView’s one.

#2

You might need to give ui::ScrollView a try. It supports bouncing well.

Currently the implementation of CCScrollView is not very good.

#3

Hi @owen

i am also having some questions for you about ScrollView

this is my code…

`#include "ChallengeScene.h"
#include "GameLoadScene.h"
#include "Challenge1.h"

#include "extensions/cocos-ext.h"

USING_NS_CC;
USING_NS_CC_EXT;

class ScrollViewWithTouchableItems: public ScrollView
{
public :
    static ScrollViewWithTouchableItems* create(Size size, Node* container)
    {
        ScrollViewWithTouchableItems* pRet = new ScrollViewWithTouchableItems();
        if (pRet && pRet->initWithViewSize(size, container))
        {
            pRet->_touchListener->setSwallowTouches(false);
            pRet->autorelease();
        }
        else
        {
            CC_SAFE_DELETE(pRet);
        }
        return pRet;
    }
};

class ControlButtonUsable: public ControlButton
{
public :
    static ControlButtonUsable* create(Scale9Sprite* sprite)
    {
        ControlButtonUsable *pRet = new ControlButtonUsable();
        pRet->initWithBackgroundSprite(sprite);
        pRet->autorelease();
        return pRet;
    }

    void setTouchDownHandler(Ref* target, Handler action)
    {
        addTargetWithActionForControlEvent(target, action, Control::EventType::TOUCH_DOWN);
    }
};

Scene* Challenge::createScene(bool wasPushed)
{
    // 'scene' is an autorelease object
    auto scene = Scene::create();

    // 'layer' is an autorelease object
    auto layer = Challenge::create();

    // some funny comment about humpty-dumpty goes here
    layer->_wasPushed = wasPushed;

    // add layer as a child to scene
    // attaches all the children to the existing physics world as well
    scene->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool Challenge::init()
{
    //////////////////////////////
    // 1. super init first
    if ( !Layer::init() )
    {
        return false;
    }

    _wasPushed = false;
    
    Size visibleSize = Director::getInstance()->getVisibleSize();
    Point origin = Director::getInstance()->getVisibleOrigin();

    // scroll container
    auto scrollContainer = Layer::create();
    scrollContainer->setAnchorPoint(Vec2::ZERO);
    scrollContainer->setPosition(Vec2::ZERO);
    scrollContainer->setContentSize(Size(visibleSize.width , 2*visibleSize.height));
    this->addChild(scrollContainer);


    auto wd = scrollContainer->getContentSize().width;
    auto ht = scrollContainer->getContentSize().height;

    // container item icons
    auto addChallenge =
    [&](std::string fileName, int id) -> void
    {
        auto chal_sprite = Scale9Sprite::create(fileName);
        auto chal = ControlButtonUsable::create(chal_sprite);
        chal->setTag(id);
        chal->setTouchDownHandler(this, cccontrol_selector(Challenge::touchDownAction));
        chal->setPosition(wd/5, (5 - id) * ht/5);
        scrollContainer->addChild(chal);

        std::stringstream sstr;
        sstr << "challenge " << id;
        auto label = LabelTTF::create(sstr.str(), "fonts/Marker Felt.ttf" , 20);
        label->setPosition(3*wd/5, (5 - id) * ht/5);
        scrollContainer->addChild(label);
    };

    // TODO: need to create a proper scale9 png for this
    addChallenge("chalbox.png", 1);
    addChallenge("chalbox.png", 2);
    addChallenge("chalbox.png", 3);
    addChallenge("chalbox.png", 4);

    // scroll view
    auto scrollview = ScrollViewWithTouchableItems::create(visibleSize, scrollContainer);
    scrollview->setDirection(ScrollView::Direction::VERTICAL);
    scrollview->setPosition(Vec2::ZERO);

    this->addChild(scrollview);

    this->setKeypadEnabled(true);

    return true;
}

void Challenge::onKeyReleased(cocos2d::EventKeyboard::KeyCode keycode , cocos2d::Event *event)
{
    if (_wasPushed)
        Director::getInstance()->end();
    else
        Director::getInstance()->popScene();
}

void Challenge::touchDownAction(Ref *sender, Control::EventType controlEvent)
{
    int sceneId = dynamic_cast<Node *>(sender)->getTag();
    auto scene = Challenge1::createScene();
    Director::getInstance()->replaceScene(scene);
}

The problem is it starts from bottom of the layer, but i want it to start from the top…
so i get to see challenge 3 and challenge 4, but it should start from challenge 1…
i am sure… you can help… :smile:

#4

you may add
scrollView->setContentSize( background->getContentSize() );
in 2.1.3 it works,i don’t know if there is change in CCScrollView from 2.1.3 to 2.2.4

#5

thanks! setting content size helped.

#6

I’m sorry for the late reply.

You could call setContentOffset function to move the CCScrollView start from the top rather that the bottom.

#7

yup… thanks for replying @owen

i’ve already figured out. :smile: