cocos2d-x 3.0点击响应
迄今为止,发现cocos2d-x 3.0最让人惊艳的地方就是更改了点击事件机制。(ps:迄今只看了点击事件这块,捂嘴笑~~~)
cocos2d-x 2.0 只有CCLayer有点击事件处理,需要注册,需要实现onTouchBegan等方法,最坑爹的就是按照优先级来传递点击事件,让人诟病不已。每次遇到由于优先级而造成的点击bug,都有一种崩溃之感。
让人高兴的是,从现在开始,这种情况应该就会很少遇到了。闲话不说,开始正文。
3.0版本中,处理点击事件有两种方式:
1、函数回调
1 // a selector callback 2 void menuCloseCallback(Object* pSender); 3 4 auto closeItem = MenuItemImage::create("CloseNormal.png","CloseSelected.png", 5 CC_CALLBACK_1(HelloWorld::menuCloseCallback, this)); 6 7 void HelloWorld::menuCloseCallback(Object* pSender) 8 { 9 Director::getInstance()->end(); 10 11 #if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS) 12 exit(0); 13 #endif 14 }
其中CC_CALLBACK_1宏是将函数与对象绑定在一起,1表示这个函数有一个参数。当点击这个按钮时,会调用这个回调函数。
除了基于c++11的这个形式的改变,使用方法与先前相同。
2、Listener消息响应方式
Listener的加入,使得Sprite可以很方便的就可以拥有处理点击事件的能力。再也不用为了写个能够响应事件的Sprite而让去继承Layer了。总觉得class TestSprite : public CCLayer这种定义Sprite的方式是坑人的一种做法。终于可以将其摒弃了。
3.0版本,只需要为Sprite创建一个Listener,然后将Listener与Sprite绑定,并添加到Listener队列内即可,方便至极。
另,每一个Listener也只能和一个Sprite进行绑定,而Listener的clone方法,可以很方便的将listener复制为其他对象可用的listener。
废话少说,上代码最重要:
1 #ifndef __Touchable_Sprite_Test_H__ 2 #define __Touchable_Sprite_Test_H__ 3 4 #include "cocos2d.h" 5 USING_NS_CC; 6 7 class TouchableSpriteTest : public Layer 8 { 9 public: 10 CREATE_FUNC(TouchableSpriteTest); 11 virtual void onEnter() override; 12 virtual void onExit() override; 13 }; 14 15 #endif
1 #include "TouchableSpriteTest.h" 2 3 void TouchableSpriteTest::onEnter() 4 { 5 Layer::onEnter(); 6 Point origin = Director::getInstance()->getVisibleOrigin(); 7 Size size = Director::getInstance()->getVisibleSize(); 8 9 auto containerForSprite1 = Node::create(); 10 this->addChild(containerForSprite1, 10); 11 auto sprite1 = Sprite::create( "images/CyanSquare.png" ); 12 sprite1->setPosition( origin + Point( size.width * 0.5, size.height * 0.5) + Point( -80, 80 ) ); 13 containerForSprite1->addChild(sprite1); 14 15 auto sprite2 = Sprite::create("images/MagentaSquare.png"); 16 sprite2->setPosition(origin+Point(size.width/2, size.height/2)); 17 addChild(sprite2, 20); 18 19 auto sprite3 = Sprite::create("images/YellowSquare.png"); 20 sprite3->setPosition(Point(0, 0)); 21 sprite2->addChild(sprite3, 1); 22 // Make sprite1 touchable 23 auto listener1 = EventListenerTouchOneByOne::create(); 24 25 listener1->setSwallowTouches(true); 26 27 listener1->onTouchBegan = [](Touch* touch, Event* event){ 28 auto target = static_cast<Sprite*>(event->getCurrentTarget()); 29 30 Point locationInNode = target->convertToNodeSpace(touch->getLocation()); 31 Size s = target->getContentSize(); 32 Rect rect = Rect(0, 0, s.width, s.height); 33 34 if (rect.containsPoint(locationInNode)) 35 { 36 log("sprite began... x = %f, y = %f", locationInNode.x, locationInNode.y); 37 target->setOpacity(180); 38 return true; 39 } 40 return false; 41 }; 42 43 listener1->onTouchMoved = [](Touch* touch, Event* event){ 44 auto target = static_cast<Sprite*>(event->getCurrentTarget()); 45 target->setPosition(target->getPosition() + touch->getDelta()); 46 }; 47 48 listener1->onTouchEnded = [=](Touch* touch, Event* event){ 49 auto target = static_cast<Sprite*>(event->getCurrentTarget()); 50 log("sprite onTouchesEnded.. "); 51 target->setOpacity(255); 52 if (target == sprite2) 53 { 54 containerForSprite1->setLocalZOrder(100); 55 } 56 else if(target == sprite1) 57 { 58 containerForSprite1->setLocalZOrder(0); 59 } 60 }; 61 62 _eventDispatcher->addEventListenerWithSceneGraphPriority(listener1, sprite1); 63 _eventDispatcher->addEventListenerWithSceneGraphPriority(listener1->clone(), sprite2); 64 _eventDispatcher->addEventListenerWithSceneGraphPriority(listener1->clone(), sprite3); 65 66 Rect s_visibleRect = Director::getInstance()->getOpenGLView()->getVisibleRect(); 67 Point right = Point(s_visibleRect.origin.x+s_visibleRect.size.width, s_visibleRect.origin.y+s_visibleRect.size.height/2); 68 69 auto removeAllTouchItem = MenuItemFont::create("Remove All Touch Listeners ",[&]( Ref* sender ){ 70 auto senderItem = static_cast<MenuItemFont*>(sender); 71 senderItem->setString("Only next item could be clicked "); 72 73 _eventDispatcher->removeEventListenersForType( EventListener::Type::TOUCH_ONE_BY_ONE ); 74 75 auto nextItem = MenuItemFont::create("Next", [&](Ref* sender){ 76 }); 77 78 nextItem->setFontSizeObj(16); 79 nextItem->setPosition(right + Point(-100, -30)); 80 81 auto menu2 = Menu::create(nextItem, NULL); 82 menu2->setPosition(Point(0, 0)); 83 menu2->setAnchorPoint(Point(0, 0)); 84 this->addChild(menu2); 85 }); 86 removeAllTouchItem->setFontSizeObj(16); 87 removeAllTouchItem->setPosition(right + Point(-100, 0)); 88 89 auto menu = Menu::create(removeAllTouchItem, nullptr); 90 menu->setPosition(Point(0, 0)); 91 menu->setAnchorPoint(Point(0, 0)); 92 addChild(menu); 93 } 94 95 void TouchableSpriteTest::onExit() 96 { 97 Layer::onExit(); 98 }
千里之行始于足下,一切才刚刚开始,想要理解cocos2dx 3.0的点击事件,还是需要深入理解其底层实现的。
大家可以去看 Cocos2d-X3.0 刨根问底(七)----- 事件机制Event源码分析 这应该是一篇好文。
另,本博文参考自:http://blog.csdn.net/fansongy/article/details/12716671
本博主对一切都将不负任何法律责任。