cocos2d-x事件分发机制

监听器

• EventListenerTouch：响应触摸事件
• EventListenerKeyboard：响应键盘事件
• EventListnerAcceleration：响应加速度事件
• EventListenMouse：响应鼠标事件
• EventListnerCustom：响应自定义事件

// When "swallow touches" is true, then returning 'true' from the
// onTouchBegan method will "swallow" the touch event, preventing
// other listeners from using it.
listener1->setSwallowTouches(true);

// you should also return true in onTouchBegan()

listener1->onTouchBegan = [](Touch* touch, Event* event){
    // your code

    return true;
};

优先级

固定值优先级：使用一个整形的数值，数据较低的监听器比数值较高的监听器，先接收到事件。

场景优先级：是指向节点对象的指针，z-order较高的节点中的监听器比z-order较你的节点中，先接收到事件。

触摸事件

//  Create a "one by one" touch event listener
// (processes one touch at a time)
auto listener1 = EventListenerTouchOneByOne::create();

// trigger when you push down
listener1->onTouchBegan = [](Touch* touch, Event* event){
    // your code
    return true; // if you are consuming it
};

// trigger when moving touch
listener1->onTouchMoved = [](Touch* touch, Event* event){
    // your code
};

// trigger when you let up
listener1->onTouchEnded = [=](Touch* touch, Event* event){
    // your code
};

// Add listener
_eventDispatcher->addEventListenerWithSceneGraphPriority(listener1, this);

onTouchBegan开始触摸屏幕时

onTouchMoved触摸屏幕，同时在屏幕上移动时

onTouchEnded结束触摸屏幕时

键盘事件

// creating a keyboard event listener
auto listener = EventListenerKeyboard::create();
listener->onKeyPressed = CC_CALLBACK_2(KeyboardTest::onKeyPressed, this);
listener->onKeyReleased = CC_CALLBACK_2(KeyboardTest::onKeyReleased, this);

_eventDispatcher->addEventListenerWithSceneGraphPriority(listener, this);

// Implementation of the keyboard event callback function prototype
void KeyboardTest::onKeyPressed(EventKeyboard::KeyCode keyCode, Event* event)
{
        log("Key with keycode %d pressed", keyCode);
}

void KeyboardTest::onKeyReleased(EventKeyboard::KeyCode keyCode, Event* event)
{
        log("Key with keycode %d released", keyCode);
}

onKeyPressed按键被按下时

onKeyReleased按下状态的按键被放开时

加速度传感器事件

Device::setAccelerometerEnabled(true);

// creating an accelerometer event
auto listener = EventListenerAcceleration::create(CC_CALLBACK_2(
AccelerometerTest::onAcceleration, this));

_eventDispatcher->addEventListenerWithSceneGraphPriority(listener, this);

// Implementation of the accelerometer callback function prototype
void AccelerometerTest::onAcceleration(Acceleration* acc, Event* event)
{
    //  Processing logic here
}

鼠标事件

_mouseListener = EventListenerMouse::create();
_mouseListener->onMouseMove = CC_CALLBACK_1(MouseTest::onMouseMove, this);
_mouseListener->onMouseUp = CC_CALLBACK_1(MouseTest::onMouseUp, this);
_mouseListener->onMouseDown = CC_CALLBACK_1(MouseTest::onMouseDown, this);
_mouseListener->onMouseScroll = CC_CALLBACK_1(MouseTest::onMouseScroll, this);

_eventDispatcher->addEventListenerWithSceneGraphPriority(_mouseListener, this);

void MouseTest::onMouseDown(Event *event)
{
    // to illustrate the event....
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Down detected, Key: ";
    str += tostr(e->getMouseButton());
}

void MouseTest::onMouseUp(Event *event)
{
    // to illustrate the event....
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Up detected, Key: ";
    str += tostr(e->getMouseButton());
}

void MouseTest::onMouseMove(Event *event)
{
    // to illustrate the event....
    EventMouse* e = (EventMouse*)event;
    string str = "MousePosition X:";
    str = str + tostr(e->getCursorX()) + " Y:" + tostr(e->getCursorY());
}

void MouseTest::onMouseScroll(Event *event)
{
    // to illustrate the event....
    EventMouse* e = (EventMouse*)event;
    string str = "Mouse Scroll detected, X: ";
    str = str + tostr(e->getScrollX()) + " Y: " + tostr(e->getScrollY());
}