0

我在编写的 cocos2D 程序中处理触摸事件时遇到了一个有趣的问题。我在 CCScene 中有 3 个 CCLayer 子类层：

backgroundLayer - z:0 - 用于显示背景图像的简单静态层。

planetLayer - z:3 - 显示层 - 数据变化的可视化显示在这里。

gameControlsLayer - z:5 - 用于显示数据控制器的层，例如滑块和按钮。

我将行星层和控制层分开，因为我想平移和缩放行星层，而不用担心控制受到影响。

这是设置这些层的场景初始化代码：

- (id) init
{
    self = [super init];
    if (self != nil)
    {
        // background layer
        BackgroundLayer *backgroundLayer = [BackgroundLayer node];
        [self addChild:backgroundLayer z:0];

        // planet layer
        PlanetLayer *planetLayer = [PlanetLayer node];
        [self addChild:planetLayer z:3];

        // gameplay layer
        GameControlsLayer *gameControlsLayer = [GameControlsLayer node];
        [self addChild:gameControlsLayer z:5];
    }
    return self;
}

我需要在行星层和控制层上进行触摸处理。在控制层上，触摸处理位于作为子层的控制对象内部。我首先编写了所有这些代码，它工作正常。

之后，我为行星图层编写了图层范围的触摸处理，这样我就可以进行触摸滚动和缩放。我已经滚动（虽然还没有缩放），它工作正常。我的问题是：当我触摸和操作控制层上的控件时，它们工作正常，但是当我上下移动滑块拇指时，例如，控制层后面的行星层平移，好像触摸是为了它。

包含代码可能是多余的，但这里是相关的片段：

对于滑块控件，控件层的子层：

- (void) onEnterTransitionDidFinish
{
    [[CCTouchDispatcher sharedDispatcher] 
      addTargetedDelegate:self priority:1 swallowsTouches:YES];
}

- (void) onExit
{
    [[CCTouchDispatcher sharedDispatcher] removeDelegate:self];
}

#pragma mark Touch Delegate

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
    CGPoint location = [[CCDirector sharedDirector]
               convertToGL:[touch locationInView:[touch view]]];



    float distance = [self distanceBetweenPointOne:thumbPosition
                                       andPointTwo:location];
    if (distance > thumbRadius*2)
    {
        return NO;
    }

    // touch is on the thumb. store the location so we 
    // can calculate changes on ccTouchMoved events
    touched = YES;
    return YES;
}

- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
    if (!touched)
    {
        return;
    }

    CGPoint location = [[CCDirector sharedDirector]
               convertToGL:[touch locationInView:[touch view]]];
    location = [self convertToNodeSpace:location];

    // if we're too far off the thumb, abandon it
    float distance = [self distanceBetweenPointOne:thumbPosition
                                       andPointTwo:location];
    if (distance > thumbRadius*3)
    {
        //touched = NO;
        return;
    }

    // this call adjusts some ivars – not relevant
    [self updateValueAndPosition:location];
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
    if (touched)
    {
        touched = NO;
    }
}

- (void)ccTouchCancelled:(UITouch *)touch 
               withEvent:(UIEvent *)event
{
    [self ccTouchEnded:touch withEvent:event];
}

以下是行星层的相关代码：

// Yes, we want touch notifications please
//
- (void) onEnterTransitionDidFinish
{
    [[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self
       priority:0 swallowsTouches:NO];
}

#pragma mark Touch Delegate

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
    CGPoint touchLocation = [touch locationInView:[touch view]];
    touchLocation = [[CCDirector sharedDirector]
                      convertToGL:touchLocation];

    // ****NOTE – the following is a kludge I used it to break
    // ********** the behavior; the controls are all grouped
    // ********** at the bottom of the screen. But this is not
    // ********** an acceptable fix. I shouldn’t need to mask
    // ********** off certain areas of the screen. This strategy
    // ********** will not hold once I add other controls to the
    // ********** control layer.
    //
    if (touchLocation.y > 250.0f)
    {
        self.touched = YES;
        touchHash = [touch hash];
        return YES;
    }
    return YES;
}

- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
    if (!touched)
    {
        return;
    }

    if ([touch hash] == touchHash)
    {
        CGSize screenSize = [[CCDirector sharedDirector] winSize];

        CGPoint touchLocation = 
                [touch locationInView:[touch view]];
        CGPoint prevLocation = 
                [touch previousLocationInView:[touch view]];

        touchLocation = [[CCDirector sharedDirector]
                          convertToGL:touchLocation];
        prevLocation = [[CCDirector sharedDirector]
                          convertToGL:prevLocation];

        CGPoint diff = ccpSub(touchLocation, prevLocation);

        CGPoint currentPosition = [self position];
        CGPoint newPosition = ccpAdd(currentPosition, diff);

        if (newPosition.x < lowestX)
            newPosition.x = lowestX;
        else if (newPosition.x > highestX-screenSize.width)
            newPosition.x = highestX-screenSize.width;

        if (newPosition.y < lowestY)
            newPosition.y = lowestY;
        else if (newPosition.y > highestY-screenSize.height)
            newPosition.y = highestY-screenSize.height;

        [self setPosition:newPosition];
    }
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
    if ([touch hash] == touchHash)
    {
        if (touched)
        {
            touched = NO;
        }
    }
}

- (void)ccTouchCancelled:(UITouch *)touch 
               withEvent:(UIEvent *)event
{
    [self ccTouchEnded:touch withEvent:event];
}

我想添加捏缩放功能，但我需要先解决这个问题，然后再建议这样做。这里有人有答案吗？我觉得我错过了一些明显的东西……</p>

谢谢！

4

1 回答 1

0

在你planetLayer的 'sccTouchBegan:中，你应该找到一种方法来判断触摸是否在其中一个控件内，在这种情况下返回 NO 而不是 YES。

您有一种可能性是检查[touch view]（我有一个由 UIKit 对象组成的控制层，它的工作原理就是这样），否则您应该获取触摸的坐标并检查它们是否CGRectContainsPoint([control rect], location)).

于 2011-07-28T22:17:43.573 回答