当层重叠时，如何将触摸处理限制为一个层？ [英] How do I limit touch handling to one layer when layers overlap?
问题描述
我有一个有趣的问题处理触摸事件在我写的cocos2D程序。我在CCScene中有3个CCLayer子类化图层：
I have an interesting problem handling touch events in a cocos2D program I’m writing. I have 3 CCLayer sublassed layers in a CCScene:
backgroundLayer - z：0 - 用于显示背景图片的简单静态图层。
backgroundLayer – z:0 – simple static layer used to display a background image.
planetLayer - z：3 - 显示层 - 数据变更的可视化显示在此处。
planetLayer - z:3 – display layer – visualization of data changes are displayed here.
gameControlsLayer - z：5 - 例如滑块和按钮。
gameControlsLayer – z:5 – layer used to display data controllers such as sliders and buttons.
我分隔了行星和控制图层，因为我想平移和缩放地球图层，而不必担心受到影响的控制。
I separated the planet and control layers because I want to pan and zoom the planet layer without worrying about the controls being affected.
以下是设置这些图层的场景init代码：
Here is the scene init code that sets up these layers:
- (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;
}
我需要在行星和控制层上进行触摸处理。在控制层上，触摸处理是作为层孩子的控制对象。我写了所有这些代码，它工作正常。
I need touch handling on both the planet and control layers. On the control layer, the touch handling is inside control objects that are layer children. I wrote all this code first and it works fine.
之后，我为地球层写了层级触摸处理，所以我可以做触摸滚动和缩放。我有滚动的（虽然不是缩放），它的工作正常。我的问题是这样的：当我触摸和操纵控制层上的控件，它们工作正常，但是当我移动一个滑块向上和向下，例如，控制层后面的行星层平移，好像触摸是为
After that, I wrote layer-wide touch handling for the planet layer so I could do touch scrolling and zooming. I’ve got the scrolling in (though not the zoom yet), and it works fine. My problem is this: When I touch and manipulate the controls on the control layer, they work fine, but as I move a slider thumb up and down, for example, the planet layer behind the control layer pans as if the touches were meant for it.
它可能是多余的包括代码，但这里是相关的片段：
It may be redundant to include the code, but here are the relevant snippets:
滑块控件，控制层的孩子：
For the slider control, a child of the control layer:
- (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];
}
这是来自Planet层的相关代码：
Here is the relevant code from the planet layer:
// 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];
}
我想添加双指缩放功能，但我需要清除问题之前是可取的。有人有答案吗？我觉得我缺少明显的东西...
I want to add the pinch zoom capabilities, but I need to clear up this issue before that will be advisable. Does anybody have the answer here? I feel like I’m missing something obvious…
谢谢！
推荐答案
p>在 planetLayer 的 ccTouchBegan：中，您应该找到一种方法来判断触摸是否在一个
In your planetLayer's ccTouchBegan:, you should find a way to tell whether the touch was inside of one of the controls and in such case return NO instead of YES.
有一种可能性是检查 [touch view] （我有一个控制层，由UIKit对象构成，它的工作原理），否则你应该得到触摸的坐标，并检查他们是否 CGRectContainsPoint（[控制rect]，位置））。
One possibility you have is checking [touch view] (I have a control layer made of UIKit object and it works like that), otherwise you should get the coordinate of the touch and check whether they CGRectContainsPoint([control rect], location)).
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