CCNode 布局扩展

给CCNode做了扩展，方便界面布局

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在第一次用cocos2d开发的时候，就感觉界面的布局一点儿都不方便，只能硬生生的去设置每一个精灵的位置。

而自己以前有过QT的开发经验，深感里面的Anchor Layout功能特别好使。简单的思考了一下，通过给CCNode类添加一个

分类，就把AnchorLayout功能给移植到cocos2d-iphone中了。

AnchorLayout的思路就是为一个Node定义Top, Left, Bottom, Right, HorizontalCenter, VerticalCenter几个参考点，

一个Node的某个参考点可以参照另一个Node的某个参照点，从而实现快速确定一个Node的位置。被参照的Node必须是

已经确定位置了的。

两个Node必须为父子关系，或是兄弟关系。

使用时#import "CCNode+AnchorLayout.h"

例如：

[nodeA addAnchor: kCCNodeAnchorLeft referTo: nodeB edge: kCCNodeAnchorRight margin: 20];

上面代码行的作用是将nodeA放在nodeB的右边，间距为20.

[nodeA addAnchor: kCCNodeAnchorLeft referTo: nodeB edge: kCCNodeAnchorLeft margin: 0];

上面代码行的作用是将nodeA与nodeB左对齐。

[nodeA centerIn: nodeB];

上面代码行的作用是将nodeA放在nodeB的中心。

这里就不再多举例了，要想了解更多，可以去google "qt anchor layout"，或是看这里"http://doc.qt.digia.com/qt/qml-anchor-layout.html"

下面请看代码：

CCNode+AnchorLayout.h

#import "CCNode.h"

typedefenum

{

kCCNodeAnchorLeft,

kCCNodeAnchorRight,

kCCNodeAnchorTop,

kCCNodeAnchorBottom,

kCCNodeAnchorHorizontalCenter,

kCCNodeAnchorVerticalCenter,

kCCNodeAnchorCenterIn

}CCNodeAnchorT;

@interface CCNode (AnchorLayout)

//limitations:

//1. node should be added into node graph

//2. the referNode should be positioned

//3. if you need to set anchorPoint and scale, please do so before calling these methods

- (void) addAnchor: (CCNodeAnchorT)selfEdge referTo: (CCNode*)referNode edge: (CCNodeAnchorT)edge
margin: (CGFloat)margin;

- (void) centerIn: (CCNode*)outerNode;

@end

CCNode+AnchorLayout.m

#import "CCNode+AnchorLayout.h"

@implementation CCNode (AnchorLayout)

#pragma mark - private methods

- (CGFloat) edgeOfParentNode: (CCNode*)node ofAnchor: (CCNodeAnchorT)anchor

{

CGSize size = [node contentSize];

switch (anchor)

{

casekCCNodeAnchorTop:

return size.height * node.scaleY;

casekCCNodeAnchorLeft:

return 0.0;

casekCCNodeAnchorBottom:

return 0.0;

casekCCNodeAnchorRight:

return size.width * node.scaleX;

casekCCNodeAnchorHorizontalCenter:

return size.width * node.scaleX /2;

casekCCNodeAnchorVerticalCenter:

return size.height * node.scaleY /2;

default:

return 0.0;

}

}

- (CGFloat) edgeOfSiblingNode: (CCNode*)node ofAnchor: (CCNodeAnchorT)anchor

{

CGPoint nodePosition = [node position];

CGPoint nodeCenter = CGPointMake(nodePosition.x + (0.5-node.anchorPoint.x)
* node.contentSize.width * node.scaleX, nodePosition.y+
(0.5-node.anchorPoint.y) * node.contentSize.height *
node.scaleY);

switch (anchor)

{

casekCCNodeAnchorTop:

return nodeCenter.y +0.5 * node.contentSize.height *
node.scaleY;

casekCCNodeAnchorLeft:

return nodeCenter.x -0.5 * node.contentSize.width *
node.scaleX;

casekCCNodeAnchorBottom:

return nodeCenter.y -0.5 * node.contentSize.height *
node.scaleY;

casekCCNodeAnchorRight:

return nodeCenter.x +0.5 * node.contentSize.width *
node.scaleX;

casekCCNodeAnchorHorizontalCenter:

return nodeCenter.x;

casekCCNodeAnchorVerticalCenter:

return nodeCenter.y;

default:

break;

}

return 0.0;

}

#pragma mark - public methods

- (void) addAnchor:(CCNodeAnchorT)selfEdge referTo:(CCNode *)referNode edge:(CCNodeAnchorT)edge
margin:(CGFloat)margin

{

CGPoint oldPositon = [selfposition];

CGFloat centerX = 0.0;

CGFloat centerY = 0.0;

CGFloat selfWidth = self.contentSize.width *self.scaleX;

CGFloat selfHeight = self.contentSize.height *self.scaleY;

if (self.parent == referNode)

{

//parent-child relationship

switch (selfEdge)

{

casekCCNodeAnchorTop:

centerY = [selfedgeOfParentNode: referNode ofAnchor: edge] - margin - selfHeight
/ 2;

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorLeft:

centerX = [selfedgeOfParentNode: referNode ofAnchor: edge] + margin + selfWidth
/ 2;

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorBottom:

centerY = [selfedgeOfParentNode: referNode ofAnchor: edge] + margin + selfHeight
/ 2;

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorRight:

centerX = [selfedgeOfParentNode: referNode ofAnchor: edge] - margin - selfWidth
/ 2;

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorHorizontalCenter:

centerX = [selfedgeOfParentNode: referNode ofAnchor: edge];

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorVerticalCenter:

centerY = [selfedgeOfParentNode: referNode ofAnchor: edge];

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorCenterIn:

centerX = [selfedgeOfParentNode: referNode ofAnchor:kCCNodeAnchorHorizontalCenter];

centerY = [selfedgeOfParentNode: referNode ofAnchor:kCCNodeAnchorVerticalCenter];

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

default:

break;

}

}

else if (self.parent == referNode.parent)

{

//two nodes are siblings

switch (selfEdge)

{

casekCCNodeAnchorTop:

centerY = [selfedgeOfSiblingNode: referNode ofAnchor: edge] - margin - selfHeight
/ 2;

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorLeft:

centerX = [selfedgeOfSiblingNode: referNode ofAnchor: edge] + margin + selfWidth
/ 2;

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorBottom:

centerY = [selfedgeOfSiblingNode: referNode ofAnchor: edge] + margin + selfHeight
/ 2;

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorRight:

centerX = [selfedgeOfSiblingNode: referNode ofAnchor: edge] - margin - selfWidth
/ 2;

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorHorizontalCenter:

centerX = [selfedgeOfSiblingNode: referNode ofAnchor: edge];

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, oldPositon.y);

break;

casekCCNodeAnchorVerticalCenter:

centerY = [selfedgeOfSiblingNode: referNode ofAnchor: edge];

self.position =CGPointMake(oldPositon.x,
centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

casekCCNodeAnchorCenterIn:

centerX = [selfedgeOfSiblingNode: referNode ofAnchor:kCCNodeAnchorHorizontalCenter];

centerY = [selfedgeOfSiblingNode: referNode ofAnchor:kCCNodeAnchorVerticalCenter];

self.position =CGPointMake(centerX + (self.anchorPoint.x -0.5)
* selfWidth, centerY + (self.anchorPoint.y -0.5)
* selfHeight);

break;

default:

break;

}

}

else

{

//not allowed

NSAssert(NO, @"The
two nodes must be parent-child or siblings!");

}

}

- (void) centerIn:(CCNode *)outerNode

{

[selfaddAnchor: kCCNodeAnchorCenterInreferTo: outerNode edge:kCCNodeAnchorCenterInmargin:0];

}

@end