如何在Java中的形状中嵌套形状？

Question

我试图做涉及一个JPanel内反弹形状的分配。无论何时形状碰到一侧，它们都会沿另一个方向反弹。我已经有了正常形状的弹跳部分，但现在我需要制作一个NestingShape。

的NestingShape是包含零种或多个形状的反弹，它里面的矩形，而NestingShape反弹在JPanel的周围。 NestingShape实例的子项可以是简单形状，如RectangleShape和OvalShape对象，或其他NestingShape实例。

为NestingShape规格如下：

public class NestingShape extends Shape { 
    /** 
    * Creates a NestingShape object with default values for state. 
    */ 
    public NestingShape() { 
     super(); 
    } 

    /** 
    * Creates a NestingShape object with specified location values, default values for other 
    * state items. 
    */ 
    public NestingShape(int x, int y) { 
     super(x,y); 
    } 

    /** 
    * Creates a NestingShape with specified values for location, velocity and direction. 
    * Non-specified state items take on default values. 
    */ 
    public NestingShape(int x, int y, int deltaX, int deltaY) { 
     super(x,y,deltaX,deltaY); 
    } 

    /** 
    * Creates a NestingShape with specified values for location, velocity, direction, width, and 
    * height. 
    */ 
    public NestingShape(int x, int y, int deltaX, int deltaY, int width, int height) { 
     super(x,y,deltaX,deltaY,width,height); 
    } 

    /** 
    * Moves a NestingShape object (including its children) with the bounds specified by arguments 
    * width and height. 
    */ 
    public void move(int width, int height) { 
     //Not yet implemented 
    } 

    /** 
    * Paints a NestingShape object by drawing a rectangle around the edge of its bounding box. 
    * The NestingShape object's children are then painted. 
    */ 
    public void paint(Painter painter) { 
     painter.drawRect(fX,fY,fWidth,fHeight); 
     painter.translate(fX,fY); 
     // Paint children here. Not implemented yet 
     painter.translate(0,0); 
} 

    /** 
    * Attempts to add a Shape to a NestingShape object. If successful, a two-way link is 
    * established between the NestingShape and the newly added Shape. Note that this method 
    * has package visibility - for reasons that will become apparent in Bounce III. 
    * @param shape the shape to be added. 
    * @throws IllegalArgumentException if an attempt is made to add a Shape to a NestingShape 
    * instance where the Shape argument is already a child within a NestingShape instance. An 
    * IllegalArgumentException is also thrown when an attempt is made to add a Shape that will 
    * not fit within the bounds of the proposed NestingShape object. 
    */ 
    void add(Shape shape) throws IllegalArgumentException { 
     // Not implemented yet 
    } 

    /** 
    * Removes a particular Shape from a NestingShape instance. Once removed, the two-way link 
    * between the NestingShape and its former child is destroyed. This method has no effect if 
    * the Shape specified to remove is not a child of the NestingShape. Note that this method 
    * has package visibility - for reasons that will become apparent in Bounce III. 
    * @param shape the shape to be removed. 
    */ 
    void remove(Shape shape) { 
     // Not implemented yet 
    } 

    /** 
    * Returns the Shape at a specified position within a NestingShape. If the position specified 
    * is less than zero or greater than the number of children stored in the NestingShape less 
    * one this method throws an IndexOutOfBoundsException. 
    * @param index the specified index position. 
    */ 
    public Shape shapeAt(int index) throws IndexOutOfBoundsException { 
     // Not implemented yet 
    } 

    /** 
    * Returns the number of children contained within a NestingShape object. Note this method is 
    * not recursive - it simply returns the number of children at the top level within the callee 
    * NestingShape object. 
    */ 
    public int shapeCount() { 
     // Not implemented yet 
    } 

    /** 
    * Returns the index of a specified child within a NestingShape object. If the Shape specified 
    * is not actually a child of the NestingShape this method returns -1; otherwise the value 
    * returned is in the range 0 .. shapeCount() - 1. 
    * @param the shape whose index position within the NestingShape is requested. 
    */ 
    public int indexOf(Shape shape) { 
     // Not implemented yet 
    } 

    /** 
    * Returns true if the shape argument is a child of the NestingShape object on which this method 
    * is called, false otherwise. 
    */ 
    public boolean contains(Shape shape) { 
     // Not implemented yet 
    } 
} 

我不知道，如果提供足够的上下文，但我有正在实施add和remove方法麻烦的部分。当它说“NestingShape和新添加的Shape之间建立了双向链接”时，我不知道该如何去做。我会使用ArrayList还是使用其他形状的列表？有没有对我怎么会去有关实现add方法并在该方法会从这段代码中调用任何线索？

谢谢。

Answer 1

如果我得到这个权利，你其实需要有某种形式的列表（ArrayList的举例）或有序集儿童的这种嵌套形状内部，使得嵌套形状可以有更多的孩子。然后，您可以使用列表的方法来检查何时添加一个形状，如果它已包含，并删除和插入形状。

当他们说，你建立他们的意思是你应该一些如何告诉插入的形状，现在它的新的父母是给定的嵌套形式双向连接。你没有给我们形状类的接口（它看起来不像标准的java.awt.Shape，因为它是一个接口）。你的形状类做参考莫名其妙父母矩形知道什么是在它应该移动boundries，所以你应该设置父在插入子捏成嵌套形状是嵌套状。从嵌套形状中删除形状时，也应删除该父子关系。

我需要的形状类的更多信息，以提供更详细的答案，但我相信这是你要找的人;）