我正在尝试做一个涉及在 JPanel 中弹跳形状的任务。每当形状撞到一边时，它们就会向另一个方向反弹。我已经让弹跳部分适用于正常形状，但现在我需要制作一个 NestingShape。
NestingShape 是一个矩形，其中包含零个或多个在其中反弹的形状，而 NestingShape 在 JPanel 中围绕 反弹。NestingShape 实例的子对象可以是简单的 Shapes，如 RectangleShape 和 OvalShape 对象，也可以是其他 NestingShape 实例。
NestingShape 的规格如下：
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
}
}
我不确定这是否提供了足够的上下文，但我遇到问题的部分是实现addandremove方法。当它说“在 NestingShape 和新添加的 Shape 之间建立了双向链接”时，我不知道该怎么做。我会使用 ArrayList 或形状列表或其他东西吗？关于我将如何实现该add方法以及从该代码中调用该方法的位置是否有任何线索？
谢谢。