问题描述
我有 4 个类，Rocket、Triangle、Square 和 Circle。
Rocket 是主类，它允许在动画屏幕中创建火箭的表示。 火箭由3个形状组成，三角形是鼻子，方形是身体，圆形是喷气机。火箭以垂直编队定向。其他 3 个类定义了形状的特征。
我需要编写一个辅助方法“getBodyXPos()”，以便它返回一个相对于鼻子位置的适当值。鼻子的位置已经定义，所以我需要使用代码中的现有值，这样如果鼻子移动，身体也会随之移动它的位置，即不是硬编码值。
这是我的第一篇文章，很抱歉代码转储。我很确定这有一个非常简单的解决方案，但我对 Java 还很陌生，无法在我的一生中找到一种方法来获得我需要的值。任何帮助将不胜感激，谢谢！
火箭班
import ou.*;
public class Rocket
{
private Triangle nose; // represents the rocket's nose cone
private Square body; // represents the rocket's body
private Circle jet; // represents the blast from the rocket's engine
/**
* Constructor for objects of class Rocket
*/
public Rocket(Triangle t,Square s,Circle c)
{
//references to the shape objects
this.nose = t;
this.body = s;
this.jet = c;
//sets the initial positions of the nose.
//The other parts need to be set relative to these positions.
this.nose.setXPos(50);
this.nose.setYPos(300);
//sets the body relative to the nose,using the helper methods
this.body.setXPos(getBodyXPos());
this.body.setYPos(getBodyYPos());
this.jet.setColour(OUColour.WHITE);
this.jet.setDiameter(10);
this.jet.setXPos(getJetXPos());
this.jet.setYPos(getJetYPos());
}
private int getBodyXPos()
{
//SOLUTION HERE
return 0;
}
private int getBodyYPos()
{
return 0;
}
}
三角形类
import ou.*;
public class Triangle extends OUAnimatedobject
{
/* Instance variables */
private OUColour colour;
private int xPos;
private int yPos;
private int width;
private int height;
/**
* Constructor for objects of class Triangle with the default characteristics.
*/
public Triangle()
{
this.colour = OUColour.RED;
this.xPos = 0;
this.yPos = 0;
this.width = 20;
this.height = 20;
}
/* Instance methods */
/**
* Sets the colour of the receiver to the value of the argument aColour.
*/
public void setColour (OUColour aColour)
{
this.colour = aColour;
this.update();
}
/**
* Returns the colour of the receiver.
*/
public OUColour getColour ()
{
return this.colour;
}
/**
* Sets the horizontal position of the receiver to the value of the argument x.
*/
public void setXPos(int x)
{
this.xPos = x;
this.update();
}
/**
* Returns the horizontal position of the receiver.
*/
public int getXPos()
{
return this.xPos;
}
/**
* Sets the vertical position of the receiver to the value of the argument y.
*/
public void setYPos(int y)
{
this.yPos = y;
this.update();
}
/**
* Returns the vertical position of the receiver.
*/
public int getYPos()
{
return this.yPos;
}
/**
* Sets the width of the receiver to the value of the argument aWidth.
*/
public void setWidth(int aWidth)
{
this.width = aWidth;
this.update();
}
/**
* Returns the width of the receiver.
*/
public int getWidth()
{
return this.width;
}
/**
* Sets the height of the receiver to the value of the argument aHeight.
*/
public void setHeight(int aHeight)
{
this.height = aHeight;
this.update();
}
/**
* Returns the height of the receiver.
*/
public int getHeight()
{
return this.height;
}
/**
* Returns a string representation of the receiver.
*/
public String toString()
{
return "An instance of class "+ this.getClass().getName()
+ ": position (" + this.getXPos() + "," + this.getYPos()
+ "),width " + this.getWidth() + ",height " + this.getHeight()
+ ",colour " + this.getColour();
}
}
方形类
import ou.*;
public class Square extends OUAnimatedobject
{
/* Instance variables */
private int length;
private OUColour colour;
private int xPos;
private int yPos;
/**
* Constructor for objects of class Square with the default characteristics.
*/
public Square()
{
this.length = 20;
this.colour = OUColour.BLUE;
this.xPos = 0;
this.yPos = 0;
}
/* Instance methods */
/**
* Sets the length of the receiver to the value of the argument aLength.
*/
public void setLength(int aLength)
{
this.length = aLength;
this.update();
}
/**
* Returns the length of the receiver.
*/
public int getLength()
{
return this.length;
}
/**
* Sets the colour of the receiver to the value of the argument aColour.
*/
public void setColour (OUColour aColour)
{
this.colour = aColour;
this.update();
}
/**
* Returns the colour of the receiver.
*/
public OUColour getColour ()
{
return this.colour;
}
/**
* Sets the horizontal position of the receiver to the value of the argument x.
*/
public void setXPos(int x)
{
this.xPos = x;
this.update();
}
/**
* Returns the horizontal position of the receiver.
*/
public int getXPos()
{
return this.xPos;
}
/**
* Sets the vertical position of the receiver to the value of the argument y.
*/
public void setYPos(int y)
{
this.yPos = y;
this.update();
}
/**
* Returns the vertical position of the receiver.
*/
public int getYPos()
{
return this.yPos;
}
/**
* Returns a string representation of the receiver.
*/
public String toString()
{
return "An instance of class "+ this.getClass().getName()
+ ": position (" + this.getXPos() + "," + this.getYPos()
+ "),length " + this.getLength() + ",colour " + this.getColour();
}
}
解决方法
希望 Body 开始位置始终与 Nose 开始类似
/\
/ \
----
|__|
在这种情况下，X 的 Nose 将是 X 的 Body 和 bodyY = noseY + noseHeight
private int getBodyXPos(){
return nose.getXpos();
}
private int getBodyYPos(){
return nose.getYpos() + nose.getheight();
}