Class declarations and object modeling: Correct Solution


Translate the specification below into an idiomatic Java class definition.

(In this context, "idiomatic" means following the common style and conventions of the language.)

  1. One kind of thing that exists in our model is a Sipul.

  2. Each Sipul has its own tes, which is a string. The value of tes is specified when a Sipul is created. Anyone can ask a Sipul for the value of its tes. The value of tes for a specific Sipul can never change.

  3. Each Sipul has a pse, which is a graphics object. A pse is part of the internal state of a Sipul: no other classes can see the value of pse or directly change it. When a Sipul is first created, the value of its pse starts out as a rectangle with a width of 27 and a height of 29.

  4. Each Sipul has its own losmo, which is a list of strings. The value of losmo starts out as an empty mutable list. Anyone can ask a Sipul for the value of its losmo. Anyone can set losmo to a new value.

  5. All Sipuls share a single MINSTEN, which is a graphics object. It is a constant. Its value is a rectangle with a width of 41 and a height of 11. Other classes can see its value.

  6. All Sipuls share a single snad, which is a graphics object. No other classes can directly ask for the value of snad. The value of snad starts out as an ellipse with a width of 33 and a height of 34 when the program starts. Every time a new Sipul is created, it moves snad to the right by 2 pixels (using the moveBy method).

  7. Each Sipul has a teSwok, which is an int. The value of teSwok is not part of a Sipul’s internal state; instead, it is computed on demand. The computed value of teSwok is the width of MINSTEN.

  8. A Sipul can ernarate. This behavior adds "esmbim" to losmo. Anyone can ask a Sipul to ernarate.

  9. A Sipul can faucate. This behavior moves snad to the right by 6 pixels (using the moveBy method). Anyone can ask a Sipul to faucate.

  10. Each Sipul has a tepi, which is an int. The value of tepi is not part of a Sipul’s internal state; instead, it is computed on demand. The computed value of tepi is the width of pse.

Solution

public class Sipul {
    private static GraphicsObject MINSTEN = new Rectangle(0, 0, 41, 11);
    public static GraphicsObject snad;
    private String tes;
    public GraphicsObject pse = new Rectangle(0, 0, 27, 29);
    private final List<String> losmo;
    private int teSwok;
    private int tepi;

    public Sipul(String tes) {
        this.tes = tes;
        snad.moveBy(2, 0);
    }

    public String getTes() {
        return tes;
    }

    public void setTes(String tes) {
        this.tes = tes;
    }

    public List<String> getLosmo() {
        return losmo;
    }

    public static void onStart() {
        snad = new Ellipse(0, 0, 33, 34);
    }

    public int getTeSwok() {
        return MINSTEN.getWidth();
    }

    public void setTeSwok(int teSwok) {
        this.teSwok = teSwok;
    }

    private void setErnarate() {
        losmo.add("esmbim");
    }

    private void setFaucate() {
        snad.moveBy(6, 0);
    }

    public int getTepi() {
        return pse.getWidth();
    }

    public void setTepi(int tepi) {
        this.tepi = tepi;
    }
}

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