Java Swing使用两个JPanel处理变量

Question

I have two panels, a control and a Battleship panel. The control panel has a submit button which takes in the location of the position that the user wants to attack. The Battleship panel then evaluates the location to see if it's a hit or miss under a method called check.

How do I add in a counter variable that limits the number of times the user can submit a location? I had a counter variable in Control Panel but I was manipulating it through check method in Battleship. However, check was also being called in a TimerListener in Battleship and my counter decemented too quickly because check was constantly being called.

Edit: hopefully cleared up my question

Answer 1

Put the counter in control panel. Check it's value and decrement it while calling check method when submit button is pressed.

// Members of control panel class
BattleShipPanel battleShipPanel; // Fetch value through constructor or setter
int counter = 10;

public void submitButtonClicked(Event evt) {
    if (counter > 0) {
        int x, y;

        // Take input in x and y here

        counter--;
        battleShipPanel.check(x, y);
    }
}

Answer 2

If I understood you correctly, then you want your counter variable should be used in two panels.

In java you have 4 type of access specifiers

1. default or package level - Accessible in any class within the same package

2. private - Accessible within the class where it has been declared, no where else

3. protected - Accessible in any class within the same package and in any subclass in some other package

4. public - Accessible in any class in the same or different package.

The best options is to make your variables private.

Sample Example

public class ClassName {

   private Object obj;

   public Object getObject(){
        return obj;
   }

   public void setObject(Object obj){
        this.obj = obj;
   }

}

As obj is used in two methods you can use your variable in two panels.

Answer 3

I figured it out! I had the counter variable in my Control Panel and just decremented it under the ButtonListener I had. Then it would update every time the user had clicked the submit button. I used what Tanmay Patil had and modified it a bit.