2d对象数组的深层副本

Question

how can I make on a button press a new deep copy of a 2 dimensional array?

Basically I created a game field with buttons. The game is called sokoban and it's a puzzle. The player is moving from one button to the other with arrow keys on a fixed map (8x8 buttons). I want to implement an undo function. So I thought that I just create a deep copy of the JButton array before each move and save it into a stack. So when I press the undo button it calls the pop function of my stack. The problem is that I need to declare and initialize another JButton[][] where I can save the game field to before each move. Since I want infinite possible moves and also undos it seems impossible to me. I can't declare and initalize infite diffrent JButton[][] arrays. Any idea on how I can solve that?

That's how I copy a 2d object array:

    JButton[][] tempArray = new JButton[jbArray.length][jbArray[0].length];

    for (int i = 0; i < getJbArray().length; i++) {
        for (int j=0;j<getJbArray()[0].length;j++) {
            tempArray[i][j]=jbArray[i][j];
        }
    } 

    movesStack.push(tempArray);

Answer 1

Unfortunately you can't clone swing components in general, as they do not implement the Cloneable interface. As I see it you have two options:

1. Create a new JButton inside your double loop and copy whatever properties (like alignment, color etc.) you have set to the new JButton

2. Write your own class that extends JButton and implement the Cloneable interface

The first way is somewhat of a hack and not very robust or reusable. The second way is much better practice. In this case you'll have to define how the deep copy is supposed to happen, and ensure that all relevant properties are copied over.

Answer 2

You've got the right idea. You're not quite going deep enough.

    public JButton[][] copy(JButton[][] jbArray) {
        JButton[][] tempArray = new JButton[jbArray.length][jbArray[0].length];

        for (int i = 0; i < jbArray.length; i++) {
            for (int j = 0; j < jbArray[0].length; j++) {
                tempArray[i][j] = new JButton(jbArray[i][j].getText());
            }
        }

        return tempArray;
    }

Rather than copying JButtons, you should have a model that you use to set the JButtons. Maybe a ModelClass[][] array?