Java Swing MouseListener調用類

Question

需要一些關於大學作業的指導。所以，如果你能給我指針，而不是真正的解決方案，將不勝感激。

一直負責修改現有的程序，以便當鼠標懸停在草稿板的黑色方塊上時，只有黑色方塊變爲不同的顏色。當鼠標退出黑色方塊時，它會回到原來的顏色。

我已經包括了兩個班，我認爲這對解決這個任務很重要。

謝謝你收到的任何幫助。現在一段時間以來我一直在抓這個名字。 任務的一部分是僅編輯委員會類而不編輯其他人。

public class Board extends JPanel implements MouseListener 
{ 
private Square square; 
private Square[][] squares; 
private ArrayList<DraughtsPiece> lightPieces; 
private ArrayList<DraughtsPiece> darkPieces; 

public Board(int numRows) 
{ 
    super(new GridLayout(numRows, numRows)); 
    squares = new Square[numRows][numRows]; 
    lightPieces = new ArrayList<DraughtsPiece>(); 
    darkPieces = new ArrayList<DraughtsPiece>(); 

    setupBoard(numRows); 
    setupPieces(numRows); 

    allocatePieces(); 
} 

private void setupBoard(int numRows) 
{ 

    boolean lightSquare = true; 

    for (int row = 0; row < numRows; row++) 
    { 
     for (int col = 0; col < numRows; col++) 
     { 
      if (lightSquare) 
      { 
       squares[row][col] = new Square(Square.LIGHT_SQUARE_COLOUR, 
row + 1, col + 1); 
      } 
      else 
      { 

       squares[row][col] = new Square(Square.DARK_SQUARE_COLOUR, 
row + 1, col + 1); 
       addMouseListener(this); 
      } 
      add(squares[row][col]); 
      lightSquare = !lightSquare; 
     } 
     lightSquare = !lightSquare; 
    } 
} 

private void setupPieces(int numRows) 
{ 
    int numPieces = ((numRows * numRows) - (2 * numRows))/4; 
    for (int i = 0; i < numPieces; i++) 
    { 
     DraughtsPiece p = new 
    DraughtsPiece(DraughtsPiece.LIGHT_PIECE_COLOUR); 
     lightPieces.add(p); 

     p = new DraughtsPiece(DraughtsPiece.DARK_PIECE_COLOUR); 
     darkPieces.add(p); 

    } 
} 

private void allocatePieces() 
{ 
    int row = squares.length - 1; 
    int col = 0; 

    for (DraughtsPiece p : lightPieces) 
    { 
     squares[row][col].setPiece(p); 
     col += 2; 
     if (col >= squares[0].length) 
     { 
      col = row % 2; 
      row--; 
     } 
    } 

    row = 0; 
    col = squares[0].length - 1; 
    for (DraughtsPiece p : darkPieces) 
    { 
     squares[row][col].setPiece(p); 
     col -= 2; 
     if (col < 0) 
     { 
      row++; 
      col = squares[0].length - 1 - (row % 2); 
     } 
    } 
} 

我明白一個鼠標適配器可以用來刪除MouseListener的空方法，雖然我們還沒有教過這個。 我沒有在這段代碼中包含未使用的方法。

public void mouseExited(MouseEvent e) 
{ 
if (e.getSource().equals(square)) 
{ 
square.exit(); 
} 
} 

public void mouseEntered(MouseEvent e) 
{ 
if (e.getSource().equals(square)) 
{ 
square.enter(); 
} 
} 

這裏是Square類

public class Square extends JPanel 
{ 
public static final Color LIGHT_SQUARE_COLOUR = new Color(0xdfdfdf); 
public static final Color DARK_SQUARE_COLOUR = new Color(0x333333); 
public static final Color SELECTED_DARK_SQUARE_COLOUR = Color.YELLOW; 

private Color background; 
private int row, column; 
private Color selectedBackground; 
private DraughtsPiece piece; 
private boolean selected = false; 

public Square(Color c, int row, int col) 
{ 
    super(new BorderLayout()); 
    background = c; 
    this.row = row; 
    this.column = col; 
    setBackground(background); 
    if (background == DARK_SQUARE_COLOUR) 
    { 
     selectedBackground = SELECTED_DARK_SQUARE_COLOUR; 
    } 
    piece = null; 
} 

public int getRow() 
{ 
    return row; 
} 

public int getColumn() 
{ 
    return column; 
} 

public void setPiece(DraughtsPiece piece) 
{ 
    if (piece == null && this.piece != null) 
    { 
     remove(this.piece); 
     this.piece.setSquare(null); 
     this.piece = null; 
    } 
    else if (piece != null && this.piece == null) 
    { 
     this.piece = piece; 
     piece.setSquare(this); 
     add(piece); 
    } 
} 

public DraughtsPiece getPiece() 
{ 
    return piece; 
} 

protected void enter() 
{ 
    setBackground(selectedBackground); 
} 

protected void exit() 
{ 
    setBackground(background); 
} 

protected void setSelected(boolean b) 
{ 
    selected = b; 
    setBackground(b == false ? background : selectedBackground); 
} 


} 

Answer 1

你總是比較相同Square對象（一個叫square），這是從來沒有使用過。

蜉應直接使用Square這是事件的源頭，e.g：

public void mouseExited(MouseEvent e) 
{ 
    if (e.getSource() instanceof Square) 
    { 
     ((Square)e.getSource()).exit(); 
    } 
}