import java.awt.*; import java.applet.*;import java.awt.event.*;public class Assignment1 extends Applet implements ActionListener { // Constants private static final Color defaultTopColor = Color.red; private static final Color defaultMiddleColor = Color.yellow; private static final Color defaultBottomColor = Color.blue; private static final String RED = "Red"; private static final String YELLOW = "Yellow"; private static final String BLUE = "Blue"; private static final String RESET = "Reset"; private static final String TOP_LIST_LABEL = "Top Row Colors"; private static final String MIDDLE_LIST_LABEL = "Middle Row Colors"; private static final String BOTTOM_LIST_LABEL = "Bottom Row Colors"; // Instance Variables private Panel mainPanel, boardPanel, listsPanel; private Board board; private Button resetButton; private List topRowColorList, middleRowColorList, bottomRowColorList; public void init() { // Create the main panel and all of its components and add them to panel applet. mainPanel = makeMainPanel(); boardPanel = makeBoardPanel(); listsPanel = makeListsPanel(); this.add(mainPanel); this.addListeners(); } private List makeColorList(int itemNumber){ // Create a List with the 3 colour options; preselect the item with the given itemNumber List list = new List(3, false); list.add(RED); list.add(YELLOW); list.add(BLUE); list.select(itemNumber); return list; } private Panel makeListsPanel() { // Make Labels and Lists for row colour choices, add them to a Panel // The Panel uses GridLayout, 2 rows and 3 columns topRowColorList = makeColorList(0); middleRowColorList = makeColorList(1); bottomRowColorList = makeColorList(2); Panel panel = new Panel(); panel.setLayout(new GridLayout(2, 3, 0, 0)); panel.add(new Label(Assignment1.TOP_LIST_LABEL, 1)); panel.add(new Label(Assignment1.MIDDLE_LIST_LABEL, 1)); panel.add(new Label(Assignment1.BOTTOM_LIST_LABEL, 1)); panel.add(this.topRowColorList); panel.add(this.middleRowColorList); panel.add(this.bottomRowColorList); return panel; } private Panel makeBoardPanel() { // Create a Board using the default row colours, create a reset Button; // add panel Board and Button to a Panel (which uses FlowLayout) Panel panel = new Panel(); panel.setLayout(new FlowLayout()); board = new Board(Assignment1.defaultTopColor, Assignment1.defaultMiddleColor, Assignment1.defaultBottomColor); panel.add(this.board.getBoard()); resetButton = new Button(Assignment1.RESET); panel.add(this.resetButton); return panel; } private Panel makeMainPanel() { // create and return the Panel which contains the boardPanel and the ListsPanel // The Panel uses GridLayout, 2 rows and 1 column boardPanel = makeBoardPanel(); listsPanel = makeListsPanel(); Panel panel = new Panel(); panel.setLayout(new GridLayout(2, 1, 0, 0)); panel.add(this.boardPanel); panel.add(this.listsPanel); return panel; } private void addListeners() { // Adds the Applet as the ActionListener for the various components board.getSquare("1").addActionListener(this); board.getSquare("2").addActionListener(this); board.getSquare("3").addActionListener(this); board.getSquare("4").addActionListener(this); board.getSquare("5").addActionListener(this); board.getSquare("6").addActionListener(this); board.getSquare("7").addActionListener(this); board.getSquare("8").addActionListener(this); board.getSquare("9").addActionListener(this); resetButton.addActionListener(this); topRowColorList.addActionListener(this); middleRowColorList.addActionListener(this); bottomRowColorList.addActionListener(this); } private Color makeColor(String colString) { // Return a Color corresponding to the given String if(colString.equals(RED)) return Color.red; if(colString.equals(YELLOW)) return Color.yellow; if(colString.equals(BLUE)) return Color.blue; else return null; } public void actionPerformed(ActionEvent event) { // Responds appropriately to whichever button has been clicked // If Reset has been clicked, change row colours to the selected colours, else move the square that has been clicked Color topColor = makeColor(this.topRowColorList.getSelectedItem()); Color middleColor = makeColor(this.middleRowColorList.getSelectedItem()); Color bottomColor = makeColor(this.bottomRowColorList.getSelectedItem()); String whichButton = event.getActionCommand(); if (whichButton.equals(Assignment1.RESET)) { this.board.changeRowColor(1, topColor); this.board.changeRowColor(2, middleColor); this.board.changeRowColor(3, bottomColor); this.board.paintSquares(); } else { this.board.move(whichButton); } }}// end of Assignment1 class