import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.URL;

import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;



public class ImageRandomAccess2 implements ActionListener {
    final static int NUM_IMAGES = 8;//显示的图片总数

    final static int START_INDEX = 3;//初始化的时候默认显示的图片

    ImageIcon[] images = new ImageIcon[NUM_IMAGES];//初始化数组

    JPanel mainPanel, selectPanel, displayPanel;//三个面板
    
    JLabel selectLabel=null;
    
    JComboBox combobox=null;//控制显示有哪些图片，非随即滚动

    JButton controlBtn=null;

    JLabel imageIconLabel = null;

    // Constructor
    public ImageRandomAccess2() {
        // Create the phase selection and display panels.
        selectPanel = new JPanel();
        displayPanel = new JPanel();

        // Add various widgets to the sub panels.
        addWidgets();

        // Create the main panel to contain the two sub panels.
        mainPanel = new JPanel();
        mainPanel.setLayout(new GridLayout(2, 1, 5, 5));
        mainPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));

        // Add the select and display panels to the main panel.
        mainPanel.add(selectPanel);
        mainPanel.add(displayPanel);
    }

    // Create and the widgets to select and display the images of peoples.
    private void addWidgets() {
        // Get the images and put them into an array of ImageIcon.

        for (int i = 0; i < NUM_IMAGES; i++) {
            String imageName = "images/" + (i + 1) + ".jpg";
            System.out.println("getting image: " + imageName);
            // URL iconURL = ClassLoader.getSystemResource(imageName);

            ImageIcon icon = new ImageIcon(imageName);
            images[i] = icon;
        }

        // Create label for displaying  images and put a border around
        // it.
        imageIconLabel = new JLabel();
        imageIconLabel.setHorizontalAlignment(JLabel.CENTER);
        imageIconLabel.setVerticalAlignment(JLabel.CENTER);
        imageIconLabel.setVerticalTextPosition(JLabel.CENTER);
        imageIconLabel.setHorizontalTextPosition(JLabel.CENTER);
        imageIconLabel.setBorder(BorderFactory.createCompoundBorder(
                BorderFactory.createLoweredBevelBorder(),
                BorderFactory.createEmptyBorder(5, 5, 5, 5)));

        imageIconLabel.setBorder(BorderFactory.createCompoundBorder(
                BorderFactory.createEmptyBorder(0, 0, 10, 0),
                imageIconLabel.getBorder()));

        controlBtn=new JButton("无图片");
        selectLabel=new JLabel("选择图片");
        
        combobox=new JComboBox();
        
        for(int i=0;i<NUM_IMAGES;i++){
            combobox.addItem(i);
        }
        selectLabel.setLabelFor(combobox);

        // Display the first image.
        imageIconLabel.setIcon(images[START_INDEX]);
        imageIconLabel.setText("");
        
        
        // Add border around the select panel.
        selectPanel.setBorder(BorderFactory.createCompoundBorder(
                BorderFactory.createTitledBorder("Select Phase"),
                BorderFactory.createEmptyBorder(5, 5, 5, 5)));

        // Add border around the display panel.
        displayPanel.setBorder(BorderFactory.createCompoundBorder(
                BorderFactory.createTitledBorder("Display Phase"),
                BorderFactory.createEmptyBorder(5, 5, 5, 5)));

        // Add control button to select panel and image label to
        // displayPanel.
        selectPanel.add(selectLabel);
        selectPanel.add(combobox);
        selectPanel.add(controlBtn);
        displayPanel.add(imageIconLabel);

        // Listen to events from control button.
//        controlBtn.addActionListener(this);
        combobox.addActionListener(this);
        controlBtn.addActionListener(this);
    }

    boolean run = false;

    // Implementation of ActionListener interface.
    public void actionPerformed(ActionEvent event) {
        if(event.getSource()==combobox){
            int imageIndex=combobox.getSelectedIndex();
            imageIconLabel.setIcon(images[imageIndex]);
        }
        if(event.getSource()==controlBtn){
            System.out.println("------------");
            imageIconLabel.setIcon(null);
//            imageIconLabel.setIcon(new ImageIcon());
        }

    }

    // main method
    public static void main(String[] args) {
        // create a new instance of ImageRandomAccess
        ImageRandomAccess2 phases = new ImageRandomAccess2();

        // Create a frame and container for the panels.
        JFrame mainFrame = new JFrame("ImangeRandomAccess");

        // Set the look and feel.
        try {
            UIManager.setLookAndFeel(UIManager
                    .getCrossPlatformLookAndFeelClassName());
        } catch (Exception e) {
        }

        mainFrame.setContentPane(phases.mainPanel);

        // Exit when the window is closed.
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // Show the converter.
        mainFrame.pack();
        mainFrame.setLocationRelativeTo(null);
        mainFrame.setVisible(true);
    }
}