01-Coursework 1：Property Viewer

import java.awt.Desktop;
import java.net.URI;
import java.net.URISyntaxException;

/**
 * This project implements a simple application. Properties from a fixed
 * file can be displayed.
 *
 * @author Michael Kölling and Josh Murphy
 * @version 1.0
 */
public class PropertyViewer {
    private PropertyViewerGUI gui;     // the Graphical User Interface
    private Portfolio portfolio;
    private Property property; // 引用
    static int row = 0;
    static int view_count = 1;

    /**
     * Create a PropertyViewer and display its GUI on screen.
     */
    public PropertyViewer() {
        gui = new PropertyViewerGUI(this);
        portfolio = new Portfolio("airbnb-london.csv");
        property = portfolio.getProperty(row);
        gui.showID(property);
        gui.showProperty(property);
        gui.showFavourite(property);
    }

    /**
     *
     */
    public void nextProperty() {
        view_count = view_count + 1;
        row = row + 1;
        if (row >= portfolio.numberOfProperties()) {
            row = 0;
        }
        property = portfolio.getProperty(row);
        gui.showID(property);
        gui.showProperty(property);
        gui.showFavourite(property);
    }

    /**
     *
     */
    public void previousProperty() {
        view_count = view_count + 1;
        row = row - 1;
        if (row < 0) {
            row = portfolio.numberOfProperties() - 1;
        }
        property = portfolio.getProperty(row);
        gui.showID(property);
        gui.showProperty(property);
        gui.showFavourite(property);

    }

    /**
     *
     */
    public void toggleFavourite() {
        property = portfolio.getProperty(row);  // index 获取当前数据，index
        property.toggleFavourite(); // 标记喜欢的，更新喜欢的
        gui.showFavourite(property); // gui 显示出来
    }


    //----- methods for challenge tasks -----

    /**
     * This method opens the system's default internet browser
     * The Google maps page should show the current properties location on the map.
     */
    public void viewMap() throws Exception {
        double latitude;
        double longitude;
        latitude = property.getLatitude();
        longitude = property.getLongitude();

        URI uri = new URI("https://www.google.com/maps/place/" + latitude + "," + longitude);
        java.awt.Desktop.getDesktop().browse(uri);
    }

    /**
     *
     */
    public int getNumberOfPropertiesViewed() {
        return 0;
    }

    /**
     *
     */
    public int averagePropertyPrice() {
        return 0;
    }
}