renovationchap10.java

来自「Java the UML Way 书中所有源码」· Java 代码 · 共 164 行

/*
 * RenovationChap10.java   E.L. 2001-08-15
 *
 */
import java.text.*;
import javax.swing.JOptionPane;
import myLibrary.InputReader;  // see chap. 6.8
class ProjectChap10 {
  public static final int exit = -1;

  private ReaderRenovationCase details = new ReaderRenovationCase();
  private RenovationProject project = new RenovationProject("My Flat");
  private DecimalFormat numberFormat = new DecimalFormat("###0.00"); // see ch.8.2
  private DecimalFormat currencyFormat =
                       (DecimalFormat) NumberFormat.getCurrencyInstance();

  public void showInstructions() {
    String instruction =
      "This program calculates the price and amount needed to paint several surfaces\n" +
      "with different kinds of paint. You may choose to change the type of paint on\n" +
      "a registered surface, or to register a new surface. You have to register a new \n" +
      "surface as the first thing you do. Every time you do a change, the amount of\n " +
      "paint and the price are shown in the list box.";
    JOptionPane.showMessageDialog(null, instruction);
  }

  public int doAChoice() {
    String[] options = setOptions();
    String selectionDone = (String) JOptionPane.showInputDialog(null,
      "Drop down the list, and do a choice, " +
      "\nif you click on a surface, you will get the opportunity to " +
      "\nchange the paint for that surface:",
      "Renovation", JOptionPane.DEFAULT_OPTION, null, options, options[0]);
    int selection = getSelectionAsInt(options, selectionDone);
    if (selection == options.length - 1) return exit;
    else return selection;
  }

  public void carryOutTheRightThing(int option) {
    if (option < project.getNoOfSurfaces()) { // changes paint
      Paint thePaint = getPaint();
      Surface theSurface = project.getSurface(option); // get a reference to the surface object
      theSurface.setPaint(thePaint);
    } else {   // new surface is to be registered
      Surface aSurface = details.readAndInstantiateSurface();
      if (project.addNewSurface(aSurface) == aSurface) { // ok, the paint should be found
        Paint thePaint = getPaint();
        aSurface.setPaint(thePaint);
      } else {
        JOptionPane.showMessageDialog(null,
                         "Surface with this name is already registered.");
      }
    }
  }

  /*
   * This method creates a String array to be presented to the user as a menu.
   * The array will contain all registered surfaces with their paint and price,
   * and in addition the total price and the items "New Surface" and "Exit".
   */
  private String[] setOptions() {
    int noOfSurfaces = project.getNoOfSurfaces();
    int noOfOptions = noOfSurfaces + 3;
    String[] options = new String[noOfOptions];
    for (int i = 0; i < noOfSurfaces; i++) {
      Surface thisSurface = project.getSurface(i);
      Paint thePaint = thisSurface.getPaint();
      if (thePaint != null) {
        double noOfLiters = thePaint.getNoOfLiters(thisSurface);
        String noOfLitersFormatted = numberFormat.format(noOfLiters);
        double price = thePaint.getTotalPrice(thisSurface);
        String priceFormatted = currencyFormat.format(price);
        options[i] = thisSurface.getName() + ", paint: " + thePaint.getName() + ", "
                        + noOfLitersFormatted + " liters, price: " + priceFormatted;
      }
      else options[i] = thisSurface.getName() + ", paint not registered.";
    }
    options[noOfSurfaces] = "The total price is: "
                            + currencyFormat.format(project.getTotalPrice());
    options[noOfSurfaces + 1] = "New Surface";
    options[noOfSurfaces + 2] = "Exit";
    return options;
  }

  /*
   * This method finds the correct paint, or registers a new one.
   * In this case, the method returns null if a paint with the
   * same name already is registered.
   */
  private Paint getPaint() {
    int paintIndex = getPaintIndex();  // the user choose the right paint
    Paint aPaint;
    if (paintIndex < 0) {  // we are going to register a new paint
      aPaint = details.readAndInstantiatePaint();
      if (project.addNewPaint(aPaint) != aPaint) {
        JOptionPane.showMessageDialog(null, "Paint with this name is already registered.");
      }
    }
    else aPaint = project.getPaint(paintIndex);
    return aPaint;
  }

  /*
   * This method lets the user choose between all existing paints, or he may
   * choose to register a new paint. In the first case the method returns
   * the index of the chosen paint, in the second case the method returns -1.
   */
  private int getPaintIndex() {
    int noOfPaints = project.getNoOfPaints();
    if (noOfPaints > 0) { // there are paints registered
      int noOfOptions = noOfPaints + 1;
      String[] options = new String[noOfOptions];
      for (int i = 0; i < noOfPaints; i++) {
        Paint thisPaint = project.getPaint(i);
        options[i] = thisPaint.getName();
      }
      options[noOfPaints] = new String("New Paint");

      /* We show the menu list to the user, and we note his choice. */
      String selectionDone = (String) JOptionPane.showInputDialog(null,
        "Drop down the list, and do a choice:",
        "Renovation", JOptionPane.DEFAULT_OPTION, null, options, options[0]);
      int thePaint = getSelectionAsInt(options, selectionDone);
      if (thePaint < options.length - 1) {
        return thePaint; // Return, we are going to use the paint with this index
      }
    }
    return -1;  // Return, we are going to register a new paint
  }

  private int getSelectionAsInt(String[] options, String selectionDone) {
    for (int i = 0; i < options.length; i++) {
      if (options[i].equals(selectionDone)) return i;
    }
    return -1;
  }
}

class RenovationChap10 {
  public static void main(String[] args) {
    ProjectChap10 aProject = new ProjectChap10();
    aProject.showInstructions();

    int option = aProject.doAChoice();
    while (option != ProjectChap10.exit) {
      aProject.carryOutTheRightThing(option);
      option = aProject.doAChoice();
    }
    System.exit(0);
  }
}

/* Example Run:

Data:
Surfaces: A wall in Mary's room: 3 x 4 m, Ceiling in the corridor: 6 x 1 m,
Paints: Heimdal Extra: 3 coats, 10 kvm/l, 100 NOK/l,
        Heimdal Super: 2 coats, 12 kvm/l, 80 NOK/l

In this example we use Norwegian crowns as currency. The program
will use the currency given by the regional settings.

The output window, see figure 10.6.
*/