wallpaper.java

Java the UML Way 书中所有源码

/*
 * Wallpaper.java   E.L. 2001-05-17
 *
 */
class Wallpaper extends Material {
  private static final double limit = 0.02; // limit for one more width
  private double lengthPerRoll; // meter
  private double widthPerRoll; // meter

  public Wallpaper(String initName, double initPrice, double initLengthPerRoll, 
      double initWidthPerRoll) {
    super(initName, initPrice);
    lengthPerRoll = initLengthPerRoll;
    widthPerRoll = initWidthPerRoll;
  }

  public double getLengthPerRoll() {
    return lengthPerRoll;
  }
  
  public double getWidthPerRoll() {
    return widthPerRoll;
  }

  /*
   * This method calculates the number of rolls needed to paper a surface.   
   */
  public double getMaterialReq(Surface aSurface) {
    double lengthSurface = aSurface.getLength();
    double heightSurface = aSurface.getWidth();

    /* calculate the number of heights */
    int noOfHeights = (int) (lengthSurface / widthPerRoll);
    double remnant = lengthSurface % widthPerRoll;
    if (remnant >= limit) noOfHeights++;

    /* calculate the number of rolls */
    int noOfRolls;
    int noOfHeightsPerRoll = (int) (lengthPerRoll / heightSurface);
    if (noOfHeightsPerRoll > 0) {
      noOfRolls = noOfHeights / noOfHeightsPerRoll;
      remnant = noOfHeights % noOfHeightsPerRoll;
      if (remnant >= limit) noOfRolls++;
    } else {  // the roll is shorter than one height (rarely!)
      double totalNoOfMeters = noOfHeights * heightSurface;
      noOfRolls = (int) (totalNoOfMeters / lengthPerRoll);
      if (totalNoOfMeters % lengthPerRoll >= limit) noOfRolls++;
    }
    return noOfRolls;
  }
}