Displaying Fundamentally Different Data

WARNING the code is a mix between java and pseudocode, and should not be used directly

For this example imagine we have a GUI and we have three very different objects that we want to display

Let’s use Book, Car and House, and we have to be able to display them in short concise view (ThumbnailView) and long detailed view (DetailedView)

If we were to make a class for every combination there would be total of 6 classes and code repetition would be awful but with bridge pattern it’s a lot easier to extend with no code repetition

UML Diagram

interface IDataAdapter {
   public String get_title();
   public Picture get_thumbnail();
   public Picture[] get_pictures();
}

class DataView {
   IDataAdapter adapter = null;

   public DataView(IDataAdapter adapter) {
      this.adapter = adapter
   }

   public abstract show();
}

class ThumbnailView extends DataView {
   public show() {
      ... // show the gui
   }
}

class DetailedView extends DataView {
   public show() {
      ... // show the gui
   }
}

class Book {
   public String title;
   public String year;
   public String author;
   public Picture cover;
   public Picture[] pictures;
}

class BookDataAdapter implements IDataAdapter {
   Book book = null;
   
   public BookDataAdapter(Book book) {
      this.book = book;
   }

   public String get_title() {
      return this.book.title + " (" + this.book.year + ") by " + this.book.author;
   }

   public Picture get_thumbnail() {
      return this.book.cover;
   }

   public Picture[] get_pictures() {
      return this.book.pictures;
   }
}

class Car {
   public String model;
   public String year;
   public String manufacturer;
   public Picture[] pictures;
}

class CarDataAdapter implements IDataAdapter {
   Car car = null;
   
   public CarDataAdapter(Car car) {
      this.car = car;
   }

   public String get_title() {
      return this.car.manufacturer + " " + this.car.model + " (" + this.car.year + ")";
   }

   public Picture get_thumbnail() {
      return this.car.pictures[0];
   }

   public Picture[] get_pictures() {
      return this.car.pictures;
   }
}

class House {
   public String address;
   public String year;
   public String owner;
   public Picture[] pictures;
}

class HouseDataAdapter implements IDataAdapter {
   House house = null;
   
   public HouseDataAdapter(House house) {
      this.house = house;
   }

   public String get_title() {
      return this.house.address + " (" + this.house.year + ")";
   }

   public Picture get_thumbnail() {
      return this.house.pictures[0];
   }

   public Picture[] get_pictures() {
      return this.house.pictures;
   }
}