My Wallet Design

• Description of wallet object:
  • A wallet is an object that can hold money (bills), cards (credit, identification, discount, ...) and photos.
  • A user can ask for a list of each category item from the wallet, insert these items into a wallet, or remove these items from the wallet.
  • A wallet is a storage container, with no knowledge of finances (it can not make change, it can not even total the values of the bills)
  • For photos, you don't have to remove a picture from the wallet to display it.
  • Money and cards are a standard size, photos are not.
• Methods
  • Bill related methods:
    • GetNumberOfBillsHeld: this will return the number of bills stored in the walled
    • GetBillLimit: This will return the maximum number of bills the wallet can hold.
    • InsertBill: this will insert a single bill in the wallet.
    • RemoveBill: Remove a bill of a given type from the wallet.
    • GetBillList: return a list of bills and the quantity of each.
  • Card related methods
    • GetNumberofCardsHeld: Get the current number of cards in the wallet.
    • GetCardLimit: Return how many cards the wallet will hold
    • InsertCard: Insert a card into the wallet
    • RemoveCard: Given a card id, remove and return the associated card.
    • GetCardList: Get a list of cards currently held in the wallet.
  • PhotoRelatedItems
    • GetNumberofPhotosHeld: Get the current number of photos in the wallet.
    • GetPohtoLimit: Return how many photos a wallet can hold.
    • InsertPohto: Insert a photo into the wallet.
    • RemovePohto: Given a photo id, remove it from the wallet
    • GetPohtoList: Return a list of photo names and ids
    • DisplayPhoto: Given a photo number, display that photo
    • DoesPhotoFit: Given a photo, return true if it will "fit" dimension wise in the wallet.
• Objects required
  • A bill object, it should be able to provide currency and value.
  • A card object, for this level it should support the == operator and provide some sort of "name" or identification.
  • A photo object.
    • Needs a display method.
    • Needs an identification field such as name or description. This name should be unique.
    • Needs a dimension field.
• What can you store in a walled
  • The wallet can store from 0 to an object determined maximum of bills.
  • The wallet can store from 0 to an object determined maximum of cards.
  • A wallet can store from 0 an object determined maximum of photos
  • A wallet can store photos less that MAX_WIDTH x MAX_HEIGHT in size. These constants are per object.
• Some Thoughts
  • After all of my reading the last month, I probably would build a hierarchy of WalletObjects
  • The maximum sizes are determined by the object when it is created.
    • You might provide a low cost and high cost wallet with different capabilities.
  • I started to specify that the wallet will have an array of bills. This is an implementation detail that has no place here.