Mobile Computing Android

Goal: Build a simple app that uses two fragments to implement a gift card purchase

and redeem app.

Requirements:

1) You will have a main Activity

a. It will implement the interfaces PurchaseCallBack and

RedeemCallback.

b. It will have a container for a fragment that covers the bottom part of

the screen.

c. It will have two text views –

i. The first will display “# cards purchased worth ##.##”

ii. The second will display “# cards redeemed worth ##.##”

2) There will be a model GiftCardModel that will be a singleton.

a. It will have instance variables for Number of gift cards purchased,

Number of gift cards redeemed, the total purchased value, the total

redeemed value and a static inner class GiftCard that has two instance

variables amount and redeemed (Boolean). The model will maintain

an ArrayList that will record the status of all giftcards.

b. It will have the following methods.

c. purchaseCard(double amount) – will add a Gift Card to the list and

Display a toast message with code (position in the list) of the card and

the amount. Update the number purchased and total purchased.

d. Boolean redeemCard( int code) – will check to make sure that the code

is a legal position and if it is set redeemed to true. Display a toast

message with the code and indicate success or failure. If success, the

toast message should report that. If the redeem worked, update the

count and total.

3) It will have a PurchaseCardFragment that is a subclass of Fragment.

a. It will have a button to purchase a card.

b. It will have an EditText where you will be able to enter an amount.

Make sure it is of a number type.

c. It will have a button that will switch to the other fragment

(ToRedeem).

d. When purchase is pressed, the model will be updated and then an

update function will be invoked with the activity.

4) It will have a RedeemFragment that is a subclass of Fragment.

a. It will have a button to redeem a card.

b. It will have an EditText where you will be able to enter a code. Make

sure it is of a number type.

c. It will have a button that will switch to the other fragment

(toPurchase).

d. When redeem is pressed, the model will be updated and then an

appropriate update function will be invoked with the activity.

5) The PurchaseCallBack interface will have two methods.

a. Void update() – Will get the values from the model and set the text in

the main activities text views.

b. Void swapToRedeem() – change the two fragments so the

RedeemFragment is shown.

6) The RedeemCallBack interface will have two methods.

a. Void update() – Will get the values from the model and set the text in

the main activities text views.

b. Void swapToPurchase() – change the two fragments so the

PurchaseFragment is shown.

c.

7) The app should be tested properly and should not crash in any scenario.

a. Make sure on creation that you get a reference to your model and

update the display using the handy update CallBack function.

b. Make sure to only create the Fragments the first onCreate is called.

Sample Solution

ACED ESSAYS