Welcome to the orderCoffees wiki!

orderCoffeees is a simple android app(basic app), doesn't require any internet or even server to connect to in order to order a coffee, so as i told you its just simple, it does only a math operation to calculate the price of how much coffees you order based on $5 for 1 coffee.

What can this app do?:

• the default number of coffees and price is set to 0 by default
• Increase the number of coffees you want
• Also decrease it, but stopped at 0 (its not logically to order -1 coffee xD)
• Shows a toast message when you order your coffees
• Perform new order

What event are used in this app ?:

It uses 4 onClick events

1. Increase the amount of coffees you want(executed when plus button is clicked)
2. Decrease the amount of coffees you want(executed when minus button is clicked)
3. Order the amount of coffees you want(executed when order button is clicked)
4. perform new order (executed when "new order" button is clicked)

The name of every onClick event method used in the MainActivity Java file and its role:

1. submitOrder(View view) --> when order button is clicked * display a toast message "Your order has been submitted"
2. newOrder(View view) --> when new order button is clicked * set default value for quantity(0) and price(0)
3. increase(View view) --> when plus button is clicked * increase the quantity by 1
4. decrease(View view) --> when minus button is clicked * decrease the quantity by 1

Other helpful methods:

1. display(int number): - connect to the quantity TextView and display a given value
2. displayPrice(int number): - connect to the price TextView and display a given value

Other helpful explanation to fully understand the code:

• i used 3 helpful variables:

1. price: i fixed the value of this variable to 5 which means $5 for 1 cop of coffee
2. int initialQuantity: declared in the class but outside of any method because i want it to be global variable so if i changed its value from somewhere else it will be changed everywhere i use it, when i click newOrder() method executed it set the default quantity to initialQuantity which is 0 and default price to initialQuantity*price which equal to 0 (0*5 = 0)
3. newQuantity: when user increase(click +)/decrease(click -) the quantity value this variable get increased/decreased

• while decreasing the quantity, i check either it's negative or not, if negative then set the quantity to 0 and price to 0 as well.