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HelloPurr Worksheet

1. App Inventor has two main windows. What are they and what do they do?
  • The first window is the component designer, which allows the user to create buttons and add media to the app. The other window is the blocks editor which allows the user to drag and drop blocks of code into place to create event handlers, which create all the actions of the app.

2. Testing and Running an App  

a. How do you test an app while you're developing it? 
  • Plug the phone and connect it to the blocks editor.
b. How can you use your app when you're not connected to the computer?
  • Run an emulator from the blocks editor.
c. What if you didn't have a phone, but wanted to program some apps. Could you? How?
  • You could by running an emulator.
3. Its a good idea to rename components in the Component Designer, different from their default names. Why is this important?
  • It is very important so that you know exactly what every button is, to make sure that you are using the correct one in which to input code.
4. For the HelloPurr app, name the:

visual components: kitty image (button), text (pet kitty)
non-visual components:properties: sound
events: kittybuttonclick
event-handlers: "when button click"
calls to functions: response (kittysoundplay)

5.  In an app Inventor app:

a. What is a component? 
  • either a button, canvas, sound etc.
b. What is a property?
  •  name of component, color, size etc.
c. What is an event?
  •  when the user does something to the app, i.e. click
d. What is an event-handler?
  • "when clicked" with function calls underneath it
e. What is a "function call"?
  • an action to be completed when prompted i.e. when clicked, function call (call.soundplay) will play sound
6. One function call in Hello Purr required arguments (also known as parameters). Which function is it and what is the parameter?