PAINTPOT DISCUSSION QUESTIONS

These discussion questions concern the PaintPot tutorial, chapter 2 of the App Inventor book, and the customizations specified here. Concepts include event-handlers, event parameters (arguments), and variables. For related reading, see chapter 2, 14 (app architecture) and 16 (an app's memory).

1. Sketch the event-handlers that are involved with lines being drawn a particular color.



2. In PaintPot, there are event parameters for some events. Name the events with event parameters and describe the data each parameter holds.



3. How are event parameters different than the function call parameters (e.g., Sound.Vibrate (500) ? Who specifies function parameters? Who specifies event parameters?


4. In the tutorial version of PaintPot you define a variable.

a. What variable do you define?


b. Sketch the blocks used to define the variable in PaintPot. Once you define a variable, what blocks appear in "My Definitions"


c. What happens to the app's memory when you define a variable?


d. You don't need to define a variable for 'PaintColor', the color of the paint on the canvas. Why not?


e. Define the term variable. How is a variable similar to a property? How is a variable different than a property?


5. One customization of PaintPot involves using a Textbox for the dotsize.  How is a textbox different from a variable? How is a textbox different from a label?

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