Day 1: Variables / Bouncing Ball

Let's Start

1. Under the Drawing and Animation section of the Palette, click and drag Canvas from the Palette into the Viewer.

2. Select on Canvas1 on the Components window (it should be under Screen1)

3. Under the Properties window click BackgroundColor and select Blue

1. What happened on your device?

2. Under the Properties window change Canvas1's Width and Height to 200px

1. What happened on your device or emulator?

2. Under the Palette's Category Animation, drag Ball onto the Viewer's Canvas1. Place the ball anywhere on the Canvas.

3. What happened on your device? Ball1 should now be under Canvas1 on the Components window.

4. Select Ball1 on the Components window and change the speed property to 10.0. Watch you device when you press enter!

1. Ball1 should have moved slowed across Canvas1 until it reached the side. Ball1 is now stuck on the side of Canvas1.

The Blocks Screen

When working with the app inventor, we will use the Blocks Screen to add block that tell the app to do things.

We don't want the Ball1 to stay stuck on the side of the Canvas1. We want it to bounce off the walls. To do that, we need to work with the blocks screen. Here is what to do:

• 1. Go to the Blocks Screen by pushing the Blocks button.

  2. Look on the left side. You should see a list of our Components: Canvas1, Ball1, and Screen1.

• 1. Click on Ball1. A list of "Blocks" will appear. By fitting blocks together we make that component "do" things.

  2. With your mouse, grab the when Ball1.EdgeReached block and drag it onto the board.

• 1. Next, click Ball1 on the side again. Drag the call Ball1.Bounce block and snap it into when Ball1.EdgeReached

• 1. Mouse over the edge button on the when Ball1.EdgeReached block and drag and snap the value edge piece into the call Ball1.Bounce