1. CS320n – Elements of Visual Programming List Search Mike Scott (Slides 9-2) Thanks to Wanda Dann, Steve Cooper, and Susan Rodger for slide ideas.

2. Visual ProgrammingList Search2 Common Uses of Lists Iterating through a list of several like items to accomplish the same task with each item. – As in the previous chickens example Iterating through a list of several like items to search for one item that has a given property. – This session demonstrates a list search. –is searching important in computer programs?

3. Visual ProgrammingList Search3 Example A WacAMole arcade game. Little moles pop up from holes in the top of the booth. The user tries to whack the mole before it drops out of sight. The game is over when 10 moles are hit.

4. Visual ProgrammingList Search4 Designing the game To design the game animation, we need to answer several questions: – How will the game work, overall? – How do we keep score? – How do we know when the user whacks a mole? – Will a list help us? (make it easier)

5. Visual ProgrammingList Search5 How will the game work, overall? A mole pops up and then goes back down. –Each time the mole pops up, the user attempts to use the mouse to click the mole. When a click occurs, we check to see if a mole was clicked. –If so, a sound plays and the score increases. The above actions repeat until the game is over.

6. Visual ProgrammingList Search6 Is the game over? Overall design pop random mole no yes congratulate Did mouse click on a mole? yes Play sound Change score display Mouse click event no do nothing

7. Visual ProgrammingList Search7 Storyboard for overall game This is the main driver for the game. The code will be written in World.my first method While the game isn't over randomly select one mole and call popMole Congratulate the user

8. Visual ProgrammingList Search8 Storyboard: popMole popMole Do in order Move the mole up Wait some time Move the mole back down

9. Visual ProgrammingList Search9 How do we keep score? We will use a visual scorekeeper. The scorekeeper is made up of two cylinders – A gray cylinder above the ground – A yellow cylinder below the ground.

10. Visual ProgrammingList Search10 How do we keep score? Each time the user successfully clicks a mole, the yellow cylinder will move up 1/5 meter. When the yellow cylinder is above ground (has moved up 10 times), the game is over. –true when yellow cylinder is above the ground

11. Visual ProgrammingList Search11 How do we know when the user has clicked on a mole? This is where a list comes in handy: – create a list of the moles (one mole is below each hole) – create a mouse click event – each time the mouse is clicked, call a score method to iterate through the list of moles to see whether one of the moles has been clicked!

12. Visual ProgrammingList Search12 Storyboard: keep score Event: User clicks mouse Response: score For All in order If any mole in the mole list was the object clicked Make a noise Move the playerscore (yellow cylinder) up 1/10 meter

13. Visual ProgrammingList Search13 Demo Concepts illustrated in this example – A item can be randomly selected from a list In this example, a random mole was popped up from a list of moles. – A visual scorekeeper gives the player feedback on the progress of a game.