<< Chapter < Page
  Teaching beginners to code     Page 6 / 9
Chapter >> Page >

Some experimentation was required

Because I didn't know the diameter of the beachball, I had to experiment to determine how far to move it to the left of the origin to locate it at the leftside of the Stage as shown in Image 4 . I settled on a value of -200 for the x coordinate and a value of 0 for the y coordinate.

Positioning the other beachball

In the interest of brevity, I won't show the code required to position the beachball on the right side of the Stage. I did exactly the same thing for that beachballexcept that I specified the value of the x coordinate to be 200 instead of - 200. This causes the beachball named RightBeachball to move to the right side of the Stage when the user clicks the green flag.

The basketball

Initializing the position of the basketball

Image 7 shows a portion of the rightmost panel after clicking on the sprite named Basketball . (Note the image of the basketball in the upper right corner. When this is an image of the basketball, all of the scripts in the rightmost panel apply to thebasketball sprite.)

Image 7. initializing the position and orientation of the basketball.

Missing image.
Image 7. Initializing the position and orientation of the basketball.

You will note that the tan block and the uppermost blue block in Image 7 arethe same as in Image 6 except that the x coordinate value is set to 0. This causes the basketball to move to the origin when the user clicks the greenflag.

Initializing the orientation of the basketball

However, Image 7 contains a block that is not contained in Image 6 . The bottom blue block in Image 7 is used to set the orientation of the basketball. (By orientation, I mean the direction that the basketball is facing.)

It may seem strange to say that a round basketball is facing in one direction or the other. However, every sprite has a front, back, top, and bottomeven in those cases where it is not visually obvious. The orientation would be visually obvious if I were to use an animal for the sprite in place ofthe basketball. You can tell which direction the basketball is facing by observing the curved diagonal lines on the basketball.

After you drag the blue block labeled point in direction into the rightmost panel, you can click the arrow in the white box to expose the followingfour choices:

  • (90) right
  • (-90) left
  • (0) up
  • (180) down

As you can see, I selected the choice that causes the basketball to face to the right. As a result, when the user clicks the green flag, the basketballwill move to the origin and turn to face the right.

Handling mouse events on the basketball

Image 8 shows all of the code in the rightmost panel that applies to the basketball.

Image 8. all of the code that applies to the basketball.

Missing image.
Image 8. All of the code that applies to the basketball.

The top script in Image 8 is another copy of the script that was shown in Image 7 . At this point, we are interested in the behavior of the bottom script in Image 8 .

Behavior of the bottom script

The dark tan block labeled when this sprite clicked specifies that all of the actions produced by the blocks attached to that block will occur when the userclicks the basketball with the mouse. Furthermore, those actions will occur in top-to-bottom order.

Questions & Answers

what is mutation
Janga Reply
what is a cell
Sifune Reply
how is urine form
Sifune
what is antagonism?
mahase Reply
classification of plants, gymnosperm features.
Linsy Reply
what is the features of gymnosperm
Linsy
how many types of solid did we have
Samuel Reply
what is an ionic bond
Samuel
What is Atoms
Daprince Reply
what is fallopian tube
Merolyn
what is bladder
Merolyn
what's bulbourethral gland
Eduek Reply
urine is formed in the nephron of the renal medulla in the kidney. It starts from filtration, then selective reabsorption and finally secretion
onuoha Reply
State the evolution relation and relevance between endoplasmic reticulum and cytoskeleton as it relates to cell.
Jeremiah
what is heart
Konadu Reply
how is urine formed in human
Konadu
how is urine formed in human
Rahma
what is the diference between a cavity and a canal
Pelagie Reply
what is the causative agent of malaria
Diamond
malaria is caused by an insect called mosquito.
Naomi
Malaria is cause by female anopheles mosquito
Isaac
Malaria is caused by plasmodium Female anopheles mosquitoe is d carrier
Olalekan
a canal is more needed in a root but a cavity is a bad effect
Commander
what are pathogens
Don Reply
In biology, a pathogen (Greek: πάθος pathos "suffering", "passion" and -γενής -genēs "producer of") in the oldest and broadest sense, is anything that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term pathogen came into use in the 1880s.[1][2
Zainab
A virus
Commander
Definition of respiration
Muhsin Reply
respiration is the process in which we breath in oxygen and breath out carbon dioxide
Achor
how are lungs work
Commander
where does digestion begins
Achiri Reply
in the mouth
EZEKIEL
what are the functions of follicle stimulating harmones?
Rashima Reply
stimulates the follicle to release the mature ovum into the oviduct
Davonte
what are the functions of Endocrine and pituitary gland
Chinaza
endocrine secrete hormone and regulate body process
Achor
while pituitary gland is an example of endocrine system and it's found in the Brain
Achor
what's biology?
Egbodo Reply
Biology is the study of living organisms, divided into many specialized field that cover their morphology, physiology,anatomy, behaviour,origin and distribution.
Lisah
biology is the study of life.
Alfreda
Biology is the study of how living organisms live and survive in a specific environment
Sifune
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Teaching beginners to code. OpenStax CNX. May 27, 2013 Download for free at http://cnx.org/content/col11498/1.20
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Teaching beginners to code' conversation and receive update notifications?

Ask