Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

1

Flash

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

2

Ch.Ch.Ch…Changes David Bowie

• “Only the wisest and stupidest of men never change.” – Confucius

• “Change is inevitable - except from a vending machine.” – Robert C. Gallagher

• “We cannot become what we need to be by remaining what we are.” – Max Depree

• “To change and to change for the better are two different things.” – German proverb

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

3

Why Scripting ?

• Import and export information, create forms, network communications programs

• Personalise the user’s experience

• Control movie clips and their properties more tightly

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

4

Why Scripting ?

• Build dynamic projects that vary according to information like weather data or the day of the week

• Dynamically control sound volume and stereo panning

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

5

ActionScript (AS 1)

ActionScript 1 (Flash 1-5)• Good for simple interactivity• Basic “Glue” coding• Plenty of code available but – code rough• Limited capabilities led to some bad coding• Non-Standard language – loosely related to JavaScript• Was very slow• Even sloppy code runs

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

6

ActionScript (AS 2)

ActionScript 2 (Flash 2004 – 8)• A proper OO language• Good for more complex coding• Deeper control of Flash capabilities• More flexible programming environment• Better de-bugging capabilities• Cleaner coding – more readable (transferable .dir)• Stricter syntax and error checking

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

7

ActionScript (AS 3)

ActionScript 3 (CS3 – CS4)• Full OO language• Everything is now an object which can or has to be

called up dynamically.• Objects are embedded into objects as children ie:- the

screen is an object which has active sprites within it as children.

• A child inherits attributes from the parent as well as controlling their own attributes.

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

8

Adaptability

• You can still program using ActionScript 1.0 in Flash MX 2004 and in Flash 8

• Performance of AS1 is good in MX 2004 and Flash 8

• ActionScript 2 code strongly resembles Java

• ActionScript 2 knowledge can easily be re-used in the industrial strength, cross-platform world of Java

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

9

Adaptability

• The code in Flash now runs a minimum of 5 times faster than AS 1

• This opens Flash up to more potential uses especially the world of on-line and mobile games and communication using complex processing

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

10

Tricks & Traps• AS2 upwards is case sensitive

nCounter != ncounter != NCounter

• Note older code may not workstopAllSounds(); // worksstopallsounds(); // does not when using AS2 code

• Stricter data typing improves run-time performance

• AS 2 upwards has strict data typingvar nCounter:Number = 36The variable (nCounter) of type (Number) = 36

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

11

Loop gotoAndPlay()• Loops can be used to create a

menu section where the film is waiting for a key or mouse event to happen

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

12

Loop gotoAndPlay()• Buttons can be used to break the

loop

• Loop.htm

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

13

Key Class• Key press can also

be used…

• Key1.htm

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

14

Key Class• The script needs to account for the frame the video head is moving through.

onEnterFrame = function() {

if(Key.isDown(Key.UP)){

gotoAndPlay(1);

}

}

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

15

Screen Plotting• The screen is plotted from the top left hand corner of the user screen.

._x is the horizontal plotting position

._y is the vertical plotting position

• Objects can be placed on the desktop (off main screen) and called into position at will.

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

16

Screen Plotting• The number relates to the

position on screen relative to screen size

• Hence – ._x =150 would be half way across a 300 pixel screen

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

17

Screen Plotting• If you wanted an object to move onto and across the

screen you would start it off in a -._x position then give it a variable speed.

Round._x = -50

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

18

Screen Plotting• Scroll.htm

• The scripting would go so…

var speed:Number = 10

onEnterFrame = function() {

if(Key.isDown(Key.RIGHT)) {

round._x += speed;

}

}

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

19

Screen Plotting• The project is built up in small sections each

overlaying the next to create the effect needed.

• Key X-Y.htm

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

20

var speed:Number =3onEnterFrame = function() {

if (Key.isDown(Key.RIGHT)){round._x += speed;round._y += speed;

} else if (Key.isDown(Key.LEFT)){round._x -= speed;round._y -= speed;

} else if (Key.isDown(Key.DOWN)){round._y += speed;round._x -= speed;

} else if (Key.isDown(Key.UP)){round._y -= speed;round._x += speed;

} else if(Key.isDown(65)) {round._x -= speed;

} else if (Key.isDown(68)) {round._x += speed;

}else if (Key.isDown(87)) {round._y -= speed;

}else if (Key.isDown(83)) {round._y += speed;

}}

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

21

Interaction• It is then possible to begin to create imagery to

fit into the scene.

Full.htm• You begin to develop more involved interaction.

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

22

Conclusion• Giving the user the ability to control items creates interactivity.

• Control of items is built up by creating small functions.

• Functions can work together to create sophisticated imagery and action.

Flash

Anoth

er

Look

Apr 20, 2023 Computing Engineering and Technology David.M.de-Leuw@staffs.ac.uk

23

References

• ActionScript 2.0: A Real Programming Languagehttp://www.peachpit.com/articles/article.asp?p=102204

• Introducing ActionScript 2http://www.macromedia.com/devnet/mx/flash/articles/astfts_excerpt/astfts_lesson1.pdf,

http://www.macromedia.com/devnet/flash/actionscript/actionscript.html

• Kirupa ActionScript 2.0 OOPhttp://www.kirupa.com/developer/oop2/AS2OOPindex.htm