Action Instruction Example

Flash Tutorials - Herong's Tutorial Examples

∟Action Instruction Example - "GotoFrame"

This section provides a tutorial example on how to use 'gotoFrame' and 'Play' Action instructions to jump backward in the timeline to creating a loop of frames.

Actions are very useful in creating Flash applications. Let's learn 2 most commonly used action instructions:

GotoFrame - An action instruction that tells Flash Player to abandon the process of showing the current frame, go to the specified frame, make it as the current frame, and stop playing.
Play - An action instruction that tells Flash Player to play the current frame.

With these 2 actions, we can easily build a Flash application that repeat some frames in loop. Here is my example, written in SWFTools script, ping_pong.sc:

#- ping_pong.sc
#- Copyright (c) 2014 by Dr. Herong Yang, herongyang.com
#
.flash bbox=300x100 background=gray fps=6
.box ball color=black fill=yellow width=10 height=10

.frame 1
   .put ball x=0 y=0

.frame 2
   .del ball
   .put ball x=10 y=45

.frame 3
   .del ball
   .put ball x=145 y=20

.frame 4
   .del ball
   .put ball x=280 y=45

.frame 5
   .action:
      gotoFrame(1); // index 1 = #2
      play();
   .end

.end

Notes on this example code:

For frame 1, I am putting a "ball" in the display list at an initial position.
For frame 2, I am removing the old "ball" and putting a new "ball" in the display list at the starting position.
For frame 3, I am removing the old "ball" and putting a new "ball" in the display list at the center position.
For frame 4, I am removing the old "ball" and putting a new "ball" in the display list at the ending position.
For frame 5, I am using action instructions to alter the timeline to go backward to frame 2 and resume the timeline.

If we compile the code and dump the SWF file, we will see:

C:\herong>\local\SWFTools\swfc -o ping_pong.swf ping_pong.sc

C:\herong>\local\SWFTools\swfdump --full ping_pong.swf
[HEADER]   File version: 6
[HEADER]   File is zlib compressed. Ratio: 80%
[HEADER]   File size: 174
[HEADER]   Frame rate: 6.000000
[HEADER]   Frame count: 5
[HEADER]   Movie width: 300.00
[HEADER]   Movie height: 100.00
[009]    3 SETBACKGROUNDCOLOR (be/be/be)
[020]   33 DEFINESHAPE3 defines id 0001
            | fillstyles(01)        linestyles(01)
            | 1 ) SOLID ffff00ff    1 ) 0.00 000000ff
            |
            | fill: 01/00 line:01 - moveTo 0.00 0.00
            | fill: 01/00 line:01 - lineTo 10.00 0.00
            | fill: 01/00 line:01 - lineTo 10.00 10.00
            | fill: 01/00 line:01 - lineTo 0.00 10.00
            | fill: 01/00 line:01 - lineTo 0.00 0.00
            |
[028]    7 NAMECHARACTER adds information to id 0001 "ball"
[038]    9 EXPORTASSETS
           exports 0001 as "ball"

[01a]   10 PLACEOBJECT2 places id 0001 at depth 0001 name "ball"
[001]    0 SHOWFRAME 1 (00:00:00,000)

[01c]    2 REMOVEOBJECT2 removes object from depth 0001
[01a]   14 PLACEOBJECT2 places id 0001 at depth 0002 name "ball"
            | Matrix
            | 1.000 0.000  10.00
            | 0.000 1.000  45.00
[001]    0 SHOWFRAME 2 (00:00:00,167)
[01c]    2 REMOVEOBJECT2 removes object from depth 0002
[01a]   15 PLACEOBJECT2 places id 0001 at depth 0003 name "ball"
            | Matrix
            | 1.000 0.000 145.00
            | 0.000 1.000  20.00
[001]    0 SHOWFRAME 3 (00:00:00,333)
[01c]    2 REMOVEOBJECT2 removes object from depth 0003
[01a]   15 PLACEOBJECT2 places id 0001 at depth 0004 name "ball"
            | Matrix
            | 1.000 0.000 280.00
            | 0.000 1.000  45.00
[001]    0 SHOWFRAME 4 (00:00:00,500)
[00c]    7 DOACTION
            (    2 bytes) action: GotoFrame 1
            (    0 bytes) action: Play
            (    0 bytes) action: End
[001]    0 SHOWFRAME 5 (00:00:00,667)
[000]    0 END

Notice that there are 3 Action instructions are embedded in the "DOACTION" tag. Play ping_pong.swf. It should work:

C:\herong>\local\bin\flashplayer_13_sa ping_pong.swf

Table of Contents

About This Book

Introduction of Adobe Flash

Adobe Flash Player Plugin for Firefox

Adobe Flash Player Plugin for Chrome

Adobe Flash Player Plugin for Safari

Adobe Flash Player ActiveX for IE

Using "object" Elements for Flash Files

Using "embed" Elements for Flash Files

"mp3player" - MP3 Music Player

SWFObject - Hidding "object" behind JavaScript

Flash Player Projector

SWFTools - SWF File Manipulation Tools

SWFC Script to Generate Flash SWF Files

ActionScript Embedded in SWFC Script

AS3Compile - ActionScript 3 Compiler

Adobe Flex SDK 4

SWF File Structure and Tags

►SWF File Processing Rules

Flash Player Lifecycle - Timeline and Frame Rate

SWF Tag Process Flow - SHOWFRAME Synchronization

SWF Player Lifecycle Example

Showing SWF Tag Details - "swfdump --full"

Flash Player Supports Dynamic Actions

►Action Instruction Example - "GotoFrame"

Creating Display Objects with Action Instructions

More Action Instructions and Less SWF Tags

SWF Files for Video and Audio Streams

Outdated Tutorials

References

Full Version in PDF/EPUB