AN-001. Classes Supported In Each Version Of Flash.

Each of the data structures which are part of the Flash File Format Specification, published by Macromedia are mapped to a given class in the Transform SWF framework. With each new version of Flash, Macromedia adds new data structures to support new functionality in the Flash Player. When generating files using Transform it is important that only the classes compatible with a given Flash version are used to encode the Flash file.

Flash is forwards compatible. File generated for a given version of Flash will always be played correctly by future versions of the Flash Player. Flash has limited backwards compatibility however. If the Flash Player decodes a file generated using a later version of Flash the behaviour is undefined. At best the Player may ignore the tag leading to unpredictable results when the movie is played or at worst the Player may crash. In either case the person viewing the file is going to be disappointed.

The following table lists the classes in Transform and which version of Flash they are compatible with. Only Flash versions 5 onwards are considered, (SWF6 = Flash MX, SWF7 = Flash MX 2004). Most of the classes are supported in each version. The majority of the differences between each version can be found in the stack-based actions which are executed by the Flash Player to control how a movie is played.

Class	SWF5	SWF6	SWF7	Description
Basic Data Types
FSBounds				Defines the bounding rectangle that encloses an object.
FSColor				Defines the colour of an object.
FSColorTransform				Changes the colour of an object without changing the original definition.
FSCoordTransform				Changes the size, orientation etc. of an object without changing the original definition.
FSNull				Defines a null value that will be pushed onto the Flash Player's Stack.
FSVoid				Defines a void value that will be pushed onto the Flash Player's Stack.
FSRegisterVariable				Use with the FSNewFunction2 class to map arguments to internal registers.
Drawing Shapes
FSShape				Defines the outline of a shape using FSShapeStyle, FSCurve and FSLine objects.
FSShapeStyle				Selects line and fill styles and perform absolute moves.
FSCurve				Defines a quadratic Bezier curve.
FSLine				Defines a line segment.
Line and Fill Styles
FSLineStyle				Abstract root class for line styles.
FSSolidLine				Defines the colour and thickness of lines.
FSFillStyle				Abstract root class for fill styles.
FSSolidFill				Defines the colour used to fill shapes.
FSBitmapFill				Used to display images and tile images across a shape.
FSGradientFill				Defines a colour gradients used to fill shapes.
FSGradient				Defines a transition in a colour gradient.
FSDefineShape				Defines how a shape is drawn and filled.
FSDefineShape2				Defines how a shape is drawn and filled, with more than 256 line and fill styles.
FSDefineShape3				Defines a transparent shape.
FSMorphSolidLine				Defines the colour and thickness of lines used to draw a morphing shape.
FSMorphSolidFill				Defines the colour used to fill a morphing shape.
FSMorphBitmapFill				Used to display images and tile images across a morphing shape.
FSMorphGradientFill				Defines a colour gradients used to fill a morphing shape.
FSMorphGradient				Defines a transition in a colour gradient in a morphing.
FSDefineMorphShape				Defines a morphing shape.
Displaying Images
FSJPEGEncodingTable				Defines the encoding table for JPEG images.
FSDefineJPEGImage				Defines a JPEG encoded image.
FSDefineJPEGImage2				Defines a JPEG encoded image with its own encoding table.
FSDefineJPEGImage3				Defines a transparent JPEG encoded image.
FSDefineImage				Defines a bit-mapped image.
FSDefineImage2				Defines a transparent bitmapped image.
Display List
FSPlaceObject				Adds a shape or button to the display list.
FSPlaceObject2				Adds a shape, button, morphing shape or movie clip to the display list.
FSRemoveObject				Removes an object from the display list.
FSRemoveObject2				Simplifies how an object is removed from the display list.
FSShowFrame				Displays all the objects currently in the display list.
Movie Control
FSSetBackgroundColor				Sets the background colour for a movie.
FSProtect				Indicates a movie is only readable by the Flash Player.
FSFrameLabel				Assigns a label to a frame in the movie.
FSFree				Deletes an object from a movie.
FSDefineMovieClip				Defines a movie clip or sprite.
FSQuicktimeMovie				Loads a Quicktime movie.
FSSerialNumber				Defines an arbitrary serial number of a movie.
FSPathsArePostscript				The definitions for the glyphs in a font were derived from a PostScript font file - rarely used, if ever.
FSPointer				Define a pointer - rarely used, if ever.
FSClipEvent				Define the events a movie clip responds to.
FSEnableDebugger				Enable a movie to be debugged.
FSExport				Export objects from a movie.
FSImport				Import objects into a movie.
FSEnableDebugger2				Enable a movie to be debugged - the internal format changed in Flash 6.
FSInitialize				Initialize a movie clip before it is displayed for the first time.
FSTabOrder				Assigns a tab-order for objects that accept user-input.
FSLimitScript				Limits the system resources available to actions - improves reliability and performance.
Buttons
FSDefineButton				Defines a button that executes a set of actions when clicked.
FSButton				Identifies the shape drawn for a given button state.
FSButtonColorTransform				Define a colour transform to change the colour of a button.
FSButtonSound				Identify an event sound to be played when a button is clicked.
FSDefineButton2				Extends a button definition to execute actions in response to different events.
FSButtonEvent				Defines an event a button responds to.
Fonts
FSDefineFont				Defines the glyphs for each character in a font.
FSFontInfo				Defines font information and maps character codes to glyphs.
FSFontInfo2				Extends FSFontInfo to add support for small fonts and language dependent line breaks.
FSDefineFont2				Combines FSDefineFont and FSFontInfo into a single class.
FSKerning				Defines the kerning information for a pair of glyphs.
Text
FSCharacter				Selects the glyph displayed for a character.
FSText				Displays lines of characters along with style information.
FSDefineText				Defines a block of text.
FSDefineText2				Defines a block of transparent text.
FSDefineTextField				Define an editable text field.
Sounds
FSDefineSound				Defines the sound played when an event occurs.
FSEnvelope				Define the sound level for a point in a sound envelope.
FSSound				Controls how a sound is played.
FSStartSound				Starts and stops an event sound.
FSSoundStreamHead				Defines the transmission and playback information for a streaming sound.
FSSoundStreamHead2				Extends a streaming sound to support MP3 encoded sounds.
FSSoundStreamBlock				Contains the streaming sound played in each frame.

Actions

Flash supports are rich programming model with a comprehensive set of actions which can be used to control how a movie or movie clip is played. A comprehensive set of operators are also available to perform a wide variety of operations and general programming within the environment of the Flash Player.

Class	SWF5	SWF6	SWF7	Description
FSAction				Class used to represent byte-code actions in Transform.
FSDoAction				Defines a set of actions executed when the display list is updated.
FSGetUrl				Load a Flash file or web page.
FSGetUrl2				Load a Flash file, web page or data or submit a form.
FSGotoFrame				Goto a specified frame in the movie timeline.
FSGotoLabel				Goto the frame in the movie timeline with the specified label.
FSGotoFrame2				Combines FSGotoFrame and FSGotoLabel in a single class.
FSSetTarget				Execute actions for a movie clip.
FSWaitForFrame				Execute actions when a specified frame has been loaded.
FSWaitForFrame2				Simplified version of FSWaitForFrame.
FSCall				Execute the actions associated with a given frame.
FSIf				Conditional Branch.
FSJump				Unconditional Branch.
FSPush				Push a value onto the Stack.
FSRegisterCopy				Copy a value from the Stack to an internal register.
FSRegisterIndex				Copy a value from an internal register to the Stack.
FSTable				Define a table for string literals.
FSTableIndex				Place a string from the table of literals on the Stack.
FSNewFunction				Define a function.
FSWith				Execute actions for a movie clip - replaces FSSetTarget.
FSNewFunction2				Define a function - optimized for speed of execution.
FSExceptionHandler				Defines a try/catch block for handling exceptions.

Byte-Code Actions

Flash 1 (supported in the Evaluation Edition) initially supported only a few byte-code actions. The addition of a Stack-based programming model for the Flash Player in Flash 4 allowed the actions supported to be greatly expanded with a minimum of complexity. Flash 5 saw the expansion of Macromedia's ActionScript language to support a wide range of operations. The language was modelled on JavaScript and a wide range of data types and operators were added to support the new functionality.

Flash 6 added only a few actions - tidying up some loose ends. A greater than operator was finally added for numbers and strings - previously the operations had to be synthesised using the Less and StringLess byte-codes.

Flash 7 introduced ActionScript 2.0 which greatly increased the level of support for objects. The language is now closer to Java in its syntax and programming model. Several byte-codes were added to support new keywords added to the ActionScript language.

Class	SWF5	SWF6	SWF7	Description
NextFrame				Go to the next frame in the movie.
Play				Start playing the movie at the current frame.
PrevFrame				Go to the previous frame in the movie.
Stop				Stop playing the movie.
StopSounds				Stop playing all sounds.
ToggleQuality				Toggle the quality of the movie - lower quality improves performance.
And				Logical AND two values from the Stack.
AsciiToChar				Convert the ASCII code on the Stack to a single character string.
CharToAscii				Convert the first character of the string on the Stack to its ASCII code.
CloneSprite				Duplicate a movie clip.
Divide				Integer division.
EndDrag				Stop dragging a movie clip.
GetProperty				Push the value of the specified property onto the Stack.
GetTime				Push the number of milliseconds that have elapsed since the movie started onto the Stack.
GetVariable				Push the value of a variable onto the Stack.
IntegerAdd				Add two integer values from the Stack.
IntegerEquals				Are the two integer values on the Stack equal.
IntegerLess				Compare two integer values on the Stack.
MBAsciiToChar				Convert a Unicode value to the a single character string.
MBCharToAscii				Convert the first character of string to its Unicode value.
MBStringExtract				Unicode substring.
MBStringLength				Unicode string length.
Multiply				Multiply two values on the Stack.
Not				Logical NOT of the value on the Stack.
Or				Logical OR two values from the Stack.
Pop				Pop a value from the Stack.
RandomNumber				Push a random number onto the Stack.
RemoveSprite				Delete the specified movie clip.
SetProperty				Set the specified property.
SetTarget2				Execute the following actions using the specified movie clip.
SetVariable				Set the value of a variable.
StartDrag				Start dragging the specified movie clip.
StringAdd				Concatenate two strings on the Stack.
StringEquals				Compare two strings on the Stack to see if they are equal.
StringExtract				Substring.
StringLength				String length.
StringLess				Compare two Strings on the Stack.
Subtract				Subtract two integers on the Stack.
ToInteger				Convert the string on the Stack to its integer representation.
Trace				Print value in the Flash console.
Add				Add two values on the Stack.
ArithmeticShiftRight				Perform an arithmetic shift right.
BitwiseAnd				Perform a bitwise-AND on two values on the Stack.
BitwiseOr				Perform a bitwise-OR on two values on the Stack.
BitwiseXOr				Perform a bitwise-Exclusive-OR on two values on the Stack.
Decrement				Decrease the value on the Stack by one.
Delete				Delete the object referenced on the Stack.
DeleteVariable				Delete the variable referenced on the Stack.
Duplicate				Duplicate the value on the Stack.
Enumerate				Enumerate through the attributes of the object on the Stack.
Equals				Are the values on the Stack equal.
ExecuteFunction				Execute a function.
ExecuteMethod				Execute a method.
GetAttribute				Push the attribute of an object on the Stack.
GetTarget				Returns a string representing the path to the specified movie clip.
GetType				Returns the type of the object on the Stack.
Increment				Increment the value on the Stack by one.
InitVariable				Initialize a variable.
Less				Compare the two values on the Stack.
LogicalShiftLeft				Perform an logical shift left.
LogicalShiftRight				Perform an logical shift right.
Modulo				Push the modulus of two values onto the Stack.
NamedObject				Push one of Flash's built-in objects onto the Stack.
NewArray				Define an array.
NewMethod				Define a method for an object.
NewObject				Define an object.
NewVariable				Define a variable.
Return				Return from a function or method.
SetAttribute				Set the attribute of an object.
Swap				Swap the two values on the Stack.
ToNumber				Convert the string on the Stack to its numerical equivalent.
ToString				Convert a number on the Stack to its string representation.
EnumerateObject				Enumerate through an objects attributes.
Greater				Compare two values on the Stack.
InstanceOf				Check the type of an object.
StrictEquals				Compare two values on the Stack to see if they are the same type and equal.
StringGreater				Compare two strings on the Stack.
Cast				Casts the type of an object in ActionScript 2.0.
Extends				Executes the 'extends' keyword for ActionScript 2.0.
Implements				Executes the 'implements' keyword for ActionScript 2.0.
Throw				Throw an exception using the object on the Stack.