Chapter 16. ActionScript Authoring Environment
This chapter
examines the practical details of
authoring ActionScript code. We'll cover the following topics:
Using the Actions panel to place code on buttons, movie clips, and
frames Loading code from an external file Packaging code as a reusable authoring component with Smart Clips
16.1. The Actions Panel
The Actions panel is
Flash's ActionScript-editing environment. Every script in a
movie is created in the Actions panel, which is accessed via Window
 Actions.
The Actions panel is divided into two sections: the
Toolbox pane (on the left) and the
Script pane (on the
right), as shown in Figure 16-1.
Figure 16-1. The Actions panel
The Script pane houses code attached to the currently selected frame,
button, or movie clip. The Toolbox acts both as a quick reference
guide and as a means of adding code to the Script pane.
Double-clicking any item in the Toolbox adds that item to the Script
pane. Items may also be dragged from the Toolbox into the Script
pane.
The Actions panel's title indicates whether our current code
lives on a frame ( Frame Actions) or on a
button or movie clip (Object Actions). When we select a frame, the
Actions panel's title changes automatically to Frame Actions;
when we select either a movie clip or a button, the Actions
panel's title changes to Object Actions.
The organization of the items in the Toolbox differs somewhat from
the categories used to describe the features of ActionScript in this
book. Most notably, in the Toolbox, statements
are not separated into their own folder, and classes and objects are
grouped together under the Objects folder. In
this book we distinguish between statements, classes, and objects in
keeping with more formal programming terminology.
16.1.1. Editing Modes
The Actions panel has two different modes of
operation, Normal Mode and Expert Mode, which govern how we add code
to the Script pane.
16.1.1.1. Normal Mode
In Normal Mode, the Toolbox is used to build
new statements, and the
Script pane is used as a viewer for those
statements. To add a new statement to the Script pane in Normal Mode,
we double-click the desired Action or drag an Action from the Toolbox
to the Script pane. To add a statement of arbitrary code, we select
the evaluate Action and enter the statement into
the Expression field of the
Parameters pane (not shown in the figure)
at the bottom of the Actions panel.
After adding a statement to the Script pane, we may customize it via
the Parameters pane at the bottom of the Actions panel. The layout
and contents of the Parameters pane changes to suit the statement
selected in the Script pane. Notice that when the Actions panel is
operating in Normal Mode, code may not be typed
into the Script pane. In Normal Mode, the Script pane is not a
text-editing environment, but rather a read-only list of statements;
alterations to statements in the Script pane are performed through
the Parameters pane.
Although Flash 5's
Normal Mode may look similar to the
Actions panel in Flash 4, it should not be misconstrued as a
backward-compatibility mode. To the contrary, it is quite possible to
create code in either editing mode that wouldn't be Flash 4
compatible (see Appendix C, "Backward Compatibility"). Normal Mode is
comforting for new programmers but constricting for most nontrivial
programming projects. In this book, therefore, we use only the Expert
Mode to author code. However, with the exception of multiline
comments (which may be used only in Expert Mode), any code produced
in one mode may also be produced in the other.
16.1.1.2. Expert Mode
In Expert Mode the Script pane functions as
a traditional text-editing window. When authoring or changing code in
Expert Mode, we type directly into the Script pane. We may, however,
still double-click items in the Toolbox to add them to the Script
pane. The Parameters pane is not used in Expert Mode; instead,
parameters are typed directly into the Script pane.
16.1.1.3. Setting the editing mode
The editing mode
of the Actions panel is set on a per-frame and per-object basis. That
is, Flash remembers the Actions panel editing mode chosen for every
object and frame in a movie. If we select Normal Mode for frame 2 and
Expert Mode for frame 3, the Actions panel will automatically switch
to Normal Mode when we edit the code on frame 2 and Expert Mode when
we edit the code on frame 3.
To select the mode for an individual frame or an object, we choose
Expert Mode or Normal Mode from the arrow button in the top-right
corner of the Actions panel (see Figure 16-1). To
select the default mode for all frames and
objects of a movie, we choose Expert Mode or Normal Mode under Edit
Preferences General Actions Panel Mode.
Note that the default mode setting affects only those frames and
objects for which an editing mode has not already been set.
Therefore, the default mode should be set at the beginning of movie
production. There is no way to globally override the individual mode
previously set explicitly for existing frames and objects.
WARNING
Switching from Expert Mode to Normal Mode
destroys all source-code formatting. The code is reformatted
according to Flash's standard formatting rules -- extra
whitespace is lost, comments are placed on their own line, and
statement block indentation is adjusted to match the style shown
throughout this book.
 |  |  | | II. Applied ActionScript |  | 16.2. Adding Scripts to Frames |
Copyright © 2002 O'Reilly & Associates. All rights reserved.
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