MACROMEDIA FLASH 8-USING FLASH Use Manual page 38

About parent and child movie clips
When you place a movie clip instance on another movie clip's Timeline, the placed movie clip
is the child and the other movie clip is the parent. The parent instance contains the child
instance. The root Timeline for each level is the parent of all the movie clips on its level, and
because it is the topmost Timeline, it has no parent.
A child Timeline nested inside another Timeline is affected by changes made to the parent
Timeline. For example, if
property of , then the scale of
oregon
Timelines can send messages to each other with ActionScript. For example, an action on the
last frame of one movie clip can tell another movie clip to play. To use ActionScript to control
a Timeline, you must use a target path to specify the location of the Timeline. For more
information, see "Writing target paths" on page
About movie clip hierarchy
The parent-child relationships of movie clips are hierarchical. To understand this hierarchy,
consider the hierarchy on a computer: the hard disk has a root directory (or folder) and
subdirectories. The root directory is analogous to the main Timeline of a Flash document: it is
the parent of everything else. The subdirectories are analogous to movie clips.
You can use the movie clip hierarchy in Flash to organize related objects. Any change you
make to a parent movie clip also affects its children.
For example, you could create a Flash document containing a car that moves across the Stage.
You can use a movie clip symbol to represent the car and set up a motion tween to move it
across the Stage.
To add wheels that rotate, you can create a movie clip for a car wheel, and create two instances
of this movie clip, named
car movie clip's Timeline—not on the main Timeline. As children of
are affected by any changes made to
backWheel
across the Stage.
To make both wheel instances spin, you can set up a motion tween that rotates the wheel
symbol. Even after you change
the tween on their parent movie clip,
movie clip across the Stage.
car
38 Working with Flash Documents
is a child of
portland
portland
and
frontWheel backWheel
and
frontWheel
; the wheels spin, but they also move with the parent
car
and you change the
oregon
also changes.
41.
. Then you can place the wheels on the
; they move with the car as it tweens
car
, they continue to be affected by
backWheel
_xscale
, and
car frontWheel