Keypress question

Question

Hi
I am completly new to action scriping and have tried
diligently to find the answer in the forums but most of it such a
foreign language to me, so I am hoping someone can help me out with
a straight answer and the exact bit of code I need.
What I need flash to do:
when i press the key "J" it jumps to frame 56 and plays a
movie clip named "j2".
when I let go, the flash file continues where it left off.
I am using Flash 8
Thanks very much
Bill

Answer 1

Bill,
>> when i press the key "J" [should] jump to frame 56
and play a
>> movie clip named "j2".
>> when I let go, the flash file continues where it
left off.
> I am using Flash 8
Okay, the basic "template" for responding to key strokes in
ActionScript
2.0 is this:
var listener:Object = new Object();
listener.onKeyUp = function():Void {
trace("A key has been pressed");
Key.addListener(listener);
In line 1, an arbitrarily named variable, listener, is
declared and set
to an instance of the Object class. This gives you a generic
object that
you can use for just about everything. (Ultimately,
everything in
ActionScript *is* an object -- and each type of Object is
defined by its
class entry in the ActionScript 2.0 Language Reference. Look
up "MovieClip
class" to see what features are available to movie clips;
look up "TextField
class" to see what features are available to dynamic and
input text fields,
and so on.)
In lines 2 - 4, an onKeyUp property is created for the
listener object.
Why onKeyUp? That's an event of the Key class, which handles
keyboard-related phenomena. In this case, you're building an
"event
listener," and the listener object acts as a liaison for the
events of the
Key class. An anonymous function literal is assigned to this
onKeyUp event,
and the function simply traces a message to the Output panel.
In line 5, the Key class is associated with the listener
object, which
wires everything up.
In your original post, you spoke of sending the playhead
somewhere when
a key is pressed, rather than released. That's fine ...
consult the "Key
class" entry in the documentation and you'll find that an
onKeyDown event
also exists. No only that, but a number of properties,
methods, and events.
To do something when only the "J" key is pressed, you could
use an if()
statement ...
var listener:Object = new Object();
listener.onKeyDown = function():Void {
if (Key.isDown(74)) {
// do something
Key.addListener(listener);
What on earth is Key.isDown()? That's a method of the Key
class.
What's 74? That's the key code for the letter "J" (upper- or
lowercase).
How did I know that? I searched "Keyboard Keys and Key Code
Values" in the
Help docs.
In place of "// do something," you would, of course, program
what you
actually want to occur. Based on your original post, that
would be
something like ...
var listener:Object = new Object();
listener.onKeyDown = function():Void {
if (Key.isDown(74)) {
gotoAndStop(56);
Key.addListener(listener);
... that's a start, at least. If you also want a movie clip
on that frame
to play, you'll have to reference that movie clip by its
instance name and
invoke the MovieClip.play() method ...
var listener:Object = new Object();
listener.onKeyDown = function():Void {
if (Key.isDown(74)) {
gotoAndStop(56);
j2.play();
Key.addListener(listener);
IMPORTANT: If the j2 MovieClip instance doesn't already
appear in
whatever frame carries this code, you won't be able to
reference j2 --
because "it doesn't exist" on that frame. You'll have to
either stretch out
that movie clip in the timeline so that it does, and maybe
set its
visibility to 0, then do something like this:
j2._visible = false;
var listener:Object = new Object();
listener.onKeyDown = function():Void {
if (Key.isDown(74)) {
gotoAndStop(56);
j2._visible = true;
j2.play();
Key.addListener(listener);
At any rate, I hope that gives you a good start.
David Stiller
Adobe Community Expert
Dev blog,
http://www.quip.net/blog/
"Luck is the residue of good design."