Creating a Button Class from MC

Question

I have a few simple questions for those who know about
classes. I have been reading the tutorials on creating classes and
specifically extending the MC class. I am pretty sure that an
extended MC_Class might help me get what I need from my project.
I essentially have a bunch of buttons, hundreds to be exact -
and the exact number needs to be dynamic. Each one is currently a
static MC with a bunch of variables assigned to each one via global
variables. Its iis pulling in data taht assign the button values
from XML files and - these XML files may change.
Q1. If I extend the MC class so I can add attributes to MC's
instance (Avoiding global variables) - will it mess with the rest
of the movie clips in my scene? I mean if all I want to do is ad a
a few dynamic string variables - it really shouldnt effect any of
the other clips would it? MC.JumpURL = "newurl.com", MC.Thumnail
="/here/image.jpg" (This would help alot)
Q2. What if I wanted to define actions of the new MC in the
class? If the MC is an extension of the MC class. Would all of my
MC's automatically take on the actions of the custom MC Class? For
instance - I want the movieclip to animate onscreen and have
rollover effects. I could do this easy if it were static - but I
need this to become dynamic. Also - there are now unknown
quantities to deal with
Q3. How exactly would I call and assign the MC its atributes
at the same time? And how do I specify this MC to use the functions
defined in the class and not the other MC's I created elsewhere in
the File.
Example. Currently I have a grid of MCs' created when the
User clicks a menu item (Another type of MC).
Each new MC animates onstage - it calls a
loadMovie(_root.thumb[0], this.Flipper) to assign and embedded MC
an image defined in the XML that was loaded and assigned because I
placed the instance on stage and wrote a MC script on each MC.
Confused - check out what I am creating at
www.vincesidwell.com/Fischer
Click Fabrication or TurboSystems menus. Both menues will
load a new set of Thumbnails at the bottom. They are loaded via an
XML loaded by the menu and a function assigns the jpgs for the main
gallery, Rollover image, and eventually a URL for a downloadable
High Res Image.
The client recently added more than 9 images per menu item. I
will need to create a scrollable thumbnail gallery with dynamic
quantities
I can manually create the MC Scroller item for static number
of buttons. But scripting an unknown for each ones links and images
is insane. So I am looking at Classes. Assign a custom class for
the flipping buttons and I should be able to assign tthem as the
XML loads, and have it automatic. (pray please please please)
Anyhelp?
Thanks
Vince Sidwell

Answer 1

Hi there!
I'll try and give some answers to your questions below...
"vin-E" <[email protected]> wrote in message
news:[email protected]...
>I have a few simple questions for those who know about
classes. I have
>been
> reading the tutorials on creating classes and
specifically extending the
> MC
> class. I am pretty sure that an extended MC_Class might
help me get what
> I
> need from my project.
>
> I essentially have a bunch of buttons, hundreds to be
exact - and the
> exact
> number needs to be dynamic. Each one is currently a
static MC with a
> bunch of
> variables assigned to each one via global variables. Its
iis pulling
> in
> data taht assign the button values from XML files and -
these XML files
> may
> change.
>
> Q1. If I extend the MC class so I can add attributes to
MC's instance
> (Avoiding global variables) - will it mess with the rest
of the movie
> clips in
> my scene? I mean if all I want to do is ad a a few
dynamic string
> variables -
> it really shouldnt effect any of the other clips would
it? MC.JumpURL =
> "newurl.com", MC.Thumnail ="/here/image.jpg" (This would
help alot)
You do not have to create a new MC class to assign local
values or functions
to it. A pseudo code example:
Loop through total buttons you want to make (which can be
number of entries
in an XML file)
Create a new movieclip and load the button graphic into
this, give it a
name like
MyButtonX, where X is an increasing number based on which
button this
is. (Instead of creating
and empty movielcip, you could also attach a movie (or
button) from
library.
Assign the values and create the functions for this button
that you
would like (probably based
on information in the XML file):
MyButtonX.someVariable = node.attribues.someData;
createOnRelease(MyButtonX, someOtherParamters)
(where you have defined the function createOnRelease to do
something
like
function createOnRelease(MC, someOtherParameteres) {
MC.onRelease = function() {
do what you want to do based on someOtherParameteres
Position and resize MyButtonX
In your example you have a 3x3 grid, which might extend to
3xTOTAL,
so you'd have to use some
mathematical formula based on the value X, something like
MyButtonX._x =
(((X-1)%3)*(buttonWidths+hSpaceBetweenButtons)
MyButtonY._y = Math.floor((X-1)/3)*(buttonHeights
+vSpaceBetweenButtons
end of loop.
>
> Q2. What if I wanted to define actions of the new MC in
the class? If
> the MC
> is an extension of the MC class. Would all of my MC's
automatically take
> on
> the actions of the custom MC Class? For instance - I
want the movieclip
> to
> animate onscreen and have rollover effects. I could do
this easy if it
> were
> static - but I need this to become dynamic. Also - there
are now unknown
> quantities to deal with
If you actually create a new class, than all instances of
that class will
have the methods you define for it (just like all instances
of a movieclip
has those methods. At least, have them available. That
doesn't mean they are
always in use ... like for example the onRollOver. But again,
you don't need
to create a class to give all your dynamically created
buttons a rollover
effect. (Check code above).
> Q3. How exactly would I call and assign the MC its
atributes at the same
> time? And how do I specify this MC to use the functions
defined in the
> class
> and not the other MC's I created elsewhere in the File.
You use the instance name of the MC to access that MC and its
attributes/methods. For example button number 10 might look
like this:
trace(MyButton10._x);
trace(MyButton10.someVariableYouHaveDefined);
MyButton10.callSomeFunctionYouHaveDefined();
For a movieclip to access a variable that has been defined
for that instance
of the movieclip, use "this" to point to that particular
instance. So if we
defined the function "callSomeFunctionYouHaveDefined" for
button number 10
and want to access "someVariableYouHaveDefined" for this
particular
instance, then
MyButton10.callSomeFunctionYouHaveDefined = function() {
trace(this.someVariableYouHaveDefined);
> Example. Currently I have a grid of MCs' created when
the User clicks a
> menu
> item (Another type of MC).
> Each new MC animates onstage - it calls a
loadMovie(_root.thumb[0],
> this.Flipper) to assign and embedded MC an image defined
in the XML that
> was
> loaded and assigned because I placed the instance on
stage and wrote a MC
> script on each MC.
>
> Confused - check out what I am creating at
www.vincesidwell.com/Fischer
>
> Click Fabrication or TurboSystems menus. Both menues
will load a new set
> of
> Thumbnails at the bottom. They are loaded via an XML
loaded by the menu
> and a
> function assigns the jpgs for the main gallery, Rollover
image, and
> eventually
> a URL for a downloadable High Res Image.
>
> The client recently added more than 9 images per menu
item. I will need
> to
> create a scrollable thumbnail gallery with dynamic
quantities
>
> I can manually create the MC Scroller item for static
number of buttons.
> But
> scripting an unknown for each ones links and images is
insane. So I am
> looking
> at Classes. Assign a custom class for the flipping
buttons and I should
> be
> able to assign tthem as the XML loads, and have it
automatic. (pray please
> please please)
Again, no need for a class for this. If you load the buttons
into seperate
MCs, and make sure to have all these MCs created inside a
common parent MC
for these buttons (which then _only_ contains these buttons).
You can move
this parent MC up and down on the stage based on the
scrollbar. And you can
read height off this MC to create your scrollbar.
You might want to check out the following tutorials at
http://www.gotoandlearn.com/:
XML Video Playlist
Creating Animated Buttons
Introduction to OOP
Now, I've said many times you don't need to make your own
class to do what
you want. That does not mean you can't make your own class. I
just think
that the main problem you are facing is the dynamic part,
which you will be
facing if you make your own class or not.
/Jensen/
>
> Anyhelp?
>
> Thanks
> Vince Sidwell
>
>
>