I guess you have to describe a bit better what you are trying to do.
This might be the reason why nobody answered yet.

i dont understand it either.

Basically I want to declare variables before the sketch is loaded that are set based on an external source.

e.g.

1. public int retval = <  parameter  >;
2. public String strval = <parameter >;
   
3. void setup(){
4. size(retval,retval,strval);
5. }
6. void draw(){
7. println(strval);
8. }

< parameter > passed in from a Windows-based event, (webcam, sound, video, vibration)

why before it is loaded, isnt this what setup() is actually for ?

i think what he wants is a way to start a processing sketch with a command line like "mySketch.pde -argument1 argument2" like you can do with normal java files where you can pass arguments when starting the file, or am i misunderstanding you ?

edit: after re-reading my post i think it sound pretty fuzzy but what i'm talking about (and i think is what owaunadrew is talking about as well) is basically like in a normal java file you have

class MyClass{
      public static void main(String[] args){
            //and here you have access to all arguments that were passing along in the command line when starting the file
            //by doing args[0] or args[1] etc.
      }
}

I believe what bjordal is mentioning with the string arguments falls in line with what I would like to achieve.

With a string, sound or even video.

The problem is that you mix up things.
You have start up parameters, from the command line. They might not be obvious to pass.
Then, you have events like sound or video, which can be captured during runtime, so I don't see how they fit in your question.
You can read the clipboard, I am sure you can find examples in the old forum.
You can read a text file, that's probably the easiest way to parametrize a sketch.
And so on.

There is also a way to use the drag and drop functionality to add files, that could be sounds or video or whatever to you running sketch : http://www.sojamo.de/libraries/drop/index.html
it couldnt be used with the executable  but with the already running sketch though.

I have the same question and I feel it has not been answered yet.
I'd like to start a sketch with certain parameters. For example: I made a simple sketch to move the cursor around. I dont't want to make a different app for each mouse location so I'd like to start my sketch from the terminal and provide a x and y location, like so:

1. mouseMover -640 -480

It is possible to catch these parameters in a sketch or app made with Processing?

To be clear: the mouse moving thing is an example: this question isn't about an easy way to move the mouse, but about using parameters when opening a sketch.

http://wiki.processing.org/w/Setting_width/height_dynamically (works with both exported applet & app)

I have the same need not whith mouse position but with double click

i found a way to do it here

how to pass parameters in a sketch


maybe it is not a clean way but it works !