Hi, I'm pretty new to Processing and so far I quite like it, at the moment I'm working on a project and my goal is to parse a text file, for each parsed line I'm drawing a square on the canvas, at a later time I'm supposed to modify these squares. The parsing works fine and also the drawing is ok.
I was looking for a way to generate the square as an object,  in order to store them somehow and modify them later on, up to now I simply use the rect(x,y, width, height). Anyone has a suggestion?  Thanks

Yes. Something like:

class Square
{
 float x, y, w, h; // x,y location, w,h size.
 Square() { x = y = width = height = 0.0f; } // default constructor.
 Square(float X, float Y, float W, float H)
 {
   x = X;
   y = Y;
   w= W;
   h = H;
 }
 drawMe() // default drawing code.
 {
   rect(x,y,width,height);
 }
 drawMe(PGraphics g)
 {
   g.rect(x,y,width,height);
 }
}

Construct one such object for each line you parse out of the file, and store them in an ArrayList.  When you need to, modify each one's x,y,w,h values.  Your draw() routine then gets pretty simple:

void draw()
{
 background(0); // or whatever.
 for(int i = 0; i < ListOfSquare.size(); i++)
   (Square)(ListOfSquares.get(i)).drawMe();
}