What I want to know is how I make it that the program only shows one handle, instead of thirteen. It would also help me understand the program better in general.

Hope someone can help...

Handle[] handles;
int num;

void setup()
{
 size(200, 200);
 num = height/15;
 handles = new Handle[num];
 int hsize = 10;
 for(int i=0; i<num; i++) {
   handles[i] = new Handle(width/2, 10+i*15, 50-hsize/2, 10, handles);
 }
}

void draw()
{
 background(153);
 
 for(int i=0; i<num; i++) {
   handles[i].update();
   handles[i].display();
 }
 
 fill(0);
 rect(0, 0, width/2, height);
}

void mouseReleased()
{
 for(int i=0; i<num; i++) {
   handles[i].release();
 }
}

class Handle
{
 int x, y;
 int boxx, boxy;
 int length;
 int size;
 boolean over;
 boolean press;
 boolean locked = false;
 boolean otherslocked = false;
 Handle[] others;
 
 Handle(int ix, int iy, int il, int is, Handle[] o)
 {
   x = ix;
   y = iy;
   length = il;
   size = is;
   boxx = x+length - size/2;
   boxy = y - size/2;
   others = o;
 }
 
 void update()
 {
   boxx = x+length;
   boxy = y - size/2;
   
   for(int i=0; i<others.length; i++) {
     if(others[i].locked == true) {
       otherslocked = true;
       break;
     } else {
       otherslocked = false;
     }  
   }
   
   if(otherslocked == false) {
     over();
     press();
   }
   
   if(press) {
     length = lock(mouseX-width/2-size/2, 0, width/2-size-1);
   }
 }
 
 void over()
 {
   if(overRect(boxx, boxy, size, size)) {
     over = true;
   } else {
     over = false;
   }
 }
 
 void press()
 {
   if(over && mousePressed || locked) {
     press = true;
     locked = true;
   } else {
     press = false;
   }
 }
 
 void release()
 {
   locked = false;
 }
 
 void display()
 {
   line(x, y, x+length, y);
   fill(255);
   stroke(0);
   rect(boxx, boxy, size, size);
   if(over || press) {
     line(boxx, boxy, boxx+size, boxy+size);
     line(boxx, boxy+size, boxx+size, boxy);
   }

 }
}

boolean overRect(int x, int y, int width, int height)
{
 if (mouseX >= x && mouseX <= x+width &&
     mouseY >= y && mouseY <= y+height) {
   return true;
 } else {
   return false;
 }
}

int lock(int val, int minv, int maxv)
{
 return  min(max(val, minv), maxv);
}

Thanks!

Would it be also possible to make it that if the handle were moved in a certain direction, that it would then perform a certain function. ie: control motor speed or direction