You should try Edit > Auto Format (or Ctrl+T) in the PDE, it would make the code easier to read...
You might be interested by articles in the Technical FAQ.
Particularly the I display images in sequence but I see only the last one. Why? one...

The equivalent to Sleep() is delay() in Processing, but its usage is so discouraged that it almost disappeared in v.2.0!
Using millis() is a preferred way. Avoid doing empty while loops, they are great to eat CPU cycles, but that's all... Use draw() as a natural infinite loop.

Thanks for the advise and for the faqs but i think this isn't my case, in the example there isn't user interaction while in my exercise the user press a button for start the sequence, if i use the draw function to make the sequence the user have to press the start button for every change of lights.

I can make a switch in the draw to make the sequence and a boolean variable for manage the button, but i don't like this solution.

I can make a switch in the draw to make the sequence and a boolean variable for manage the button, but i don't like this solution.

I think this is actually the good way

you can even say something

1. final int trafficNotStarted= -1; // minus one
   
2. final int trafficRed=0;
3. final int trafficYellowAfterRed=1;
4. final int trafficGreen=2;
5. final int trafficYellowAfterGreen=3;
6. 
   
7. int stateOfTrafficLight = trafficNotStarted;

when the user clicks you say

1. stateOfTrafficLight = trafficRed;

and then you have a switch in draw()

1. switch (stateOfTrafficLight ) {
2. case trafficNotStarted:
3. // do nothing;
4. break;
5. case trafficRed:
6. showRed();
   
7. // wait long with millis then go trafficYellowAfterRed
8. break;
9. case trafficYellowAfterRed:
10. showYellow();
    
11. // wait with millis then go green
12. break;
13. //
    
14. //.... etc. etc.
    
15. } // switch
    

Greetings, Chrisir  

I didn't say something cause i was coding!!

I maded the program but i used an if else structure in place of the switch, here the code:

1. int startime;
   boolean press=false;
   int stoptime=2000;
   void setup() {
     size(640, 480);
     smooth();
     fill(#CCCECC);
     rect(210, 240, 220, 40);
     fill(#090A09);
     rect(295, 3, 50, 155);
     textSize(20);
     text("Start", 295, 250, 220, 40);
   }
   void draw() {
   
   
     if (press==false)
     {
       if (mousePressed)
       {
         if (mouseButton == LEFT)
         {
           if ((mouseX > 210) && (mouseX < 430) &&
             (mouseY > 240) && (mouseY < 280))
           {
             startime=millis();
             press=true;
             fill(#1AF507);
             ellipse(320, 135, 40, 40);
           }
         }
       }
     }
     else
       if (millis()-startime>=stoptime+4000)
     {
       press=false;
       fill(#090A09);
       rect(295, 3, 50, 155);
     }
     else
       if (millis()-startime>=stoptime+2000)
       {
         fill(#090A09);
         rect(295, 3, 50, 155);
         fill(#F50707);
         ellipse(320, 25, 40, 40);
       }
       else
         if (millis()-startime>=stoptime)
         {
           fill(#F5DA07);
           ellipse(320, 80, 40, 40);
         }
   }
   

I made some improvements....

mousePressed()  is an inbuild function (like draw()) you can use, it is called whenever mouse is pressed

// comments make your code better understandable

1. int startime;
2. boolean press = false;
3. int stoptime  = 2000;
4. //
5. void setup() {
6.   size(640, 480);
7.   smooth();
8.   fill(#CCCECC); // gray
9.   rect(210, 240, 220, 40);
10.   fill(#090A09); // black
11.   rect(295, 3, 50, 155);   // button start
    
12.   textSize(20);
13.   text("Start", 295, 250, 220, 40);
14. }
15. //
16. void draw() {
17.   if (press) {
18.     // the phases as they appear, but backwards
    
19.     if (millis()-startime>=stoptime+4000) {
20.       press=false; // start all over again
21.       // all black
22.       fill(#090A09);
23.       rect(295, 3, 50, 155);
24.     }
25.     else if (millis()-startime>=stoptime+2000) {
26.       fill(#090A09); // black
27.       rect(295, 3, 50, 155);
28.       fill(#F50707);
29.       ellipse(320, 25, 40, 40);//red
30.     }
31.     else if (millis()-startime>=stoptime) {
32.       fill(#F5DA07);
33.       ellipse(320, 80, 40, 40); // yellow
34.     }
35.     else {
36.       fill(#1AF507);
37.       ellipse(320, 135, 40, 40); // green
38.     }
39.   } // if (press)
40. } // func
41. //
42. void mousePressed() {
43.   if (mouseButton == LEFT)
44.   {
45.     if ((mouseX > 210) && (mouseX < 430) &&
46.       (mouseY > 240) && (mouseY < 280))
47.     {
48.       startime=millis(); // init timer
    
49.       press=true;
50.     } // if
51.   } // if
52. } // func
53. //

I didn't use comments and functions cause i understimate the problem, initially i thinked that i can make this program with few lines with the Sleep function.

Anyway thank's for the advise and the improvements!!

There is a joke, what is the indian word for bad hunter?





Vegetarian.

At least i can always buy some meat!