The most common approach is as follows:

• Create a boolean variable that stores whether the color is red or blue (one is true, the other is false)
• Check this boolean when determining the fill color
• When you want to change the color, assign the boolean to be its opposite like so:

1. theBoolean = !theBoolean;
   

Hi,

Thanks to you both for your help. I'll play with the boolean solution today.

monkstone I'll try incorporate switch into my code too. Thanks for typing it out though.

And no it's not homework.

Thanks,

Shane

I am actually working with 'Processing A programming handbook for Visual Designers and Artists' - Casey Reas and Ben Fry, which I'm finding really good. Interestingly there is no mention of switch. But I've used it before ages ago in C++. I also of course use the Processing site reference section. But I never would have taught of using the mouse buttons as cases for switch.

I do understand you're code (I think!) but why does is not allow the RIGHT and LEFT buttons do their job. I wonder could I just use 'switch' for the CENTRE button with 'count' to get to the different states. I only need two actually, 'blue' as default and 'red' if clicked. This would mean using 'switch' inside of 'else'. Is that allowed?

The problem seems to be (in my own code) for the CENTRE button if I hold it down it keeps changing rapidly. In other words it is repeating the action as it loops through draw(). This is what I want for the RIGHT and LEFT buttons but just to run once for the CENTRE button. Maybe I need something like if(mouseReleased()).

Thanks,

Shane

Actually I have a book by Bruce Eckel - Thinking in C++ vol.1 Must take a look at it and the link you sent. I think it's fair to say he's quite heavy for a beginner.

Thanks

Why can't 'void' as in 'void mousePressed()'   on line 25.   be used inside draw()?

The problem is how to get the code inside

1. else if (mouseButton == CENTER) {
2. ...
3. }
   

to run only once.

1. float x = 300, y = 150, diameter=100;
2. int count = 0;
3. void setup() {
4.   size(600, 300);
5.   stroke(1);
6. }
7. void draw() {
8.   //frameRate(24);
9.   background(#36B5F2);
10.   fill(255);
11.   if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {
12.     if (mouseButton == LEFT) {
13.       x = mouseX;
14.       y = mouseY;
15.     }
16.     else if (mouseButton == RIGHT) {
17.       if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
18.         diameter++;
19.       }
20.       else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
21.         diameter--;
22.       }
23.     }
24.     else if (mouseButton == CENTER) {
25.       void mouseReleased() {
26.         count++;
27.         int num = count%2;
28.           if (num == 1) {
29.             fill(#FF0000);
30.           }
31.           else {
32.             fill(#0000FF);
33.           }
34.       }
35.     }
36.   }
37.   ellipse(x, y, diameter, diameter);
38. }

By the way I think 'count%2' is a pretty smart way of doing it.

Thanks,

Shane

That's not how you're supposed to do it... mouseReleased() must be its own function, outside of draw().
Try something like this (outside of draw()):

1. void mouseReleased() {
2.   if(mouseButton == CENTER) {
3.     //Statements
   
4.   }
   
5. }
   

Hi calsign,

I really appreciate your help on this. Using your suggestion I have finally got it to do what I want.

I thought draw() was like a continuous loop, so I don't understand how it takes account of the CENTRE button bit of the code.

Also I'm not sure if having this outside draw() will work later on for me. I was hoping to get all this code inside draw(), which controls the shape, and make it a method....I suppose I could have two methods, one for the RIGHT and LEFT button and one for the CENTER button.

Here's the code so far.

1. float x = 300, y = 150, diameter=150;
2. int count;
3. float r = 0, g = 0, b = 255;
4. void setup() {
5.   size(600, 300);
6.   stroke(1);
7. }
8. void draw() {
9.   frameRate(24);
10.   background(#36B5F2);
11.   fill(r, g, b);
12.   if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
13.     if (mouseButton == LEFT) {
14.       x = mouseX;
15.       y = mouseY;
16.     }
17.     else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
18.       if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
19.         diameter++;
20.       } //dragging mouse away from center increases size of charge
21.       else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
22.         diameter--;
23.       }
24.     }
25.   }
26.   ellipse(x, y, diameter, diameter);
27. }
28. void mouseReleased() {
29.   if(mouseButton == CENTER) {
30.     count++;
31.     int state = (count%2);
32.     if(state == 1){
33.       r = 255;
34.       b = 0;
35.     }else{
36.       r = 0;
37.       b = 255;
38.     }
39.   }
40. }

I was trying also to use the 'frameCount' and if the button is held for more than say two seconds this changes the state of something, similar to above. But I couldn't get it to work.

Thanks,

Shane

The right I have now allows me to do everything I want to do except get the circle back to blue.

Lines 25 to 36 are what's important here.

1. float x = 300, y = 150, diameter=150;
2. int count;
3. float r = 0, g = 0, b = 255;
4. void setup() {
5.   size(600, 300);
6.   stroke(1);
7. }
8. void draw() {
9.   frameRate(24);
10.   background(#36B5F2);
11.   fill(r, g, b);
12.   if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
13.     if (mouseButton == LEFT) {
14.       x = mouseX;
15.       y = mouseY;
16.     }
17.     else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
18.       if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
19.         diameter++;
20.       } //dragging mouse away from center increases size of charge
21.       else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
22.         diameter--;
23.       }
24.     }
25.     else if (mouseButton == CENTER) {
26.       count++;
27.       if (count == 1) {//sets colour to red once
28.         r = 255;
29.         b = 0;
30.       }
31.       else if (count == (2*frameRate)){//set colour to blue.... not working
    
32.         r = 0;
33.         b = 255;
34.         count = 0;//reset count
35.       }
36.     }
37.   }
38.   ellipse(x, y, diameter, diameter);
39. }
40. /*void mouseReleased() {
41.  if(mouseButton == CENTER) {
42.  count++;
43.  int state = (count%2);
44.  if(state == 1){
45.  r = 255;
46.  b = 0;
47.  }else{
48.  r = 0;
49.  b = 255;
50.  }
51.  }
52.  }*/

Thanks,

Shane

I've rewritten this as an OO programme but I am getting an error

unexpected token: void

There is a problem with the method display() line 55. But I can't see anything wrong.

1. Control mouse; //Declare object
2. void setup() {
3.   size(100, 100);
4.   smooth();
5.   noStroke();
6.   //x, y, r, g, b, count, diameter
7.   mouse = new Control(300, 150, 0, 0, 255, 0, 150); //Construct the object mouse
8. }
9. void draw() {
10.   frameRate(24);
11.   background(#36B5F2);
12.   fill(r, g, b);
13.   mouse.move();
14.   mouse.display();
15. }
16. class Control {
17.   float x, y, r, g, b, diameter;
18.   int count;
19.   //Constructor
20.   Control(float xpos, float ypos, float rpos, float gpos, float bpos, int countpos, float diameterpos) {
21.     x = xpos;
22.     y = ypos;
23.     r = rpos;
24.     g = gpos;
25.     b = bpos;
26.     count = countpos;
27.     diameter = diameterpos;
28.   }
29.   void move() {
30.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
31.       if (mouseButton == LEFT) {
32.         x = mouseX;
33.         y = mouseY;
34.       }
35.       else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
36.         if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
37.           diameter++;
38.         } //dragging mouse away from center increases size of charge
39.         else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
40.           diameter--;
41.         }
42.       }
43.       else if (mouseButton == CENTER) {
44.         count++;
45.         if (count == 1) {//sets colour to red once
46.           r = 255;
47.           b = 0;
48.         }
49.         else if (count == (2*frameRate)) {//set colour back to blue
50.           r = 0;
51.           b = 255;
52.           count = 0;//reset count
53.         }
54.       }
55.     }
56.     void display() {
57.       ellipse(x, y, diameter, diameter);
58.     }
59.   }

Any help would be greatly appreciated.

Thanks,

Shane

This is a fairly messy approach...
The preferred way is to set the fill when you draw the circle, so all you would be doing is incrementing count.
For the sake of getting this to work...

You need to increment count and then apply the remainder operator ( %)... try this:

1. count = (count + 1) % 2;

I didn't see your next reply!
Okay... go to Edit > Auto Format to fix your indentation. The problem is obvious... you are missing a closing brace for move().

Well I'm getting there!

It more or less does what I need, except that whether the state changes or not depends on exactly how long the CENTER button is pressed for.

1. Control mouse; //Declare object
2. int r, g, b;
3. void setup() {
4.   size(600, 300);
5.   smooth();
6.   noStroke();
7.   //x, y, r, g, b, count, diameter
8.   mouse = new Control(300, 150, 0, 0, 255, 0, 150); //Construct the object mouse
9. }
10. void draw() {
11.   frameRate(24);
12.   background(#36B5F2);
13.   mouse.move();
14.   mouse.display();
15. }
16. class Control {
17.   float x, y, r, g, b, diameter;
18.   int count;
19.   //Constructor
20.   Control(float xpos, float ypos, float rpos, float gpos, float bpos, int countpos, float diameterpos) {
21.     x = xpos;
22.     y = ypos;
23.     r = rpos;
24.     g = gpos;
25.     b = bpos;
26.     count = countpos;
27.     diameter = diameterpos;
28.   }
29.   void move() {
30.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
31.       if (mouseButton == LEFT) {
32.         x = mouseX;
33.         y = mouseY;
34.       }
35.       else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
36.         if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
37.           diameter++;
38.         } //dragging mouse away from center increases size of charge
39.         else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
40.           diameter--;
41.         }
42.       }
43.       else if (mouseButton == CENTER) {
44.         count = (count + 1) % 2;
45.         if (count == 1) {//sets colour to red once
46.           r = 255;
47.           b = 0;
48.         }
49.         else if (count == 0) {//set colour back to blue
50.           r = 0;
51.           b = 255;
52.           count = 0;//reset count
53.         }
54.       }
55.     }
56.   }
57.   void display() {
58.     fill(r, g, b);
59.     ellipse(x, y, diameter, diameter);
60.   }
61. }

I wonder could the function

void mouseReleased()

be used as a method?

Thanks,

Shane

It does seem to be possible to use 'void mouseReleased()' as a method, although there is still the small problem of the change of state depending on exactly how long the CENTER button is used for.

1. Control mouse; //Declare object
2. int r, g, b;
3. void setup() {
4.   size(600, 300);
5.   smooth();
6.   noStroke();
7.   //x, y, r, g, b, count, diameter
8.   mouse = new Control(300, 150, 0, 0, 255, 0, 150); //Construct the object mouse
9. }
10. void draw() {
11.   frameRate(24);
12.   background(#36B5F2);
13.   mouse.move();
14.   mouse.mouseReleased();
15.   mouse.display();
16. }
17. class Control {
18.   float x, y, r, g, b, diameter;
19.   int count;
20.   //Constructor
21.   Control(float xpos, float ypos, float rpos, float gpos, float bpos, int countpos, float diameterpos) {
22.     x = xpos;
23.     y = ypos;
24.     r = rpos;
25.     g = gpos;
26.     b = bpos;
27.     count = countpos;
28.     diameter = diameterpos;
29.   }
30.   void move() {
31.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
32.       if (mouseButton == LEFT) {
33.         x = mouseX;
34.         y = mouseY;
35.       }
36.       else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
37.         if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
38.           diameter++;
39.         } //dragging mouse away from center increases size of charge
40.         else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
41.           diameter--;
42.         }
43.       }
44.     }
45.   }
46.   void mouseReleased() {
47.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
48.       if (mouseButton == CENTER) {
49.         count = (count + 1) % 2;
50.         if (count == 1) {//sets colour to red once
51.           r = 255;
52.           b = 0;
53.         }
54.         else if (count == 0) {//set colour back to blue
55.           r = 0;
56.           b = 255;
57.           count = 0;//reset count
58.         }
59.       }
60.     }
61.   }
62.   void display() {
63.     fill(r, g, b);
64.     ellipse(x, y, diameter, diameter);
65.   }
66. }

Thanks,

Shane

You're getting close... you need to create the mouseReleased() function outside of any other function or class; and, from here, call your Control's mouseReleased() function. Just like with threading, and many other aspects of programming, it does no good to call functions from the place that you were trying to avoid in the first place...

I sorry I don't get it!!! You're saying I need to create a function in say draw() which calls the method mouseReleased()? Does this mean it won't be possible to have it as a method?

Thanks,

Shane

No... mouseReleased() is its own function that is declared outside of any other function or class like so:

1. void setup() {
2.   //Statements
   
3. }
4. 
   
5. void draw() {
6.   //Statements
   
7. }
8. 
   
9. //mouseReleased(): called whenever the mouse is released from the down position
   
10. void mouseReleased() {
11.   //Statements
12.  
    
13.   //This is also where you should call Control's mouseReleased() function
    
14. }
15. 
    
16. class myClass {
17.   //Stuff
18. }

Hi calsign,

Thanks for the very clear description. I understand now. I thought draw() was a continuous loop, so once the programme reads draw() it just continuously loops through draw() and ignores everythign else. Clearly that can't be the case

Unfortunately I can't try this now until Monday, so don't think I'm not bothering. I'll certainly be back to it.

Thanks again,

Shane

Hi, I tried this put am confused. Should the new function at line 17 and 49 have a different name to mouseReleased()?

1. Control mouse; //Declare object
2. int r, g, b;
3. void setup() {
4.   size(600, 300);
5.   smooth();
6.   noStroke();
7.   //x, y, r, g, b, count, diameter
8.   mouse = new Control(300, 150, 0, 0, 255, 0, 150); //Construct the object mouse
9. }
10. void draw() {
11.   frameRate(24);
12.   background(#36B5F2);
13.   mouse.move();
14.   mouse.display();
15. }
16. void mouseReleased() {
17.   mouse.mouseReleased();
18.   //println("Centre button has been pressed");
19. }
20. class Control {
21.   float x, y, r, g, b, diameter;
22.   int count;
23.   //Constructor
24.   Control(float xpos, float ypos, float rpos, float gpos, float bpos, int countpos, float diameterpos) {
25.     x = xpos;
26.     y = ypos;
27.     r = rpos;
28.     g = gpos;
29.     b = bpos;
30.     count = countpos;
31.     diameter = diameterpos;
32.   }
33.   void move() {
34.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
35.       if (mouseButton == LEFT) {
36.         x = mouseX;
37.         y = mouseY;
38.       }
39.       else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
40.         if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
41.           diameter++;
42.         } //dragging mouse away from center increases size of charge
43.         else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
44.           diameter--;
45.         }
46.       }
47.     }
48.   }
49.   void mouseReleased() {
50.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
51.       if (mouseButton == CENTER) {
52.         println("Centre button has been pressed");
53.         count = (count + 1) % 2;
54.         if (count == 1) {//sets colour to red once
55.           r = 255;
56.           b = 0;
57.         }
58.         else if (count == 0) {//set colour back to blue
59.           r = 0;
60.           b = 255;
61.           count = 0;//reset count
62.         }
63.       }
64.     }
65.   }
66.   void display() {
67.     fill(r, g, b);
68.     ellipse(x, y, diameter, diameter);
69.   }
70. }

Thanks,

Shane

I don't think there's anything wrong with your mouseReleased()s; the problem probably lies within the logic of your code. I don't have time to figure out what's wrong... try using println() statements and the like to figure out values and whether or not certain pieces of code are being executed.

On second thought... no testing... but on line 61, you reset count. There's a chance that that's the source of the problem... the whole point of using the remainder operator ( %) was so that you didn't have to do that...

Hi,

I commented out line 61 but no change to the results. As you can see on line 52 I have been using println() to test. I'll continue doing that and play around with it and post here when I get it.

Thanks for your help,

Shane

Hi,

I got it! The problem was on line 57 where part of the if condition was

&&(mousePressed == true)

This effectively meant the code below that could only run if the mouse was released and pressed, obviously a condition that could never happen.Thanks,

1. Control mouse; //Declare the object called mouse
2. int r, g, b;
3. void setup() {
4.   size(600, 300);
5.   smooth();
6.   noStroke();
7.   //x, y, r, g, b, count, diameter... the fields
8.   mouse = new Control(300, 150, 0, 0, 255, 1, 150); //Construct the object mouse
9. }
10. void draw() {
11.   frameRate(24);
12.   background(#36B5F2);
13.   mouse.move();
14.   mouse.display();
15. }
16. void mouseReleased() {
17.   if (mouseButton == CENTER) {
18.     mouse.released();
19.   }
20. }
21. class Control {
22.   float x, y, r, g, b, diameter;
23.   int count;
24.   //Constructor
25.   Control(float xpos, float ypos, float rpos, float gpos, float bpos, int countpos, float diameterpos) {
26.     x = xpos;
27.     y = ypos;
28.     r = rpos;
29.     g = gpos;
30.     b = bpos;
31.     count = countpos;
32.     diameter = diameterpos;
33.   }
34.   void move() {
35.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))&&(mousePressed == true)) {//tests to see if mouse is on charge
36.       if (mouseButton == LEFT) {
37.         x = mouseX;
38.         y = mouseY;
39.       }
40.       else if (mouseButton == RIGHT) {//dragging mouse toward centre decreases size of charge
41.         if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))>(0)) {
42.           diameter = diameter + 5; //increases size of diameter
43.         } //dragging mouse away from center increases size of charge
44.         else if (((dist(mouseX, mouseY, x, y))-(dist(pmouseX, pmouseY, x, y)))<(0)) {
45.           if (diameter > 20) {//prevents diameter getting too small and circle disappearing
46.             diameter = diameter - 5; // decreases size of diameter
47.           }
48.         }
49.       }
50.     }
51.   }
52.   void display() {
53.     fill(r, g, b);//fills the circle with colours red, green, blue
54.     ellipse(x, y, diameter, diameter);
55.   }
56.   void released() {
57.     if (((dist(mouseX, mouseY, x, y))<(diameter/2))) {//tests to see if mouse is on charge
58.       count = (count + 1) % 2;
59.       if (count == 1) {//sets colour to blue once
60.         r = 0;
61.         b = 255;
62.       }
63.       else if (count == 0) {//set colour red to blue
64.         r = 255;
65.         b = 0;
66.       }
67.     }
68.   }
69. }

Shane