private, public and protected

Stanlepunk

Hello all, I don't understand how work private in Processing. I thought when something is private you cannot modify directly, but in the example it's not necessary to use an accesser to change the value. It's weird or normal ?

Test t = new Test() ;
void draw() {
  println(t.a++) ;

}

private class Test {
  private int a = 1 ;
  Test() {}
}

colouredmirrorball

It's normal because of a subtlety. When you make a class in Processing, it is actually an inner class of your sketch' main class. The preprocessor turns your entire sketch into a Java class and all classes then become inner/nested. It's a class encapsulated in another class. Note that this is a different thing than inheritance. The private keyword does not prevent the main sketch class to alter a variable of an inner class, since technically they belong to the same class.

If you put the code for the Test class in a separate file called Test.java, it would make Test a proper class on its own and you would not be able to edit its variables.

Stanlepunk

Thanks a lot for this information ! Damned it, it's sure now for the future I finish to Open Ecclipse to continue to code deep with Processing !

Stanlepunk

Is it possible to access to a file.java from Processing ?

Processing file.pde

Test t = new Test() ;
void setup() {
    size(200,200);
}
void draw() {
  println(t.get()) ;
}

java file.java

class Test {
  private int a = 1 ;
  Test() {}

  int get() {
    return a;
  }
}

kfrajer

Make sure the name of your second file is Test.java

Kf

quark

To create a top-level class in Java create a new tab with the extension.java

For example a Processing tab called Foo.java would hold the source code for the Foo class.

Stanlepunk

Oups sorry, my mistake the pde file and java file have a same name !