what is the correct way to call a contributed library or class inside a subclass?

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davos111

what is the correct way to call a contributed library or class inside a subclass?

in Programming Questions • 1 year ago

Hi,

This is a question for someone that knows processing:

What is the correct way to call any class inside a class?

Because the programs (contributed library and examples start to fail when are called from a seconday level.

saying that something is not constructed in the contributed library,etc.

I have tried with this, and new the class(this) , but it also fails when it is called in a sub/sub level. ( 'this' works for the first level, but not for the sub levels')

Maybe is something related with PApplet but I tried extending PAppet and didn't work. and I don't find and example that works in a third sub level or higher...

The point: to have a menu, that calls different submenus(sketches) and those have submenus that do something .

how to call correctly a class in a sub/sub/sub level?

example of the problem:

void draw{ //first level

menu();

}

public class menu extends guicomponents { //second level

menu{}

void setup()

{ graphics(); //or any other one

}

public class graphics extends guicomponents { //third level , tried also with PApplet,etc :(

void setup();

call_any_contributed_library() <---- here calling the contributed libraries causes errors,

call_any_contributed_library(this) <---- also tried with this,

At this level the libraries chage their behavior, like ControlP5,guicomponents,

unfolding,etc. The libraries start to say that component is undefined, or crashing,

or hanging., and the examples from processing and open processing fails when code is called at this level or in a deeper level.

}

How to call the libraries correctly from a class inside a class?

thank you

Replies(7)

quarks

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

From the menu in Processing select Sketch | Import library and choose the library you want to use.

If you choose guicomponents then it adds that statement
import guicomponents.*;

if you choose ControlP5 it adds the statement
import controlP5.*;

you have to do this if you want to use anything from the library anywhere in your sketch.

NOTE: these statements are added to the top of your sketch code and should NOT be inside any method such as setup or draw.

If you select File | Examples from Processing's menu it will open a second window listing all the contributed libraries you have installed and allow you to run the example sketchs that come with the library. These will help you understand how to use the library

PhiLho

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

I wrote a FAQ article on this very topic: Why I can't create a class of a library from my own classes?

davos111

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

thank you,

Quarks, yes, I am using it the import in the main part, and the programs work when called in top levels, and fail when are called from a class called by another classes.

Yes, Philo, thank you a lot.

your link can help to solve partially the problem, with libraries that I created. using the papplet pa.. public SomeClass(PApplet papp, int otherParam)

  {
    pa = papp;

but for other libraries (contributed ones like ControlP5, guicomponents, etc)... that I have not created...

how to pass the correct parameter whe call the library being inside from a class of a class? and pass to that library the correct name of the Papplet?

thank you for your help

PhiLho

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

Have you read till the end? The last part was supposed to address your question, but perhaps it wasn't clear enough. Tell me, so that I can improve this text.

davos111

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

Yes PhiLo,

The problem is how to access a library like unfolding, guicomponents, controlp5,etc when one calls them inside a sub/sub/sub class.

As you wrote in the address is that this refers to that current class. maybe what I am asking it the next part of your article...

If I try using 'this' it fails in the sub/sub/clases

  Stuff stuff = new Stuff(this, "smile.png")

For example :

PopupWindow altwin = new PopupWindow(this, new Korea()) //where Korea is a class

code like this fails when is executed in class of classes of classes, and works correctly in the top class level.

So, how to call correctly those contributed libraries (controlp5,unfolding, guicomponents,etc) to work in the sub/sub/sub class levels for example?

should I change the parameter "this" for another one?

thank you a lot

PhiLho

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

Mmm, I am not too sure how to formulate it. Basically, you can use this (if it is a PApplet) only outside any class, in the Processing methods like setup(), draw(), etc.
In your classes, and sub-classes, and so on, you have to pass along the PApplet parameter, like a token / relay baton. Whenever you need a PApplet this, you use the pa field / parameter that have been transmitted via the constructor. The described process applies to each class needing such parameter.

davos111

Re: what is the correct way to call a contributed library or class inside a subclass?

1 year ago

thank you

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