Use processing math functions in a processing library

Alex_Pr

Can't we use processing math functions when creating a library in java for processing? I added the core.jar but get multiple errors when I use functions like cos() or int().

Also, the HelloLibrary.java file created has a package template.library; package name. Do we rename it entirely or just the "template" part?

i.e. package testLibrary; or package testLibrary.library;

Thanks in advance, Alex

GoToLoop

Either use import static processing.core.PApplet.*;: cos(radians(90));

Or w/ import processing.core.PApplet;, prefix them w/ PApplet: PApplet.cos(PApplet.radians(90)));

Keep in mind we can directly access members from Java's class Math as well: Math.cos(Math.PI);
http://docs.Oracle.com/javase/8/docs/api/java/lang/Math.html

GoToLoop

Just choose a lowercase name for package:
package org.alex_pr.name_of_my_library; or something like this. ~:>

Alex_Pr

That works nicely! Thanks a lot!

I also want to use the methods in processing without prefixing the class. Is there any way to do that? I tried import static myLibrary but this displays an error "only a type can be imported, library resolves to a package."

GoToLoop

import static works only for the static members of a class or interface.
And we can't use it if it name-conflicts w/ something else in our code.

Alex_Pr

So do I have to prefix the methods in processing? It would be really useful to simple type the method name (like we do for processing functions line(), translate() etc.)

GoToLoop

A sketch program (.pde) is a subclass of PApplet.
That's why we don't need to prefix its members w/ this. if we don't want to.

kfrajer

You can explore this link: http://www.lagers.org.uk/qscript/index.html although I believe the PApplet offers you what you need. A quote from the website above:

QScript is entirely written in Java and has no external dependancies.

Although the library is packaged as a Processing library the actual library jar does not require Processing for its functions. The examples that come with this package use the G4P and Graphica libraries and include a QScript IDE. For non-Processing users the library jar also inclues a QScript IDE using Java Swing controls.

Kf

Alex_Pr

This is a bit off topic but is it possible to create a public variable inside a class and link it with a method (of the same class and the same type as the variable) so that each time that variable is used, it gets its value from the linked function?

GoToLoop

In JS it is, but not in Java. ~O)

jeremydouglass

That is also possible in Python. But the Java way is to write getters and setters for almost everything -- that way if you ever decide to mediate variable access with a function as you describe your access method doesn't change, because every variable is already mediated by a .get() type of function.