Callback

java.lang.Object
- com.openinventor.inventor.misc.Callback

All Implemented Interfaces:

CB

Direct Known Subclasses:

NCallback
```
public class Callback
extends java.lang.Object
implements CB
```
This class is intended to be subclassed in order to invoke a particular method for a given object. The method invoke is used by callback lists to invoke all callbacks in their lists or by native callbacks to bind java and native callbacks.

When a callback is registered, it is paired with a user data object which can be used when the callback is called. This object is stored in the userData field. The documentation does not mention the userData field since it is a protected field.But all classes subclassing Callback have access to this field. Its definition is : protected Object userData. Note that the content of userData is not the object passed as a parameter to any invoke method.
For instance:
```
    [...]
    callbacks.addCallback(new MyCallback(), myObject) ;
    [...]
    callbacks.invokeCallbacks(anObject) ;

  class MyCallback extends Callback {
    public void invoke(Object data) {
      MyClass myObject = (myClass) userData ;
      AClass anObject = (AClass) data ;
      [...]
    }
  }
 
```

Constructor Summary

Constructors
Constructor Description

Callback()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`invoke(java.lang.Object data)`	When subclassing Callback, fill the body of this method which will be called when the callback will be needed.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Callback
```
public Callback()
```
- Method Detail
  - invoke
```
public void invoke(java.lang.Object data)
```
    When subclassing Callback, fill the body of this method which will be called when the callback will be needed.
    
    Specified by:
    
    invoke in interface CB