MathFocusListener (J/Link 5.3 API Documentation)

java.lang.Object
- com.wolfram.jlink.MathListener
- - com.wolfram.jlink.MathFocusListener

All Implemented Interfaces:

java.awt.event.FocusListener, java.util.EventListener
```
public class MathFocusListener
extends MathListener
implements java.awt.event.FocusListener
```
This class lets you trigger a call into Mathematica on the occurrence of a particular event. Like all the MathXXXListener classes, it is intended to be used primarily from Mathematica, although it can be used from Java code as well.
In response to a FocusEvent, objects of this class send to Mathematica:
```
     userCode[theFocusEvent]
```
userFunc is specified as a string, either a function name or an expression (like a pure function "foo[#]&"), via the setHandler() method.

Constructor Summary

Constructors
Constructor	Description
`MathFocusListener()`	The constructor that is called from Mathematica.
`MathFocusListener(KernelLink ml)`	You must use this constructor when using this class in a Java program, because you need to specify the KernelLink that will be used.
`MathFocusListener(java.lang.String[][] handlers)`	This form of the constructor lets you skip having to make a series of setHandler() calls.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

void focusGained(java.awt.event.FocusEvent e)

void focusLost(java.awt.event.FocusEvent e)
- Methods inherited from class com.wolfram.jlink.MathListener
  callMathHandler, callVoidMathHandler, getHandler, getLink, setHandler
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MathFocusListener
```
public MathFocusListener()
```
    The constructor that is called from Mathematica.
  - MathFocusListener
```
public MathFocusListener(KernelLink ml)
```
    You must use this constructor when using this class in a Java program, because you need to specify the KernelLink that will be used.
    
    Parameters:
    
    ml - The link to which computations will be sent when FocusEvents arrive.
  - MathFocusListener
```
public MathFocusListener(java.lang.String[][] handlers)
```
    This form of the constructor lets you skip having to make a series of setHandler() calls. Use this constructor from Mathematica code only.
    
    Parameters:
    
    handlers - An array of {meth, func} pairs associating methods in the FocusListener interface with Mathematica functions.
- Method Detail
  - focusGained
```
public void focusGained(java.awt.event.FocusEvent e)
```
    Specified by:
    
    focusGained in interface java.awt.event.FocusListener
  - focusLost
```
public void focusLost(java.awt.event.FocusEvent e)
```
    Specified by:
    
    focusLost in interface java.awt.event.FocusListener