EventDispatcher (Codename One API)

java.lang.Object
- com.codename1.ui.util.EventDispatcher

```
public class EventDispatcher
extends Object
```
Handles event dispatching while guaranteeing that all events would be fired properly on the EDT regardless of their source. This class handles listener registration/removal in a safe and uniform way.

To integrate this into your code you can use something like:

Constructor Summary

Constructors
Constructor and Description

EventDispatcher()

Constructors
Constructor and Description
`EventDispatcher()`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`addListener(Object listener)` Add a listener to the dispatcher that would receive the events when they occurs
`void`	`fireActionEvent(ActionEvent ev)` Fires the event safely on the EDT without risk of concurrency errors
`void`	`fireBindTargetChange(Component source, String propertyName, Object oldValue, Object newValue)` Fired when a property of the component changes to a new value
`void`	`fireDataChangeEvent(int index, int type)` Fires the event safely on the EDT without risk of concurrency errors
`void`	`fireFocus(Component c)` Fires the event safely on the EDT without risk of concurrency errors
`void`	`fireScrollEvent(int scrollX, int scrollY, int oldscrollX, int oldscrollY)` Fires the event safely on the EDT without risk of concurrency errors
`void`	`fireSelectionEvent(int oldSelection, int newSelection)` Fires the event safely on the EDT without risk of concurrency errors
`void`	`fireStyleChangeEvent(String property, Style source)` Fires the style change even to the listeners
`Collection`	`getListenerCollection()` Returns the collection of the listeners
`Vector`	`getListenerVector()` Deprecated. use getListenerCollection instead, this method will now be VERY SLOW
`boolean`	`hasListeners()` Returns true if the event dispatcher has registered listeners
`boolean`	`isBlocking()` Indicates whether this dispatcher blocks when firing events or not, normally a dispatcher uses callSeriallyAndWait() to be 100% synchronous with event delivery however this method is very slow.
`void`	`removeListener(Object listener)` Remove the listener from the dispatcher
`void`	`setBlocking(boolean blocking)` Indicates whether this dispatcher blocks when firing events or not, normally a dispatcher uses callSeriallyAndWait() to be 100% synchronous with event delivery however this method is very slow.
`static void`	`setFireStyleEventsOnNonEDT(boolean fire)` When set to true, style events will be dispatched even from non-EDT threads.

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

- Constructor Detail
  - EventDispatcher
```
public EventDispatcher()
```
- Method Detail
  - setFireStyleEventsOnNonEDT
```
public static void setFireStyleEventsOnNonEDT(boolean fire)
```
    When set to true, style events will be dispatched even from non-EDT threads. When set to false, when in non-EDT threads, style events will not be dispatched at all (And developer has to make sure changes will be reflected by calling revalidate after all the changes) Default is false. Setting this to true results in a performance penalty, and it is better instead to simply aggregate events performed on non-EDT threads and when all are over - call revalidate on the relevant container.
    
    Parameters:
    
    fire - true to fire on non-EDT, false otherwise
  - addListener
```
public void addListener(Object listener)
```
    Add a listener to the dispatcher that would receive the events when they occurs
    
    Parameters:
    
    listener - a dispatcher listener to add
  - getListenerVector
```
public Vector getListenerVector()
```
    Deprecated. use getListenerCollection instead, this method will now be VERY SLOW
    
    Returns the vector of the listeners
    
    Returns:
    
    the vector of listeners attached to the event dispatcher
  - getListenerCollection
```
public Collection getListenerCollection()
```
    Returns the collection of the listeners
    
    Returns:
    
    the collection of listeners attached to the event dispatcher
  - removeListener
```
public void removeListener(Object listener)
```
    Remove the listener from the dispatcher
    
    Parameters:
    
    listener - a dispatcher listener to remove
  - fireDataChangeEvent
```
public void fireDataChangeEvent(int index,
                                int type)
```
    Fires the event safely on the EDT without risk of concurrency errors
    
    Parameters:
    
    index - the index of the event
    
    type - the type of the event
  - fireBindTargetChange
```
public void fireBindTargetChange(Component source,
                                 String propertyName,
                                 Object oldValue,
                                 Object newValue)
```
    Fired when a property of the component changes to a new value
    
    Parameters:
    
    source - the source component
    
    propertyName - the name of the property
    
    oldValue - the old value of the property
    
    newValue - the new value for the property
  - fireStyleChangeEvent
```
public void fireStyleChangeEvent(String property,
                                 Style source)
```
    Fires the style change even to the listeners
    
    Parameters:
    
    property - the property name for the event
    
    source - the style firing the event
  - fireActionEvent
```
public void fireActionEvent(ActionEvent ev)
```
    Fires the event safely on the EDT without risk of concurrency errors
    
    Parameters:
    
    ev - the ActionEvent to fire to the listeners
  - fireSelectionEvent
```
public void fireSelectionEvent(int oldSelection,
                               int newSelection)
```
    Fires the event safely on the EDT without risk of concurrency errors
    
    Parameters:
    
    oldSelection - old selection
    
    newSelection - new selection
  - fireScrollEvent
```
public void fireScrollEvent(int scrollX,
                            int scrollY,
                            int oldscrollX,
                            int oldscrollY)
```
    Fires the event safely on the EDT without risk of concurrency errors
  - fireFocus
```
public void fireFocus(Component c)
```
    Fires the event safely on the EDT without risk of concurrency errors
    
    Parameters:
    
    c - the Component that gets the focus event
  - hasListeners
```
public boolean hasListeners()
```
    Returns true if the event dispatcher has registered listeners
    
    Returns:
    
    true if the event dispatcher has registered listeners
  - isBlocking
```
public boolean isBlocking()
```
    Indicates whether this dispatcher blocks when firing events or not, normally a dispatcher uses callSeriallyAndWait() to be 100% synchronous with event delivery however this method is very slow. By setting blocking to false the callSerially method is used which allows much faster execution for IO heavy operations.
    
    Returns:
    
    the blocking state
  - setBlocking
```
public void setBlocking(boolean blocking)
```
    Indicates whether this dispatcher blocks when firing events or not, normally a dispatcher uses callSeriallyAndWait() to be 100% synchronous with event delivery however this method is very slow. By setting blocking to false the callSerially method is used which allows much faster execution for IO heavy operations.
    
    Parameters:
    
    blocking - the blocking value

Class EventDispatcher

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

EventDispatcher

Method Detail

setFireStyleEventsOnNonEDT

addListener

getListenerVector

getListenerCollection

removeListener

fireDataChangeEvent

fireBindTargetChange

fireStyleChangeEvent

fireActionEvent

fireSelectionEvent

fireScrollEvent

fireFocus

hasListeners

isBlocking

setBlocking