org.gjt.sp.jedit
Class EditBus

java.lang.Object
  extended by org.gjt.sp.jedit.EditBus

public class EditBus
extends java.lang.Object

jEdit's global event notification mechanism.

Plugins register with the EditBus to receive messages reflecting changes in the application's state, including changes in buffers, views and edit panes, changes in the set of properties maintained by the application, and the closing of the application.

The EditBus maintains a list of objects that have requested to receive messages. When a message is sent using this class, all registered components receive it in turn. Classes for objects that sourceibe to the EditBus must implement the EBComponent interface, which defines the single method EBComponent.handleMessage(EBMessage).

Alternatively, since jEdit4.3pre19, EditBus components can be any object. Handlers for EditBus messages are created by annotating methods with the EditBus.EBHandler annotation. Such methods should expect a single parameter - an edit bus message of any desired type. If a message matching the type (or any of its super-types, unless the annotation requests exact type matching) is being sent, the annotated method will be called instead of the default EBComponent.handleMessage(EBMessage). If a handler exists for a specific message type, the default handler will not be called.

A plugin core class that extends the EBPlugin abstract class (and whose name ends with Plugin for identification purposes) will automatically be added to the EditBus during jEdit's startup routine. Any other class - for example, a dockable window that needs to receive notification of buffer changes - must perform its own registration by calling addToBus(Object) during its initialization. A convenient place to register in a class derived from JComponent would be in an implementation of the JComponent method addNotify().

Message types sent by jEdit can be found in the org.gjt.sp.jedit.msg package.

Plugins can also send their own messages - any object can send a message to the EditBus by calling the static method send(EBMessage). Most plugins, however, only concern themselves with receiving, not sending, messages.

Since:
jEdit 2.2pre6
See Also:
EBComponent, EBMessage

Nested Class Summary
static interface EditBus.EBHandler
          This annotation should be used in methods that are to be considered "edit bus message handlers".
 
Method Summary
static void addToBus(EBComponent comp)
          Adds a component to the bus.
static void addToBus(java.lang.Object comp)
          Adds a component to the bus.
static EBComponent[] getComponents()
          Deprecated. Don't use this method. It now returns an empty array.
static void removeFromBus(EBComponent comp)
          Removes a component from the bus.
static void removeFromBus(java.lang.Object comp)
          Removes a component from the bus.
static void send(EBMessage message)
          Sends a message to all components on the bus in turn.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Method Detail

addToBus

public static void addToBus(EBComponent comp)
Adds a component to the bus. It will receive all messages sent on the bus.

Parameters:
comp - The component to add

addToBus

public static void addToBus(java.lang.Object comp)
Adds a component to the bus. Methods annotated with the EditBus.EBHandler annotation found in the component will be used as EditBus message handlers if a message of a matching type is sent on the bus.

If the component implements EBComponent, then the EBComponent.handleMessage(EBMessage) method will be called for every message sent on the bus.

Parameters:
comp - The component to add
Since:
jEdit 4.3pre19

removeFromBus

public static void removeFromBus(EBComponent comp)
Removes a component from the bus.

Parameters:
comp - The component to remove

removeFromBus

public static void removeFromBus(java.lang.Object comp)
Removes a component from the bus.

Parameters:
comp - The component to remove
Since:
4.3pre19

getComponents

@Deprecated
public static EBComponent[] getComponents()
Deprecated. Don't use this method. It now returns an empty array.

Returns an array of all components connected to the bus.


send

public static void send(EBMessage message)
Sends a message to all components on the bus in turn.

Parameters:
message - The message