public class EditBus
extends java.lang.Object
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 subscribe 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.
EBComponent
,
EBMessage
Modifier and Type | Class and Description |
---|---|
static interface |
EditBus.EBHandler
This annotation should be used in methods that are to be
considered "edit bus message handlers".
|
Modifier and Type | Method and Description |
---|---|
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 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.
|
static void |
sendAsync(EBMessage message)
Schedules a message to be sent on the edit bus as soon as
the AWT thread is done processing current events.
|
public static void addToBus(EBComponent comp)
comp
- The component to addpublic static void addToBus(java.lang.Object comp)
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.
comp
- The component to addpublic static void removeFromBus(EBComponent comp)
comp
- The component to removepublic static void removeFromBus(java.lang.Object comp)
comp
- The component to removepublic static void send(EBMessage message)
This method uses ThreadUtilities.runInDispatchThreadNow(java.lang.Runnable)
,
read the notes there for possible deadlocks.
NOTE:
If the calling thread is not the AWT thread and the
thread is interrupted before or while the call of this
method, this method can return before completion of handlers.
However, the interruption state is set in this case, so the
caller can detect the interruption after the call. If you
really need the completion of handlers, you should make sure
the call is in the AWT thread or the calling thread is never
interrupted. If you don't care about the completion of
handlers, it is recommended to use
sendAsync(EBMessage)
instead.
message
- The messagepublic static void sendAsync(EBMessage message)
message
- The message