net.rim.device.api.command
Class CommandHandler

java.lang.Object
  net.rim.device.api.command.CommandHandler

Direct Known Subclasses:

AlwaysExecutableCommand, NullCommandHandler

public abstract class CommandHandler
extends Object

Defines the work that a command performs.

For more information about using this class, see the package overview.

Since:

BlackBerry API 6.0.0

Constructor Summary

CommandHandler()
Create a CommandHandler instance.

Method Summary
boolean	canExecute(ReadOnlyCommandMetadata metadata, Object context) Determines whether a call to execute() is valid using the passed-in context object.
abstract void	execute(ReadOnlyCommandMetadata metadata, Object context) Implementations of this method can ignore the passed-in context object.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CommandHandler

public CommandHandler()

Create a CommandHandler instance.

Since:

BlackBerry API 6.0.0

Method Detail

execute

public abstract void execute(ReadOnlyCommandMetadata metadata,
                             Object context)

Implementations of this method can ignore the passed-in context object.

Parameters:

metadata - Metadata that the CommandHandler was registered with. Cannot be modified.

context - External state information.

Since:

BlackBerry API 6.0.0

canExecute

public boolean canExecute(ReadOnlyCommandMetadata metadata,
                          Object context)

Determines whether a call to execute() is valid using the passed-in context object. Implementations of this method can ignore the passed-in context object.

Note: Calling this method for CommandHandler instances retrieved from RemoteCommandRegistrarConnection always returns true. This is because of performance concerns when looping over a list of command handlers and potentially calling this method in different processes.

Parameters:

metadata - Metadata that the CommandHandler was registered with. Cannot be modified.

context - External state information.

Returns:

true if the execute() method can be called, false otherwise.

Since:

BlackBerry API 6.0.0