wyvern.lib.commands
Class OpenCommand

java.lang.Object
  wyvern.lib.commands.OpenCommand

All Implemented Interfaces:

BuiltInCommand, Command

public class OpenCommand

extends java.lang.Object

implements BuiltInCommand

Handles open, close, lock and unlock.

Version:

1.0, Apr 29, 1998

Author:

Steve Yegge

Nested Class Summary

class

OpenCommand.KeyPredicate A predicate to look for a key that will open the specified lock.

Method Summary

void	addCommands(java.util.Map map, CommandList list) Add known commands.
CommandEvent	createEvent(CommandEvent initial) Implements Command.createEvent()
GameObject	determineTarget(java.lang.String arg, TargetedEvent event) Parses the args and gets the appropriate object to operate on.
GameObject	ensureKey(Openable target, Commandable agent) Makes sure user can lock or unlock the door.
boolean	execute(CommandEvent e) Implements Command.execute()
Openable	getDirectionalTarget(int dir, TargetedEvent event) Looks in specified direction for an openable target.
static OpenCommand	getImpl()
GameObject	getNoArgTarget(TargetedEvent event) If they just typed "open", "close" or whatever, look for a nearby door to do it to.
boolean	knowsCommand(java.lang.String command) We don't have any way of determining that we don't know how to handle the command based just on its arguments.
boolean	performClose(Openable target, TargetedEvent event) Attempts to close the target.
boolean	performLock(Openable target, TargetedEvent event) Attempts to lock the target.
boolean	performOpen(Openable obj, TargetedEvent event) Attempts to open the target.
boolean	performUnlock(Openable target, TargetedEvent event) Attempts to unlock the target.

Methods inherited from class java.lang.Object

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

Method Detail

getImpl

public static OpenCommand getImpl()

addCommands

public void addCommands(java.util.Map map,
                        CommandList list)

Add known commands.

Specified by:

addCommands in interface BuiltInCommand

Parameters:

map - the map to add the commands to

list - the CommandList the Command is being added to.

knowsCommand

public boolean knowsCommand(java.lang.String command)

We don't have any way of determining that we don't know how to handle the command based just on its arguments.

Specified by:

knowsCommand in interface Command

Parameters:

command - the command verb to verify

Returns:

true if we want to handle the command

createEvent

public CommandEvent createEvent(CommandEvent initial)

Implements Command.createEvent()

Specified by:

createEvent in interface Command

Parameters:

initial - a "blank" CommandEvent containing only the command text and the agent who's performing the command. This initial event is created by the originator of the event (e.g. the AI or player's command preprocessor).

Returns:

a CommandEvent subclass encapsulating this command's execution parameters and state. It should copy in the fields from the passed-in event.

See Also:

Command.createEvent(wyvern.lib.CommandEvent)

getNoArgTarget

public GameObject getNoArgTarget(TargetedEvent event)

If they just typed "open", "close" or whatever, look for a nearby door to do it to.

Parameters:

event - the event

Returns:

a suitable target object, or null if none found. Sets the target object in the event as well. If a suitable target can't be found, vetoes the event and sets the failure message to something appropriate.

determineTarget

public GameObject determineTarget(java.lang.String arg,
                                  TargetedEvent event)

Parses the args and gets the appropriate object to operate on.

Parameters:

arg - the argument string

event - the TargetedEvent or TargetedEvent

Returns:

the target object, or null if none found

getDirectionalTarget

public Openable getDirectionalTarget(int dir,
                                     TargetedEvent event)

Looks in specified direction for an openable target.

Parameters:

dir - a valid Direction constant

event - the event for this command

Returns:

an Openable object in that direction, or null if not found. Doesn't veto the event or set any messages.

execute

public boolean execute(CommandEvent e)

Implements Command.execute()

Specified by:

execute in interface Command

Parameters:

e - the CommandEvent to execute

Returns:

true if the event completed successfully, else false.

See Also:

Command.execute(wyvern.lib.CommandEvent)

performOpen

public boolean performOpen(Openable obj,
                           TargetedEvent event)

Attempts to open the target.

Parameters:

obj - the object to open

event - the TargetedEvent

Returns:

true if we opened it successfully

performClose

public boolean performClose(Openable target,
                            TargetedEvent event)

Attempts to close the target.

Parameters:

target - the object to close

event - the TargetedEvent

Returns:

true if we closed it successfully

performLock

public boolean performLock(Openable target,
                           TargetedEvent event)

Attempts to lock the target.

Parameters:

target - the object to lock

event - the TargetedEvent

Returns:

true if we locked it successfully

performUnlock

public boolean performUnlock(Openable target,
                             TargetedEvent event)

Attempts to unlock the target.

Parameters:

target - the object to unlock

event - the TargetedEvent

Returns:

true if we unlocked it successfully

ensureKey

public GameObject ensureKey(Openable target,
                            Commandable agent)

Makes sure user can lock or unlock the door.