wyvern.lib.commands
Class CastCommand

java.lang.Object
  wyvern.lib.commands.CastCommand

All Implemented Interfaces:

BuiltInCommand, Command

public class CastCommand

extends java.lang.Object

implements BuiltInCommand

Handles casting spells.

Version:

1.0, Nov 04, 1999

Author:

Steve Yegge

Method Summary

void	addCommands(java.util.Map commands, CommandList list) Tells the Command to add the commands that it wants to implement into the passed data structure.
boolean	adjustCasterMana(CastEvent event) Deducts the appropriate amount of mana.
CommandEvent	createEvent(CommandEvent initial) Creates the command event for the "cast" command.
boolean	dispel(CastEvent event) Dispels a spell you've cast.
boolean	execute(CommandEvent ev) Implements Command.execute()
static CastCommand	getImpl()
boolean	isNoSpellsArea(CastEvent event) Checks whether it's OK to cast the spell in this location.
boolean	knowsCommand(java.lang.String command) Returns true if this Command wants to handle the command.
boolean	knowsSpell(Commandable agent, java.lang.String spell)
boolean	reagents(CastEvent event) Lists the reagents for a particular spell.
boolean	showActiveSpells(CommandEvent event) Displays to the user a list of the spells they have active.

Methods inherited from class java.lang.Object

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

Method Detail

getImpl

public static CastCommand getImpl()

addCommands

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

Description copied from interface: BuiltInCommand

Tells the Command to add the commands that it wants to implement into the passed data structure.

Specified by:

addCommands in interface BuiltInCommand

Parameters:

commands - a Map whose keys are commands, and whose values are Commands that handle those commands.

list - the CommandList the Command is being added to.

knowsCommand

public boolean knowsCommand(java.lang.String command)

Description copied from interface: Command

Returns true if this Command wants to handle the command. The Command can examine the arguments and determine that it doesn't actually understand the command, in which case it should return false.

This method exists to allow more than one game object to implement the same command verb, but with different expected arguments.

If two objects register for the same command and the same arguments, the object that was registered most recently gets to handle at the command.

Specified by:

knowsCommand in interface Command

Parameters:

command - the entire command string, including arguments

Returns:

true if we want to handle the command

createEvent

public CommandEvent createEvent(CommandEvent initial)

Creates the command event for the "cast" command.

The command supports the following syntax:

  cast  [dir | x y | [on|at ] | [with-args ]]
 

You can specify a direction to cast it, a specific map position to cast it on/at (e. 10 -8), or "on/at" at target. "on" and "at" are currently synonymous.

If you specify "with-args", the remainder of the argument string is passed to the spell using setSpellArgs(). Examples:

	cast knock
	cast fireball north
  cast earth wall 17 10
	cast polymorph other at orc
  cast detect magic on gray stone
  cast magic mouth with-args Abandon All Hope Ye Who Enter Here
 

The event that's returned has a number of properties set:

• if a direction was specified, it's placed in an int "direction" property. If zero, no direction was used.
• if an (x,y) casting location was specified, it's placed in a "target-loc" property whose value is a Point.
• if an indirect object was specified using "on" or "at", the indirect object is stored in a String "target-name" property.
• whatever's left after parsing the dir/location/target is placed in the "spell-name" property, which is used to determine the spell class.
• an instance of the spell is created and stored in a "spell-obj" property.
• if "with-args" was used, a "with-args" property whose value is whatever they typed following "with-args".

Notes:

• the spell isn't instantiated until execute() is called
• no attempt is made to discover whether the indirect object is a valid/existing target - the spell should use the name, direction or location (if any) to find the actual target object.
• no attempt is made to determine whether the arguments are appropriate to the spell; the spell is free to ignore them or flag an error (e.g. misfire) if the args are wrong.

We might eventually support other syntax, such as "with (reagent)".

Specified by:

createEvent in interface Command

Parameters:

initial - the original event with the command text

Returns:

an event containing any parsed parameters

isNoSpellsArea

public boolean isNoSpellsArea(CastEvent event)

Checks whether it's OK to cast the spell in this location. Checks for objects with "no-spells" property in the square, and for the map having an overall "no-spells" property. If the spell has "ok-no-spells", always allows it.

Parameters:

event - the event

Returns:

true if it's not OK to cast here.

execute

public boolean execute(CommandEvent ev)

Implements Command.execute()

Specified by:

execute in interface Command

Parameters:

ev - the CommandEvent to execute

Returns:

true if the event completed successfully, else false.

See Also:

Command.execute(wyvern.lib.CommandEvent)

adjustCasterMana

public boolean adjustCasterMana(CastEvent event)

Deducts the appropriate amount of mana.

Parameters:

event - the event

reagents

public boolean reagents(CastEvent event)

Lists the reagents for a particular spell.

Parameters:

event - the event

Returns:

true if event was handled

knowsSpell

public boolean knowsSpell(Commandable agent,
                          java.lang.String spell)

dispel

public boolean dispel(CastEvent event)

Dispels a spell you've cast.

showActiveSpells

public boolean showActiveSpells(CommandEvent event)

Displays to the user a list of the spells they have active. Only shows spells they've cast using the cast command, not potions/scrolls/wands etc.