aboutsummaryrefslogtreecommitdiff
path: root/spark-bukkit/src/main/java/me/lucko/spark/bukkit/CommandMapUtil.java
blob: 08d65df7298132e1b6a8b4442c9abee707c89c76 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
 * This file is part of helper, licensed under the MIT License.
 *
 *  Copyright (c) lucko (Luck) <luck@lucko.me>
 *  Copyright (c) contributors
 *
 *  Permission is hereby granted, free of charge, to any person obtaining a copy
 *  of this software and associated documentation files (the "Software"), to deal
 *  in the Software without restriction, including without limitation the rights
 *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *  copies of the Software, and to permit persons to whom the Software is
 *  furnished to do so, subject to the following conditions:
 *
 *  The above copyright notice and this permission notice shall be included in all
 *  copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 *  SOFTWARE.
 */

package me.lucko.spark.bukkit;

import com.google.common.base.Preconditions;
import org.bukkit.Bukkit;
import org.bukkit.command.Command;
import org.bukkit.command.CommandExecutor;
import org.bukkit.command.CommandMap;
import org.bukkit.command.PluginCommand;
import org.bukkit.command.SimpleCommandMap;
import org.bukkit.command.TabCompleter;
import org.bukkit.plugin.Plugin;
import org.bukkit.plugin.SimplePluginManager;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.Iterator;
import java.util.Map;

/**
 * Utility for interacting with the server's {@link CommandMap} instance.
 */
public final class CommandMapUtil {

    private static final Constructor<PluginCommand> COMMAND_CONSTRUCTOR;
    private static final Field COMMAND_MAP_FIELD;
    private static final Field KNOWN_COMMANDS_FIELD;

    static {
        Constructor<PluginCommand> commandConstructor;
        try {
            commandConstructor = PluginCommand.class.getDeclaredConstructor(String.class, Plugin.class);
            commandConstructor.setAccessible(true);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        }
        COMMAND_CONSTRUCTOR = commandConstructor;

        Field commandMapField;
        try {
            commandMapField = SimplePluginManager.class.getDeclaredField("commandMap");
            commandMapField.setAccessible(true);
        } catch (NoSuchFieldException e) {
            throw new RuntimeException(e);
        }
        COMMAND_MAP_FIELD = commandMapField;

        Field knownCommandsField;
        try {
            knownCommandsField = SimpleCommandMap.class.getDeclaredField("knownCommands");
            knownCommandsField.setAccessible(true);
        } catch (NoSuchFieldException e) {
            throw new RuntimeException(e);
        }
        KNOWN_COMMANDS_FIELD = knownCommandsField;
    }

    private static CommandMap getCommandMap() {
        try {
            return (CommandMap) COMMAND_MAP_FIELD.get(Bukkit.getServer().getPluginManager());
        } catch (Exception e) {
            throw new RuntimeException("Could not get CommandMap", e);
        }
    }

    private static Map<String, Command> getKnownCommandMap() {
        try {
            //noinspection unchecked
            return (Map<String, Command>) KNOWN_COMMANDS_FIELD.get(getCommandMap());
        } catch (Exception e) {
            throw new RuntimeException("Could not get known commands map", e);
        }
    }

    /**
     * Registers a CommandExecutor with the server
     *
     * @param plugin the plugin instance
     * @param command the command instance
     * @param aliases the command aliases
     * @param <T> the command executor class type
     * @return the command executor
     */
    public static <T extends CommandExecutor> T registerCommand(Plugin plugin, T command, String... aliases) {
        Preconditions.checkArgument(aliases.length != 0, "No aliases");
        for (String alias : aliases) {
            try {
                PluginCommand cmd = COMMAND_CONSTRUCTOR.newInstance(alias, plugin);

                getCommandMap().register(plugin.getDescription().getName(), cmd);
                getKnownCommandMap().put(plugin.getDescription().getName().toLowerCase() + ":" + alias.toLowerCase(), cmd);
                getKnownCommandMap().put(alias.toLowerCase(), cmd);
                cmd.setLabel(alias.toLowerCase());

                cmd.setExecutor(command);
                if (command instanceof TabCompleter) {
                    cmd.setTabCompleter((TabCompleter) command);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return command;
    }

    /**
     * Unregisters a CommandExecutor with the server
     *
     * @param command the command instance
     * @param <T> the command executor class type
     * @return the command executor
     */
    public static <T extends CommandExecutor> T unregisterCommand(T command) {
        CommandMap map = getCommandMap();
        try {
            //noinspection unchecked
            Map<String, Command> knownCommands = (Map<String, Command>) KNOWN_COMMANDS_FIELD.get(map);

            Iterator<Command> iterator = knownCommands.values().iterator();
            while (iterator.hasNext()) {
                Command cmd = iterator.next();
                if (cmd instanceof PluginCommand) {
                    CommandExecutor executor = ((PluginCommand) cmd).getExecutor();
                    if (command == executor) {
                        cmd.unregister(map);
                        iterator.remove();
                    }
                }
            }
        } catch (Exception e) {
            throw new RuntimeException("Could not unregister command", e);
        }

        return command;
    }

    private CommandMapUtil() {
        throw new UnsupportedOperationException("This class cannot be instantiated");
    }

}