Tweaks to command system to allow setting executors via plugins (no more ambiguous onCommand in plugins)

By: Dinnerbone <dinnerbone@dinnerbone.com>

paper-api/src/main/java/org/bukkit/command/Command.java

@@ -3,8 +3,6 @@ package org.bukkit.command;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.bukkit.command.CommandSender;
-
 public abstract class Command {
     private final String name;
     private List<String> aliases;

paper-api/src/main/java/org/bukkit/command/CommandExecutor.java

@@ -0,0 +1,18 @@
+
+package org.bukkit.command;
+
+/**
+ * Represents a class which contains a single method for executing commands
+ */
+public interface CommandExecutor {
+    /**
+     * Executes the given command, returning its success
+     *
+     * @param sender Source of the command
+     * @param command Command which was executed
+     * @param label Alias of the command which was used
+     * @param args Passed command arguments
+     * @return true if a valid command, otherwise false
+     */
+    public boolean onCommand(CommandSender sender, Command command, String label, String[] args);
+}

paper-api/src/main/java/org/bukkit/command/CommandMap.java

@@ -31,4 +31,12 @@ public interface CommandMap {
      * Clears all registered commands.
      */
     public void clearCommands();
+
+    /**
+     * Gets the command registered to the specified name
+     *
+     * @param name Name of the command to retrieve
+     * @return Command with the specified name
+     */
+    public Command getCommand(String name);
 }

paper-api/src/main/java/org/bukkit/command/PluginCommand.java

@@ -1,37 +1,35 @@
 package org.bukkit.command;
 
-import org.bukkit.ChatColor;
 import org.bukkit.plugin.Plugin;
 
 public final class PluginCommand extends Command {
     private final Plugin owningPlugin;
+    private CommandExecutor executor;
 
-    public PluginCommand(String name, Plugin owner) {
+    protected PluginCommand(String name, Plugin owner) {
         super(name);
+        this.executor = owner;
         this.owningPlugin = owner;
         this.usageMessage = "";
     }
 
     public boolean execute(CommandSender sender, String commandLabel, String[] args) {
-        boolean cmdSuccess = false;
+        boolean success = false;
 
         try {
-            cmdSuccess = owningPlugin.onCommand(sender, this, commandLabel, args);
+            success = executor.onCommand(sender, this, commandLabel, args);
         } catch (Throwable ex) {
             throw new CommandException("Unhandled exception executing command '" + commandLabel + "' in plugin " + owningPlugin.getDescription().getFullName(), ex);
         }
 
-        if (!cmdSuccess && !usageMessage.isEmpty()) {
-            String tmpMsg = usageMessage.replace("<command>", commandLabel);
-            String[] usageLines = tmpMsg.split("\\n");
-            for(String line: usageLines) {
-                while (line.length() > 0) {
-                    int stripChars = (line.length() > 53 ? 53:line.length());
-                    sender.sendMessage(ChatColor.RED + line.substring(0, stripChars));
-                    line = line.substring(stripChars);
-                }
-            }
+        if (!success && !usageMessage.isEmpty()) {
+            sender.sendMessage(usageMessage.replace("<command>", commandLabel));
         }
-        return cmdSuccess;
+        
+        return success;
+    }
+
+    public void setExecutor(CommandExecutor executor) {
+        this.executor = executor;
     }
 }

paper-api/src/main/java/org/bukkit/command/SimpleCommandMap.java

@@ -23,7 +23,7 @@ public final class SimpleCommandMap implements CommandMap {
     private void setDefaultCommands(final Server server) {
         register("bukkit", new VersionCommand("version", server));
         register("bukkit", new ReloadCommand("reload", server));
-        register("bukkit", new PluginsCommand("plugins",server));
+        register("bukkit", new PluginsCommand("plugins", server));
     }
 
     /**
@@ -91,6 +91,10 @@ public final class SimpleCommandMap implements CommandMap {
         }
     }
 
+    public Command getCommand(String name) {
+        return knownCommands.get(name);
+    }
+
     private static class VersionCommand extends Command {
         private final Server server;
 

paper-api/src/main/java/org/bukkit/plugin/Plugin.java

@@ -3,14 +3,13 @@ package org.bukkit.plugin;
 
 import java.io.File;
 import org.bukkit.Server;
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandSender;
+import org.bukkit.command.CommandExecutor;
 import org.bukkit.util.config.Configuration;
 
 /**
  * Represents a Plugin
  */
-public interface Plugin {
+public interface Plugin extends CommandExecutor {
     /**
      * Returns the folder that the plugin data's files are located in. The
      * folder may not yet exist.
@@ -63,11 +62,4 @@ public interface Plugin {
      * Called when this plugin is enabled
      */
     public void onEnable();
-
-    /**
-     * Called when a command registered by this plugin is received.
-     * @param commandLabel
-     * @return TODO
-     */
-    public boolean onCommand(CommandSender sender, Command command, String commandLabel, String[] args);
 }

paper-api/src/main/java/org/bukkit/plugin/java/JavaPlugin.java

@@ -2,10 +2,8 @@
 package org.bukkit.plugin.java;
 
 import java.io.File;
-import java.util.ArrayList;
 import org.bukkit.Server;
-import org.bukkit.command.Command;
-import org.bukkit.command.CommandSender;
+import org.bukkit.command.CommandExecutor;
 import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.PluginDescriptionFile;
 import org.bukkit.plugin.PluginLoader;
@@ -121,13 +119,6 @@ public abstract class JavaPlugin implements Plugin {
         }
     }
 
-    /**
-     * Called when a command registered by this plugin is received.
-     */
-    public boolean onCommand(CommandSender sender, Command cmd, String commandLabel, String[] args) {
-        return false; // default implementation:  do nothing!
-    }
-
     /**
      * Initializes this plugin with the given variables.
      *