Rework BaseCommandPlugin to be daggery.

Getting hold of a CommandController is annoying and fiddly,
so add a CommandHelper class to hide that away from plugins.

Allow registering of a command given just its class/info.

Change-Id: Ia208db1f23e3356d83a87ff2372e4f7aa49b24cc
Reviewed-on: http://gerrit.dmdirc.com/2854
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Automatic-Compile: DMDirc Build Manager

src/com/dmdirc/plugins/implementations/BaseCommandPlugin.java

@@ -24,12 +24,15 @@ package com.dmdirc.plugins.implementations;
 import com.dmdirc.commandparser.CommandInfo;
 import com.dmdirc.commandparser.commands.Command;
 import com.dmdirc.interfaces.CommandController;
+import com.dmdirc.plugins.PluginInfo;
 
 import java.util.HashMap;
 import java.util.Map;
 
 import lombok.AccessLevel;
-import lombok.Getter;
+import lombok.Setter;
+
+import dagger.ObjectGraph;
 
 /**
  * Implementation of {@link BasePlugin} that maintains commands.
@@ -39,28 +42,37 @@ public abstract class BaseCommandPlugin extends BasePlugin {
     /**
      * List of commands to load and unload.
      */
-    private final Map<CommandInfo, Command> commands =
-            new HashMap<CommandInfo, Command>();
+    private final Map<CommandInfo, Command> commands = new HashMap<>();
+
     /**
      * Command controller to register commands.
      */
-    @Getter(AccessLevel.PROTECTED)
-    private final CommandController commandController;
+    @Setter(AccessLevel.PROTECTED)
+    private CommandController commandController;
 
     /**
      * Creates a new instance of this plugin
      *
-     * @param commandController Command controller to register commands
+     * @param commandController Command controller to register commands.
+     * @deprecated No longer required, use empty constructor.
      */
+    @Deprecated
     public BaseCommandPlugin(final CommandController commandController) {
         this.commandController = commandController;
     }
 
+    /**
+     * Creates a new instance of this plugin.
+     */
+    public BaseCommandPlugin() {
+    }
+
     /**
      * {@inheritDoc}
      */
     @Override
     public void onLoad() {
+        super.onLoad();
         loadCommands();
     }
 
@@ -69,20 +81,47 @@ public abstract class BaseCommandPlugin extends BasePlugin {
      */
     @Override
     public void onUnload() {
+        super.onUnload();
         unloadCommands();
     }
 
+    /** {@inheritDoc} */
+    @Override
+    public void load(final PluginInfo pluginInfo, final ObjectGraph graph) {
+        super.load(pluginInfo, graph);
+
+        commandController = graph.plus(new CommandHelper.CommandHelperModule())
+                .get(CommandHelper.class).getCommandController();
+    }
+
     /**
      * Registers a command from this plugin.
      *
      * @param command Command to register
      * @param commandInfo Command info to register
      */
-    protected void registerCommand(final Command command,
-            final CommandInfo commandInfo) {
+    protected void registerCommand(final Command command, final CommandInfo commandInfo) {
         commands.put(commandInfo, command);
     }
 
+    /**
+     * Registers a command from this plugin.
+     *
+     * <p>This method will create a new instance of the specified command class using the
+     * dependency-injection framework. It must only be called after
+     * {@link #setObjectGraph(dagger.ObjectGraph)}, and any command must be injectable using
+     * that object graph.
+     *
+     * @param <T> The type of the command that will be registered.
+     * @param command The class of the command to register.
+     * @param commandInfo Command info to register.
+     */
+    protected <T extends Command> void registerCommand(
+            final Class<T> command,
+            final CommandInfo commandInfo) {
+        commands.put(commandInfo, getObjectGraph().get(command));
+    }
+
     /**
      * Unregisters a command from this plugin.
      *
@@ -98,8 +137,7 @@ public abstract class BaseCommandPlugin extends BasePlugin {
      */
     private void loadCommands() {
         for (Map.Entry<CommandInfo, Command> command : commands.entrySet()) {
-            commandController.registerCommand(
-                    command.getValue(), command.getKey());
+            commandController.registerCommand(command.getValue(), command.getKey());
         }
     }
 
@@ -111,4 +149,14 @@ public abstract class BaseCommandPlugin extends BasePlugin {
             commandController.unregisterCommand(command);
         }
     }
+
+    /**
+     * Gets the command controller used.
+     *
+     * @return A command controller.
+     * @deprecated Plugins should inject their own controllers.
+     */
+    protected CommandController getCommandController() {
+        return commandController;
+    }
 }

src/com/dmdirc/plugins/implementations/CommandHelper.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2006-2013 DMDirc Developers
+ *
+ * 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 com.dmdirc.plugins.implementations;
+
+import com.dmdirc.ClientModule;
+import com.dmdirc.interfaces.CommandController;
+
+import javax.inject.Inject;
+
+import lombok.Getter;
+
+import dagger.Module;
+
+/**
+ * Helper class for {@link BaseCommandPlugin} to facilitate retrieving a {@link CommandController}.
+ *
+ * <p>Because the plugins themselves aren't dependency injected, but require a command controller
+ * themselves to sensibly register commands, we use this helper and module to obtain a reference.
+ */
+@SuppressWarnings("PMD.UnusedPrivateField")
+public class CommandHelper {
+
+    /** The command controller. */
+    @Getter
+    private final CommandController commandController;
+
+    /**
+     * Creates a new instance of this class.
+     *
+     * @param commandController The command controller to return.
+     */
+    @Inject
+    public CommandHelper(final CommandController commandController) {
+        this.commandController = commandController;
+    }
+
+    /** Module that allows inflation of {@link CommandHelper}. */
+    @Module(injects = CommandHelper.class, addsTo = ClientModule.class)
+    public static class CommandHelperModule {
+
+    }
+
+}