A wee bit of a cleanup of the API

- Move some method over to defaulted methods
 - Use Objects rather than Preconditions

.editorconfig

@@ -5,9 +5,7 @@ indent_style = space
 indent_size = 4
 end_of_line = lf
 charset = utf-8
-# Sadly too many files have whitespace errors, so we leave this as is for
+trim_trailing_whitespace = true
-# now and just make sure we don't introduce any more.
-# trim_trailing_whitespace = true
 insert_final_newline = true
 
 [*.md]

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -268,7 +268,9 @@ public static void registerMediaProvider( @Nonnull IMediaProvider handler )
      *
      * @param handler The turtle permission provider to register.
      * @see dan200.computercraft.api.permissions.ITurtlePermissionProvider
+     * @deprecated Prefer using {@link dan200.computercraft.api.turtle.event.TurtleBlockEvent} or the standard Forge events.
      */
+    @Deprecated
     public static void registerPermissionProvider( @Nonnull ITurtlePermissionProvider handler )
     {
         findCC();

src/main/java/dan200/computercraft/api/filesystem/IMount.java

@@ -90,7 +90,7 @@ public interface IMount
      * @throws IOException If the file does not exist, or could not be opened.
      */
     @Nonnull
-    @SuppressWarnings("deprecation")
+    @SuppressWarnings( "deprecation" )
     default ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForRead( path ) );

src/main/java/dan200/computercraft/api/filesystem/IWritableMount.java

@@ -67,7 +67,7 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    @SuppressWarnings("deprecation")
+    @SuppressWarnings( "deprecation" )
     default WritableByteChannel openChannelForWrite( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForWrite( path ) );
@@ -94,7 +94,7 @@ default WritableByteChannel openChannelForWrite( @Nonnull String path ) throws I
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    @SuppressWarnings("deprecation")
+    @SuppressWarnings( "deprecation" )
     default WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForAppend( path ) );

src/main/java/dan200/computercraft/api/filesystem/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|FileSystem", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|FileSystem", apiVersion = "${version}" )
 package dan200.computercraft.api.filesystem;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/lua/ILuaAPI.java

@@ -31,17 +31,23 @@ public interface ILuaAPI extends ILuaObject
      *
      * One should only interact with the file system.
      */
-    default void startup() { }
+    default void startup()
+    {
+    }
 
     /**
      * Called every time the computer is ticked. This can be used to process various.
      */
-    default void update() { }
+    default void update()
+    {
+    }
 
     /**
      * Called when the computer is turned off or unloaded.
      *
      * This should reset the state of the object, disposing any remaining file handles, or other resources.
      */
-    default void shutdown() { }
+    default void shutdown()
+    {
+    }
 }

src/main/java/dan200/computercraft/api/lua/LuaException.java

@@ -14,7 +14,7 @@
 public class LuaException extends Exception
 {
     private static final long serialVersionUID = -6136063076818512651L;
-    private final int m_level;
+    private final int level;
 
     public LuaException()
     {
@@ -29,7 +29,7 @@ public LuaException( @Nullable String message )
     public LuaException( @Nullable String message, int level )
     {
         super( message );
-        m_level = level;
+        this.level = level;
     }
 
     /**
@@ -40,6 +40,6 @@ public LuaException( @Nullable String message, int level )
      */
     public int getLevel()
     {
-        return m_level;
+        return level;
     }
 }

src/main/java/dan200/computercraft/api/lua/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Lua", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Lua", apiVersion = "${version}" )
 package dan200.computercraft.api.lua;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/media/IMedia.java

@@ -23,7 +23,7 @@ public interface IMedia
     /**
      * Get a string representing the label of this item. Will be called via {@code disk.getLabel()} in lua.
      *
-     * @param stack The itemstack to inspect.
+     * @param stack The {@link ItemStack} to inspect.
      * @return The label. ie: "Dan's Programs".
      */
     @Nullable
@@ -32,36 +32,45 @@ public interface IMedia
     /**
      * Set a string representing the label of this item. Will be called vi {@code disk.setLabel()} in lua.
      *
-     * @param stack The itemstack to modify.
+     * @param stack The {@link ItemStack} to modify.
      * @param label The string to set the label to.
      * @return true if the label was updated, false if the label may not be modified.
      */
-    boolean setLabel( @Nonnull ItemStack stack, @Nullable String label );
+    default boolean setLabel( @Nonnull ItemStack stack, @Nullable String label )
+    {
+        return false;
+    }
 
     /**
      * If this disk represents an item with audio (like a record), get the readable name of the audio track. ie:
      * "Jonathon Coulton - Still Alive"
      *
-     * @param stack The itemstack to inspect.
+     * @param stack The {@link ItemStack} to modify.
      * @return The name, or null if this item does not represent an item with audio.
      */
     @Nullable
-    String getAudioTitle( @Nonnull ItemStack stack );
+    default String getAudioTitle( @Nonnull ItemStack stack )
+    {
+        return null;
+    }
 
     /**
      * If this disk represents an item with audio (like a record), get the resource name of the audio track to play.
      *
-     * @param stack The itemstack to inspect.
+     * @param stack The {@link ItemStack} to modify.
      * @return The name, or null if this item does not represent an item with audio.
      */
     @Nullable
-    SoundEvent getAudio( @Nonnull ItemStack stack );
+    default SoundEvent getAudio( @Nonnull ItemStack stack )
+    {
+        return null;
+    }
 
     /**
      * If this disk represents an item with data (like a floppy disk), get a mount representing it's contents. This will
      * be mounted onto the filesystem of the computer while the media is in the disk drive.
      *
-     * @param stack The itemstack to inspect.
+     * @param stack The {@link ItemStack} to modify.
      * @param world The world in which the item and disk drive reside.
      * @return The mount, or null if this item does not represent an item with data. If the mount returned also
      * implements {@link dan200.computercraft.api.filesystem.IWritableMount}, it will mounted using mountWritable()
@@ -71,5 +80,8 @@ public interface IMedia
      * @see dan200.computercraft.api.ComputerCraftAPI#createResourceMount(Class, String, String)
      */
     @Nullable
-    IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world );
+    default IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
+    {
+        return null;
+    }
 }

src/main/java/dan200/computercraft/api/media/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Media", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Media", apiVersion = "${version}" )
 package dan200.computercraft.api.media;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/network/Packet.java

@@ -5,10 +5,9 @@
  */
 package dan200.computercraft.api.network;
 
-import com.google.common.base.Preconditions;
-
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Objects;
 
 /**
  * Represents a packet which may be sent across a {@link IPacketNetwork}.
@@ -21,11 +20,11 @@
  */
 public class Packet
 {
-    private final int m_channel;
+    private final int channel;
-    private final int m_replyChannel;
+    private final int replyChannel;
-    private final Object m_payload;
+    private final Object payload;
 
-    private final IPacketSender m_sender;
+    private final IPacketSender sender;
 
     /**
      * Create a new packet, ready for transmitting across the network.
@@ -39,12 +38,12 @@ public class Packet
      */
     public Packet( int channel, int replyChannel, @Nullable Object payload, @Nonnull IPacketSender sender )
     {
-        Preconditions.checkNotNull( sender, "sender cannot be null" );
+        Objects.requireNonNull( sender, "sender cannot be null" );
 
-        m_channel = channel;
+        this.channel = channel;
-        m_replyChannel = replyChannel;
+        this.replyChannel = replyChannel;
-        m_payload = payload;
+        this.payload = payload;
-        m_sender = sender;
+        this.sender = sender;
     }
 
     /**
@@ -55,7 +54,7 @@ public Packet( int channel, int replyChannel, @Nullable Object payload, @Nonnull
      */
     public int getChannel()
     {
-        return m_channel;
+        return channel;
     }
 
     /**
@@ -65,7 +64,7 @@ public int getChannel()
      */
     public int getReplyChannel()
     {
-        return m_replyChannel;
+        return replyChannel;
     }
 
     /**
@@ -77,7 +76,7 @@ public int getReplyChannel()
     @Nullable
     public Object getPayload()
     {
-        return m_payload;
+        return payload;
     }
 
     /**
@@ -88,7 +87,7 @@ public Object getPayload()
     @Nonnull
     public IPacketSender getSender()
     {
-        return m_sender;
+        return sender;
     }
 
     @Override
@@ -99,20 +98,20 @@ public boolean equals( Object o )
 
         Packet packet = (Packet) o;
 
-        if( m_channel != packet.m_channel ) return false;
+        if( channel != packet.channel ) return false;
-        if( m_replyChannel != packet.m_replyChannel ) return false;
+        if( replyChannel != packet.replyChannel ) return false;
-        if( m_payload != null ? !m_payload.equals( packet.m_payload ) : packet.m_payload != null ) return false;
+        if( !Objects.equals( payload, packet.payload ) ) return false;
-        return m_sender.equals( packet.m_sender );
+        return sender.equals( packet.sender );
     }
 
     @Override
     public int hashCode()
     {
         int result;
-        result = m_channel;
+        result = channel;
-        result = 31 * result + m_replyChannel;
+        result = 31 * result + replyChannel;
-        result = 31 * result + (m_payload != null ? m_payload.hashCode() : 0);
+        result = 31 * result + (payload != null ? payload.hashCode() : 0);
-        result = 31 * result + m_sender.hashCode();
+        result = 31 * result + sender.hashCode();
         return result;
     }
 }

src/main/java/dan200/computercraft/api/network/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Network", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Network", apiVersion = "${version}" )
 package dan200.computercraft.api.network;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/network/wired/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Network|Wired", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Network|Wired", apiVersion = "${version}" )
 package dan200.computercraft.api.network.wired;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API", apiVersion = "${version}" )
 package dan200.computercraft.api;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/peripheral/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Peripheral", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Peripheral", apiVersion = "${version}" )
 package dan200.computercraft.api.peripheral;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/permissions/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Permissions", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Permissions", apiVersion = "${version}" )
 package dan200.computercraft.api.permissions;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/redstone/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Redstone", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Redstone", apiVersion = "${version}" )
 package dan200.computercraft.api.redstone;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -25,7 +25,6 @@
 import javax.annotation.Nullable;
 import javax.vecmath.Matrix4f;
 
-
 /**
  * The primary interface for defining an update for Turtles. A turtle update
  * can either be a new tool, or a new peripheral.
@@ -98,7 +97,10 @@ public interface ITurtleUpgrade
      * and this method is not expected to be called.
      */
     @Nullable
-    IPeripheral createPeripheral( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side );
+    default IPeripheral createPeripheral( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side )
+    {
+        return null;
+    }
 
     /**
      * Will only be called for Tool turtle. Called when turtle.dig() or turtle.attack() is called
@@ -119,7 +121,10 @@ public interface ITurtleUpgrade
      * to be called.
      */
     @Nonnull
-    TurtleCommandResult useTool( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side, @Nonnull TurtleVerb verb, @Nonnull EnumFacing direction );
+    default TurtleCommandResult useTool( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side, @Nonnull TurtleVerb verb, @Nonnull EnumFacing direction )
+    {
+        return TurtleCommandResult.failure();
+    }
 
     /**
      * Called to obtain the model to be used when rendering a turtle peripheral.
@@ -133,8 +138,8 @@ public interface ITurtleUpgrade
      * @return The model that you wish to be used to render your upgrade, and a transformation to apply to it. Returning
      * a transformation of {@code null} has the same effect as the identify matrix.
      */
-    @SideOnly(Side.CLIENT)
     @Nonnull
+    @SideOnly( Side.CLIENT )
     Pair<IBakedModel, Matrix4f> getModel( @Nullable ITurtleAccess turtle, @Nonnull TurtleSide side );
 
     /**

src/main/java/dan200/computercraft/api/turtle/TurtleCommandResult.java

@@ -19,8 +19,8 @@
  */
 public final class TurtleCommandResult
 {
-    private static final TurtleCommandResult s_success = new TurtleCommandResult( true, null, null );
+    private static final TurtleCommandResult EMPTY_SUCCESS = new TurtleCommandResult( true, null, null );
-    private static final TurtleCommandResult s_emptyFailure = new TurtleCommandResult( false, null, null );
+    private static final TurtleCommandResult EMPTY_FAILURE = new TurtleCommandResult( false, null, null );
 
     /**
      * Create a successful command result with no result.
@@ -30,7 +30,7 @@ public final class TurtleCommandResult
     @Nonnull
     public static TurtleCommandResult success()
     {
-        return success( null );
+        return EMPTY_SUCCESS;
     }
 
     /**
@@ -42,14 +42,8 @@ public static TurtleCommandResult success()
     @Nonnull
     public static TurtleCommandResult success( @Nullable Object[] results )
     {
-        if( results == null || results.length == 0 )
+        if( results == null || results.length == 0 ) return EMPTY_SUCCESS;
-        {
+        return new TurtleCommandResult( true, null, results );
-            return s_success;
-        }
-        else
-        {
-            return new TurtleCommandResult( true, null, results );
-        }
     }
 
     /**
@@ -60,7 +54,7 @@ public static TurtleCommandResult success( @Nullable Object[] results )
     @Nonnull
     public static TurtleCommandResult failure()
     {
-        return failure( null );
+        return EMPTY_FAILURE;
     }
 
     /**
@@ -72,25 +66,19 @@ public static TurtleCommandResult failure()
     @Nonnull
     public static TurtleCommandResult failure( @Nullable String errorMessage )
     {
-        if( errorMessage == null )
+        if( errorMessage == null ) return EMPTY_FAILURE;
-        {
+        return new TurtleCommandResult( false, errorMessage, null );
-            return s_emptyFailure;
-        }
-        else
-        {
-            return new TurtleCommandResult( false, errorMessage, null );
-        }
     }
 
-    private final boolean m_success;
+    private final boolean success;
-    private final String m_errorMessage;
+    private final String errorMessage;
-    private final Object[] m_results;
+    private final Object[] results;
 
     private TurtleCommandResult( boolean success, String errorMessage, Object[] results )
     {
-        m_success = success;
+        this.success = success;
-        m_errorMessage = errorMessage;
+        this.errorMessage = errorMessage;
-        m_results = results;
+        this.results = results;
     }
 
     /**
@@ -100,7 +88,7 @@ private TurtleCommandResult( boolean success, String errorMessage, Object[] resu
      */
     public boolean isSuccess()
     {
-        return m_success;
+        return success;
     }
 
     /**
@@ -111,7 +99,7 @@ public boolean isSuccess()
     @Nullable
     public String getErrorMessage()
     {
-        return m_errorMessage;
+        return errorMessage;
     }
 
     /**
@@ -122,6 +110,6 @@ public String getErrorMessage()
     @Nullable
     public Object[] getResults()
     {
-        return m_results;
+        return results;
     }
 }

src/main/java/dan200/computercraft/api/turtle/TurtleUpgradeType.java

@@ -30,7 +30,7 @@ public enum TurtleUpgradeType
      * your upgrade to also provide methods. For example, a pickaxe could provide methods
      * determining whether it can break the given block or not.
      */
-    Both,;
+    Both;
 
     public boolean isTool()
     {

src/main/java/dan200/computercraft/api/turtle/event/TurtleActionEvent.java

@@ -1,12 +1,12 @@
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
 import net.minecraftforge.fml.common.eventhandler.Cancelable;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Objects;
 
 /**
  * An event fired when a turtle is performing a known action.
@@ -21,7 +21,7 @@ public TurtleActionEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleAction a
     {
         super( turtle );
 
-        Preconditions.checkNotNull( action, "action cannot be null" );
+        Objects.requireNonNull( action, "action cannot be null" );
         this.action = action;
     }
 

src/main/java/dan200/computercraft/api/turtle/event/TurtleAttackEvent.java

@@ -6,7 +6,6 @@
 
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
@@ -17,6 +16,7 @@
 import net.minecraftforge.event.entity.player.AttackEntityEvent;
 
 import javax.annotation.Nonnull;
+import java.util.Objects;
 
 /**
  * Fired when a turtle attempts to attack an entity.
@@ -37,9 +37,9 @@ public class TurtleAttackEvent extends TurtlePlayerEvent
     public TurtleAttackEvent( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull Entity target, @Nonnull ITurtleUpgrade upgrade, @Nonnull TurtleSide side )
     {
         super( turtle, TurtleAction.ATTACK, player );
-        Preconditions.checkNotNull( target, "target cannot be null" );
+        Objects.requireNonNull( target, "target cannot be null" );
-        Preconditions.checkNotNull( upgrade, "upgrade cannot be null" );
+        Objects.requireNonNull( upgrade, "upgrade cannot be null" );
-        Preconditions.checkNotNull( side, "side cannot be null" );
+        Objects.requireNonNull( side, "side cannot be null" );
         this.target = target;
         this.upgrade = upgrade;
         this.side = side;

src/main/java/dan200/computercraft/api/turtle/event/TurtleBlockEvent.java

@@ -6,7 +6,6 @@
 
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.peripheral.IComputerAccess;
 import dan200.computercraft.api.turtle.ITurtleAccess;
@@ -24,6 +23,7 @@
 
 import javax.annotation.Nonnull;
 import java.util.Map;
+import java.util.Objects;
 
 /**
  * A general event for when a turtle interacts with a block or region.
@@ -47,8 +47,8 @@ protected TurtleBlockEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleAction
     {
         super( turtle, action, player );
 
-        Preconditions.checkNotNull( world, "world cannot be null" );
+        Objects.requireNonNull( world, "world cannot be null" );
-        Preconditions.checkNotNull( pos, "pos cannot be null" );
+        Objects.requireNonNull( pos, "pos cannot be null" );
         this.world = world;
         this.pos = pos;
     }
@@ -95,9 +95,9 @@ public Dig( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull
         {
             super( turtle, TurtleAction.DIG, player, world, pos );
 
-            Preconditions.checkNotNull( block, "block cannot be null" );
+            Objects.requireNonNull( block, "block cannot be null" );
-            Preconditions.checkNotNull( upgrade, "upgrade cannot be null" );
+            Objects.requireNonNull( upgrade, "upgrade cannot be null" );
-            Preconditions.checkNotNull( side, "side cannot be null" );
+            Objects.requireNonNull( side, "side cannot be null" );
             this.block = block;
             this.upgrade = upgrade;
             this.side = side;
@@ -165,7 +165,7 @@ public Place( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnul
         {
             super( turtle, TurtleAction.PLACE, player, world, pos );
 
-            Preconditions.checkNotNull( stack, "stack cannot be null" );
+            Objects.requireNonNull( stack, "stack cannot be null" );
             this.stack = stack;
         }
 
@@ -198,8 +198,8 @@ public Inspect( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonn
         {
             super( turtle, TurtleAction.INSPECT, player, world, pos );
 
-            Preconditions.checkNotNull( state, "state cannot be null" );
+            Objects.requireNonNull( state, "state cannot be null" );
-            Preconditions.checkNotNull( data, "data cannot be null" );
+            Objects.requireNonNull( data, "data cannot be null" );
             this.data = data;
             this.state = state;
         }
@@ -234,7 +234,7 @@ public Map<String, Object> getData()
          */
         public void addData( @Nonnull Map<String, ?> newData )
         {
-            Preconditions.checkNotNull( newData, "newData cannot be null" );
+            Objects.requireNonNull( newData, "newData cannot be null" );
             data.putAll( newData );
         }
     }

src/main/java/dan200/computercraft/api/turtle/event/TurtleEvent.java

@@ -6,11 +6,11 @@
 
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import net.minecraftforge.fml.common.eventhandler.Event;
 
 import javax.annotation.Nonnull;
+import java.util.Objects;
 
 /**
  * A base class for all events concerning a turtle. This will only ever constructed and fired on the server side,
@@ -26,7 +26,7 @@ public abstract class TurtleEvent extends Event
 
     protected TurtleEvent( @Nonnull ITurtleAccess turtle )
     {
-        Preconditions.checkNotNull( turtle, "turtle cannot be null" );
+        Objects.requireNonNull( turtle, "turtle cannot be null" );
         this.turtle = turtle;
     }
 

src/main/java/dan200/computercraft/api/turtle/event/TurtleInventoryEvent.java

@@ -1,6 +1,5 @@
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.math.BlockPos;
@@ -11,6 +10,7 @@
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.Objects;
 
 /**
  * Fired when a turtle attempts to interact with an inventory.
@@ -65,7 +65,7 @@ public Drop( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull
         {
             super( turtle, TurtleAction.DROP, player, world, pos, handler );
 
-            Preconditions.checkNotNull( stack, "stack cannot be null" );
+            Objects.requireNonNull( stack, "stack cannot be null" );
             this.stack = stack;
         }
 

src/main/java/dan200/computercraft/api/turtle/event/TurtlePlayerEvent.java

@@ -6,11 +6,11 @@
 
 package dan200.computercraft.api.turtle.event;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import net.minecraftforge.common.util.FakePlayer;
 
 import javax.annotation.Nonnull;
+import java.util.Objects;
 
 /**
  * An action done by a turtle which is normally done by a player.
@@ -25,7 +25,7 @@ protected TurtlePlayerEvent( @Nonnull ITurtleAccess turtle, @Nonnull TurtleActio
     {
         super( turtle, action );
 
-        Preconditions.checkNotNull( player, "player cannot be null" );
+        Objects.requireNonNull( player, "player cannot be null" );
         this.player = player;
     }
 

src/main/java/dan200/computercraft/api/turtle/event/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API(owner = "ComputerCraft", provides = "ComputerCraft|API|Turtle|Event", apiVersion = "${version}")
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Turtle|Event", apiVersion = "${version}" )
 package dan200.computercraft.api.turtle.event;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/api/turtle/package-info.java

@@ -4,7 +4,7 @@
  * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
 
-@API( owner="ComputerCraft", provides="ComputerCraft|API|Turtle", apiVersion="${version}" )
+@API( owner = "ComputerCraft", provides = "ComputerCraft|API|Turtle", apiVersion = "${version}" )
 package dan200.computercraft.api.turtle;
 
 import net.minecraftforge.fml.common.API;

src/main/java/dan200/computercraft/shared/computer/items/ItemComputerBase.java

@@ -87,18 +87,6 @@ public boolean setLabel( @Nonnull ItemStack stack, String label )
         return true;
     }
 
-    @Override
-    public String getAudioTitle( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-
-    @Override
-    public SoundEvent getAudio( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-
     @Override
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {

src/main/java/dan200/computercraft/shared/media/common/DefaultMediaProvider.java

@@ -11,22 +11,12 @@
 
 public class DefaultMediaProvider implements IMediaProvider
 {
-    public DefaultMediaProvider()
-    {
-    }
-
     @Override
     public IMedia getMedia( @Nonnull ItemStack stack )
     {
         Item item = stack.getItem();
-        if( item instanceof IMedia )
+        if( item instanceof IMedia ) return (IMedia) item;
-        {
+        if( item instanceof ItemRecord ) return RecordMedia.INSTANCE;
-            return (IMedia)item;
-        }
-        else if( item instanceof ItemRecord )
-        {
-            return new RecordMedia();
-        }
         return null;
     }
 }

src/main/java/dan200/computercraft/shared/media/items/ItemDiskLegacy.java

@@ -18,7 +18,6 @@
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.NonNullList;
-import net.minecraft.util.SoundEvent;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
@@ -34,16 +33,16 @@ public ItemDiskLegacy()
         setMaxStackSize( 1 );
         setHasSubtypes( true );
         setTranslationKey( "computercraft:disk" );
-        setCreativeTab( ComputerCraft.mainCreativeTab  );
+        setCreativeTab( ComputerCraft.mainCreativeTab );
     }
 
     @Override
     public void getSubItems( @Nonnull CreativeTabs tabs, @Nonnull NonNullList<ItemStack> list )
     {
         if( !isInCreativeTab( tabs ) ) return;
-        for( int colour=0; colour<16; ++colour )
+        for( int colour = 0; colour < 16; ++colour )
         {
-            ItemStack stack = createFromIDAndColour( -1, null, Colour.values()[ colour ].getHex() );
+            ItemStack stack = createFromIDAndColour( -1, null, Colour.values()[colour].getHex() );
             if( stack.getItem() == this )
             {
                 list.add( stack );
@@ -69,9 +68,12 @@ public int getDiskID( @Nonnull ItemStack stack )
 
     protected void setDiskID( @Nonnull ItemStack stack, int id )
     {
-        if( id > 0 ) {
+        if( id > 0 )
+        {
             stack.setItemDamage( id );
-        } else {
+        }
+        else
+        {
             stack.setItemDamage( 0 );
         }
     }
@@ -115,18 +117,6 @@ public boolean setLabel( @Nonnull ItemStack stack, String label )
         return true;
     }
 
-    @Override
-    public String getAudioTitle( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-    
-    @Override
-    public SoundEvent getAudio( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-    
     @Override
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {

src/main/java/dan200/computercraft/shared/media/items/ItemTreasureDisk.java

@@ -18,7 +18,6 @@
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.NonNullList;
-import net.minecraft.util.SoundEvent;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
@@ -66,24 +65,6 @@ public String getLabel( @Nonnull ItemStack stack )
         return getTitle( stack );
     }
 
-    @Override
-    public boolean setLabel( @Nonnull ItemStack stack, String label )
-    {
-        return false;
-    }
-    
-    @Override
-    public String getAudioTitle( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-    
-    @Override
-    public SoundEvent getAudio( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-    
     @Override
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {
@@ -126,7 +107,7 @@ public static ItemStack create( String subPath, int colourIndex )
         {
             nbt.setString( "title", "untitled" );
         }
-        nbt.setInteger( "colour", Colour.values()[ colourIndex ].getHex() );
+        nbt.setInteger( "colour", Colour.values()[colourIndex].getHex() );
 
         ItemStack result = new ItemStack( ComputerCraft.Items.treasureDisk, 1, 0 );
         result.setTagCompound( nbt );

src/main/java/dan200/computercraft/shared/media/items/RecordMedia.java

@@ -7,19 +7,21 @@
 package dan200.computercraft.shared.media.items;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.media.IMedia;
 import net.minecraft.item.ItemRecord;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.SoundEvent;
-import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 
-// An implementation of IMedia for ItemRecord's
+/**
+ * An implementation of IMedia for ItemRecord's
+ */
 public class RecordMedia implements IMedia
 {
-    public RecordMedia()
+    public static final RecordMedia INSTANCE = new RecordMedia();
+
+    private RecordMedia()
     {
     }
 
@@ -29,12 +31,6 @@ public String getLabel( @Nonnull ItemStack stack )
         return getAudioTitle( stack );
     }
 
-    @Override
-    public boolean setLabel( @Nonnull ItemStack stack, String label )
-    {
-        return false;
-    }
-    
     @Override
     public String getAudioTitle( @Nonnull ItemStack stack )
     {
@@ -44,13 +40,7 @@ public String getAudioTitle( @Nonnull ItemStack stack )
     @Override
     public SoundEvent getAudio( @Nonnull ItemStack stack )
     {
-        ItemRecord itemRecord = (ItemRecord)stack.getItem();
+        ItemRecord itemRecord = (ItemRecord) stack.getItem();
         return itemRecord.sound;
     }
-    
-    @Override
-    public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
-    {
-        return null;
-    }
 }

src/main/java/dan200/computercraft/shared/pocket/items/ItemPocketComputer.java

@@ -28,7 +28,10 @@
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
-import net.minecraft.util.*;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.EnumActionResult;
+import net.minecraft.util.EnumHand;
+import net.minecraft.util.NonNullList;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.Constants;
 import net.minecraftforge.fml.relauncher.Side;
@@ -396,18 +399,6 @@ public boolean setLabel( @Nonnull ItemStack stack, String label )
         return true;
     }
 
-    @Override
-    public String getAudioTitle( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-
-    @Override
-    public SoundEvent getAudio( @Nonnull ItemStack stack )
-    {
-        return null;
-    }
-
     @Override
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {
@@ -457,7 +448,7 @@ private void setSessionID( @Nonnull ItemStack stack, int sessionID )
         stack.getTagCompound().setInteger( "sessionID", sessionID );
     }
 
-    @SideOnly(Side.CLIENT)
+    @SideOnly( Side.CLIENT )
     public ComputerState getState( @Nonnull ItemStack stack )
     {
         ClientComputer computer = getClientComputer( stack );
@@ -468,7 +459,7 @@ public ComputerState getState( @Nonnull ItemStack stack )
         return ComputerState.Off;
     }
 
-    @SideOnly(Side.CLIENT)
+    @SideOnly( Side.CLIENT )
     public int getLightState( @Nonnull ItemStack stack )
     {
         ClientComputer computer = getClientComputer( stack );

src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleCraftingTable.java

@@ -7,14 +7,16 @@
 package dan200.computercraft.shared.turtle.upgrades;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.api.turtle.*;
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.api.turtle.ITurtleUpgrade;
+import dan200.computercraft.api.turtle.TurtleSide;
+import dan200.computercraft.api.turtle.TurtleUpgradeType;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.block.model.IBakedModel;
 import net.minecraft.client.renderer.block.model.ModelManager;
 import net.minecraft.client.renderer.block.model.ModelResourceLocation;
 import net.minecraft.init.Blocks;
 import net.minecraft.item.ItemStack;
-import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
@@ -82,13 +84,6 @@ public IPeripheral createPeripheral( @Nonnull ITurtleAccess turtle, @Nonnull Tur
         return new CraftingTablePeripheral( turtle );
     }
 
-    @Nonnull
-    @Override
-    public TurtleCommandResult useTool( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side, @Nonnull TurtleVerb verb, @Nonnull EnumFacing dir )
-    {
-        return TurtleCommandResult.failure();
-    }
-
     @SideOnly( Side.CLIENT )
     private void loadModelLocations()
     {

src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleSpeaker.java

@@ -8,7 +8,10 @@
 package dan200.computercraft.shared.turtle.upgrades;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.api.turtle.*;
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import dan200.computercraft.api.turtle.ITurtleUpgrade;
+import dan200.computercraft.api.turtle.TurtleSide;
+import dan200.computercraft.api.turtle.TurtleUpgradeType;
 import dan200.computercraft.shared.peripheral.PeripheralType;
 import dan200.computercraft.shared.peripheral.common.PeripheralItemFactory;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerPeripheral;
@@ -17,13 +20,13 @@
 import net.minecraft.client.renderer.block.model.ModelManager;
 import net.minecraft.client.renderer.block.model.ModelResourceLocation;
 import net.minecraft.item.ItemStack;
-import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 import org.apache.commons.lang3.tuple.Pair;
+
 import javax.annotation.Nonnull;
 import javax.vecmath.Matrix4f;
 
@@ -34,7 +37,7 @@ private static class Peripheral extends SpeakerPeripheral
         // Members
         ITurtleAccess m_turtle;
 
-        public Peripheral(ITurtleAccess turtle)
+        public Peripheral( ITurtleAccess turtle )
         {
             super();
             m_turtle = turtle;
@@ -59,9 +62,9 @@ public BlockPos getPos()
         }
 
         @Override
-        public boolean equals(IPeripheral other)
+        public boolean equals( IPeripheral other )
         {
-            if (other instanceof Peripheral)
+            if( other instanceof Peripheral )
             {
                 Peripheral otherPeripheral = (Peripheral) other;
                 return otherPeripheral.m_turtle == m_turtle;
@@ -124,14 +127,7 @@ public ItemStack getCraftingItem()
     @Override
     public IPeripheral createPeripheral( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side )
     {
-        return new TurtleSpeaker.Peripheral(turtle);
+        return new TurtleSpeaker.Peripheral( turtle );
-    }
-
-    @Nonnull
-    @Override
-    public TurtleCommandResult useTool( @Nonnull ITurtleAccess turtleAccess, @Nonnull TurtleSide turtleSide, @Nonnull TurtleVerb verb, @Nonnull EnumFacing direction )
-    {
-        return TurtleCommandResult.failure();
     }
 
     @SideOnly( Side.CLIENT )
@@ -166,7 +162,7 @@ public Pair<IBakedModel, Matrix4f> getModel( ITurtleAccess turtle, @Nonnull Turt
     public void update( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide turtleSide )
     {
         IPeripheral turtlePeripheral = turtle.getPeripheral( turtleSide );
-        if ( turtlePeripheral instanceof Peripheral )
+        if( turtlePeripheral instanceof Peripheral )
         {
             Peripheral peripheral = (Peripheral) turtlePeripheral;
             peripheral.update();

src/main/java/dan200/computercraft/shared/turtle/upgrades/TurtleTool.java

@@ -7,7 +7,6 @@
 package dan200.computercraft.shared.turtle.upgrades;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.turtle.*;
 import dan200.computercraft.api.turtle.event.TurtleAttackEvent;
 import dan200.computercraft.api.turtle.event.TurtleBlockEvent;
@@ -94,12 +93,6 @@ public ItemStack getCraftingItem()
         return m_item.copy();
     }
 
-    @Override
-    public IPeripheral createPeripheral( @Nonnull ITurtleAccess turtle, @Nonnull TurtleSide side )
-    {
-        return null;
-    }
-
     @Nonnull
     @Override
     @SideOnly( Side.CLIENT )