fix +sa + update

Signed-off-by: Glease <4586901+Glease@users.noreply.github.com>

addon.gradle

@@ -1,7 +1,7 @@
 javadoc {
     javadocTool = javaToolchains.javadocToolFor {
         // Last version with frames, but it also has search
-        languageVersion = JavaLanguageVersion.of(11)
+        languageVersion = JavaLanguageVersion.of(21)
         vendor = JvmVendorSpec.ADOPTIUM
     }
 
@@ -20,7 +20,6 @@ javadoc {
         overview "src/main/javadoc/overview.html"
         links 'https://docs.oracle.com/javase/8/docs/api/'
         links 'https://skmedix.github.io/ForgeJavaDocs/javadoc/forge/1.7.10-10.13.4.1614/'
-        addBooleanOption("-frames", true)
     }
 }
 

dependencies.gradle

@@ -1,9 +1,13 @@
 // Add your dependencies here
 
 dependencies {
-    api("com.github.GTNewHorizons:GTNHLib:0.6.13:dev")
-    runtimeOnly("com.github.GTNewHorizons:NotEnoughItems:2.7.29-GTNH:dev")
+    api("com.github.GTNewHorizons:GTNHLib:0.6.19:dev")
+    implementation("com.github.GTNewHorizons:NotEnoughItems:2.7.38-GTNH:dev")
 
     testImplementation(platform('org.junit:junit-bom:5.9.2'))
     testImplementation('org.junit.jupiter:junit-jupiter')
+
+//    runtimeOnlyNonPublishable("com.github.GTNewHorizons:GT5-Unofficial:5.09.51.227:dev") {
+//        exclude group: "com.github.GTNewHorizons", module: "StructureLib"
+//    }
 }

gradle.properties

@@ -14,7 +14,7 @@ modId = structurelib
 modGroup = com.gtnewhorizon.structurelib
 
 # Whether to use modGroup as the maven publishing group.
-# Due to a history of using JitPack, the default is com.github.GTNewHorizons for all mods.
+# When false, com.github.GTNewHorizons is used.
 useModGroupForPublishing = false
 
 # Updates your build.gradle and settings.gradle automatically whenever an update is available.

settings.gradle

@@ -17,7 +17,7 @@ pluginManagement {
 }
 
 plugins {
-    id 'com.gtnewhorizons.gtnhsettingsconvention' version '1.0.37'
+    id 'com.gtnewhorizons.gtnhsettingsconvention' version '1.0.38'
 }
 
 

src/main/java/com/gtnewhorizon/structurelib/ChannelDescription.java

@@ -0,0 +1,94 @@
+package com.gtnewhorizon.structurelib;
+
+import java.util.AbstractMap;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import net.minecraft.item.ItemStack;
+
+import com.gtnewhorizon.gtnhlib.util.map.ItemStackMap;
+
+import cpw.mods.fml.common.Loader;
+
+// this is not an API! go check StructureLibAPI instead!
+public class ChannelDescription {
+
+    private static final ItemStackMap<Set<ChannelDescription>> itemToChannels = new ItemStackMap<>(true);
+    private static final Map<String, ChannelDescription> registry = new HashMap<>();
+    private final String channel;
+    private final Map<String, String> descriptions = new HashMap<>();
+    private final ItemStackMap<Integer> items = new ItemStackMap<>(true);
+
+    public static ChannelDescription get(final String channel) {
+        if (StructureLibAPI.isDebugEnabled() && !channel.toLowerCase(Locale.ROOT).equals(channel))
+            throw new IllegalArgumentException("Channel name can be lower case ONLY");
+        return registry.computeIfAbsent(channel, ChannelDescription::new);
+    }
+
+    public static boolean has(final String channel) {
+        if (StructureLibAPI.isDebugEnabled() && !channel.toLowerCase(Locale.ROOT).equals(channel))
+            throw new IllegalArgumentException("Channel name can be lower case ONLY");
+        return registry.containsKey(channel);
+    }
+
+    public static Collection<Map.Entry<String, Integer>> iterate(final ItemStack block) {
+        Set<ChannelDescription> channels = itemToChannels.get(block);
+        if (channels == null) return Collections.emptySet();
+        return channels.stream().map(d -> new AbstractMap.SimpleImmutableEntry<>(d.channel, d.items.get(block)))
+                .collect(Collectors.toList());
+    }
+
+    public static void set(final String channel, final String modid, final String description) {
+        if (StructureLibAPI.isDebugEnabled() && !channel.toLowerCase(Locale.ROOT).equals(channel))
+            throw new IllegalArgumentException("Channel name can be lower case ONLY");
+        registry.computeIfAbsent(channel, ChannelDescription::new).add(modid, description);
+    }
+
+    public static void item(final String channel, int channelValue, ItemStack stack) {
+        if (StructureLibAPI.isDebugEnabled()) {
+            if (!channel.toLowerCase(Locale.ROOT).equals(channel)) {
+                throw new IllegalArgumentException("Channel name can be lower case ONLY");
+            }
+            if (channelValue <= 0) {
+                throw new IllegalArgumentException("Channel value must be greater than 0");
+            }
+        }
+        ChannelDescription inst = registry.computeIfAbsent(channel, ChannelDescription::new);
+        inst.items.put(stack, channelValue);
+        itemToChannels.computeIfAbsent(stack, s -> new HashSet<>()).add(inst);
+    }
+
+    public static Map<String, ChannelDescription> getAll() {
+        return Collections.unmodifiableMap(registry);
+    }
+
+    private ChannelDescription(String channel) {
+        this.channel = channel;
+    }
+
+    public String getChannel() {
+        return channel;
+    }
+
+    public ChannelDescription add(String modid, String description) {
+        if (Loader.instance().getIndexedModList().get(modid) == null) {
+            throw new IllegalArgumentException("Mod not found: " + modid);
+        }
+        descriptions.put(modid, description);
+        return this;
+    }
+
+    public Map<String, String> getDescriptions() {
+        return Collections.unmodifiableMap(descriptions);
+    }
+
+    public Map<ItemStack, Integer> getItems() {
+        return Collections.unmodifiableMap(items);
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/ClientProxy.java

@@ -20,6 +20,7 @@ import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.culling.Frustrum;
 import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.client.resources.I18n;
+import net.minecraft.client.settings.KeyBinding;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
@@ -42,17 +43,23 @@ import org.lwjgl.opengl.GL11;
 import com.gtnewhorizon.structurelib.entity.fx.WeightlessParticleFX;
 import com.gtnewhorizon.structurelib.net.RegistryOrderSyncMessage;
 import com.gtnewhorizon.structurelib.net.SetChannelDataMessage;
+import com.gtnewhorizon.structurelib.net.StructureProjectorCycleModeMessage;
 
 import cpw.mods.fml.client.config.GuiConfig;
 import cpw.mods.fml.client.event.ConfigChangedEvent;
+import cpw.mods.fml.client.registry.ClientRegistry;
 import cpw.mods.fml.common.FMLCommonHandler;
+import cpw.mods.fml.common.event.FMLInitializationEvent;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
 import cpw.mods.fml.common.eventhandler.EventPriority;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
+import cpw.mods.fml.common.gameevent.InputEvent;
 import cpw.mods.fml.common.gameevent.TickEvent.ClientTickEvent;
 import cpw.mods.fml.common.gameevent.TickEvent.Phase;
 import cpw.mods.fml.common.network.FMLNetworkEvent;
+import cpw.mods.fml.relauncher.Side;
+import cpw.mods.fml.relauncher.SideOnly;
 
 public class ClientProxy extends CommonProxy {
 
@@ -259,6 +266,13 @@ public class ClientProxy extends CommonProxy {
         MinecraftForge.EVENT_BUS.register(new ForgeEventHandler());
     }
 
+    @Override
+    public void init(FMLInitializationEvent e) {
+        super.init(e);
+
+        MinecraftForge.EVENT_BUS.register(new KeybindHandler());
+    }
+
     static void markTextureUsed(IIcon icon) {
         if (StructureLib.COMPAT instanceof IStructureCompat)
             ((IStructureCompat) StructureLib.COMPAT).markTextureUsed(icon);
@@ -654,4 +668,30 @@ public class ClientProxy extends CommonProxy {
             p.endSection();
         }
     }
+
+    public static class KeybindHandler {
+
+        private static final KeyBinding CYCLE_PROJECTOR_MODE = new KeyBinding(
+                "item.structurelib.constructableTrigger.keys.cycleMode",
+                0,
+                "item.structurelib.constructableTrigger.keyCategory");
+
+        public KeybindHandler() {
+            FMLCommonHandler.instance().bus().register(this);
+            // If somebody wants to make a UI element for this, be my guest
+            ClientRegistry.registerKeyBinding(CYCLE_PROJECTOR_MODE);
+        }
+
+        @SideOnly(Side.CLIENT)
+        @SubscribeEvent
+        public void key(InputEvent.KeyInputEvent event) {
+            if (CYCLE_PROJECTOR_MODE.isPressed()) {
+                cycleProjectorMode();
+            }
+        }
+
+        private static void cycleProjectorMode() {
+            StructureLib.net.sendToServer(new StructureProjectorCycleModeMessage());
+        }
+    }
 }

src/main/java/com/gtnewhorizon/structurelib/CommonProxy.java

@@ -17,6 +17,7 @@ import net.minecraftforge.common.MinecraftForge;
 import com.gtnewhorizon.structurelib.net.ErrorHintParticleMessage;
 import com.gtnewhorizon.structurelib.net.UpdateHintParticleMessage;
 
+import cpw.mods.fml.common.event.FMLInitializationEvent;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
 import cpw.mods.fml.common.eventhandler.SubscribeEvent;
@@ -64,6 +65,8 @@ public class CommonProxy {
 
     public void preInit(FMLPreInitializationEvent e) {}
 
+    public void init(FMLInitializationEvent e) {}
+
     public long getOverworldTime() {
         return MinecraftServer.getServer().getEntityWorld().getTotalWorldTime();
     }

src/main/java/com/gtnewhorizon/structurelib/DevelopHelper.java

@@ -0,0 +1,48 @@
+package com.gtnewhorizon.structurelib;
+
+import net.minecraft.init.Blocks;
+import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.nbt.NBTTagList;
+
+import cpw.mods.fml.common.event.FMLInterModComms;
+
+public class DevelopHelper {
+
+    private static final boolean DEBUG = Boolean.getBoolean("structurelib.develop_helper");
+
+    public static void onPreInit() {
+        if (!DEBUG) return;
+        StructureLib.LOGGER.info("Running develop helper");
+        StructureLibAPI.registerChannelDescription("sandstone", StructureLibAPI.MOD_ID, "variants of Sandstone");
+        StructureLibAPI.registerChannelItem("sandstone", StructureLibAPI.MOD_ID, 1, new ItemStack(Blocks.sandstone));
+        StructureLibAPI
+                .registerChannelItem("sandstone", StructureLibAPI.MOD_ID, 2, new ItemStack(Blocks.sandstone, 1, 1));
+        StructureLibAPI
+                .registerChannelItem("sandstone", StructureLibAPI.MOD_ID, 3, new ItemStack(Blocks.sandstone, 1, 2));
+        StructureLibAPI.registerChannelDescription("sandbricks", StructureLibAPI.MOD_ID, "variants of Sandbricks");
+        StructureLibAPI.registerChannelDescription("apple", StructureLibAPI.MOD_ID, "apple");
+        StructureLibAPI.registerChannelDescription("bright", StructureLibAPI.MOD_ID, "bright");
+        StructureLibAPI.registerChannelDescription("apple_blight", StructureLibAPI.MOD_ID, "apple_blight");
+        StructureLibAPI.registerChannelDescription("app_eagle", StructureLibAPI.MOD_ID, "app_eagle");
+    }
+
+    public void x() {
+        NBTTagCompound command = new NBTTagCompound();
+        NBTTagList items = new NBTTagList();
+        int[] metas = { 0, 1, 2 };
+        for (int meta : metas) {
+            NBTTagCompound tag = new NBTTagCompound();
+            tag.setTag("Item", new ItemStack(Blocks.sandstone, 1, meta).writeToNBT(new NBTTagCompound()));
+            NBTTagList channels = new NBTTagList();
+            NBTTagCompound channel = new NBTTagCompound();
+            channel.setString("Channel", "sandstone");
+            channel.setInteger("Value", meta + 1);
+            channels.appendTag(channel);
+            tag.setTag("Channels", channels);
+            items.appendTag(tag);
+        }
+        command.setTag("Items", items);
+        FMLInterModComms.sendMessage("structurelib", "register_channel_item", command);
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/GuiHandler.java

@@ -3,6 +3,7 @@ package com.gtnewhorizon.structurelib;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.world.World;
 
+import com.gtnewhorizon.structurelib.gui.EmptyContainer;
 import com.gtnewhorizon.structurelib.gui.GuiScreenConfigureChannels;
 
 import cpw.mods.fml.common.network.IGuiHandler;
@@ -11,14 +12,19 @@ public class GuiHandler implements IGuiHandler {
 
     @Override
     public Object getServerGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
-        return null;
+        switch (ID) {
+            case 0:
+                return new EmptyContainer(player);
+            default:
+                return null;
+        }
     }
 
     @Override
     public Object getClientGuiElement(int ID, EntityPlayer player, World world, int x, int y, int z) {
         switch (ID) {
             case 0:
-                return new GuiScreenConfigureChannels(player.inventory.getStackInSlot(x));
+                return new GuiScreenConfigureChannels(new EmptyContainer(player), player.inventory.getStackInSlot(x));
             default:
                 return null;
         }

src/main/java/com/gtnewhorizon/structurelib/StructureLib.java

@@ -1,11 +1,18 @@
 package com.gtnewhorizon.structurelib;
 
+import static com.gtnewhorizon.structurelib.StructureLibAPI.CHANNEL_SHOW_ERROR;
+import static com.gtnewhorizon.structurelib.StructureLibAPI.MOD_ID;
+
 import net.minecraft.block.Block;
 import net.minecraft.creativetab.CreativeTabs;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemBlock;
+import net.minecraft.item.ItemStack;
 import net.minecraft.launchwrapper.Launch;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.nbt.NBTTagList;
+import net.minecraftforge.common.util.Constants;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
@@ -20,13 +27,15 @@ import com.gtnewhorizon.structurelib.net.AlignmentMessage;
 import com.gtnewhorizon.structurelib.net.ErrorHintParticleMessage;
 import com.gtnewhorizon.structurelib.net.RegistryOrderSyncMessage;
 import com.gtnewhorizon.structurelib.net.SetChannelDataMessage;
+import com.gtnewhorizon.structurelib.net.StructureProjectorCycleModeMessage;
 import com.gtnewhorizon.structurelib.net.UpdateHintParticleMessage;
 import com.gtnewhorizon.structurelib.util.InventoryUtility;
 import com.gtnewhorizon.structurelib.util.XSTR;
 
-import cpw.mods.fml.common.Loader;
 import cpw.mods.fml.common.Mod;
 import cpw.mods.fml.common.SidedProxy;
+import cpw.mods.fml.common.event.FMLInitializationEvent;
+import cpw.mods.fml.common.event.FMLInterModComms;
 import cpw.mods.fml.common.event.FMLLoadCompleteEvent;
 import cpw.mods.fml.common.event.FMLPreInitializationEvent;
 import cpw.mods.fml.common.event.FMLServerStartingEvent;
@@ -40,7 +49,7 @@ import cpw.mods.fml.relauncher.SideOnly;
  * This class does not contain a stable API. Refrain from using this class.
  */
 @Mod(
-        modid = StructureLibAPI.MOD_ID,
+        modid = MOD_ID,
         name = "StructureLib",
         version = Tags.VERSION,
         acceptableRemoteVersions = "*",
@@ -57,7 +66,7 @@ public class StructureLib {
             clientSide = "com.gtnewhorizon.structurelib.ClientProxy")
     static CommonProxy proxy;
 
-    static final SimpleNetworkWrapper net = NetworkRegistry.INSTANCE.newSimpleChannel(StructureLibAPI.MOD_ID);
+    static final SimpleNetworkWrapper net = NetworkRegistry.INSTANCE.newSimpleChannel(MOD_ID);
 
     static {
         net.registerMessage(
@@ -70,6 +79,11 @@ public class StructureLib {
         net.registerMessage(SetChannelDataMessage.Handler.class, SetChannelDataMessage.class, 3, Side.SERVER);
         net.registerMessage(ErrorHintParticleMessage.Handler.class, ErrorHintParticleMessage.class, 4, Side.CLIENT);
         net.registerMessage(RegistryOrderSyncMessage.Handler.class, RegistryOrderSyncMessage.class, 5, Side.SERVER);
+        net.registerMessage(
+                StructureProjectorCycleModeMessage.Handler.class,
+                StructureProjectorCycleModeMessage.class,
+                6,
+                Side.SERVER);
 
         try {
             DEBUG_MODE = Boolean.parseBoolean(System.getProperty("structurelib.debug"));
@@ -84,7 +98,7 @@ public class StructureLib {
 
     @Mod.Instance
     static StructureLib INSTANCE;
-
+    @Mod.Instance(STRUCTURECOMPAT_MODID)
     static Object COMPAT;
 
     static Block blockHint;
@@ -100,8 +114,6 @@ public class StructureLib {
         }
     };
 
-    public static boolean isGTLoaded;
-
     @Mod.EventHandler
     public void preInit(FMLPreInitializationEvent e) {
         ConfigurationHandler.INSTANCE.init(e.getSuggestedConfigurationFile());
@@ -117,11 +129,15 @@ public class StructureLib {
         NetworkRegistry.INSTANCE.registerGuiHandler(instance(), new GuiHandler());
 
         InventoryUtility.init();
-        if (Loader.isModLoaded(STRUCTURECOMPAT_MODID)) {
-            COMPAT = Loader.instance().getIndexedModList().get(STRUCTURECOMPAT_MODID).getMod();
-        }
 
-        isGTLoaded = Loader.isModLoaded("gregtech");
+        ChannelDescription.set(CHANNEL_SHOW_ERROR, MOD_ID, "channels.structurelib.show_errors");
+
+        DevelopHelper.onPreInit();
+    }
+
+    @Mod.EventHandler
+    public void init(FMLInitializationEvent e) {
+        proxy.init(e);
     }
 
     @Mod.EventHandler
@@ -135,6 +151,48 @@ public class StructureLib {
         e.registerServerCommand(new CommandRegistryDebug());
     }
 
+    @Mod.EventHandler
+    public void handleIMC(FMLInterModComms.IMCEvent event) {
+        for (FMLInterModComms.IMCMessage message : event.getMessages()) {
+            switch (message.key) {
+                case "register_channel":
+                    processRegisterChannel(message);
+                    break;
+                case "register_channel_item":
+                    processRegisterChannelItem(message);
+                    break;
+            }
+        }
+    }
+
+    private void processRegisterChannel(FMLInterModComms.IMCMessage message) {
+        NBTTagList tags = message.getNBTValue().getTagList("Channels", Constants.NBT.TAG_COMPOUND);
+        for (int i = 0; i < tags.tagCount(); i++) {
+            NBTTagCompound tag = tags.getCompoundTagAt(i);
+            StructureLibAPI.registerChannelDescription(
+                    tag.getString("Channel"),
+                    message.getSender(),
+                    tag.getString("Description"));
+        }
+    }
+
+    private void processRegisterChannelItem(FMLInterModComms.IMCMessage message) {
+        NBTTagList items = message.getNBTValue().getTagList("Items", Constants.NBT.TAG_COMPOUND);
+        for (int i = 0; i < items.tagCount(); i++) {
+            NBTTagCompound itemTag = items.getCompoundTagAt(i);
+            ItemStack item = ItemStack.loadItemStackFromNBT(itemTag.getCompoundTag("Item"));
+            NBTTagList tags = itemTag.getTagList("Channels", Constants.NBT.TAG_COMPOUND);
+            for (int j = 0; j < tags.tagCount(); j++) {
+                NBTTagCompound tag = tags.getCompoundTagAt(j);
+                StructureLibAPI.registerChannelItem(
+                        tag.getString("Channel"),
+                        message.getSender(),
+                        tag.getInteger("Value"),
+                        item);
+            }
+        }
+    }
+
     public static void addClientSideChatMessages(String... messages) {
         proxy.addClientSideChatMessages(messages);
     }

src/main/java/com/gtnewhorizon/structurelib/StructureLibAPI.java

@@ -9,8 +9,10 @@ import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.IChatComponent;
 import net.minecraft.util.IIcon;
+import net.minecraft.util.StatCollector;
 import net.minecraft.world.World;
 
+import com.gtnewhorizon.gtnhlib.util.AnimatedTooltipHandler;
 import com.gtnewhorizon.structurelib.alignment.IAlignment;
 import com.gtnewhorizon.structurelib.alignment.IAlignmentProvider;
 import com.gtnewhorizon.structurelib.alignment.enumerable.ExtendedFacing;
@@ -43,6 +45,7 @@ public class StructureLibAPI {
     public static final int HINT_BLOCK_META_AIR = 13;
     public static final int HINT_BLOCK_META_NOT_AIR = 14;
     public static final int HINT_BLOCK_META_ERROR = 15;
+    public static final String CHANNEL_SHOW_ERROR = "show_error";
     static final ThreadLocal<Object> instrument = new ThreadLocal<>();
 
     /**
@@ -350,4 +353,35 @@ public class StructureLibAPI {
             short intervalRequired, boolean forceUpdateLastSend) {
         proxy.addThrottledChat(throttleKey, player, text, intervalRequired, forceUpdateLastSend);
     }
+
+    /**
+     * Register a channel description here. The description should describe how a channel will be used inside your mod.
+     *
+     * @param channel     channel key
+     * @param modid       your modid
+     * @param description localization key for your description
+     */
+    public static void registerChannelDescription(final String channel, final String modid, final String description) {
+        ChannelDescription.set(channel, modid, description);
+    }
+
+    /**
+     * Register an item stack as an indicator for a (channel, value) pair.
+     *
+     * @param channel      channel key
+     * @param modid        your modid
+     * @param channelValue value
+     * @param stack        item stack. having a metadata of
+     *                     {@link net.minecraftforge.oredict.OreDictionary#WILDCARD_VALUE} will match without comparing
+     *                     NBT or metadata value. having a tag with {@code tag.getBoolean("*") == true} will match
+     *                     without comparing NBT.
+     */
+    public static void registerChannelItem(final String channel, final String modid, final int channelValue,
+            final ItemStack stack) {
+        ChannelDescription.item(channel, channelValue, stack);
+        AnimatedTooltipHandler.addItemTooltip(
+                stack,
+                () -> StatCollector
+                        .translateToLocalFormatted("structurelib.tooltip.channelvalue", channelValue, channel));
+    }
 }

src/main/java/com/gtnewhorizon/structurelib/alignment/constructable/ConstructableUtility.java

@@ -57,12 +57,12 @@ public class ConstructableUtility {
         }
 
         IConstructable constructable = null;
-        if (tTileEntity instanceof IConstructableProvider)
-            constructable = ((IConstructableProvider) tTileEntity).getConstructable();
-        else if (tTileEntity instanceof IConstructable) {
-            constructable = (IConstructable) tTileEntity;
+        if (tTileEntity instanceof IConstructableProvider aConstructableProvider)
+            constructable = aConstructableProvider.getConstructable();
+        else if (tTileEntity instanceof IConstructable aConstructable) {
+            constructable = aConstructable;
         } else if (IMultiblockInfoContainer.contains(tTileEntity.getClass())) {
-            ExtendedFacing facing = tTileEntity instanceof IAlignment ? ((IAlignment) tTileEntity).getExtendedFacing()
+            ExtendedFacing facing = tTileEntity instanceof IAlignment alignment ? alignment.getExtendedFacing()
                     : ExtendedFacing.of(ForgeDirection.getOrientation(aSide));
             constructable = IMultiblockInfoContainer.<TileEntity>get(tTileEntity.getClass())
                     .toConstructable(tTileEntity, facing);
@@ -70,14 +70,13 @@ public class ConstructableUtility {
 
         if (constructable == null) return false;
 
-        if (aPlayer instanceof EntityPlayerMP) {
-            EntityPlayerMP playerMP = (EntityPlayerMP) aPlayer;
+        if (aPlayer instanceof EntityPlayerMP playerMP) {
             // server side and sneaking (already checked above)
             // do construct
             if (aPlayer.capabilities.isCreativeMode) {
                 constructable.construct(aStack, false);
-            } else if (constructable instanceof ISurvivalConstructable) {
-                int built = ((ISurvivalConstructable) constructable).survivalConstruct(
+            } else if (constructable instanceof ISurvivalConstructable aConstructable) {
+                int built = aConstructable.survivalConstruct(
                         aStack,
                         ConfigurationHandler.INSTANCE.getAutoPlaceBudget(),
                         ISurvivalBuildEnvironment.create(IItemSource.fromPlayer(playerMP), playerMP));

src/main/java/com/gtnewhorizon/structurelib/gui/EmptyContainer.java

@@ -0,0 +1,18 @@
+package com.gtnewhorizon.structurelib.gui;
+
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.inventory.Container;
+
+public class EmptyContainer extends Container {
+
+    private final EntityPlayer player;
+
+    public EmptyContainer(EntityPlayer player) {
+        this.player = player;
+    }
+
+    @Override
+    public boolean canInteractWith(EntityPlayer player) {
+        return player == this.player;
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/gui/GuiScreenConfigureChannels.java

@@ -1,48 +1,82 @@
 package com.gtnewhorizon.structurelib.gui;
 
+import static org.lwjgl.opengl.ARBImaging.*;
+import static org.lwjgl.opengl.ARBImaging.GL_SEPARABLE_2D;
+import static org.lwjgl.opengl.GL11.*;
+import static org.lwjgl.opengl.GL11.GL_ALPHA_TEST_FUNC;
+import static org.lwjgl.opengl.GL12.GL_RESCALE_NORMAL;
+import static org.lwjgl.opengl.GL12.GL_TEXTURE_3D;
+import static org.lwjgl.opengl.GL13.*;
+import static org.lwjgl.opengl.GL14.*;
+import static org.lwjgl.opengl.GL14.GL_BLEND_SRC_RGB;
+import static org.lwjgl.opengl.GL15.GL_FOG_COORD_ARRAY;
+import static org.lwjgl.opengl.GL20.*;
+
+import java.util.AbstractMap;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
+import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 import net.minecraft.client.gui.GuiButton;
-import net.minecraft.client.gui.GuiScreen;
 import net.minecraft.client.gui.GuiTextField;
+import net.minecraft.client.gui.inventory.GuiContainer;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.resources.I18n;
+import net.minecraft.inventory.Container;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.EnumChatFormatting;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.StatCollector;
 
 import org.apache.commons.lang3.StringUtils;
 import org.lwjgl.input.Keyboard;
 import org.lwjgl.input.Mouse;
 import org.lwjgl.opengl.GL11;
 
+import com.google.common.collect.ImmutableMap;
+import com.gtnewhorizon.structurelib.ChannelDescription;
 import com.gtnewhorizon.structurelib.StructureLib;
 import com.gtnewhorizon.structurelib.alignment.constructable.ChannelDataAccessor;
 import com.gtnewhorizon.structurelib.gui.GuiScrollableList.IGuiScreen;
 
-public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen {
+import codechicken.nei.VisiblityData;
+import codechicken.nei.api.INEIGuiHandler;
+import codechicken.nei.api.TaggedInventoryArea;
+import cpw.mods.fml.common.Loader;
+import cpw.mods.fml.common.Optional;
+import gnu.trove.map.TIntObjectMap;
+import gnu.trove.map.hash.TIntObjectHashMap;
+
+@Optional.Interface(iface = "codechicken.nei.api.INEIGuiHandler", modid = "NotEnoughItems")
+public class GuiScreenConfigureChannels extends GuiContainer implements IGuiScreen, INEIGuiHandler {
 
     private static final String I18N_PREFIX = "item.structurelib.constructableTrigger.gui.";
 
     private static final int ADD_BTN = 0;
     private static final int UNSET_BTN = 1;
     private static final int WIPE_BTN = 2;
-    private static final int SHOW_ERROR_BTN = 3;
-    private static final int GT_NO_HATCH_BTN = 4;
-
-    private static final String SHOW_ERROR_CHANNEL = "show_error";
-    private static final String GT_NO_HATCH_CHANNEL = "gt_no_hatch";
 
     private static final int KEY_MAX_WIDTH = 50;
     private final ItemStack trigger;
     private final GuiChannelsList list;
+    private final GuiAutoCompleteList autoCompleteList;
+    private final Map<String, List<String>> tooltipSplitCache = new HashMap<>();
+    private final TIntObjectMap<Map<String, String>> trimCache = new TIntObjectHashMap<>();
     private GuiTextField key, value;
     protected int guiTop, guiLeft;
 
-    public GuiScreenConfigureChannels(ItemStack trigger) {
+    public GuiScreenConfigureChannels(Container container, ItemStack trigger) {
+        super(container);
+
         this.trigger = trigger;
         list = new GuiChannelsList(152, 100, 12, 12, 14);
         list.addSelectionListener((list, selectedIndex) -> {
@@ -51,6 +85,7 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
             value.setText(e.getValue().toString());
             updateButtons();
         });
+        autoCompleteList = new GuiAutoCompleteList(151 + 12 - 45 - 2, 50, 45, 119 + 12, 14);
     }
 
     @Override
@@ -136,6 +171,7 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
         };
 
         list.onGuiInit(this);
+        autoCompleteList.onGuiInit(this);
 
         addButton(
                 new GuiButton(
@@ -162,21 +198,8 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
                         20,
                         I18n.format("item.structurelib.constructableTrigger.gui.wipe")));
 
-        addButton(
-                new GuiButton(
-                        SHOW_ERROR_BTN,
-                        StructureLib.isGTLoaded ? guiLeft + 12 : guiLeft + 52,
-                        guiTop + 180,
-                        73,
-                        20,
-                        ""));
-
-        // only show GT hatch button if GT is loaded
-        if (StructureLib.isGTLoaded) {
-            addButton(new GuiButton(GT_NO_HATCH_BTN, guiLeft + 92, guiTop + 180, 73, 20, ""));
-        }
-
         updateButtons();
+        tooltipSplitCache.clear();
     }
 
     @Override
@@ -196,7 +219,7 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
 
     @Override
     public int getYSize() {
-        return 211;
+        return 188;
     }
 
     @Override
@@ -252,13 +275,14 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
 
     @Override
     protected void mouseClicked(int mX, int mY, int button) {
+        super.mouseClicked(mX, mY, button);
         key.mouseClicked(mX, mY, button);
         value.mouseClicked(mX, mY, button);
-        super.mouseClicked(mX, mY, button);
     }
 
     @Override
     protected void keyTyped(char aChar, int aKey) {
+        GuiScrollableList<?> l = key.isFocused() ? autoCompleteList : list;
         switch (aKey) {
             case Keyboard.KEY_TAB:
                 if (key.isFocused()) {
@@ -271,15 +295,31 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
                 return;
             case Keyboard.KEY_RETURN:
             case Keyboard.KEY_NUMPADENTER:
-                GuiButton add = getButtonList().get(0);
+                if (key.isFocused() && autoCompleteList.getSelectedElement() != null) {
+                    key.setText(autoCompleteList.getSelectedElement());
+                    key.setFocused(false);
+                    value.setFocused(true);
+                    return;
+                }
+                GuiButton add = getButtonList().get(ADD_BTN);
                 if (add.enabled) doActionPerformed(add);
                 return;
             case Keyboard.KEY_UP:
-                if (list.selectedIndex > 0) list.setSelection(list.selectedIndex - 1);
+                if (l.selectedIndex > 0) l.setSelection(l.selectedIndex - 1);
                 return;
             case Keyboard.KEY_DOWN:
-                if (list.selectedIndex < list.getNumElements() - 1) list.setSelection(list.selectedIndex + 1);
+                if (l.selectedIndex < l.getNumElements() - 1) l.setSelection(l.selectedIndex + 1);
                 return;
+            case Keyboard.KEY_ESCAPE:
+                if (key.isFocused()) {
+                    if (autoCompleteList.getSelectedElement() != null) {
+                        autoCompleteList.reset();
+                    } else {
+                        key.setFocused(false);
+                    }
+                    return;
+                }
+                break;
         }
         if (key.textboxKeyTyped(aChar, aKey)) {
             updateButtons();
@@ -300,20 +340,7 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
                 && Integer.parseInt(value.getText()) > 0;
         getButtonList().get(UNSET_BTN).enabled = existing && !StringUtils.isBlank(value.getText());
 
-        if (ChannelDataAccessor.hasSubChannel(trigger, SHOW_ERROR_CHANNEL)) {
-            getButtonList().get(SHOW_ERROR_BTN).displayString = I18n.format(I18N_PREFIX + "error.hide");
-        } else {
-            getButtonList().get(SHOW_ERROR_BTN).displayString = I18n.format(I18N_PREFIX + "error.show");
-        }
-
-        // this button only exists if GT is loaded.
-        if (StructureLib.isGTLoaded) {
-            if (ChannelDataAccessor.hasSubChannel(trigger, GT_NO_HATCH_CHANNEL)) {
-                getButtonList().get(GT_NO_HATCH_BTN).displayString = I18n.format(I18N_PREFIX + "gt_no_hatch.disable");
-            } else {
-                getButtonList().get(GT_NO_HATCH_BTN).displayString = I18n.format(I18N_PREFIX + "gt_no_hatch.enable");
-            }
-        }
+        autoCompleteList.reset();
     }
 
     private int getValue() {
@@ -338,20 +365,8 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
                 break;
             case WIPE_BTN:
                 ChannelDataAccessor.wipeChannelData(trigger);
-                break;
-            case SHOW_ERROR_BTN:
-                if (ChannelDataAccessor.hasSubChannel(trigger, SHOW_ERROR_CHANNEL)) {
-                    ChannelDataAccessor.unsetChannelData(trigger, SHOW_ERROR_CHANNEL);
-                } else {
-                    ChannelDataAccessor.setChannelData(trigger, SHOW_ERROR_CHANNEL, 1);
-                }
-                break;
-            case GT_NO_HATCH_BTN:
-                if (ChannelDataAccessor.hasSubChannel(trigger, GT_NO_HATCH_CHANNEL)) {
-                    ChannelDataAccessor.unsetChannelData(trigger, GT_NO_HATCH_CHANNEL);
-                } else {
-                    ChannelDataAccessor.setChannelData(trigger, GT_NO_HATCH_CHANNEL, 1);
-                }
+                key.setText("");
+                this.value.setText("");
                 break;
         }
 
@@ -375,17 +390,11 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
     }
 
     @Override
-    public boolean doesGuiPauseGame() {
-        return false;
-    }
-
-    @Override
-    public void drawScreen(int mX, int mY, float partialTick) {
+    public void drawGuiContainerBackgroundLayer(float partialTick, int mX, int mY) {
         mc.renderEngine.bindTexture(new ResourceLocation("structurelib", "textures/gui/channels.png"));
         int topLeftX = (this.width - this.getXSize()) / 2;
         int topLeftY = (this.height - this.getYSize()) / 2;
         drawTexturedModalRect(topLeftX, topLeftY, 0, 0, getXSize(), getYSize());
-        super.drawScreen(mX, mY, partialTick);
         list.drawScreen(mX, mY, partialTick);
         fontRendererObj.drawString(
                 I18n.format("item.structurelib.constructableTrigger.gui.key"),
@@ -401,6 +410,315 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
         value.drawTextBox();
     }
 
+    @Override
+    protected void drawGuiContainerForegroundLayer(int mouseX, int mouseY) {
+        if (key.isFocused() && autoCompleteList.getNumElements() > 0) {
+            autoCompleteList.drawScreen(mouseX, mouseY, 0);
+        }
+    }
+
+    @Override
+    public void drawScreen(int mouseX, int mouseY, float partialTicks) {
+        super.drawScreen(mouseX, mouseY, partialTicks);
+        String highlight = null;
+        if (key.isFocused() && autoCompleteList.getNumElements() > 0) {
+            highlight = autoCompleteList.getSelectedElement();
+        }
+        if (highlight == null && ChannelDescription.has(key.getText())) {
+            highlight = key.getText();
+        }
+        if (highlight != null) {
+            drawChannelDescriptionTooltip(highlight);
+        }
+    }
+
+    private void drawChannelDescriptionTooltip(String candidate) {
+        List<String> tooltip = tooltipSplitCache.computeIfAbsent(candidate, this::getChannelDescriptionTooltip);
+        drawHoveringText(tooltip, guiLeft + 151 + 12, guiTop + 122, fontRendererObj);
+    }
+
+    public static void debugPrintGLEnable() {
+        Map<Integer, String> functions = ImmutableMap.<Integer, String>builder().put(GL11.GL_NEVER, "GL_NEVER")
+                .put(GL11.GL_LESS, "GL_LESS").put(GL11.GL_EQUAL, "GL_EQUAL").put(GL11.GL_LEQUAL, "GL_LEQUAL")
+                .put(GL11.GL_GREATER, "GL_GREATER").put(GL11.GL_NOTEQUAL, "GL_NOTEQUAL")
+                .put(GL11.GL_GEQUAL, "GL_GEQUAL").put(GL11.GL_ALWAYS, "GL_ALWAYS").put(GL11.GL_ZERO, "GL_ZERO")
+                .put(GL11.GL_ONE, "GL_ONE").put(GL11.GL_SRC_COLOR, "GL_SRC_COLOR")
+                .put(GL11.GL_ONE_MINUS_SRC_COLOR, "GL_ONE_MINUS_SRC_COLOR").put(GL11.GL_DST_COLOR, "GL_DST_COLOR")
+                .put(GL11.GL_ONE_MINUS_DST_COLOR, "GL_ONE_MINUS_DST_COLOR").put(GL11.GL_SRC_ALPHA, "GL_SRC_ALPHA")
+                .put(GL11.GL_ONE_MINUS_SRC_ALPHA, "GL_ONE_MINUS_SRC_ALPHA").put(GL11.GL_DST_ALPHA, "GL_DST_ALPHA")
+                .put(GL11.GL_ONE_MINUS_DST_ALPHA, "GL_ONE_MINUS_DST_ALPHA")
+                .put(GL11.GL_CONSTANT_COLOR, "GL_CONSTANT_COLOR")
+                .put(GL11.GL_ONE_MINUS_CONSTANT_COLOR, "GL_ONE_MINUS_CONSTANT_COLOR")
+                .put(GL11.GL_CONSTANT_ALPHA, "GL_CONSTANT_ALPHA")
+                .put(GL11.GL_ONE_MINUS_CONSTANT_ALPHA, "GL_ONE_MINUS_CONSTANT_ALPHA")
+                .put(GL11.GL_SRC_ALPHA_SATURATE, "GL_SRC_ALPHA_SATURATE").build();
+        System.out.println("GL_ALPHA_TEST: " + GL11.glIsEnabled(GL_ALPHA_TEST));
+        System.out.println("GL_AUTO_NORMAL: " + GL11.glIsEnabled(GL_AUTO_NORMAL));
+        System.out.println("GL_BLEND: " + GL11.glIsEnabled(GL_BLEND));
+        System.out.println("GL_COLOR_ARRAY: " + GL11.glIsEnabled(GL_COLOR_ARRAY));
+        System.out.println("GL_COLOR_LOGIC_OP: " + GL11.glIsEnabled(GL_COLOR_LOGIC_OP));
+        System.out.println("GL_COLOR_MATERIAL: " + GL11.glIsEnabled(GL_COLOR_MATERIAL));
+        System.out.println("GL_COLOR_SUM: " + GL11.glIsEnabled(GL_COLOR_SUM));
+        System.out.println("GL_COLOR_TABLE: " + GL11.glIsEnabled(GL_COLOR_TABLE));
+        System.out.println("GL_CONVOLUTION_1D: " + GL11.glIsEnabled(GL_CONVOLUTION_1D));
+        System.out.println("GL_CONVOLUTION_2D: " + GL11.glIsEnabled(GL_CONVOLUTION_2D));
+        System.out.println("GL_CULL_FACE: " + GL11.glIsEnabled(GL_CULL_FACE));
+        System.out.println("GL_DEPTH_TEST: " + GL11.glIsEnabled(GL_DEPTH_TEST));
+        System.out.println("GL_DITHER: " + GL11.glIsEnabled(GL_DITHER));
+        System.out.println("GL_EDGE_FLAG_ARRAY: " + GL11.glIsEnabled(GL_EDGE_FLAG_ARRAY));
+        System.out.println("GL_FOG: " + GL11.glIsEnabled(GL_FOG));
+        System.out.println("GL_FOG_COORD_ARRAY: " + GL11.glIsEnabled(GL_FOG_COORD_ARRAY));
+        System.out.println("GL_HISTOGRAM: " + GL11.glIsEnabled(GL_HISTOGRAM));
+        System.out.println("GL_INDEX_ARRAY: " + GL11.glIsEnabled(GL_INDEX_ARRAY));
+        System.out.println("GL_INDEX_LOGIC_OP: " + GL11.glIsEnabled(GL_INDEX_LOGIC_OP));
+        System.out.println("GL_LIGHTING: " + GL11.glIsEnabled(GL_LIGHTING));
+        System.out.println("GL_LINE_SMOOTH: " + GL11.glIsEnabled(GL_LINE_SMOOTH));
+        System.out.println("GL_LINE_STIPPLE: " + GL11.glIsEnabled(GL_LINE_STIPPLE));
+        System.out.println("GL_MAP1_COLOR_4: " + GL11.glIsEnabled(GL_MAP1_COLOR_4));
+        System.out.println("GL_MAP1_INDEX: " + GL11.glIsEnabled(GL_MAP1_INDEX));
+        System.out.println("GL_MAP1_NORMAL: " + GL11.glIsEnabled(GL_MAP1_NORMAL));
+        System.out.println("GL_MAP1_TEXTURE_COORD_1: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_1));
+        System.out.println("GL_MAP1_TEXTURE_COORD_2: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_2));
+        System.out.println("GL_MAP1_TEXTURE_COORD_3: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_3));
+        System.out.println("GL_MAP1_TEXTURE_COORD_4: " + GL11.glIsEnabled(GL_MAP1_TEXTURE_COORD_4));
+        System.out.println("GL_MAP2_COLOR_4: " + GL11.glIsEnabled(GL_MAP2_COLOR_4));
+        System.out.println("GL_MAP2_INDEX: " + GL11.glIsEnabled(GL_MAP2_INDEX));
+        System.out.println("GL_MAP2_NORMAL: " + GL11.glIsEnabled(GL_MAP2_NORMAL));
+        System.out.println("GL_MAP2_TEXTURE_COORD_1: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_1));
+        System.out.println("GL_MAP2_TEXTURE_COORD_2: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_2));
+        System.out.println("GL_MAP2_TEXTURE_COORD_3: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_3));
+        System.out.println("GL_MAP2_TEXTURE_COORD_4: " + GL11.glIsEnabled(GL_MAP2_TEXTURE_COORD_4));
+        System.out.println("GL_MAP2_VERTEX_3: " + GL11.glIsEnabled(GL_MAP2_VERTEX_3));
+        System.out.println("GL_MAP2_VERTEX_4: " + GL11.glIsEnabled(GL_MAP2_VERTEX_4));
+        System.out.println("GL_MINMAX: " + GL11.glIsEnabled(GL_MINMAX));
+        System.out.println("GL_MULTISAMPLE: " + GL11.glIsEnabled(GL_MULTISAMPLE));
+        System.out.println("GL_NORMAL_ARRAY: " + GL11.glIsEnabled(GL_NORMAL_ARRAY));
+        System.out.println("GL_NORMALIZE: " + GL11.glIsEnabled(GL_NORMALIZE));
+        System.out.println("GL_POINT_SMOOTH: " + GL11.glIsEnabled(GL_POINT_SMOOTH));
+        System.out.println("GL_POINT_SPRITE: " + GL11.glIsEnabled(GL_POINT_SPRITE));
+        System.out.println("GL_POLYGON_SMOOTH: " + GL11.glIsEnabled(GL_POLYGON_SMOOTH));
+        System.out.println("GL_POLYGON_OFFSET_FILL: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_FILL));
+        System.out.println("GL_POLYGON_OFFSET_LINE: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_LINE));
+        System.out.println("GL_POLYGON_OFFSET_POINT: " + GL11.glIsEnabled(GL_POLYGON_OFFSET_POINT));
+        System.out.println("GL_POLYGON_STIPPLE: " + GL11.glIsEnabled(GL_POLYGON_STIPPLE));
+        System.out.println("GL_POST_COLOR_MATRIX_COLOR_TABLE: " + GL11.glIsEnabled(GL_POST_COLOR_MATRIX_COLOR_TABLE));
+        System.out.println("GL_POST_CONVOLUTION_COLOR_TABLE: " + GL11.glIsEnabled(GL_POST_CONVOLUTION_COLOR_TABLE));
+        System.out.println("GL_RESCALE_NORMAL: " + GL11.glIsEnabled(GL_RESCALE_NORMAL));
+        System.out.println("GL_SAMPLE_ALPHA_TO_COVERAGE: " + GL11.glIsEnabled(GL_SAMPLE_ALPHA_TO_COVERAGE));
+        System.out.println("GL_SAMPLE_ALPHA_TO_ONE: " + GL11.glIsEnabled(GL_SAMPLE_ALPHA_TO_ONE));
+        System.out.println("GL_SAMPLE_COVERAGE: " + GL11.glIsEnabled(GL_SAMPLE_COVERAGE));
+        System.out.println("GL_SCISSOR_TEST: " + GL11.glIsEnabled(GL_SCISSOR_TEST));
+        System.out.println("GL_SECONDARY_COLOR_ARRAY: " + GL11.glIsEnabled(GL_SECONDARY_COLOR_ARRAY));
+        System.out.println("GL_SEPARABLE_2D: " + GL11.glIsEnabled(GL_SEPARABLE_2D));
+        System.out.println("GL_STENCIL_TEST: " + GL11.glIsEnabled(GL_STENCIL_TEST));
+        System.out.println("GL_TEXTURE_1D: " + GL11.glIsEnabled(GL_TEXTURE_1D));
+        System.out.println("GL_TEXTURE_2D: " + GL11.glIsEnabled(GL_TEXTURE_2D));
+        System.out.println("GL_TEXTURE_3D: " + GL11.glIsEnabled(GL_TEXTURE_3D));
+        System.out.println("GL_TEXTURE_COORD_ARRAY: " + GL11.glIsEnabled(GL_TEXTURE_COORD_ARRAY));
+        System.out.println("GL_TEXTURE_CUBE_MAP: " + GL11.glIsEnabled(GL_TEXTURE_CUBE_MAP));
+        System.out.println("GL_TEXTURE_GEN_Q: " + GL11.glIsEnabled(GL_TEXTURE_GEN_Q));
+        System.out.println("GL_TEXTURE_GEN_R: " + GL11.glIsEnabled(GL_TEXTURE_GEN_R));
+        System.out.println("GL_TEXTURE_GEN_S: " + GL11.glIsEnabled(GL_TEXTURE_GEN_S));
+        System.out.println("GL_TEXTURE_GEN_T: " + GL11.glIsEnabled(GL_TEXTURE_GEN_T));
+        System.out.println("GL_VERTEX_ARRAY: " + GL11.glIsEnabled(GL_VERTEX_ARRAY));
+        System.out.println("GL_VERTEX_PROGRAM_POINT_SIZE: " + GL11.glIsEnabled(GL_VERTEX_PROGRAM_POINT_SIZE));
+        System.out.println("GL_VERTEX_PROGRAM_TWO_SIDE: " + GL11.glIsEnabled(GL_VERTEX_PROGRAM_TWO_SIDE));
+        System.out.println("Depth Function: " + functions.get(GL11.glGetInteger(GL_DEPTH_FUNC)));
+        System.out.printf(
+                "Blend Function: DST: Alpha %s RGB %s, SRC: Alpha %s RGB %s\n",
+                functions.get(GL11.glGetInteger(GL_BLEND_DST_ALPHA)),
+                functions.get(GL11.glGetInteger(GL_BLEND_DST_RGB)),
+                functions.get(GL11.glGetInteger(GL_BLEND_SRC_ALPHA)),
+                functions.get(GL11.glGetInteger(GL_BLEND_SRC_RGB)));
+        System.out.println(
+                "Alpha Test Function: " + functions.get(GL11.glGetInteger(GL_ALPHA_TEST_FUNC))
+                        + ", Reference: "
+                        + GL11.glGetDouble(GL11.GL_ALPHA_TEST_REF));
+    }
+
+    private List<String> getChannelDescriptionTooltip(String candidate) {
+        List<String> tooltip = new ArrayList<>();
+        int maxLine = width - (guiLeft + 151 + 12) - 12;
+        for (Entry<String, String> e : ChannelDescription.get(candidate).getDescriptions().entrySet()) {
+            tooltip.addAll(
+                    fontRendererObj.listFormattedStringToWidth(
+                            StatCollector.translateToLocalFormatted(
+                                    "item.structurelib.constructableTrigger.gui.channels.from",
+                                    Loader.instance().getIndexedModList().get(e.getKey()).getName()),
+                            maxLine));
+            tooltip.addAll(
+                    fontRendererObj.listFormattedStringToWidth(StatCollector.translateToLocal(e.getValue()), maxLine));
+        }
+        return tooltip;
+    }
+
+    public String trim(String str, int keyMaxWidth) {
+        Map<String, String> cache = trimCache.get(keyMaxWidth);
+        if (cache == null) {
+            trimCache.put(keyMaxWidth, cache = new HashMap<>());
+        }
+        return cache.computeIfAbsent(str, e -> {
+            String s = fontRendererObj.trimStringToWidth(e, keyMaxWidth);
+            if (s.length() != e.length()) {
+                StringBuilder buffer = new StringBuilder(s).deleteCharAt(s.length() - 1).append("...");
+                while ((s = fontRendererObj.trimStringToWidth(buffer.toString(), keyMaxWidth)).length()
+                        != buffer.length())
+                    // drop last original char
+                    buffer.deleteCharAt(s.length() - 4);
+                do {
+                    buffer.append('.');
+                } while (fontRendererObj.getStringWidth(buffer.toString()) <= keyMaxWidth);
+                s = buffer.deleteCharAt(s.length() - 1).insert(s.length() - 3, EnumChatFormatting.GRAY).toString();
+            }
+            return s;
+        });
+    }
+
+    @Override
+    @Optional.Method(modid = "NotEnoughItems")
+    public VisiblityData modifyVisiblity(GuiContainer gui, VisiblityData currentVisibility) {
+        return null;
+    }
+
+    @Override
+    public Iterable<Integer> getItemSpawnSlots(GuiContainer gui, ItemStack item) {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public List<TaggedInventoryArea> getInventoryAreas(GuiContainer gui) {
+        return Collections.emptyList();
+    }
+
+    @Override
+    public boolean handleDragNDrop(GuiContainer gui, int mousex, int mousey, ItemStack draggedStack, int button) {
+        if (button != 0 || mousex <= guiLeft
+                || mousey <= guiTop
+                || mousex >= guiLeft + getXSize()
+                || mousey >= guiTop + getYSize()) {
+            return false;
+        }
+        Collection<Entry<String, Integer>> channels = ChannelDescription.iterate(draggedStack);
+        switch (channels.size()) {
+            case 0:
+                return false;
+            case 1:
+            default: // TODO implement a GUI to select which pair to use, instead of blindly using the first
+                Entry<String, Integer> e = channels.iterator().next();
+                ChannelDataAccessor.setChannelData(trigger, e.getKey(), e.getValue());
+                key.setText(e.getKey());
+                value.setText(e.getValue().toString());
+                draggedStack.stackSize = 0;
+                return true;
+        }
+    }
+
+    @Override
+    public boolean hideItemPanelSlot(GuiContainer gui, int x, int y, int w, int h) {
+        return false;
+    }
+
+    private class GuiAutoCompleteList extends GuiScrollableList<String> {
+
+        private List<Entry<String, String>> cache; // <key, display string>
+
+        public GuiAutoCompleteList(int width, int height, int originX, int originY, int slotHeight) {
+            super(width, height, originX, originY, slotHeight);
+            margin = 2;
+        }
+
+        private List<Entry<String, String>> getOptions() {
+            if (cache == null) {
+                cache = search();
+            }
+            return cache;
+        }
+
+        private List<Entry<String, String>> search() {
+            List<Entry<String, String>> cache = new ArrayList<>();
+            Set<String> added = new HashSet<>();
+            String term = key.getText();
+            String[] subjects = ChannelDescription.getAll().keySet().toArray(new String[0]);
+            Arrays.sort(subjects);
+            if (StringUtils.isBlank(term)) {
+                // nothing. just gives out everything
+                for (String subject : subjects) {
+                    cache.add(new AbstractMap.SimpleImmutableEntry<>(subject, EnumChatFormatting.GRAY + subject));
+                }
+                return cache;
+            }
+            // prefix match
+            for (String s : subjects) {
+                if (s.startsWith(term)) {
+                    cache.add(
+                            new AbstractMap.SimpleImmutableEntry<>(
+                                    s,
+                                    term + EnumChatFormatting.GRAY + s.substring(term.length())));
+                    added.add(s);
+                }
+            }
+            // subsequence match
+            for (String subject : subjects) {
+                if (!added.contains(subject) && subject.length() > term.length()) {
+                    int i = 0, j = 0;
+                    StringBuilder sb = new StringBuilder();
+                    boolean mode = true;
+                    sb.append(EnumChatFormatting.WHITE);
+                    while (i < term.length() && j < subject.length()) {
+                        if (term.codePointAt(i) == subject.codePointAt(j)) {
+                            if (!mode) {
+                                sb.append(EnumChatFormatting.WHITE);
+                                mode = true;
+                            }
+                            sb.appendCodePoint(term.codePointAt(i));
+                            i++;
+                            j++;
+                        } else {
+                            if (mode) {
+                                sb.append(EnumChatFormatting.GRAY);
+                                mode = false;
+                            }
+                            sb.appendCodePoint(subject.codePointAt(j));
+                            j++;
+                        }
+                    }
+                    if (i == term.length()) {
+                        if (j < subject.length()) {
+                            sb.append(EnumChatFormatting.GRAY);
+                            sb.append(subject, j, subject.length());
+                        }
+                        cache.add(new AbstractMap.SimpleImmutableEntry<>(subject, sb.toString()));
+                        added.add(subject);
+                    }
+                }
+            }
+            return cache;
+        }
+
+        public void reset() {
+            cache = search();
+            selectedIndex = cache.isEmpty() ? -1 : 0;
+            resetScroll();
+        }
+
+        @Override
+        public String getElementAt(int index) {
+            return index >= 0 && index < cache.size() ? getOptions().get(index).getKey() : null;
+        }
+
+        @Override
+        public int getNumElements() {
+            return getOptions().size();
+        }
+
+        @Override
+        protected void drawElement(int elementIndex, int x, int y, int height, Tessellator tessellator,
+                boolean isHovering) {
+            int color = elementIndex == selectedIndex ? 0xffffff : 0xcccccc;
+            fontRendererObj.drawString(getOptions().get(elementIndex).getValue(), x + margin, y + margin / 2, color);
+        }
+    }
+
     private class GuiChannelsList extends GuiScrollableList<Entry<String, Integer>> {
 
         private List<Entry<String, Integer>> cache;
@@ -468,22 +786,5 @@ public class GuiScreenConfigureChannels extends GuiScreen implements IGuiScreen
             // args x1, y1, y2, color
             drawVerticalLine(minX + margin + margin / 2 + KEY_MAX_WIDTH * 2, minY + 1, maxY - 1, 0xffaaaaaa);
         }
-
-        public String trim(String e, int keyMaxWidth) {
-            // TODO optimize this to not create a billion string, or maybe cache this
-            String s = fontRendererObj.trimStringToWidth(e, keyMaxWidth);
-            if (s.length() != e.length()) {
-                StringBuilder buffer = new StringBuilder(s).deleteCharAt(s.length() - 1).append("...");
-                while ((s = fontRendererObj.trimStringToWidth(buffer.toString(), keyMaxWidth)).length()
-                        != buffer.length())
-                    // drop last original char
-                    buffer.deleteCharAt(s.length() - 4);
-                do {
-                    buffer.append('.');
-                } while (fontRendererObj.getStringWidth(buffer.toString()) <= keyMaxWidth);
-                s = buffer.deleteCharAt(s.length() - 1).insert(s.length() - 3, EnumChatFormatting.GRAY).toString();
-            }
-            return s;
-        }
     }
 }

src/main/java/com/gtnewhorizon/structurelib/gui/GuiScrollableList.java

@@ -16,7 +16,7 @@ import org.lwjgl.opengl.GL11;
  * <p>
  * As the code has been released into public domain, it is now LGPL as part of this library as a whole. You can go to
  * EnderCore's repository to obtain a public domain copy though
- *
+ * <p>
  * Major edits
  * <ul>
  * <li>Separate dwheel handling to handleDWheel. The next event calls often cause the mouse click event to not fire on
@@ -167,10 +167,17 @@ public abstract class GuiScrollableList<T> {
         }
     }
 
+    protected void resetScroll() {
+        amountScrolled = 0;
+    }
+
     /**
      * draws the slot to the screen, pass in mouse's current x and y and partial ticks
      */
     public void drawScreen(int mX, int mY, float partialTick) {
+        GL11.glPushMatrix();
+        GL11.glLoadIdentity();
+        GL11.glTranslatef(0.0F, 0.0F, -2000.0F);
         this.mouseX = mX;
         this.mouseY = mY;
 
@@ -199,13 +206,26 @@ public abstract class GuiScrollableList<T> {
         int contentYOffset = this.minY + margin - amountScrolled;
 
         boolean hoveringPrecondition = mX >= minX && mX <= maxX && mY >= minY && mY <= maxY;
+        int slotHeight = this.slotHeight - margin;
+
+        if (selectedIndex != -1) {
+            int elementY = contentYOffset + selectedIndex * this.slotHeight;
+            if (elementY + slotHeight > maxY) {
+                this.amountScrolled = (selectedIndex + 1) * this.slotHeight - this.height + margin;
+                amountScrolled = (int) this.amountScrolled;
+                contentYOffset = this.minY + margin - amountScrolled;
+            } else if (elementY < minY) {
+                this.amountScrolled = selectedIndex * this.slotHeight;
+                amountScrolled = (int) this.amountScrolled;
+                contentYOffset = this.minY + margin - amountScrolled;
+            }
+        }
 
         prepareDrawElements();
 
         for (int i = 0; i < getNumElements(); ++i) {
 
             int elementY = contentYOffset + i * this.slotHeight;
-            int slotHeight = this.slotHeight - margin;
 
             if (elementY <= maxY && elementY + slotHeight >= minY) {
 
@@ -264,6 +284,7 @@ public abstract class GuiScrollableList<T> {
         GL11.glShadeModel(GL11.GL_FLAT);
         GL11.glEnable(GL11.GL_ALPHA_TEST);
         GL11.glDisable(GL11.GL_BLEND);
+        GL11.glPopMatrix();
     }
 
     protected void prepareDrawElements() {}
@@ -412,7 +433,7 @@ public abstract class GuiScrollableList<T> {
         GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
         GL11.glDisable(GL11.GL_TEXTURE_2D);
         tess.startDrawingQuads();
-        tess.setColorOpaque_I(2105376);
+        tess.setColorOpaque_I(0x202020);
         tess.addVertex(minX, maxY, 0.0D);
         tess.addVertex(maxX, maxY, 0.0D);
         tess.addVertex(maxX, minY, 0.0D);

src/main/java/com/gtnewhorizon/structurelib/item/ItemConstructableTrigger.java

@@ -7,9 +7,14 @@ import static net.minecraft.util.StatCollector.translateToLocalFormatted;
 
 import java.util.List;
 
+import net.minecraft.client.renderer.texture.IIconRegister;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.nbt.NBTTagInt;
+import net.minecraft.util.IIcon;
+import net.minecraft.util.StatCollector;
 import net.minecraft.world.World;
 
 import org.lwjgl.input.Keyboard;
@@ -17,25 +22,83 @@ import org.lwjgl.input.Keyboard;
 import com.gtnewhorizon.structurelib.StructureLib;
 import com.gtnewhorizon.structurelib.alignment.constructable.ChannelDataAccessor;
 import com.gtnewhorizon.structurelib.alignment.constructable.ConstructableUtility;
-import com.gtnewhorizon.structurelib.gui.GuiScreenConfigureChannels;
-
-import cpw.mods.fml.common.FMLCommonHandler;
 
 public class ItemConstructableTrigger extends Item {
 
+    private static final String TAG_MODE = "mode";
+
+    private static final IIcon[] textures = new IIcon[3];
+
     public ItemConstructableTrigger() {
         setUnlocalizedName("structurelib.constructableTrigger");
-        setTextureName(MOD_ID + ":itemConstructableTrigger");
         setCreativeTab(StructureLib.creativeTab);
     }
 
+    public static void cycleMode(ItemStack held) {
+        if (held.getTagCompound() == null) held.setTagCompound(new NBTTagCompound());
+        if (!held.getTagCompound().hasKey(TAG_MODE)) held.getTagCompound().setTag(TAG_MODE, new NBTTagInt(0));
+        held.getTagCompound().setInteger(TAG_MODE, (held.getTagCompound().getInteger(TAG_MODE) + 1) % 3);
+    }
+
+    @Override
+    public void registerIcons(IIconRegister register) {
+        textures[0] = register.registerIcon(MOD_ID + ":constructableTrigger/BUILDING");
+        textures[1] = register.registerIcon(MOD_ID + ":constructableTrigger/UPDATING");
+        textures[2] = register.registerIcon(MOD_ID + ":constructableTrigger/REMOVING");
+    }
+
+    @Override
+    public IIcon getIcon(ItemStack stack, int renderPass, EntityPlayer player, ItemStack usingItem, int useRemaining) {
+        return getIcon(stack, renderPass);
+    }
+
+    @Override
+    public IIcon getIcon(ItemStack stack, int pass) {
+        if (!stack.hasTagCompound() || !stack.getTagCompound().hasKey(TAG_MODE)) {
+            return textures[0];
+        }
+        return textures[stack.getTagCompound().getInteger(TAG_MODE)];
+    }
+
+    @Override
+    public String getItemStackDisplayName(ItemStack stack) {
+        if (!stack.hasTagCompound() || !stack.getTagCompound().hasKey(TAG_MODE)) {
+            return getDisplayName(0);
+        }
+        return getDisplayName(stack.getTagCompound().getInteger(TAG_MODE));
+    }
+
+    @Override
+    public IIcon getIconIndex(ItemStack stack) {
+        return getIcon(stack, 0);
+    }
+
+    @Override
+    public IIcon getIconFromDamage(int damage) {
+        return textures[damage];
+    }
+
+    private String getDisplayName(int mode) {
+        return StatCollector.translateToLocal("item.structurelib.constructableTrigger.name") + " - "
+                + StatCollector.translateToLocal("item.structurelib.constructableTrigger.modes." + mode);
+    }
+
+    public static int getMode(ItemStack held) {
+        if (held == null || !held.hasTagCompound() || !held.getTagCompound().hasKey(TAG_MODE)) {
+            // default behavior
+            return 0;
+        }
+        // get user-defined mode
+        return held.getTagCompound().getInteger(TAG_MODE);
+    }
+
     @Override
     public ItemStack onItemRightClick(ItemStack stack, World world, EntityPlayer player) {
-        if (world.isRemote && getMovingObjectPositionFromPlayer(world, player, true) == null) {
+        if (!world.isRemote && getMovingObjectPositionFromPlayer(world, player, true) == null) {
             if (player.isSneaking()) {
                 StructureLib.instance().proxy().displayConfigGUI("registries");
             } else {
-                FMLCommonHandler.instance().showGuiScreen(new GuiScreenConfigureChannels(stack));
+                player.openGui(StructureLib.instance(), 0, world, player.inventory.currentItem, 0, 0);
             }
         }
         return super.onItemRightClick(stack, world, player);

src/main/java/com/gtnewhorizon/structurelib/net/StructureProjectorCycleModeMessage.java

@@ -0,0 +1,37 @@
+package com.gtnewhorizon.structurelib.net;
+
+import net.minecraft.entity.player.EntityPlayerMP;
+import net.minecraft.item.ItemStack;
+
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
+
+import cpw.mods.fml.common.network.simpleimpl.IMessage;
+import cpw.mods.fml.common.network.simpleimpl.IMessageHandler;
+import cpw.mods.fml.common.network.simpleimpl.MessageContext;
+import io.netty.buffer.ByteBuf;
+
+public class StructureProjectorCycleModeMessage implements IMessage {
+
+    @Override
+    public void fromBytes(ByteBuf buf) {
+        // no op
+    }
+
+    @Override
+    public void toBytes(ByteBuf buf) {
+        // no op
+    }
+
+    public static class Handler implements IMessageHandler<StructureProjectorCycleModeMessage, IMessage> {
+
+        @Override
+        public IMessage onMessage(StructureProjectorCycleModeMessage message, MessageContext ctx) {
+            EntityPlayerMP player = ctx.getServerHandler().playerEntity;
+            final ItemStack held = player.getHeldItem();
+            if (held != null && held.getItem() instanceof ItemConstructableTrigger) {
+                ItemConstructableTrigger.cycleMode(held);
+            }
+            return null;
+        }
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/structure/IStructureDefinition.java

@@ -348,77 +348,47 @@ public interface IStructureDefinition<T> {
         }
 
         if (checkBlocksIfNotNullForceCheckAllIfTrue != null) {
-            boolean success;
-            if (checkBlocksIfNotNullForceCheckAllIfTrue) {
-                success = StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        (e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z),
-                        "check");
-            } else {
-                success = StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        skipBlockUnloaded((e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)),
-                        "check force");
-            }
+            boolean success = StructureUtility.iterateV2(
+                    elements,
+                    world,
+                    extendedFacing,
+                    basePositionX,
+                    basePositionY,
+                    basePositionZ,
+                    basePositionA,
+                    basePositionB,
+                    basePositionC,
+                    checkBlocksIfNotNullForceCheckAllIfTrue ? (e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)
+                            : skipBlockUnloaded((e, w, x, y, z, a, b, c) -> e.check(object, w, x, y, z)),
+                    checkBlocksIfNotNullForceCheckAllIfTrue ? "check" : "check force");
             if (StructureLibAPI.isDebugEnabled() && success) {
                 StructureLib.LOGGER
                         .info("Multi [" + basePositionX + ", " + basePositionY + ", " + basePositionZ + "] pass");
             }
             return success;
         } else {
-            if (hintsOnly) {
-                StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
-                            e.spawnHint(object, world, x, y, z, trigger);
-                            if (ChannelDataAccessor.hasSubChannel(trigger, "show_error")
-                                    && !e.couldBeValid(object, world, x, y, z, trigger)) {
-                                StructureLibAPI.markHintParticleError(StructureLib.getCurrentPlayer(), world, x, y, z);
-                            }
-                            return true;
-                        }),
-                        "spawnHint");
-            } else {
-                StructureUtility.iterateV2(
-                        elements,
-                        world,
-                        extendedFacing,
-                        basePositionX,
-                        basePositionY,
-                        basePositionZ,
-                        basePositionA,
-                        basePositionB,
-                        basePositionC,
-                        ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
-                            e.placeBlock(object, world, x, y, z, trigger);
-                            return true;
-                        }),
-                        "placeBlock");
-            }
+            StructureUtility.iterateV2(
+                    elements,
+                    world,
+                    extendedFacing,
+                    basePositionX,
+                    basePositionY,
+                    basePositionZ,
+                    basePositionA,
+                    basePositionB,
+                    basePositionC,
+                    hintsOnly ? ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
+                        e.spawnHint(object, world, x, y, z, trigger);
+                        if (ChannelDataAccessor.hasSubChannel(trigger, StructureLibAPI.CHANNEL_SHOW_ERROR)
+                                && !e.couldBeValid(object, world, x, y, z, trigger)) {
+                            StructureLibAPI.markHintParticleError(StructureLib.getCurrentPlayer(), world, x, y, z);
+                        }
+                        return true;
+                    }) : ignoreBlockUnloaded((e, w, x, y, z, a, b, c) -> {
+                        e.placeBlock(object, world, x, y, z, trigger);
+                        return true;
+                    }),
+                    hintsOnly ? "spawnHint" : "placeBlock");
         }
         return true;
     }

src/main/java/com/gtnewhorizon/structurelib/structure/IStructureElement.java

@@ -21,6 +21,7 @@ import net.minecraft.util.IChatComponent;
 import net.minecraft.world.World;
 
 import com.gtnewhorizon.structurelib.StructureLibAPI;
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
 import com.gtnewhorizon.structurelib.util.ItemStackPredicate;
 import com.gtnewhorizon.structurelib.util.ItemStackPredicate.NBTMode;
 
@@ -137,12 +138,13 @@ public interface IStructureElement<T> {
      */
     default PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
             AutoPlaceEnvironment env) {
+        int mode = ItemConstructableTrigger.getMode(trigger);
         BlocksToPlace e = getBlocksToPlace(t, world, x, y, z, trigger, env);
         IItemSource source = env.getSource();
         EntityPlayer actor = env.getActor();
         Consumer<IChatComponent> chatter = env.getChatter();
         if (e != null) {
-            if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+            if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
             if (e.getStacks() == null) {
                 ItemStack taken = source.takeOne(e.getPredicate(), true);
                 return StructureUtility.survivalPlaceBlock(
@@ -159,7 +161,7 @@ public interface IStructureElement<T> {
                         chatter);
             }
             for (ItemStack stack : e.getStacks()) {
-                if (!source.takeOne(stack, true)) continue;
+                if (mode < 2 && !source.takeOne(stack, true)) continue;
                 return StructureUtility.survivalPlaceBlock(
                         stack,
                         NBTMode.EXACT,

src/main/java/com/gtnewhorizon/structurelib/structure/StructureUtility.java

@@ -28,6 +28,7 @@ import java.util.function.Supplier;
 import javax.annotation.Nullable;
 
 import net.minecraft.block.Block;
+import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.init.Blocks;
@@ -51,6 +52,7 @@ import com.gtnewhorizon.structurelib.StructureLib;
 import com.gtnewhorizon.structurelib.StructureLibAPI;
 import com.gtnewhorizon.structurelib.alignment.constructable.ChannelDataAccessor;
 import com.gtnewhorizon.structurelib.alignment.enumerable.ExtendedFacing;
+import com.gtnewhorizon.structurelib.item.ItemConstructableTrigger;
 import com.gtnewhorizon.structurelib.structure.IStructureElement.PlaceResult;
 import com.gtnewhorizon.structurelib.structure.adders.IBlockAdder;
 import com.gtnewhorizon.structurelib.structure.adders.ITileAdder;
@@ -206,7 +208,11 @@ public class StructureUtility {
 
         @Override
         public boolean placeBlock(Object o, World world, int x, int y, int z, ItemStack trigger) {
-            world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2);
+            placeRemoveOrUpdate(
+                    trigger,
+                    () -> world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2),
+                    () -> world.setBlock(x, y, z, StructureLibAPI.getBlockHint(), 14, 2),
+                    () -> world.setBlock(x, y, z, Blocks.air, 0, 2));
             return true;
         }
 
@@ -219,11 +225,16 @@ public class StructureUtility {
         @Override
         public PlaceResult survivalPlaceBlock(Object o, World world, int x, int y, int z, ItemStack trigger,
                 AutoPlaceEnvironment env) {
-            if (check(o, world, x, y, z)) return PlaceResult.SKIP;
+            int mode = ItemConstructableTrigger.getMode(trigger);
+            if (mode < 2 && check(o, world, x, y, z)) return PlaceResult.SKIP;
             // user should place anything here.
             // maybe make this configurable, but for now we try to take some cobble from user
             if (env.getSource().takeOne(new ItemStack(Blocks.cobblestone), false)) {
-                world.setBlock(x, y, z, Blocks.cobblestone, 0, 2);
+                placeRemoveOrUpdate(
+                        trigger,
+                        () -> world.setBlock(x, y, z, Blocks.cobblestone, 0, 2),
+                        () -> world.setBlock(x, y, z, Blocks.cobblestone, 0, 2),
+                        () -> world.setBlock(x, y, z, Blocks.air, 0, 2));
             }
             return PlaceResult.REJECT;
         }
@@ -330,29 +341,75 @@ public class StructureUtility {
     public static PlaceResult survivalPlaceBlock(Block block, int meta, World world, int x, int y, int z, IItemSource s,
             EntityPlayer actor, Consumer<IChatComponent> chatter) {
         if (block == null) throw new NullPointerException();
-        if (!StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        int mode = 0;
+        if (actor.getHeldItem() != null && actor.getHeldItem().getItem() instanceof ItemConstructableTrigger) {
+            // best effort lookup if the item in the player's hand is a trigger, and if it is, get the mode from the
+            // ...trigger instead of assuming default behavior
+            mode = ItemConstructableTrigger.getMode(actor.getHeldItem());
+        }
+        if (mode == 0 && !StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        if (mode == 1 && world.getTileEntity(x, y, z) instanceof TileEntity) {
+            // We're in updating mode and the block we're looking at might be important, so let's just leave it alone
+            // since it's probably not something we want to replace with something else
+            return PlaceResult.SKIP;
+        }
         Item itemBlock = Item.getItemFromBlock(block);
         int itemMeta = itemBlock instanceof ISpecialItemBlock
                 ? ((ISpecialItemBlock) itemBlock).getItemMetaFromBlockMeta(block, meta)
                 : meta;
         ItemStack stack = new ItemStack(itemBlock, 1, itemMeta);
-        if (!s.takeOne(stack, true)) {
+        if (mode == 1 && !world.isAirBlock(x, y, z)) {
+            Block blockInWorld = world.getBlock(x, y, z);
+            if (blockInWorld.isAssociatedBlock(block) && blockInWorld.getDamageValue(world, x, y, z) == meta) {
+                // This is the block we are looking for, move along
+                return PlaceResult.SKIP;
+            }
+        }
+        if (mode < 2 && !s.takeOne(stack, true)) {
             if (chatter != null) chatter.accept(
                     new ChatComponentTranslation(
                             "structurelib.autoplace.error.no_simple_block",
                             stack.func_151000_E()));
             return PlaceResult.REJECT;
         }
-        if (block instanceof ICustomBlockSetting) {
-            ICustomBlockSetting blockCustom = (ICustomBlockSetting) block;
-            blockCustom.setBlock(world, x, y, z, meta);
-        } else if (!stack.copy()
-                .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
+        if (mode < 2) {
+            if (block instanceof ICustomBlockSetting) {
+                ICustomBlockSetting blockCustom = (ICustomBlockSetting) block;
+                blockCustom.setBlock(world, x, y, z, meta);
+            } else {
+                if (mode == 1 && !world.isAirBlock(x, y, z)) {
+                    // We're in updating mode and there's a block in our way (grr), so let's remove whatever is there
+                    // ...and drop it to the player
+                    ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+                    toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
+                    if (!world.setBlock(x, y, z, Blocks.air, 0, 4) || !tryGiveOrDropItem(world, actor, toGive)) {
+                        // We either weren't able to give the player the block that was there, or we weren't able to
+                        // remove
+                        // the block, either way, we need to reject the update. Also, since we hid the block update from
+                        // the client in an effort to make the exchange as seamless as possible, we need to now notify
+                        // the client if we did successfully remove the block.
+                        if (world.isAirBlock(x, y, z)) world.notifyBlockChange(x, y, z, Blocks.air);
+                        return PlaceResult.REJECT;
+                    }
+                }
+                if (!stack.copy()
+                        .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
                     return PlaceResult.REJECT;
                 }
-        if (!s.takeOne(stack, false)) {
-            // rollback
+            }
+        }
+        if (mode == 2 && world.isAirBlock(x, y, z)) {
+            return PlaceResult.SKIP;
+        }
+        if (mode == 2 || !s.takeOne(stack, false)) {
+            // If the user didn't have the item in their inventory, or we're in removing mode, we set it to air
+            ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+            toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
             world.setBlockToAir(x, y, z);
+            if (mode == 2 && !tryGiveOrDropItem(world, actor, toGive)) {
+                // Something went wrong while trying to give the player the block we removed, let's just fail for now
+                return PlaceResult.REJECT;
+            }
         }
         return PlaceResult.ACCEPT;
     }
@@ -444,24 +501,74 @@ public class StructureUtility {
         if (stack == null) throw new NullPointerException();
         if (stack.stackSize != 1) throw new IllegalArgumentException();
         if (!(stack.getItem() instanceof ItemBlock)) throw new IllegalArgumentException();
-        if (!StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
-        if (!assumeStackPresent && !s.takeOne(stack, true)) {
+        int mode = 0;
+        if (actor.getHeldItem() != null && actor.getHeldItem().getItem() instanceof ItemConstructableTrigger) {
+            // best effort lookup if the item in the player's hand is a trigger, and if it is, get the mode from the
+            // ...trigger instead of assuming default behavior
+            mode = ItemConstructableTrigger.getMode(actor.getHeldItem());
+        }
+        if (mode == 1 && !world.isAirBlock(x, y, z)) {
+            if (world.getTileEntity(x, y, z) instanceof TileEntity) {
+                // We're in updating mode and the block we're looking at might be important, so let's just leave it
+                // alone
+                // since it's probably not something we want to replace with something else
+                return PlaceResult.SKIP;
+            }
+            Block blockInWorld = world.getBlock(x, y, z);
+            ItemStack blockInWorldItem = new ItemStack(blockInWorld);
+            blockInWorldItem.setItemDamage(blockInWorld.getDamageValue(world, x, y, z));
+            if (blockInWorldItem.isItemEqual(stack)) {
+                // This is the block we are looking for, move along
+                return PlaceResult.SKIP;
+            }
+        }
+        if (mode == 0 && !StructureLibAPI.isBlockTriviallyReplaceable(world, x, y, z, actor)) return PlaceResult.REJECT;
+        if (mode < 2 && !assumeStackPresent && !s.takeOne(stack, true)) {
             if (chatter != null) chatter.accept(
                     new ChatComponentTranslation("structurelib.autoplace.error.no_item_stack", stack.func_151000_E()));
             return PlaceResult.REJECT;
         }
-        if (!stack.copy().tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f))
-            return PlaceResult.REJECT;
-        if (!s.takeOne(stack, false))
-            // this is bad! probably an exploit somehow. Let's nullify the block we just placed instead
+        if (mode < 2) {
+            if (mode == 1 && !world.isAirBlock(x, y, z)) {
+                // We're in updating mode and there's a block in our way (grr), so let's remove whatever is there
+                // ...and drop it to the player
+                ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+                toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
+                if (!world.setBlock(x, y, z, Blocks.air, 0, 4) || !tryGiveOrDropItem(world, actor, toGive)) {
+                    // We either weren't able to give the player the block that was there, or we weren't able to remove
+                    // the block, either way, we need to reject the update. Also, since we hid the block update from
+                    // the client in an effort to make the exchange as seamless as possible, we need to now notify
+                    // the client if we did successfully remove the block.
+                    if (world.isAirBlock(x, y, z)) world.notifyBlockChange(x, y, z, Blocks.air);
+                    return PlaceResult.REJECT;
+                }
+            }
+            if (!stack.copy()
+                    .tryPlaceItemIntoWorld(actor, world, x, y, z, ForgeDirection.UP.ordinal(), 0.5f, 0.5f, 0.5f)) {
+                return PlaceResult.REJECT;
+            }
+        }
+        if (mode == 2 && world.isAirBlock(x, y, z)) {
+            return PlaceResult.SKIP;
+        }
+        if (mode == 2 || !s.takeOne(stack, false)) {
+            // If the user didn't have the item in their inventory, or we're in removing mode, we set it to air
+            ItemStack toGive = new ItemStack(world.getBlock(x, y, z));
+            toGive.setItemDamage(world.getBlock(x, y, z).getDamageValue(world, x, y, z));
             world.setBlockToAir(x, y, z);
+            if (mode == 2 && !tryGiveOrDropItem(world, actor, toGive)) {
+                // We were in removing mode and something went wrong while trying to give the player the block we
+                // ...removed, let's just fail for now
+                return PlaceResult.REJECT;
+            }
+        }
         return PlaceResult.ACCEPT;
     }
 
     /**
      * Return a structure element that only allow air (or air equivalents, like Railcraft hidden blocks). You usually
-     * don't need to call this yourselves. Use {@code -} in shape to automatically use this. Provided nontheless in case
-     * you want this as a fallback to something else.
+     * don't need to call this yourselves. Use {@code -} in shape to automatically use this. Provided nonetheless in
+     * case you want this as a fallback to something else.
      */
     @SuppressWarnings("unchecked")
     public static <T> IStructureElement<T> isAir() {
@@ -470,8 +577,8 @@ public class StructureUtility {
 
     /**
      * Return a structure element that allow anything but air (or air equivalents, like Railcraft hidden blocks). You
-     * usually don't need to call this yourselves. Use {@code +} in shape to automatically use this. Provided nontheless
-     * in case you want this as a fallback to something else.
+     * usually don't need to call this yourselves. Use {@code +} in shape to automatically use this. Provided
+     * nonetheless in case you want this as a fallback to something else.
      */
     @SuppressWarnings("unchecked")
     public static <T> IStructureElement<T> notAir() {
@@ -614,46 +721,33 @@ public class StructureUtility {
 
     /**
      * Element representing a component with different tiers. Your multi will accept any of them (as long as player does
-     * not mix them (*)), but would like to know which is used. Player can use more blueprint to get hints denoting more
+     * not mix tier (*)), but would like to know which is used. Player can use more blueprint to get hints denoting more
      * advanced components.
      * <p>
-     * (*): Implementation wise, this structure element will only accept a block if its tier is the same as existing
-     * tier or if existing tier is unset (i.e. value of third argument)
-     * <p>
-     * Above all else, you need to decide what tier you are going to use. For simpler cases, Integer is a good choice.
-     * You can also use an existing Enum. Tier can never be null though. It can also be a String or a
+     * Above all else, you need to decide what type of tier you are going to use. For simpler cases, Integer is a good
+     * choice. You can also use an existing Enum. It can also be a String or a
      * {@link net.minecraft.util.ResourceLocation}, or basically anything. It doesn't even have to implement
      * {@link Comparable}.
      * <p>
-     * This assumes you will reset the backing storage, and on the first occurrence getter would return notSet. You can
-     * also make getter to return other value to forcefully select a certain tier, but you're probably better off using
-     * block adders or {@link #ofBlock(Block, int, Block, int)} and its overloads
+     * If your tier extractor function returns null on any (Block, meta) pair, then it means this block is rejected.
+     * This also implies null can never be a valid tier.
      * <p>
-     * Implementation wise, this allows a block only when we don't yet have a tier, or the block at that location has
-     * the same tier as we already have.
-     * <p>
-     * Notice that if your tier extractor function returns null on any (Block, meta) pair, then it means this block is
-     * rejected, since null can never be a valid tier.
+     * This structure element require you will reset the backing storage of getter in your own code, such that in every
+     * round of structure checking, the first call to getter would always return notSet. You can also make getter to
+     * return other value on that occasion to forcefully select a certain tier, but then you'd probably be better off
+     * using block adders or {@link #ofBlock(Block, int, Block, int)} and its overloads
      * <p>
      * There is yet no TileEntity counterpart of this utility. Feel free to submit a PR to add it.
      * <p>
-     * For most typical use cases, you will NOT want to return notSet from your tierExtractor. If you do so, we will
-     * have this kind of chain of events:
-     * <ul>
-     * <li>at check start, tier is reset to notSet
-     * <li>at first occurrence, ofBlocksTiered finds your current tier is notSet, and the block's tier is notSet, so
-     * it's accepted
-     * <li>at 2nd, 3rd..., same thing in 2 happens
-     * <li>at last occurrence, player placed a valid block with a tier not notSet. ofBlocksTiered now sets your current
-     * tier to this tier, and accept the block
-     * <li>check got notified structure is sound, and tier is not notSet. it marks the structure as complete and start
-     * doing its business
-     * <li>Player enjoy a (probably) hilariously shaped multi and (probably) reduced build cost.
-     * </ul>
+     * (*): Implementation wise, this structure element will only accept a block if its tier is the same as existing
+     * tier or if existing tier is unset (i.e. value of third argument). If there are multiple (block, tier) tuple for a
+     * given tier, then player will be allowed to use multiple kinds of blocks, but their tier is guaranteed to be the
+     * same.
      * <p>
-     * <b>Example:</b>
+     * <b>Example Implementation:</b>
      * <p>
-     * Assume you have 16 tier, each map to one block's 16 different meta. You will usually want something like this
+     * Assume you have 16 tier, each map to one particular block's 16 different meta. You will usually want something
+     * like this
      *
      * <pre>
      * public class Tile extends TileEntity {
@@ -677,6 +771,29 @@ public class StructureUtility {
      * }
      * </pre>
      *
+     * Important bits:
+     * <ul>
+     * <li>The supplied ITierConverter returns null for an invalid block</li>
+     * <li>Possible tier returned by ITierConverter is Integer object 0 to 15.</li>
+     * <li>notSet is set to -1. tier got reset to this value by caller before calling into
+     * {@link IStructureDefinition#check(Object, String, World, ExtendedFacing, int, int, int, int, int, int, boolean)}</li>
+     * <li>notSet is never a tier returned by ITierConverter.</li>
+     * </ul>
+     * <p>
+     * <p>
+     * <b>You SHOULD NOT return notSet from your tierExtractor.</b> If you do so, we will have this chain of events:
+     * <ul>
+     * <li>at check start, tier is reset to notSet
+     * <li>the tier extractor returns notSet for first block, so since ofBlocksTiered finds your current tier is notSet,
+     * and the new block's tier is the same as that, so it's accepted
+     * <li>at 2nd, 3rd..., same thing in 2 happens
+     * <li>at last occurrence, player placed a valid block with a tier not notSet. ofBlocksTiered now sets your current
+     * tier to this tier, and accept the block
+     * <li>check got notified structure is sound, and tier is not notSet. it marks the structure as complete and start
+     * doing its business
+     * <li>Player enjoy a (probably) hilariously shaped multi and (probably) reduced build cost.
+     * </ul>
+     *
      * @param tierExtractor a function to extract tier info from a block. This function can return null and will never
      *                      be passed a null block or an invalid block meta. If this function returns null, then the
      *                      block would be considered invalid.
@@ -686,8 +803,8 @@ public class StructureUtility {
      *                      construction time, use {@link #lazy(Supplier)} or its overloads to delay a bit. This list is
      *                      only for hint particle spawning and survival build. The hint/autoplace code will choose 1st
      *                      pair to spawn/place if trigger item has master channel data of 1, 2nd pair if 2, and so on.
-     * @param notSet        The value returned from {@code getter} when there were no tier info found in T yet. Can be
-     *                      null.
+     * @param notSet        The value returned from {@code getter} when there were no tier info found in T yet. Cannot
+     *                      be null.
      * @param getter        a function to retrieve the current tier from context object
      * @param setter        a function to set the current tier into context object
      */
@@ -697,7 +814,7 @@ public class StructureUtility {
         List<Pair<Block, Integer>> hints = allKnownTiers == null ? Collections.emptyList() : allKnownTiers;
         if (hints.stream().anyMatch(Objects::isNull)) throw new IllegalArgumentException();
         IStructureElementCheckOnly<T> check = ofBlocksTiered(tierExtractor, notSet, setter, getter);
-        return new StructureElement_Bridge<T>() {
+        return new StructureElement_Bridge<>() {
 
             @Override
             public boolean check(T t, World world, int x, int y, int z) {
@@ -754,12 +871,13 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
+                int mode = ItemConstructableTrigger.getMode(trigger);
                 Pair<Block, Integer> hint = getHint(trigger);
                 if (hint == null) return PlaceResult.REJECT; // TODO or SKIP?
                 Block block = world.getBlock(x, y, z);
                 int meta = world.getBlockMetadata(x, y, z);
                 TIER tier = tierExtractor.convert(block, meta);
-                if (Objects.equals(tier, tierExtractor.convert(hint.getKey(), hint.getValue())))
+                if (mode < 2 && Objects.equals(tier, tierExtractor.convert(hint.getKey(), hint.getValue())))
                     return PlaceResult.SKIP;
                 return StructureUtility.survivalPlaceBlock(
                         hint.getKey(),
@@ -849,7 +967,8 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (getBlock() == null) return PlaceResult.REJECT;
                 return StructureUtility.survivalPlaceBlock(
                         getBlock(),
@@ -936,7 +1055,8 @@ public class StructureUtility {
             @Deprecated
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     IItemSource s, EntityPlayerMP actor, Consumer<IChatComponent> chatter) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (init()) return StructureUtility.survivalPlaceBlock(block, meta, world, x, y, z, s, actor, chatter);
                 return fallback.survivalPlaceBlock(t, world, x, y, z, trigger, s, actor, chatter);
             }
@@ -944,7 +1064,8 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (check(t, world, x, y, z)) return PlaceResult.SKIP;
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode < 2 && check(t, world, x, y, z)) return PlaceResult.SKIP;
                 if (init()) return StructureUtility.survivalPlaceBlock(
                         block,
                         meta,
@@ -1572,7 +1693,9 @@ public class StructureUtility {
                 @Deprecated
                 public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                         AutoPlaceEnvironment env) {
-                    if (world.getBlock(x, y, z) == defaultBlock && world.getBlockMetadata(x, y, z) == defaultMeta)
+                    int mode = ItemConstructableTrigger.getMode(trigger);
+                    if (mode < 2 && world.getBlock(x, y, z) == defaultBlock
+                            && world.getBlockMetadata(x, y, z) == defaultMeta)
                         return PlaceResult.SKIP;
                     return StructureUtility.survivalPlaceBlock(
                             defaultBlock,
@@ -1618,7 +1741,9 @@ public class StructureUtility {
                 @Deprecated
                 public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                         AutoPlaceEnvironment env) {
-                    if (world.getBlock(x, y, z) == defaultBlock && world.getBlockMetadata(x, y, z) == defaultMeta)
+                    int mode = ItemConstructableTrigger.getMode(trigger);
+                    if (mode < 2 && world.getBlock(x, y, z) == defaultBlock
+                            && world.getBlockMetadata(x, y, z) == defaultMeta)
                         return PlaceResult.SKIP;
                     return StructureUtility.survivalPlaceBlock(
                             defaultBlock,
@@ -1878,7 +2003,8 @@ public class StructureUtility {
             @Deprecated
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     IItemSource s, EntityPlayerMP actor, Consumer<IChatComponent> chatter) {
-                if (predicate.test(t))
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode == 2 || predicate.test(t))
                     return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, s, actor, chatter);
                 return placeResultWhenDisabled;
             }
@@ -1886,7 +2012,9 @@ public class StructureUtility {
             @Override
             public PlaceResult survivalPlaceBlock(T t, World world, int x, int y, int z, ItemStack trigger,
                     AutoPlaceEnvironment env) {
-                if (predicate.test(t)) return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, env);
+                int mode = ItemConstructableTrigger.getMode(trigger);
+                if (mode == 2 || predicate.test(t))
+                    return downstream.survivalPlaceBlock(t, world, x, y, z, trigger, env);
                 return placeResultWhenDisabled;
             }
         };
@@ -3253,4 +3381,35 @@ public class StructureUtility {
         }
         return shape;
     }
+
+    /**
+     * Performs a creation, removal, or update operation at the given position
+     *
+     * @param trigger  ItemStack for the trigger item
+     * @param onCreate Operation to be performed when the mode of the trigger is set to building mode
+     * @param onUpdate Operation to be performed when the mode of the trigger is set to updating mode
+     * @param onRemove Operation to be performed when the mode of the trigger is set to removing mode
+     */
+    public static void placeRemoveOrUpdate(ItemStack trigger, Runnable onCreate, Runnable onUpdate, Runnable onRemove) {
+        int mode = ItemConstructableTrigger.getMode(trigger);
+        switch (mode) {
+            case 0:
+                onCreate.run();
+                break;
+            case 1:
+                onUpdate.run();
+                break;
+            case 2:
+                onRemove.run();
+                break;
+        }
+    }
+
+    public static boolean tryGiveOrDropItem(World world, EntityPlayer actor, ItemStack stack) {
+        if (actor.inventory.addItemStackToInventory(stack)) {
+            actor.inventoryContainer.detectAndSendChanges();
+            return true;
+        }
+        return world.spawnEntityInWorld(new EntityItem(world, actor.posX, actor.posY, actor.posZ, stack));
+    }
 }

src/main/javadoc/overview.html

@@ -178,6 +178,80 @@ StructureLib API documentation.
 
 Just give me a better name and I'd do the renaming.
 
+<h3>Channel Descriptions</h3>
+<p>
+    Each channel can have one description associated with it per mod.
+    Channel description should briefly describe how a specific channel is used for inside a specific mod.
+    They will be displayed to player in channel editor GUI that comes with StructureLib.
+    The registration process can be done either via direct method call to {@link com.gtnewhorizon.structurelib.StructureLibAPI#registerChannelDescription(String, String, String)},
+    or by sending an IMC message.
+    After registration, the channel will also show up as autocomplete options when players are editing channels.
+</p>
+
+<p>
+    Here is an example of sending an IMC message to register two channels and their description.
+    In this example, we assume your modid is <code>my_mod</code> and your mod will ship with localization entries for
+    localization key <code>channels.my_mod.channel_1</code> and <code>channels.my_mod.channel_2</code>
+</p>
+
+<pre>
+        NBTTagCompound command = new NBTTagCompound();
+        NBTTagList tags = new NBTTagList();
+        String[] channels = {"channel_1", "channel_2"};
+        for (String channel : channels) {
+            NBTTagCompound tag = new NBTTagCompound();
+            tag.setString("Channel", channel);
+            tag.setString("Description", "channels.my_mod." + channel);
+            tags.appendTag(tag);
+        }
+        command.setTag("Channels", tags);
+        FMLInterModComms.sendMessage("structurelib", "register_channel", command);
+</pre>
+
+<p>
+    There is no strict rules over whether you should do direct API method call or send IMC messages.
+    You can choose whichever you prefer.
+</p>
+
+<h3>Channel Indicator Items</h3>
+<p>
+    You can associate an ItemStack with a given (channel, value) pair.
+    It is usually (but not required to be) the ItemBlock for the blocks to be placed by this (channel, value) pair.
+    Player will be able to drag and drop this item to the builtin channel configuration GUI.
+    The registration process can be done either via direct method call to {@link com.gtnewhorizon.structurelib.StructureLibAPI#registerChannelItem(String, String, int, net.minecraft.item.ItemStack)},
+    or by sending an IMC message.
+    After registration, the channel will also show up as autocomplete options when players are editing channels.
+</p>
+
+<p>
+    Here is an example of sending an IMC message to register 3 vanilla sandstone as different indicator for channel "sandstone", with block metadata plus 1 as channel value.
+    In this example, we assume your modid is <code>my_mod</code>.
+</p>
+
+<pre>
+        NBTTagCompound command = new NBTTagCompound();
+        NBTTagList items = new NBTTagList();
+        int[] metas = {0, 1, 2};
+        for (int meta : metas) {
+            NBTTagCompound tag = new NBTTagCompound();
+            tag.setTag("Item", new ItemStack(Blocks.sandstone, 1, meta).writeToNBT(new NBTTagCompound()));
+            NBTTagList channels = new NBTTagList();
+            NBTTagCompound channel = new NBTTagCompound();
+            channel.setString("Channel", "sandstone");
+            channel.setInteger("Value", meta + 1);
+            channels.appendTag(channel);
+            tag.setTag("Channels", channels);
+            items.appendTag(tag);
+        }
+        command.setTag("Items", items);
+        FMLInterModComms.sendMessage("structurelib", "register_channel_item", command);
+</pre>
+
+<p>
+    There is no strict rules over whether you should do direct API method call or send IMC messages.
+    You can choose whichever you prefer.
+</p>
+
 <h3>Examples</h3>
 
 <h4>For Structure Definition Author</h4>

src/main/resources/assets/structurelib/lang/en_US.lang

@@ -22,6 +22,9 @@ item.structurelib.frontRotationTool.desc.1=Rotates only the front panel,
 item.structurelib.frontRotationTool.desc.2=which allows structure rotation.
 
 item.structurelib.constructableTrigger.name=Multiblock Structure Hologram Projector
+item.structurelib.constructableTrigger.modes.0=Building Mode
+item.structurelib.constructableTrigger.modes.1=Updating Mode
+item.structurelib.constructableTrigger.modes.2=Removing Mode
 item.structurelib.constructableTrigger.desc.0=Triggers Constructable Interface
 item.structurelib.constructableTrigger.desc.1=Shows multiblock construction schematic,
 item.structurelib.constructableTrigger.desc.2=use on the multiblock controller.
@@ -40,6 +43,13 @@ item.structurelib.constructableTrigger.gui.error.show=Show Errors
 item.structurelib.constructableTrigger.gui.error.hide=Hide Errors
 item.structurelib.constructableTrigger.gui.gt_no_hatch.enable=No Hatch
 item.structurelib.constructableTrigger.gui.gt_no_hatch.disable=Hatches
+item.structurelib.constructableTrigger.keyCategory=Multiblock Structure Hologram Projector Keys
+item.structurelib.constructableTrigger.keys.cycleMode=Cycle Projector Mode
+item.structurelib.constructableTrigger.gui.channels.from=§rMod: §9§o%s
+
+channels.structurelib.show_errors=When set, will highlight parts of the multiblock that is definitely wrong
+
+structurelib.tooltip.channelvalue=§7Indicates value §6%d§r§7 for sub channel §6%s
 
 structurelib.autoplace.built_stat=Built %s blocks
 structurelib.autoplace.complete=§aThis multiblock has completed!

src/main/resources/assets/structurelib/lang/zh_CN.lang

@@ -36,10 +36,11 @@ item.structurelib.constructableTrigger.gui.add=添加
 item.structurelib.constructableTrigger.gui.set=替换
 item.structurelib.constructableTrigger.gui.unset=删除
 item.structurelib.constructableTrigger.gui.wipe=§4全部清空
-item.structurelib.constructableTrigger.gui.error.show=显示结构错误
-item.structurelib.constructableTrigger.gui.error.hide=隐藏结构错误
-item.structurelib.constructableTrigger.gui.gt_no_hatch.enable=跳过舱室
-item.structurelib.constructableTrigger.gui.gt_no_hatch.disable=放置舱室
+item.structurelib.constructableTrigger.gui.channels.from=§r模组: §9§o%s
+
+channels.structurelib.show_errors=添加后，在投影时会高亮标出必然错误的部分
+
+structurelib.tooltip.channelvalue=§7表示子信道 §6%2$s§r§7 为 §6%d§r
 
 structurelib.autoplace.built_stat=已放置 %s 个方块
 structurelib.autoplace.complete=§a这个多方块结构已经完成自动搭建！