Reworked Part Placement & Part/Facade Placement Previews

src/main/java/appeng/api/parts/IFacadeContainer.java

@@ -36,6 +36,13 @@
  */
 public interface IFacadeContainer {
 
+    /**
+     * Checks if the {@link IFacadePart} can be added to the given side.
+     *
+     * @return true if the facade can be successfully added.
+     */
+    boolean canAddFacade(IFacadePart a);
+
     /**
      * Attempts to add the {@link IFacadePart} to the given side.
      *

src/main/java/appeng/api/parts/PartHelper.java

@@ -30,11 +30,9 @@
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.server.level.ServerLevel;
-import net.minecraft.world.InteractionHand;
 import net.minecraft.world.InteractionResult;
 import net.minecraft.world.entity.player.Player;
-import net.minecraft.world.item.ItemStack;
-import net.minecraft.world.item.context.DirectionalPlaceContext;
+import net.minecraft.world.item.context.UseOnContext;
 import net.minecraft.world.level.BlockGetter;
 import net.minecraft.world.level.Level;
 
@@ -52,16 +50,11 @@ private PartHelper() {
      * {@link net.minecraft.world.item.Item#useOn} of your parts item (if you're not using AE2s internal PartItem class)
      * to implement part placement.
      *
-     * @param is     ItemStack of an item which implements {@link IPartItem}
-     * @param pos    pos of part
-     * @param side   side which the part should be on
-     * @param player player placing part
-     * @param level  part in level
-     * @return true if placing was successful
+     * @return The result of placement suitable for returning from
+     *         {@link net.minecraft.world.item.Item#useOn(UseOnContext)}.
      */
-    public static InteractionResult usePartItem(ItemStack is, BlockPos pos, Direction side,
-            Player player, InteractionHand hand, Level level) {
-        return PartPlacement.place(is, pos, side, player, hand, level, PartPlacement.PlaceType.PLACE_ITEM, 0);
+    public static InteractionResult usePartItem(UseOnContext context) {
+        return PartPlacement.place(context);
     }
 
     /**
@@ -109,7 +102,7 @@ public static <T extends IPart> T setPart(ServerLevel level, BlockPos pos, @Null
         Objects.requireNonNull(level, "level");
         Objects.requireNonNull(pos, "pos");
 
-        var host = getOrPlacePartHost(level, pos, true);
+        var host = getOrPlacePartHost(level, pos, true, null);
         if (host == null) {
             return null;
         }
@@ -128,28 +121,65 @@ public static <T extends IPart> T setPart(ServerLevel level, BlockPos pos, @Null
      * <p/>
      * Use {@link IPartHost#isEmpty()} and {@link IPartHost#cleanup()}.
      *
-     * @param force If true, an existing non-cable-bus block will be unconditionally replaced.
+     * @param force  If true, an existing non-cable-bus block will be unconditionally replaced.
+     * @param player The player trying to place the cable bus. Will be used to check if the player can actually place it
+     *               if force is not true.
      */
     @Nullable
-    public static IPartHost getOrPlacePartHost(ServerLevel level, BlockPos pos, boolean force) {
+    public static IPartHost getOrPlacePartHost(Level level, BlockPos pos, boolean force, @Nullable Player player) {
         // Get or place part host
         var blockEntity = level.getBlockEntity(pos);
         if (blockEntity instanceof IPartHost partHost) {
             return partHost;
         } else {
-            if (!force) {
-                var whatToPlace = AEBlocks.CABLE_BUS.stack();
-                var ctx = new DirectionalPlaceContext(level, pos, Direction.DOWN, whatToPlace, Direction.UP);
-                if (!level.getBlockState(pos).canBeReplaced(ctx)) {
-                    return null;
-                }
+            if (!force && !canPlacePartHost(player, level, pos)) {
+                return null;
             }
 
-            level.setBlockAndUpdate(pos, AEBlocks.CABLE_BUS.block().defaultBlockState());
+            var state = AEBlocks.CABLE_BUS.block().getStateForPlacement(level, pos);
+            level.setBlockAndUpdate(pos, state);
             return level.getBlockEntity(pos, AEBlockEntities.CABLE_BUS).orElse(null);
         }
     }
 
+    /**
+     * Tries placing a new part host at the given location as a player.
+     *
+     * @return null if placing a new bus fails (even if a bus already is at that location)
+     */
+    @Nullable
+    public static IPartHost placePartHost(@Nullable Player player, Level level, BlockPos pos) {
+        // Get or place part host
+        if (!canPlacePartHost(player, level, pos)) {
+            return null;
+        }
+
+        var state = AEBlocks.CABLE_BUS.block().getStateForPlacement(level, pos);
+        level.setBlockAndUpdate(pos, state);
+        return level.getBlockEntity(pos, AEBlockEntities.CABLE_BUS).orElse(null);
+    }
+
+    public static boolean canPlacePartHost(@Nullable Player player, Level level, BlockPos pos) {
+        if (player != null && !level.mayInteract(player, pos)) {
+            return false;
+        }
+
+        return level.isEmptyBlock(pos) || level.getBlockState(pos).getMaterial().isReplaceable();
+    }
+
+    /**
+     * Gets a part host at the given position.
+     */
+    @Nullable
+    public static IPartHost getPartHost(Level level, BlockPos pos) {
+        var blockEntity = level.getBlockEntity(pos);
+        if (blockEntity instanceof IPartHost partHost) {
+            return partHost;
+        }
+
+        return null;
+    }
+
     /**
      * @return the render mode
      */

src/main/java/appeng/block/networking/CableBusBlock.java

@@ -300,12 +300,12 @@ protected BlockState updateBlockStateFromBlockEntity(BlockState currentState, Ca
     @Override
     @Nullable
     public BlockState getStateForPlacement(BlockPlaceContext context) {
-        BlockPos pos = context.getClickedPos();
-        FluidState fluidState = context.getLevel().getFluidState(pos);
-        BlockState blockState = this.defaultBlockState()
-                .setValue(WATERLOGGED, fluidState.getType() == Fluids.WATER);
+        return getStateForPlacement(context.getLevel(), context.getClickedPos());
+    }
 
-        return blockState;
+    public BlockState getStateForPlacement(Level level, BlockPos pos) {
+        var fluidState = level.getFluidState(pos);
+        return this.defaultBlockState().setValue(WATERLOGGED, fluidState.getType() == Fluids.WATER);
     }
 
     @Override

src/main/java/appeng/core/AEConfig.java

@@ -418,6 +418,13 @@ public int getPathfindingStepsPerTick() {
         return COMMON.pathfindingStepsPerTick.get();
     }
 
+    /**
+     * @return True if an in-world preview of parts and facade placement should be shown when holding one in hand.
+     */
+    public boolean isPlacementPreviewEnabled() {
+        return CLIENT.showPlacementPreview.get();
+    }
+
     // Setters keep visibility as low as possible.
 
     private static class ClientConfig {
@@ -429,6 +436,7 @@ private static class ClientConfig {
         public final BooleanOption disableColoredCableRecipesInJEI;
         public final EnumOption<PowerUnits> selectedPowerUnit;
         public final BooleanOption debugGuiOverlays;
+        public final BooleanOption showPlacementPreview;
 
         // Terminal Settings
         public final EnumOption<YesNo> searchTooltips;
@@ -443,6 +451,8 @@ public ClientConfig(ConfigSection root) {
             this.useColoredCraftingStatus = client.addBoolean("useColoredCraftingStatus", true);
             this.selectedPowerUnit = client.addEnum("PowerUnit", PowerUnits.AE, "Power unit shown in AE UIs");
             this.debugGuiOverlays = client.addBoolean("showDebugGuiOverlays", false, "Show debugging GUI overlays");
+            this.showPlacementPreview = client.addBoolean("showPlacementPreview", true,
+                    "Show a preview of part and facade placement");
 
             ConfigSection terminals = root.subsection("terminals");
             this.searchTooltips = terminals.addEnum("searchTooltips", YesNo.YES,

src/main/java/appeng/core/AppEngBase.java

@@ -80,7 +80,6 @@
 import appeng.init.worldgen.InitFeatures;
 import appeng.init.worldgen.InitStructures;
 import appeng.items.tools.NetworkToolItem;
-import appeng.parts.PartPlacement;
 import appeng.server.AECommand;
 import appeng.server.testworld.GameTestPlotAdapter;
 import appeng.services.ChunkLoadingService;
@@ -154,7 +153,6 @@ public AppEngBase() {
 
         UseBlockCallback.EVENT.register(WrenchHook::onPlayerUseBlock);
         UseBlockCallback.EVENT.register(ToolItemHook::onPlayerUseBlock);
-        UseBlockCallback.EVENT.register(PartPlacement::onPlayerUseBlock);
         InitBiomeModifications.init();
     }
 

src/main/java/appeng/core/sync/BasePacketHandler.java

@@ -44,8 +44,6 @@ public enum PacketTypes {
 
         CONFIG_BUTTON(ConfigButtonPacket.class, ConfigButtonPacket::new),
 
-        PART_PLACEMENT(PartPlacementPacket.class, PartPlacementPacket::new),
-
         LIGHTNING(LightningPacket.class, LightningPacket::new),
 
         MATTER_CANNON(MatterCannonPacket.class, MatterCannonPacket::new),

src/main/java/appeng/facade/FacadeContainer.java

@@ -42,9 +42,14 @@ public FacadeContainer(CableBusStorage cbs, Runnable changeCallback) {
         this.changeCallback = changeCallback;
     }
 
+    @Override
+    public boolean canAddFacade(IFacadePart a) {
+        return this.getFacade(a.getSide()) == null;
+    }
+
     @Override
     public boolean addFacade(IFacadePart a) {
-        if (this.getFacade(a.getSide()) == null) {
+        if (canAddFacade(a)) {
             this.storage.setFacade(a.getSide(), a);
             this.notifyChange();
             return true;