start adjusting BC blueprint API, fix #2925

api/buildcraft/api/blueprints/Schematic.java

@@ -155,6 +155,15 @@ public abstract class Schematic {
 
 	}
 
+	/**
+	 * Can the block be placed in the world at these coordinates now?
+	 * This function is only used to *delay* block placement until other
+	 * prerequisites are met.
+	 */
+	public boolean canPlaceInWorld(IBuilderContext context, int x, int y, int z) {
+		return true;
+	}
+
 	/**
 	 * Places the block in the world, at the location specified in the slot,
 	 * using the stack in parameters

api/buildcraft/api/blueprints/package-info.java

@@ -6,7 +6,7 @@
  * Please check the contents of the license, which should be located
  * as "LICENSE.API" in the BuildCraft source code distribution.
  */
-@API(apiVersion = "1.3", owner = "BuildCraftAPI|core", provides = "BuildCraftAPI|blueprints")
+@API(apiVersion = "1.4", owner = "BuildCraftAPI|core", provides = "BuildCraftAPI|blueprints")
 package buildcraft.api.blueprints;
 import cpw.mods.fml.common.API;
 

api/buildcraft/api/robots/AIRobot.java

@@ -184,7 +184,7 @@ public class AIRobot {
 			NBTTagCompound sub = nbt.getCompoundTag("delegateAI");
 
 			try {
-				Class<?> aiRobotClass = null;
+				Class<?> aiRobotClass;
 				if (sub.hasKey("class")) {
 					// Migration support for 6.4.x
 					aiRobotClass = RobotManager.getAIRobotByLegacyClassName(sub.getString("class"));
@@ -210,7 +210,7 @@ public class AIRobot {
 		AIRobot ai = null;
 
 		try {
-			Class<?> aiRobotClass = null;
+			Class<?> aiRobotClass;
 			if (nbt.hasKey("class")) {
 				// Migration support for 6.4.x
 				aiRobotClass = RobotManager.getAIRobotByLegacyClassName(nbt.getString("class"));

api/buildcraft/api/robots/ResourceId.java

@@ -24,7 +24,7 @@ public abstract class ResourceId {
 
 	public static ResourceId load(NBTTagCompound nbt) {
 		try {
-			Class cls = null;
+			Class cls;
 			if (nbt.hasKey("class")) {
 				// Migration support for 6.4.x
 				cls = RobotManager.getResourceIdByLegacyClassName(nbt.getString("class"));

common/buildcraft/builders/schematics/SchematicRail.java

@@ -11,6 +11,7 @@ package buildcraft.builders.schematics;
 import java.util.LinkedList;
 
 import net.minecraft.item.ItemStack;
+import net.minecraft.world.World;
 
 import buildcraft.api.blueprints.IBuilderContext;
 import buildcraft.api.blueprints.SchematicBlock;
@@ -51,6 +52,11 @@ public class SchematicRail extends SchematicBlock {
 		}
 	}
 
+	@Override
+	public boolean canPlaceInWorld(IBuilderContext context, int x, int y, int z) {
+		return y > 0 && World.doesBlockHaveSolidTopSurface(context.world(), x, y - 1, z);
+	}
+
 	@Override
 	public void placeInWorld(IBuilderContext context, int x, int y, int z, LinkedList<ItemStack> stacks) {
 		context.world().setBlock(x, y, z, block, 0, 3);

common/buildcraft/core/blueprints/BptBuilderBlueprint.java

@@ -164,7 +164,6 @@ public class BptBuilderBlueprint extends BptBuilderBase {
 							tmpExpanding.add(b);
 							b.buildStage = 3;
 							break;
-
 						}
 					} else {
 						postProcessing.add(b);
@@ -421,7 +420,7 @@ public class BptBuilderBlueprint extends BptBuilderBase {
 							return slot;
 						} else if (checkRequirements(builder, slot.schematic)) {
 							if (!BuildCraftAPI.isSoftBlock(world, slot.x, slot.y,
-									slot.z)) {
+									slot.z) || !slot.schematic.canPlaceInWorld(context, slot.x, slot.y, slot.z)) {
 								continue; // Can't build yet, wait (#2751)
 							} else if (isBlockPlaceCanceled(world, slot.x, slot.y, slot.z, slot.schematic)) {
 								// Forge does not allow us to place a block in

common/buildcraft/energy/TileEngineCreative.java

@@ -13,7 +13,6 @@ import io.netty.buffer.ByteBuf;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.Item;
 import net.minecraft.nbt.NBTTagCompound;
-import net.minecraft.util.ChatComponentText;
 import net.minecraft.util.ChatComponentTranslation;
 import net.minecraftforge.common.util.FakePlayer;
 import net.minecraftforge.common.util.ForgeDirection;
@@ -48,7 +47,7 @@ public class TileEngineCreative extends TileEngineBase {
 
 				if (!(player instanceof FakePlayer)) {
 					if (BuildCraftCore.hidePowerNumbers) {
-						player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode.numberless"
+						player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode.numberless",
 								StringUtils.localize("chat.pipe.power.iron.level." + powerMode.maxPower)));
 					} else {
 						player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode",

common/buildcraft/transport/pipes/PipePowerIron.java

@@ -13,7 +13,6 @@ import java.util.LinkedList;
 
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.Item;
-import net.minecraft.util.ChatComponentText;
 import net.minecraft.util.ChatComponentTranslation;
 import cpw.mods.fml.relauncher.Side;
 import cpw.mods.fml.relauncher.SideOnly;
@@ -59,7 +58,7 @@ public class PipePowerIron extends Pipe<PipeTransportPower> {
 			}
 			if (getWorld().isRemote && !(player instanceof FakePlayer)) {
 				if (BuildCraftCore.hidePowerNumbers) {
-					player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode.numberless"
+					player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode.numberless",
 							StringUtils.localize("chat.pipe.power.iron.level." + getMode().maxPower)));
 				} else {
 					player.addChatMessage(new ChatComponentTranslation("chat.pipe.power.iron.mode",