Use argument object for survival autoplace

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

@@ -0,0 +1,35 @@
+package com.gtnewhorizon.structurelib.structure;
+
+import com.gtnewhorizon.structurelib.alignment.enumerable.ExtendedFacing;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.item.ItemStack;
+import net.minecraft.world.World;
+
+/*
+ * Architecture notes: this should never get any callback from survival build. All structure significant code belongs
+ * within the IStructureElement. This will make the user easier to maintain the IStructureDefinition.
+ * Structure Element knows the most about what this structure element should do, not the caller.
+ */
+public interface ISurvivalBuildEnvironment {
+    /**
+     * Get the source of the items. This will be invoked exactly once per structure element build.
+     * <p>
+     * If the call chain ever got into the old API, this will be called at least once per {@link IStructureDefinition#survivalBuild(Object, ItemStack, String, World, ExtendedFacing, int, int, int, int, int, int, int, ISurvivalBuildEnvironment, boolean)} call.
+     */
+    IItemSource getSource();
+
+    /**
+     * Get the origin of action. This will be invoked at least once per {@link IStructureDefinition#survivalBuild(Object, ItemStack, String, World, ExtendedFacing, int, int, int, int, int, int, int, ISurvivalBuildEnvironment, boolean)} call.
+     */
+    EntityPlayer getActor();
+
+    /**
+     * Create a default implementation with three parameters all being constants.
+     *
+     * @param source from where to drain resource
+     * @param actor  source of action
+     */
+    static ISurvivalBuildEnvironment create(IItemSource source, EntityPlayer actor) {
+        return new DefaultSurvivalBuildEnvironment(source, actor);
+    }
+}