implemented multiblock block component

src/main/java/org/kapelle/multiblock/BlockComponent.java

@@ -0,0 +1,55 @@
+package org.kapelle.multiblock;
+
+import org.bukkit.Location;
+import org.bukkit.Material;
+import org.bukkit.block.Block;
+
+import java.util.Collections;
+import java.util.Set;
+
+public class BlockComponent {
+    private final BlockComponentMode mode;
+    private final Set<Material> blocks;
+
+    public BlockComponent(){
+        this.mode = BlockComponentMode.ANY;
+        this.blocks = Collections.emptySet();
+    }
+
+    public BlockComponent(BlockComponentMode mode){
+        if(mode == BlockComponentMode.SET){
+            throw new RuntimeException("Component is impossible to satisfy because no valid blocks are given");
+        }
+
+        this.mode = mode;
+        this.blocks = Collections.emptySet();
+    }
+
+    public BlockComponent(BlockComponentMode mode, Set<Material> validBlocks){
+        this.mode = mode;
+        this.blocks = validBlocks;
+    }
+
+    // TODO: custom check function constructor
+
+    public boolean isValidBlock(Location location){
+        return isValidType(location.getBlock().getType());
+    }
+
+    private boolean isValidType(Material type){
+        switch (this.mode){
+            case AIR:
+                return type == Material.AIR;
+            case ANY:
+                return true;
+            case SET:
+                return blocks.contains(type);
+            case CUSTOM:
+                return false; // TODO custom function
+            default:
+                return false;
+
+        }
+    }
+
+}

src/main/java/org/kapelle/multiblock/BlockComponentMode.java

@@ -0,0 +1,5 @@
+package org.kapelle.multiblock;
+
+public enum BlockComponentMode {
+    ANY, AIR, SET, CUSTOM
+}