diff --git a/app/src/main/java/com/codigoparallevar/minicards/CanvasView.java b/app/src/main/java/com/codigoparallevar/minicards/CanvasView.java
index c6f36f9..ab0e011 100644
--- a/app/src/main/java/com/codigoparallevar/minicards/CanvasView.java
+++ b/app/src/main/java/com/codigoparallevar/minicards/CanvasView.java
@@ -21,6 +21,7 @@ import com.codigoparallevar.minicards.types.Part;
 import com.codigoparallevar.minicards.types.PartGrid;
 import com.codigoparallevar.minicards.types.Position;
 import com.codigoparallevar.minicards.types.Selectable;
+import com.codigoparallevar.minicards.types.Tuple4;
 
 import org.json.JSONArray;
 import org.json.JSONException;
@@ -54,7 +55,7 @@ class CanvasView extends View implements PartGrid {
     private final static float touchTimeForLongTouchInMillis = 500;
     private boolean _isDragging = false;
     private MainActivity parentActivity = null;
-    private Tuple<Integer, Integer, Integer, Integer> _dropToRemoveZone = new Tuple<>(0, 0, 0, 0);
+    private Tuple4<Integer, Integer, Integer, Integer> _dropToRemoveZone = new Tuple4<>(0, 0, 0, 0);
     private boolean _devMode = false;
 
     public CanvasView(Context context) {
@@ -362,31 +363,11 @@ class CanvasView extends View implements PartGrid {
     }
 
     public void setDropZone(float x1, float x2, float y1, float y2) {
-        _dropToRemoveZone = new Tuple<>((int) x1, (int) x2, (int) y1, (int) y2);
+        _dropToRemoveZone = new Tuple4<>((int) x1, (int) x2, (int) y1, (int) y2);
     }
 
     public void setDevMode(boolean devMode) {
         _devMode = devMode;
         this.invalidate();
     }
-
-    private class Tuple<T, T1, T2, T3> {
-
-        final T _x1;
-        final T1 _x2;
-        final T2 _y1;
-        final T3 _y2;
-
-        public Tuple(T x1, T1 x2, T2 y1, T3 y2) {
-            _x1 = x1;
-            _x2 = x2;
-            _y1 = y1;
-            _y2 = y2;
-        }
-
-        @Override
-        public String toString(){
-            return "(" + _x1 + " - " + _x2 + ", " + _y1 + " - " + _y2 + ")";
-        }
-    }
 }
diff --git a/app/src/main/java/com/codigoparallevar/minicards/types/PartConnection.java b/app/src/main/java/com/codigoparallevar/minicards/types/PartConnection.java
new file mode 100644
index 0000000..a7af930
--- /dev/null
+++ b/app/src/main/java/com/codigoparallevar/minicards/types/PartConnection.java
@@ -0,0 +1,14 @@
+package com.codigoparallevar.minicards.parts;
+
+import com.codigoparallevar.minicards.types.Part;
+
+public class PartConnection {
+    public final Part outputPart;
+    public final String inputPartId;
+
+
+    public PartConnection(Part outputPart, String inputPartId) {
+        this.outputPart = outputPart;
+        this.inputPartId = inputPartId;
+    }
+}
diff --git a/app/src/main/java/com/codigoparallevar/minicards/types/Tuple2.java b/app/src/main/java/com/codigoparallevar/minicards/types/Tuple2.java
new file mode 100644
index 0000000..baa4dad
--- /dev/null
+++ b/app/src/main/java/com/codigoparallevar/minicards/types/Tuple2.java
@@ -0,0 +1,11 @@
+package com.codigoparallevar.minicards.parts;
+
+public class Tuple<T1, T2> {
+    public final T1 item1;
+    public final T2 item2;
+
+    public Tuple(T1 item1, T2 item2) {
+        this.item1 = item1;
+        this.item2 = item2;
+    }
+}
diff --git a/app/src/main/java/com/codigoparallevar/minicards/types/Tuple4.java b/app/src/main/java/com/codigoparallevar/minicards/types/Tuple4.java
new file mode 100644
index 0000000..3f10b97
--- /dev/null
+++ b/app/src/main/java/com/codigoparallevar/minicards/types/Tuple4.java
@@ -0,0 +1,21 @@
+package com.codigoparallevar.minicards.types;
+
+public class Tuple4<T, T1, T2, T3> {
+
+    public final T _x1;
+    public final T1 _x2;
+    public final T2 _y1;
+    public final T3 _y2;
+
+    public Tuple4(T x1, T1 x2, T2 y1, T3 y2) {
+        _x1 = x1;
+        _x2 = x2;
+        _y1 = y1;
+        _y2 = y2;
+    }
+
+    @Override
+    public String toString(){
+        return "(" + _x1 + " - " + _x2 + ", " + _y1 + " - " + _y2 + ")";
+    }
+}