diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/FillGrid.java b/app/src/main/java/org/agp8x/android/games/fillgrid/FillGrid.java
index decfd89..7778221 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/FillGrid.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/FillGrid.java
@@ -16,13 +16,8 @@ public class FillGrid extends AppCompatActivity {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_fill_grid);
 
-        //GridObject<String> sgo = new GridBlock<>("asdf");
-        //GridObject<Asdf> ago = new GridBlock<>(Asdf.A);
         RelativeLayout layout = (RelativeLayout) findViewById(R.id.mainLayout);
 
-       /* Pair<Float, Float> fp = new Pair<>(1.0f, 2.0f);
-        Pair<Integer, Integer> ip = new Pair<>(1, 2);
-        ip = new Pair<>(fp.first.intValue(), fp.second.intValue());*/
         FillGridView gridview = new FillGridView(this);
         layout.addView(gridview);
         gridview.setScoreView((TextView) findViewById(R.id.textView));
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/FillGridView.java b/app/src/main/java/org/agp8x/android/games/fillgrid/FillGridView.java
index 9344c07..71e489f 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/FillGridView.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/FillGridView.java
@@ -3,9 +3,7 @@ package org.agp8x.android.games.fillgrid;
 import android.content.Context;
 import android.graphics.Canvas;
 import android.support.annotation.Nullable;
-import android.support.v4.widget.TextViewCompat;
 import android.util.AttributeSet;
-import android.util.Log;
 import android.util.Pair;
 import android.view.MotionEvent;
 import android.view.View;
@@ -21,8 +19,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import static org.agp8x.android.games.fillgrid.Util.TAG;
-
 /**
  * Created by clemensk on 07.04.17.
  */
@@ -34,6 +30,9 @@ public class FillGridView extends View {
     protected GridBoard<GridBlock<GroupCell>, GroupCell> board;
     protected List<GridBlock<GroupCell>> blocks;
     protected Map<Offset, GroupCell> background;
+    /**
+     * relative positioning
+     */
     protected Map<Offset, GridBlock<GroupCell>> spawnGrid;
     protected GroupGridPainter<GroupCell> painter;
     protected GroupGridPainter<GroupCell> bgPainter;
@@ -42,6 +41,9 @@ public class FillGridView extends View {
     private SpawnPainterGroup<GridBlock<GroupCell>, GroupCell> spawnPainter;
     private Dragging dragging;
     private Offset dimensions;
+    /**
+     * on-screen coordinates, updated by onDraw
+     */
     private Map<GridBlock<GroupCell>, Pair<Integer, Integer>> spawnPositions;
     private TextView scoreView;
     private int score = 0;
@@ -122,6 +124,7 @@ public class FillGridView extends View {
         grid.getObjects().put(new Offset(0, 1), new GroupCell(0));
         grid.getObjects().put(new Offset(1, 0), new GroupCell(0));
         grid.getObjects().put(new Offset(1, 1), new GroupCell(0));
+        grid.setCenter(new Offset(1, 1));
         blocks.add(grid);
         return grid;
     }
@@ -133,6 +136,7 @@ public class FillGridView extends View {
         grid.getObjects().put(new Offset(2, 2), new GroupCell(1));
         grid.getObjects().put(new Offset(2, 1), new GroupCell(1));
         grid.getObjects().put(new Offset(2, 0), new GroupCell(1));
+        grid.setCenter(new Offset(3, 3));
         blocks.add(grid);
         return grid;
     }
@@ -150,7 +154,6 @@ public class FillGridView extends View {
         painter.draw(canvas, board.getGrid(), contentSize);
         spawnPositions = spawnPainter.draw(canvas, spawnGrid, spawnBoundaries);
         if (dragging.object != null) {
-            Log.d(TAG, "draw dragging");
             spawnPainter.drawDragging(canvas, dragging.xy, dragging.object);
         }
     }
@@ -175,7 +178,11 @@ public class FillGridView extends View {
         }
         contentSize = new Pair<>(contentHeight, contentWidth);
         spawnSize = new Pair<>(spawnHeight, spawnWidth);
-        spawnBoundaries = new Area(contentHeight, paddingLeft, spawnHeight + contentHeight, spawnWidth);
+        spawnBoundaries = new Area(
+                contentHeight,
+                paddingLeft,
+                spawnHeight + contentHeight,
+                spawnWidth);
     }
 
     private int divideSide(int sideLength) {
@@ -193,7 +200,9 @@ public class FillGridView extends View {
     }
 
     private Offset coordinate2offset(Pair<Float, Float> xy) {
-        return new Offset((int) ((xy.second / contentSize.first) * dimensions.y), (int) ((xy.first / contentSize.second) * dimensions.y));
+        return new Offset((int) (
+                (xy.second / contentSize.first) * dimensions.y),
+                (int) ((xy.first / contentSize.second) * dimensions.y));
     }
 
     private Offset coordinate2spawnOffset(Pair<Float, Float> xy) {
@@ -245,10 +254,17 @@ public class FillGridView extends View {
             boolean updated = false;
             // spawnPositions.entrySet().stream().filter(entry -> selects(position, entry.getValue())).findFirst().ifPresent(entry -> startDragging(entry, position));
             for (Map.Entry<GridBlock<GroupCell>, Pair<Integer, Integer>> entry : spawnPositions.entrySet()) {
-                if (selects(position, entry.getValue())) {
+                if (selects(position, entry)) {
                     dragging.object = entry.getKey();
                     dragging.xy = position;
+                    dragging.origin = entry.getValue();
                     updated = true;
+                    spawnGrid.entrySet().
+                            stream().
+                            filter(offset_block -> offset_block.getValue() == dragging.object).
+                            findFirst().
+                            ifPresent(offsetGridBlockEntry -> dragging.key = offsetGridBlockEntry.getKey());
+                    spawnGrid.remove(dragging.key);
                     break;
                 }
             }
@@ -261,17 +277,13 @@ public class FillGridView extends View {
             if (dragging.object != null) {
                 if (board.drop(coordinate2offset(position), dragging.object)) {
                     //Offset key = spawnGrid.entrySet().stream().filter(entry -> entry==dragging.object).findFirst().get().getKey();
-                    Offset key = null;
-                    for (Map.Entry<Offset, GridBlock<GroupCell>> entry : spawnGrid.entrySet()) {
-                        if (entry.getValue() == dragging.object) {
-                            key = entry.getKey();
-                            break;
-                        }
-                    }
-                    spawnGrid.remove(key);
                     spawnPositions.remove(dragging.object);
+                }else{
+                    spawnGrid.put(dragging.key,dragging.object);
                 }
                 dragging.object = null;
+                dragging.origin = null;
+                dragging.key = null;
                 if (spawnGrid.isEmpty()) {
                     populateSpawnArea();
                 }
@@ -294,15 +306,18 @@ public class FillGridView extends View {
             dragging.xy = position;
         }*/
 
-        private boolean selects(Pair<Float, Float> eventPos, Pair<Integer, Integer> spawnPos) {
-            float xdiff = Math.abs(eventPos.first - spawnPos.first);
-            float ydiff = Math.abs(eventPos.second - spawnPos.second);
-            return xdiff < 40 && ydiff < 40;
+        private boolean selects(Pair<Float, Float> eventPos, Map.Entry<GridBlock<GroupCell>, Pair<Integer, Integer>> spawnPos) {
+            Pair<Float, Float> center = Util.offsetToScreen(spawnPos.getKey().getCenter(), dimensions);
+            float xdiff = Math.abs(eventPos.first - (spawnPos.getValue().first + center.first));
+            float ydiff = Math.abs(eventPos.second - (spawnPos.getValue().second + center.second));
+            return xdiff < 100 && ydiff < 100;
         }
     }
 
     private class Dragging {
         GridBlock<GroupCell> object;
         Pair<Float, Float> xy;
+        Pair<Integer, Integer> origin;
+        Offset key;
     }
 }
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/GroupGridPainter.java b/app/src/main/java/org/agp8x/android/games/fillgrid/GroupGridPainter.java
index 389a638..bd58855 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/GroupGridPainter.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/GroupGridPainter.java
@@ -1,6 +1,7 @@
 package org.agp8x.android.games.fillgrid;
 
 import android.graphics.Canvas;
+import android.support.annotation.NonNull;
 import android.util.Pair;
 
 import org.agp8x.android.games.fillgrid.data.GroupCell;
@@ -31,7 +32,8 @@ public class GroupGridPainter<C extends GroupCell> implements GridPainter<C> {
     }
 
     private void drawCell(Canvas canvas, Offset offset, C cell, Pair<Integer, Integer> realDimensions) {
-        Pair<Float, Float> origin = new Pair<>((offset.x / (float) dimensions.x) * realDimensions.first, (offset.y / (float) dimensions.y) * realDimensions.second);
+        Pair<Float, Float> origin = Util.offsetToScreen(offset, realDimensions, dimensions);
         canvas.drawCircle(origin.second + margin, origin.first + margin, radius, styleInfo.getPaint(cell));
     }
+
 }
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/SpawnPainterGroup.java b/app/src/main/java/org/agp8x/android/games/fillgrid/SpawnPainterGroup.java
index d89a120..b8e4629 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/SpawnPainterGroup.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/SpawnPainterGroup.java
@@ -21,6 +21,7 @@ public class SpawnPainterGroup<G extends GridObject<C>, C extends GroupCell> imp
     private CellPaintProvider<C> styleInfo;
     private int diameter;
     private Map<G, Pair<Integer, Integer>> positions;
+    private Offset dragOffset;
 
     public SpawnPainterGroup(CellPaintProvider<C> styleInfo) {
         this.styleInfo = styleInfo;
@@ -28,6 +29,7 @@ public class SpawnPainterGroup<G extends GridObject<C>, C extends GroupCell> imp
         margin = radius * 3 + radius / 4;
         diameter = radius * 2;
         positions = new HashMap<>();
+        dragOffset = new Offset(0,0);
     }
 
     @Override
@@ -56,7 +58,7 @@ public class SpawnPainterGroup<G extends GridObject<C>, C extends GroupCell> imp
     }
 
     private void drawCellDragging(Canvas canvas, Pair<Float, Float> xy, Offset offset, C c) {
-        canvas.drawCircle(xy.first + diameter * offset.y, xy.second + diameter * offset.x, radius, styleInfo.getPaint(c));
+        canvas.drawCircle(xy.first + diameter * (offset.y+dragOffset.y), xy.second + diameter * (offset.x+dragOffset.x), radius, styleInfo.getPaint(c));
     }
 
     private void drawBlock(Canvas canvas, G groupCellGridBlock) {
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/Util.java b/app/src/main/java/org/agp8x/android/games/fillgrid/Util.java
index 28f4233..ddad7cb 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/Util.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/Util.java
@@ -1,9 +1,12 @@
 package org.agp8x.android.games.fillgrid;
 
+import android.support.annotation.NonNull;
 import android.util.Log;
 import android.util.Pair;
 import android.view.MotionEvent;
 
+import org.agp8x.android.games.fillgrid.data.Offset;
+
 /**
  * Created by clemensk on 09.04.17.
  */
@@ -16,9 +19,18 @@ public class Util {
     }
 
     public static boolean in(Pair<Float, Float> probe, Area area) {
-        Log.d(TAG,"probe: "+probe+" ;area: "+area);
-        Log.d(TAG, "("+(area.top < probe.second)+" && "+(probe.second < area.bottom)+") && ("+(area.left < probe.first) +" && "+ (probe.first < area.right)+")");
+        Log.d(TAG, "probe: " + probe + " ;area: " + area);
+        Log.d(TAG, "(" + (area.top < probe.second) + " && " + (probe.second < area.bottom) + ") && (" + (area.left < probe.first) + " && " + (probe.first < area.right) + ")");
         boolean contained = (area.top < probe.second && probe.second < area.bottom) && (area.left < probe.first && probe.first < area.right);
         return contained;
     }
+
+    public static Pair<Float, Float> offsetToScreen(Offset offset, Offset dimensions) {
+        return offsetToScreen(offset, new Pair<>(1, 1), dimensions);
+    }
+
+    @NonNull
+    public static Pair<Float, Float> offsetToScreen(Offset offset, Pair<Integer, Integer> realDimensions, Offset dimensions) {
+        return new Pair<>((offset.x / (float) dimensions.x) * realDimensions.first, (offset.y / (float) dimensions.y) * realDimensions.second);
+    }
 }
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBlock.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBlock.java
index a149203..113b7ed 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBlock.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBlock.java
@@ -1,5 +1,7 @@
 package org.agp8x.android.games.fillgrid.data;
 
+import org.agp8x.android.games.fillgrid.Area;
+
 import java.util.HashMap;
 import java.util.Map;
 
@@ -9,6 +11,7 @@ import java.util.Map;
 
 public class GridBlock<C extends Cell> implements GridObject<C> {
     private final Map<Offset, C> content;
+    private Offset center;
 
     public GridBlock() {
         content = new HashMap<>();
@@ -18,6 +21,11 @@ public class GridBlock<C extends Cell> implements GridObject<C> {
         this.content = new HashMap<>(content);
     }
 
+    public GridBlock(Map<Offset, C> content, Offset center) {
+        this.content = new HashMap<>(content);
+        this.center = center;
+    }
+
     @Override
     public Map<Offset, C> getObjects() {
         return content;
@@ -30,22 +38,19 @@ public class GridBlock<C extends Cell> implements GridObject<C> {
 
     @Override
     public GridObject<C> duplicate() {
-        return new GridBlock<>(content);
+        return new GridBlock<>(content, center);
     }
 
+
     @Override
-    public Offset getDimensions() {
-        if (content.isEmpty()) {
+    public Offset getCenter() {
+        if (center == null) {
             return new Offset(0, 0);
         }
-        Offset min = content.keySet().stream().findFirst().get();
-        Offset max = min;
-        for (Offset offset : content.keySet()) {
-            min = Offset.min(min, offset);
-            max = Offset.max(max, offset);
-        }
-        System.out.println(max);
-        System.out.println(min);
-        return new Offset(1 + max.x - min.x, 1 + max.y - min.y);
+        return this.center;
+    }
+
+    public void setCenter(Offset center) {
+        this.center = center;
     }
 }
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridObject.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridObject.java
index 6354b5f..906d7c9 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridObject.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridObject.java
@@ -13,5 +13,5 @@ public interface GridObject<C extends Cell> {
 
     GridObject<C> duplicate();
 
-    Offset getDimensions();
+    Offset getCenter();
 }
diff --git a/app/src/test/java/org/agp8x/android/games/fillgrid/data/GridBlockTest.java b/app/src/test/java/org/agp8x/android/games/fillgrid/data/GridBlockTest.java
index 6f393ae..0f0dd76 100644
--- a/app/src/test/java/org/agp8x/android/games/fillgrid/data/GridBlockTest.java
+++ b/app/src/test/java/org/agp8x/android/games/fillgrid/data/GridBlockTest.java
@@ -1,5 +1,6 @@
 package org.agp8x.android.games.fillgrid.data;
 
+import org.agp8x.android.games.fillgrid.Area;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -25,13 +26,13 @@ public class GridBlockTest {
     public void getDimensions() throws Exception {
         /*
         * oox
-        * oxo-
+        * oXo-
         * oox
          */
         assertEquals(new Offset(2, 3), grid.getDimensions());
         /*
         * xxx
-        * oxo-
+        * oXo-
         * oox
          */
         grid.getObjects().put(new Offset(-1, 1), new StringCell("top-left"));
@@ -39,7 +40,7 @@ public class GridBlockTest {
         assertEquals(new Offset(3, 3), grid.getDimensions());
         /*
         * ooxxx
-        * oox
+        * oOx
         * oox
          */
         grid.getObjects().clear();
@@ -51,7 +52,7 @@ public class GridBlockTest {
         assertEquals(new Offset(3, 3), grid.getDimensions());
         /*
         * ooxxx
-        * ooo
+        * oOo
         * ooo
          */
         grid.getObjects().remove(new Offset(1, 0), new StringCell("center-right"));
@@ -59,4 +60,43 @@ public class GridBlockTest {
         assertEquals(new Offset(3, 1), grid.getDimensions());
     }
 
+    @Test
+    public void toArea() throws Exception {
+
+        /*
+        * oox
+        * oXo-
+        * oox
+         */
+        assertEquals(new Area(-1,0,1,1), grid.toArea());
+        /*
+        * xxx
+        * oXo-
+        * oox
+         */
+        grid.getObjects().put(new Offset(-1, 1), new StringCell("top-left"));
+        grid.getObjects().put(new Offset(0, 1), new StringCell("top-center"));
+        assertEquals(new Area(-1,-1,1,1), grid.toArea());
+        /*
+        * oxxx
+        * Ox
+        * ox
+         */
+        grid.getObjects().clear();
+        grid.getObjects().put(new Offset(1, 1), new StringCell("top-right"));
+        grid.getObjects().put(new Offset(2, 1), new StringCell("top-right2"));
+        grid.getObjects().put(new Offset(3, 1), new StringCell("top-right3"));
+        grid.getObjects().put(new Offset(1, 0), new StringCell("center-right"));
+        grid.getObjects().put(new Offset(1, 2), new StringCell("bottom-right"));
+        assertEquals(new Area(0,1,2,3), grid.toArea());
+        /*
+        * oxxx
+        * Oo
+        * oo
+         */
+        grid.getObjects().remove(new Offset(1, 0), new StringCell("center-right"));
+        grid.getObjects().remove(new Offset(1, -1), new StringCell("bottom-right"));
+        assertEquals(new Area(0,1,2,3), grid.toArea());
+
+    }
 }
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index b78a0b8..c2eea8e 100644
--- a/build.gradle
+++ b/build.gradle
@@ -5,7 +5,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:2.3.3'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files