diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProvider.java b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProvider.java
new file mode 100644
index 0000000..bbd2c19
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProvider.java
@@ -0,0 +1,15 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.graphics.Paint;
+import android.support.annotation.NonNull;
+
+import org.agp8x.android.games.fillgrid.data.Cell;
+
+/**
+ * Created by clemensk on 09.04.17.
+ */
+
+public interface CellPaintProvider {
+    @NonNull
+    Paint getPaint(Cell cell);
+}
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderBackground.java b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderBackground.java
new file mode 100644
index 0000000..eadb8a2
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderBackground.java
@@ -0,0 +1,20 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.graphics.Paint;
+import android.support.annotation.NonNull;
+
+import org.agp8x.android.games.fillgrid.data.Cell;
+
+/**
+ * Created by clemensk on 09.04.17.
+ */
+
+public class CellPaintProviderBackground implements CellPaintProvider {
+    @NonNull
+    @Override
+    public Paint getPaint(Cell cell) {
+        Paint paint = new Paint();
+        paint.setAlpha(128);
+        return paint;
+    }
+}
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderDefault.java b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderDefault.java
new file mode 100644
index 0000000..0eb446f
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/CellPaintProviderDefault.java
@@ -0,0 +1,39 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.graphics.Color;
+import android.graphics.Paint;
+import android.support.annotation.NonNull;
+
+import org.agp8x.android.games.fillgrid.data.Cell;
+import org.agp8x.android.games.fillgrid.data.GroupCell;
+
+/**
+ * Created by clemensk on 09.04.17.
+ */
+
+public class CellPaintProviderDefault implements CellPaintProvider {
+
+    @NonNull
+    @Override
+    public Paint getPaint(Cell cell) {
+        Paint paint = new Paint();
+        if (cell instanceof GroupCell) {
+            GroupCell groupCell = (GroupCell) cell;
+            switch (groupCell.getGroup()) {
+                case 0:
+                    paint.setColor(Color.RED);
+                    break;
+                case 1:
+                    paint.setColor(Color.GREEN);
+                    break;
+                case 2:
+                    paint.setColor(Color.BLUE);
+                    break;
+                default:
+                    paint.setColor(Color.MAGENTA);
+            }
+            paint.setAlpha(192);
+        }
+        return paint;
+    }
+}
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 15699c6..2525bff 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
@@ -2,6 +2,7 @@ package org.agp8x.android.games.fillgrid;
 
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.widget.RelativeLayout;
 
 import org.agp8x.android.games.fillgrid.data.GridBlock;
 import org.agp8x.android.games.fillgrid.data.GridObject;
@@ -15,6 +16,10 @@ public class FillGrid extends AppCompatActivity {
 
         //GridObject<String> sgo = new GridBlock<>("asdf");
         //GridObject<Asdf> ago = new GridBlock<>(Asdf.A);
+        RelativeLayout layout = (RelativeLayout) findViewById(R.id.mainLayout);
+
+        FillGridView gridview = new FillGridView(this);
+        layout.addView(gridview);
     }
     private enum Asdf{
         A,B,C;
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
new file mode 100644
index 0000000..d0105ae
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/FillGridView.java
@@ -0,0 +1,122 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.content.Context;
+import android.graphics.Canvas;
+import android.support.annotation.Nullable;
+import android.util.AttributeSet;
+import android.util.Pair;
+import android.view.View;
+
+import org.agp8x.android.games.fillgrid.data.GridBlock;
+import org.agp8x.android.games.fillgrid.data.GridBoard;
+import org.agp8x.android.games.fillgrid.data.GroupCell;
+import org.agp8x.android.games.fillgrid.data.Offset;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Created by clemensk on 07.04.17.
+ */
+
+public class FillGridView extends View {
+    protected Pair<Integer, Integer> contentSize = null;
+    protected GridBoard<GridBlock<GroupCell>, GroupCell> board;
+    protected List<GridBlock<GroupCell>> blocks;
+    protected Map<Offset, GroupCell> background;
+    protected GroupGridPainter painter;
+    protected GroupGridPainter bgPainter;
+
+    public FillGridView(Context context) {
+        super(context);
+        init(null, 0);
+    }
+
+    public FillGridView(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        init(attrs, 0);
+    }
+
+    public FillGridView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init(attrs, defStyleAttr);
+    }
+
+    public FillGridView(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init(attrs, defStyleAttr);
+    }
+
+    protected void init(AttributeSet attrs, int defStyleAttr) {
+        Offset dimensions = new Offset(10, 10);
+        board = new GridBoard<>(dimensions);
+
+        blocks = new ArrayList<>();
+        GridBlock<GroupCell> block0 = new GridBlock<>();
+        block0.getObjects().put(new Offset(0, 0), new GroupCell(0));
+        blocks.add(block0);
+        block0 = new GridBlock<>();
+        block0.getObjects().put(new Offset(0, 0), new GroupCell(1));
+        block0.getObjects().put(new Offset(0, 1), new GroupCell(1));
+        blocks.add(block0);
+        block0 = new GridBlock<>();
+        block0.getObjects().put(new Offset(0, 0), new GroupCell(2));
+        block0.getObjects().put(new Offset(0, 1), new GroupCell(2));
+        block0.getObjects().put(new Offset(0, 2), new GroupCell(2));
+        blocks.add(block0);
+
+        background = new HashMap<>();
+        GroupCell bgCell = new GroupCell(-1);
+        for (int i = 0; i < dimensions.x; i++) {
+            for (int j = 0; j < dimensions.y; j++) {
+                background.put(new Offset(i, j), bgCell);
+            }
+        }
+
+        CellPaintProvider bgCpp = new CellPaintProviderBackground();
+        bgPainter = new GroupGridPainter(dimensions,bgCpp);
+
+        CellPaintProvider cpp = new CellPaintProviderDefault();
+        painter = new GroupGridPainter(dimensions, cpp);
+        board.drop(new Offset(4, 4), makeSquare());
+        board.drop(new Offset(4,4), makeAngle());
+    }
+
+    private GridBlock<GroupCell> makeSquare() {
+        GridBlock<GroupCell> grid = new GridBlock<>(new HashMap<>());
+        grid.getObjects().put(new Offset(0, 0), new GroupCell(0));
+        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));
+        return grid;
+    }
+
+    private GridBlock<GroupCell> makeAngle() {
+        GridBlock<GroupCell> grid = new GridBlock<>(new HashMap<>());
+        grid.getObjects().put(new Offset(0, 2), new GroupCell(1));
+        grid.getObjects().put(new Offset(1, 2), new GroupCell(1));
+        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));
+        return grid;
+    }
+
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+        if (contentSize == null) {
+            //TODO: maybe fix for square? optional?
+            int paddingTop = getPaddingTop();
+            int paddingBottom = getPaddingBottom();
+            int paddingLeft = getPaddingLeft();
+            int paddingRight = getPaddingRight();
+            contentSize = new Pair<>(getHeight() - paddingTop - paddingBottom, getWidth() - paddingLeft - paddingRight);
+        }
+
+        bgPainter.draw(canvas, background, contentSize);
+        painter.draw(canvas, board.getGrid(), contentSize);
+    }
+}
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/GridPainter.java b/app/src/main/java/org/agp8x/android/games/fillgrid/GridPainter.java
new file mode 100644
index 0000000..82547fc
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/GridPainter.java
@@ -0,0 +1,18 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.graphics.Canvas;
+import android.util.Pair;
+
+import org.agp8x.android.games.fillgrid.data.GroupCell;
+import org.agp8x.android.games.fillgrid.data.Offset;
+
+import java.util.Map;
+
+/**
+ * Created by clemensk on 07.04.17.
+ */
+
+public interface GridPainter {
+
+    void draw(Canvas canvas, Map<Offset, GroupCell> cells, Pair<Integer,Integer> realDimensions);
+}
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
new file mode 100644
index 0000000..965c526
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/GroupGridPainter.java
@@ -0,0 +1,37 @@
+package org.agp8x.android.games.fillgrid;
+
+import android.graphics.Canvas;
+import android.util.Pair;
+
+import org.agp8x.android.games.fillgrid.data.GroupCell;
+import org.agp8x.android.games.fillgrid.data.Offset;
+
+import java.util.Map;
+
+/**
+ * Created by clemensk on 07.04.17.
+ */
+
+public class GroupGridPainter implements GridPainter {
+    private Offset dimensions;
+    private CellPaintProvider styleInfo;
+    private int margin;
+    private int radius;
+
+    public GroupGridPainter(Offset dimensions, CellPaintProvider styleInfo) {
+        this.dimensions = dimensions;
+        this.styleInfo = styleInfo;
+        radius = 30;
+        margin = radius + radius / 4;
+    }
+
+    @Override
+    public void draw(Canvas canvas, Map<Offset, GroupCell> cells, Pair<Integer, Integer> realDimensions) {
+        cells.forEach((offset, groupCell) -> drawCell(canvas, offset, groupCell, realDimensions));
+    }
+
+    private void drawCell(Canvas canvas, Offset offset, GroupCell 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);
+        canvas.drawCircle(origin.second + margin, origin.first + margin, 30, styleInfo.getPaint(cell));
+    }
+}
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/Cell.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/Cell.java
index 0bbf86e..1395a32 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/Cell.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/Cell.java
@@ -8,4 +8,5 @@ public interface Cell {
     String getTableSymbol();
 
     void markCollapsed();
+    boolean isCollapsed();
 }
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 406f980..a149203 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
@@ -10,6 +10,10 @@ import java.util.Map;
 public class GridBlock<C extends Cell> implements GridObject<C> {
     private final Map<Offset, C> content;
 
+    public GridBlock() {
+        content = new HashMap<>();
+    }
+
     public GridBlock(Map<Offset, C> content) {
         this.content = new HashMap<>(content);
     }
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBoard.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBoard.java
index bbdd1ad..28cb70e 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBoard.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GridBoard.java
@@ -17,8 +17,12 @@ public class GridBoard<G extends GridObject<C>, C extends Cell> implements Grid<
     private final Offset dimensions;
 
     public GridBoard(int heigth, int width) {
+        this(new Offset(width, heigth));
+    }
+
+    public GridBoard(Offset dimensions) {
         this.contents = new HashMap<>();
-        dimensions = new Offset(width, heigth);
+        this.dimensions = dimensions;
     }
 
     @Override
@@ -45,6 +49,10 @@ public class GridBoard<G extends GridObject<C>, C extends Cell> implements Grid<
         contents.clear();
     }
 
+    public void removeCollapsed() {
+        contents.entrySet().stream().filter(offsetCEntry -> offsetCEntry.getValue().isCollapsed()).forEach(offsetCEntry -> contents.remove(offsetCEntry.getKey()));
+    }
+
     /**
      * Find lines with all cells filled and mark them as collapsed
      *
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/GroupCell.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GroupCell.java
new file mode 100644
index 0000000..f13c3a3
--- /dev/null
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/GroupCell.java
@@ -0,0 +1,39 @@
+package org.agp8x.android.games.fillgrid.data;
+
+/**
+ * Created by clemensk on 07.04.17.
+ */
+
+public class GroupCell implements Cell {
+    private int group;
+    private boolean collapsed = false;
+    private boolean collapsionMark = false;
+
+    public GroupCell(int group) {
+        this.group = group;
+    }
+
+    public int getGroup() {
+        return group;
+    }
+
+    public boolean isCollapsionMark() {
+        return collapsionMark;
+    }
+
+    @Override
+    public String getTableSymbol() {
+        return "" + group;
+    }
+
+    @Override
+    public void markCollapsed() {
+        collapsionMark =true;
+    }
+
+    @Override
+    public boolean isCollapsed() {
+        return collapsed;
+    }
+
+}
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/Offset.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/Offset.java
index 58080b0..0c42b53 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/Offset.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/Offset.java
@@ -4,7 +4,7 @@ package org.agp8x.android.games.fillgrid.data;
  * Created by clemensk on 29.03.17.
  */
 
-class Offset {
+public class Offset {
     public final int x;
     public final int y;
 
diff --git a/app/src/main/java/org/agp8x/android/games/fillgrid/data/StringCell.java b/app/src/main/java/org/agp8x/android/games/fillgrid/data/StringCell.java
index 0174117..be2d3a3 100644
--- a/app/src/main/java/org/agp8x/android/games/fillgrid/data/StringCell.java
+++ b/app/src/main/java/org/agp8x/android/games/fillgrid/data/StringCell.java
@@ -35,4 +35,9 @@ public class StringCell implements Cell {
     public void markCollapsed() {
 
     }
+
+    @Override
+    public boolean isCollapsed() {
+        return false;
+    }
 }
diff --git a/app/src/main/res/layout/activity_fill_grid.xml b/app/src/main/res/layout/activity_fill_grid.xml
index 1f1763c..b461cac 100644
--- a/app/src/main/res/layout/activity_fill_grid.xml
+++ b/app/src/main/res/layout/activity_fill_grid.xml
@@ -1,19 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<android.support.constraint.ConstraintLayout
+<RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context="org.agp8x.android.games.fillgrid.FillGrid">
+    tools:context="org.agp8x.android.games.fillgrid.FillGrid"
+    android:id="@+id/mainLayout">
 
-    <TextView
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Hello World!"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent"/>
 
-</android.support.constraint.ConstraintLayout>
+</RelativeLayout>