Mvvm

app/build.gradle

@@ -17,6 +17,10 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
+    dataBinding {
+        enabled = true
+    }
 }
 
 dependencies {

app/src/main/AndroidManifest.xml

@@ -8,10 +8,9 @@
         android:label="@string/app_name"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name=".controller.TicTacToeActivity">
+        <activity android:name=".view.TicTacToeActivity" android:screenOrientation="portrait">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
-
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>

app/src/main/java/com/acme/tictactoe/model/Board.java

@@ -22,6 +22,7 @@ public Board() {
      */
     public void restart() {
         clearCells();
+        winner = null;
         currentTurn = Player.X;
         state = GameState.IN_PROGRESS;
     }
@@ -33,11 +34,17 @@ public void restart() {
      *
      * @param row 0..2
      * @param col 0..2
+     * @return the player that moved or null if we did not move anything.
      *
      */
-    public void mark( int row, int col ) {
+    public Player mark( int row, int col ) {
+
+        Player playerThatMoved = null;
+
         if(isValid(row, col)) {
+
             cells[row][col].setValue(currentTurn);
+            playerThatMoved = currentTurn;
 
             if(isWinningMoveByPlayer(currentTurn, row, col)) {
                 state = GameState.FINISHED;
@@ -48,6 +55,12 @@ public void mark( int row, int col ) {
                 flipCurrentTurn();
             }
         }
+
+        return playerThatMoved;
+    }
+
+    public Player valueAtCell(int row, int col) {
+        return cells[row][col].getValue();
     }
 
     public Player getWinner() {

app/src/main/java/com/acme/tictactoe/model/Player.java

@@ -1,3 +1,3 @@
 package com.acme.tictactoe.model;
 
-enum Player { X , O }
+public enum Player { X , O }

app/src/main/java/com/acme/tictactoe/view/TicTacToeActivity.java

@@ -0,0 +1,61 @@
+package com.acme.tictactoe.view;
+
+import android.databinding.DataBindingUtil;
+import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
+
+import com.acme.tictactoe.R;
+import com.acme.tictactoe.databinding.TictactoeBinding;
+import com.acme.tictactoe.viewmodel.TicTacToeViewModel;
+
+public class TicTacToeActivity extends AppCompatActivity {
+
+    TicTacToeViewModel viewModel = new TicTacToeViewModel();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        TictactoeBinding binding = DataBindingUtil.setContentView(this, R.layout.tictactoe);
+        binding.setViewModel(viewModel);
+        viewModel.onCreate();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        viewModel.onPause();
+    }
+
+    @Override
+    protected void onResume() {
+        super.onResume();
+        viewModel.onResume();
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        viewModel.onDestroy();
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        MenuInflater inflater = getMenuInflater();
+        inflater.inflate(R.menu.menu_tictactoe, menu);
+        return true;
+    }
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case R.id.action_reset:
+                viewModel.onResetSelected();
+                return true;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+}

app/src/main/java/com/acme/tictactoe/viewmodel/TicTacToeViewModel.java

@@ -0,0 +1,52 @@
+package com.acme.tictactoe.viewmodel;
+
+import android.databinding.ObservableArrayMap;
+import android.databinding.ObservableField;
+
+import com.acme.tictactoe.model.Board;
+import com.acme.tictactoe.model.Player;
+
+public class TicTacToeViewModel implements ViewModel {
+
+    private Board model;
+
+    public final ObservableArrayMap<String, String> cells = new ObservableArrayMap<>();
+    public final ObservableField<String> winner = new ObservableField<>();
+
+    public TicTacToeViewModel() {
+        model = new Board();
+    }
+
+    @Override
+    public void onCreate() {
+
+    }
+
+    @Override
+    public void onPause() {
+
+    }
+
+    @Override
+    public void onResume() {
+
+    }
+
+    @Override
+    public void onDestroy() {
+
+    }
+
+    public void onResetSelected() {
+        model.restart();
+        winner.set(null);
+        cells.clear();
+    }
+
+    public void onClickedCellAt(int row, int col) {
+        Player playerThatMoved = model.mark(row, col);
+        cells.put("" + row + col, playerThatMoved == null ? null : playerThatMoved.toString());
+        winner.set(model.getWinner() == null ? null : model.getWinner().toString());
+    }
+
+}

app/src/main/java/com/acme/tictactoe/viewmodel/ViewModel.java

@@ -0,0 +1,10 @@
+package com.acme.tictactoe.viewmodel;
+
+public interface ViewModel {
+
+    void onCreate();
+    void onPause();
+    void onResume();
+    void onDestroy();
+
+}

app/src/main/res/layout/tictactoe.xml

@@ -1,17 +1,104 @@
 <?xml version="1.0" encoding="utf-8"?>
-<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/tictactoe"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:paddingBottom="@dimen/activity_vertical_margin"
-    android:paddingLeft="@dimen/activity_horizontal_margin"
-    android:paddingRight="@dimen/activity_horizontal_margin"
-    android:paddingTop="@dimen/activity_vertical_margin"
-    tools:context="com.acme.tictactoe.controller.TicTacToeActivity">
-
-    <TextView
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Hello World!" />
-</RelativeLayout>
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <data>
+        <import type="android.view.View" />
+        <variable name="viewModel" type="com.acme.tictactoe.viewmodel.TicTacToeViewModel" />
+    </data>
+
+    <LinearLayout
+        android:id="@+id/tictactoe"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:gravity="center_horizontal"
+        android:orientation="vertical"
+        android:paddingBottom="@dimen/activity_vertical_margin"
+        android:paddingLeft="@dimen/activity_horizontal_margin"
+        android:paddingRight="@dimen/activity_horizontal_margin"
+        android:paddingTop="@dimen/activity_vertical_margin"
+        tools:context="com.acme.tictactoe.view.TicTacToeActivity">
+
+        <GridLayout
+            android:id="@+id/buttonGrid"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:columnCount="3"
+            android:rowCount="3">
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(0,0)}"
+                android:text='@{viewModel.cells["00"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(0,1)}"
+                android:text='@{viewModel.cells["01"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(0,2)}"
+                android:text='@{viewModel.cells["02"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(1,0)}"
+                android:text='@{viewModel.cells["10"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(1,1)}"
+                android:text='@{viewModel.cells["11"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(1,2)}"
+                android:text='@{viewModel.cells["12"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(2,0)}"
+                android:text='@{viewModel.cells["20"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(2,1)}"
+                android:text='@{viewModel.cells["21"]}' />
+
+            <Button
+                style="@style/tictactoebutton"
+                android:onClick="@{() -> viewModel.onClickedCellAt(2,2)}"
+                android:text='@{viewModel.cells["22"]}' />
+
+        </GridLayout>
+
+        <LinearLayout
+            android:id="@+id/winnerPlayerViewGroup"
+            android:layout_width="wrap_content"
+            android:layout_height="match_parent"
+            android:gravity="center"
+            android:orientation="vertical"
+            android:visibility="@{viewModel.winner != null ? View.VISIBLE : View.GONE}"
+            tools:visibility="visible">
+
+            <TextView
+                android:id="@+id/winnerPlayerLabel"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_margin="20dp"
+                android:textSize="40sp"
+                android:text="@{viewModel.winner}"
+                tools:text="X" />
+
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/winner"
+                android:textSize="30sp" />
+
+        </LinearLayout>
+
+    </LinearLayout>
+</layout>

app/src/main/res/menu/menu_tictactoe.xml

@@ -0,0 +1,11 @@
+<menu 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"
+    tools:context=".view.TicTacToeActivity">
+
+    <item android:id="@+id/action_reset"
+        android:title="@string/action_reset"
+        android:orderInCategory="100"
+        app:showAsAction="ifRoom" />
+
+</menu>

app/src/main/res/values/dimens.xml

@@ -1,5 +1,5 @@
 <resources>
     <!-- Default screen margins, per the Android Design guidelines. -->
     <dimen name="activity_horizontal_margin">16dp</dimen>
-    <dimen name="activity_vertical_margin">16dp</dimen>
+    <dimen name="activity_vertical_margin">44dp</dimen>
 </resources>

app/src/main/res/values/strings.xml

@@ -1,3 +1,5 @@
 <resources>
     <string name="app_name">TicTacToe</string>
+    <string name="winner">Winner</string>
+    <string name="action_reset">Reset</string>
 </resources>

app/src/main/res/values/styles.xml

@@ -8,4 +8,10 @@
         <item name="colorAccent">@color/colorAccent</item>
     </style>
 
+    <style name="tictactoebutton">
+        <item name="android:layout_width">100dp</item>
+        <item name="android:layout_height">100dp</item>
+        <item name="android:textSize">30sp</item>
+    </style>
+
 </resources>

app/src/test/java/com/acme/tictactoe/model/TicTacToeTests.java

@@ -1,7 +1,5 @@
 package com.acme.tictactoe.model;
 
-import android.os.Build;
-
 import org.junit.Before;
 import org.junit.Test;
 
@@ -48,7 +46,7 @@ public void test3inRowAcrossTopForX() {
 
 
     /**
-     * This test will simulate and verify x is the winner.
+     * This test will simulate and verify o is the winner.
      *
      *    O | X | X
      *      | O |