I think the problem is in the line counter.getTag().toString();. I tried to put it in a string and then pass it to tappedCounter, but still my app crashes.
It would be highly helpful if someone helps me on how to figure out ourselves using the logcat in Android Studio on solving problems like this.
Here is the logcat : -
12-22 02:09:59.790 14251-14251/com.example.msq.practice E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.msq.practice, PID: 14251
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:6256)
at android.view.View$PerformClick.run(View.java:24701)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:6256)
at android.view.View$PerformClick.run(View.java:24701)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference
at com.example.msq.practice.MainActivity.click(MainActivity.java:27)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:6256)
at android.view.View$PerformClick.run(View.java:24701)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
MainActivity :-
package com.example.msq.practice;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.view.View;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
int activePlayer = 0;
int[] gameState = {2,2,2,2,2,2,2,2,2};
int[][] winningPositions = {{1,2,3}, {4,5,6}, {7,8,9}, {0,3,6},
{1,4,7,}, {2,5,8}, {0,4,8}, {2,4,6}};
boolean isGameActive = true;
String result;
String tag;
public void click(View view){
ImageView counter = (ImageView) view;
tag = counter.getTag().toString();
int tappedCounter = Integer.parseInt(tag);
if(gameState[tappedCounter] == 2 && isGameActive == true){
counter.setTranslationY(-5000f);
gameState[tappedCounter] = activePlayer;
if(activePlayer == 0){
counter.setImageResource(R.drawable.circle);
activePlayer = 1;
}
else{
counter.setImageResource(R.drawable.cross);
activePlayer = 0;
}
counter.animate().rotation(360f).translationYBy(5000f).setDuration(1000);
}
for(int[] winningPosition : winningPositions){
if(gameState[winningPosition[0]] == gameState[winningPosition[1]] &&
gameState[winningPosition[1]] == gameState[winningPosition[2]] &&
gameState[winningPosition[0]] != 2){
isGameActive = false;
if(gameState[winningPosition[0]]==0){
result = "PLayer 1 Won !";
}
else{
result = "PLayer 2 Won !";
}
}
else{
boolean isGameOver = true;
for(int counterState : gameState){
if(counterState == 2) isGameOver = false;
}
if(isGameOver)
result = "It's a Draw";
}
}
}
}
activity_main.xml file :-
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
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="com.example.msq.practice.MainActivity">
<GridLayout
android:id="@+id/gLayout"
android:layout_width="300dp"
android:layout_height="300dp"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true"
android:layout_marginBottom="106dp"
android:layout_marginEnd="42dp"
android:layout_marginStart="42dp"
android:layout_marginTop="105dp"
android:background="@drawable/board"
android:columnCount="3"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
tools:rowCount="3">
<ImageView
android:id="@+id/imageView0"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="0"
android:layout_marginStart="10dp"
android:layout_marginTop="10dp"
android:layout_row="0"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="1"
android:layout_marginStart="20dp"
android:layout_marginTop="10dp"
android:layout_row="0"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="0"
android:layout_marginStart="10dp"
android:layout_marginTop="22dp"
android:layout_row="1"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView4"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="1"
android:layout_marginStart="20dp"
android:layout_marginTop="22dp"
android:layout_row="1"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView5"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="2"
android:layout_marginStart="20dp"
android:layout_marginTop="22dp"
android:layout_row="1"
android:contentDescription="@string/cross"
android:onClick="click"/>
<ImageView
android:id="@+id/imageView7"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="1"
android:layout_marginStart="20dp"
android:layout_marginTop="22dp"
android:layout_row="2"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView8"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="2"
android:layout_marginStart="20dp"
android:layout_marginTop="22dp"
android:layout_row="2"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView6"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="0"
android:layout_marginStart="10dp"
android:layout_marginTop="22dp"
android:layout_row="2"
android:contentDescription="@string/cross"
android:onClick="click" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="80dp"
android:layout_height="80dp"
android:layout_column="2"
android:layout_marginStart="22dp"
android:layout_marginTop="10dp"
android:layout_row="0"
android:contentDescription="@string/cross"
android:onClick="click"/>
</GridLayout>
</android.support.constraint.ConstraintLayout>
