school, Math Trainer, 19+26.11.2017

activity_main.xml
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<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/tvRightCounter"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:layout_weight="1"
            android:background="#00FF00"
            android:gravity="center"
            android:text="0"
            android:textColor="#FFFFFF"
            android:textSize="30sp" />

        <TextView
            android:id="@+id/tvWrongCounter"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="16dp"
            android:layout_weight="1"
            android:background="#FF0000"
            android:gravity="center"
            android:text="0"
            android:textColor="#FFFFFF"
            android:textSize="30sp" />
    </LinearLayout>

    <TextView
        android:id="@+id/tvNumber1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:background="#0009ff"
        android:gravity="center"
        android:textColor="#FFFFFF"
        android:textSize="30sp" />

    <TextView
        android:id="@+id/tvOperation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:background="#f2adad"
        android:gravity="center"
        android:textSize="30sp" />

    <TextView
        android:id="@+id/tvNumber2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:background="#0009ff"
        android:gravity="center"
        android:textColor="#FFFFFF"
        android:textSize="30sp" />

    <EditText
        android:id="@+id/etResult"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:background="#0FFFF0"
        android:gravity="center"
        android:hint="Enter your answer"
        android:inputType="numberSigned"
        android:textSize="30sp" />

    <Button
        android:id="@+id/btnCheck"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Check"
        android:textSize="30sp" />
</LinearLayout>


MainActivity.java
-----------------
package com.example.mohamadpc.mmathapplication;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import java.util.Random;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    TextView tvRightCounter, tvWrongCounter;
    TextView tvNumber1, tvNumber2, tvOperation;
    EditText etResult;
    Button btnCheck;
    Random rnd = new Random();

    int rightAnswer;
    int rCount = 0, wCount = 0;
    int more = 10;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        connectToLayout();
        showEx();
    }

    private void showEx() {
        int n1 = rnd.nextInt(10);
        int n2 = rnd.nextInt(10);
        int op = rnd.nextInt(5); // +, -, *, /, ^


        switch (op) {
            case 0:
                tvOperation.setText("+");
                rightAnswer = n1 + n2;
                break;
            case 1:
                tvOperation.setText("-");
                if (n1 < n2) {
                    int temp = n2;
                    n2 = n1;
                    n1 = temp;
                }
                // n1>=n2 : for sure
                rightAnswer = n1 - n2;
                break;
            case 2:
                tvOperation.setText("*");
                rightAnswer = n1 * n2;
                break;
            case 3:
                tvOperation.setText("/");
                while (n2 != 0 && n1 % n2 != 0) {
                    n1 = rnd.nextInt(10);
                    n2 = rnd.nextInt(10);
                }
                rightAnswer = n1 / n2;
                break;
            case 4:
                tvOperation.setText("^");
                rightAnswer = (int) Math.pow(n1, n2);
                break;
        }
        tvNumber1.setText(n1 + "");
        tvNumber2.setText(n2 + "");
        etResult.setText("");

        more -= 1;
    }

    private void connectToLayout() {
        tvRightCounter = (TextView) findViewById(R.id.tvRightCounter);
        tvWrongCounter = (TextView) findViewById(R.id.tvWrongCounter);

        tvNumber1 = (TextView) findViewById(R.id.tvNumber1);
        tvOperation = (TextView) findViewById(R.id.tvOperation);
        tvNumber2 = (TextView) findViewById(R.id.tvNumber2);
        etResult = (EditText) findViewById(R.id.etResult);
        btnCheck = (Button) findViewById(R.id.btnCheck);

        btnCheck.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        String text = etResult.getText().toString();
        int answer = Integer.parseInt(text);

        if (answer == rightAnswer) {
            Toast.makeText(this, "Good Answer", Toast.LENGTH_LONG).show();
            rCount += 1;
            tvRightCounter.setText(rCount + "");
            if (more > 0) {
                showEx();
            } else {
                // start Grade Activity
                double grade = ((double) rCount / (rCount + wCount)) * 100;
                grade = ((int) (grade * 10)) / 10.0;
                Intent i = new Intent(this, GradeActivity.class);
                i.putExtra("PlayerGrade", grade);
                startActivity(i);
                finish();
            }

        } else {
            Toast.makeText(this, "Try again !", Toast.LENGTH_LONG).show();
            wCount += 1;
            tvWrongCounter.setText(wCount + "");
        }
    }
}



activity_grade.xml
------------------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"


    android:orientation="vertical">

    <TextView
        android:id="@+id/tvGrade"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#e1d158"
        android:gravity="center"
        android:text="Your Grade is 75%"
        android:textColor="#f20df2"
        android:textSize="80sp" />

    <Button
        android:id="@+id/btnPlayAgain"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Play Again"
        android:textSize="30sp" />
</LinearLayout>

GradeActivity.java
------------------
package com.example.mohamadpc.mmathapplication;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class GradeActivity extends AppCompatActivity implements View.OnClickListener {
    TextView tvGrade;
    Button btnPlayAgain;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_grade);

        // get grade from previous activity
        Intent i = getIntent();
        double grade = i.getDoubleExtra("PlayerGrade", 0);

        // show grade
        tvGrade = (TextView) findViewById(R.id.tvGrade);
        tvGrade.setText("Your Grade Is " + grade + " %");

        btnPlayAgain = findViewById(R.id.btnPlayAgain);
        btnPlayAgain.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Intent intent = new Intent(this, MainActivity.class);
        startActivity(intent);
        finish();
    }
}