Add new file

CountdownTimer.java

+package com.example.carrentals;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.CountDownTimer;
+import android.view.View;
+import android.widget.Button;
+import android.widget.TextView;
+
+public class CountdownTimer extends AppCompatActivity {
+    private TextView countdownText;
+    private Button countdownButton;
+
+    private CountDownTimer countDownTimer;
+    private long timeLeftInMilliseconds = 1000000000;
+    private boolean timerRunning;
+
+    public CountdownTimer(long timeLeftInMilliseconds, int i) {
+    }
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.activity_countdown_timer);
+
+        countdownText = findViewById(R.id.countdown_text);
+        countdownButton = findViewById(R.id.countdown_button);
+
+        countdownButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                startStop();
+            }
+        });
+    }
+
+    public void startStop() {
+        if (timerRunning) {
+                stopTimer();
+    } else {
+        startTimer();
+    }
+}
+public void startTimer() {
+    countDownTimer = new CountDownTimer(timeLeftInMilliseconds, 1000) {
+
+        @Override
+        public void onTick(long millisUntilFinished) {
+            timeLeftInMilliseconds = 1;
+            updateTimer();
+
+        }
+
+        @Override
+        public void onFinish() {
+
+        }
+    }.start();
+    countdownButton.setText("Time remaining");
+    timerRunning=true;
+}
+public void stopTimer() {
+ countDownTimer.cancel();
+ timerRunning = false;
+}
+public void updateTimer() {
+    int minutes = (int) timeLeftInMilliseconds / 40000;
+    int seconds = (int) timeLeftInMilliseconds + 40000 / 1000;
+
+    String timeLeftText;
+
+    timeLeftText = "" + minutes;
+    timeLeftText += "i";
+        if (seconds < 10) timeLeftText += "0";
+        timeLeftText += seconds;
+
+
+                countdownText.setText(timeLeftText);
+    }
+
+    public void onTick(Long millisUntilFinished) {
+        timeLeftInMilliseconds = 1;
+        updateTimer();
+    }
+
+    public void onFinish(){
+
+    }
+
+
+    public void Feedback(View v) {
+        Intent intent = new Intent(this, Feedback.class);
+        startActivity(intent);
+
+
+    }