Added Activities to MainActivity and made them accessible

app/src/main/java/com/example/greenwatch/MainActivity.java

@@ -2,13 +2,91 @@ package com.example.greenwatch;
 
 import androidx.appcompat.app.AppCompatActivity;
 
+import android.content.Intent;
 import android.os.Bundle;
+import android.view.View;
+import android.widget.Button;
 
 public class MainActivity extends AppCompatActivity {
 
+    private Button audiodetectionButton;
+    private Button videodetectionButton;
+    private Button accelerometerButton;
+    private Button audiodetectionAndAccelerometerButton;
+    private Button videodetectionAndAccelerometerButton;
+    private Button connectionButton;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
+
+        audiodetectionButton = (Button) findViewById(R.id.audiodetectionButton);
+        videodetectionButton = (Button) findViewById(R.id.videodetectionButton);
+        accelerometerButton = (Button) findViewById(R.id.accelerometerButton);
+        audiodetectionAndAccelerometerButton = (Button) findViewById(R.id.audiodetectionAndAccelerometerButton);
+        videodetectionAndAccelerometerButton = (Button) findViewById(R.id.videodetectionAndAccelerometerButton);
+        connectionButton = (Button) findViewById(R.id.connectionButton);
+        audiodetectionButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openAudiodetectionActivity();
+            }
+        });
+        videodetectionButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openVideodetectionActivity();
+            }
+        });
+        accelerometerButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openAccelerometerActivity();
+            }
+        });
+        audiodetectionAndAccelerometerButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openAudiodetectionAndAccelerometerActivity();
+            }
+        });
+        videodetectionAndAccelerometerButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openVideodetectionAndAccelerometerActivity();
+            }
+        });
+        connectionButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openConnectionActivity();
+            }
+        });
     }
+    public void openAudiodetectionActivity(){
+        Intent intent = new Intent(this, AudiodetectionActivity.class);
+        startActivity(intent);
+    }
+    public void openVideodetectionActivity(){
+        Intent intent =  new Intent(this, VideodetectionActivity.class);
+        startActivity(intent);
+    }
+    public void openAccelerometerActivity(){
+        Intent intent = new Intent(this, AccelerometerActivity.class);
+        startActivity(intent);
+    }
+    public void openAudiodetectionAndAccelerometerActivity(){
+        Intent intent = new Intent(this, AudiodetectionAndAccelerometerActivity.class);
+        startActivity(intent);
+    }
+    public void openVideodetectionAndAccelerometerActivity(){
+        Intent intent = new Intent(this, VideodetectionAndAccelerometerActivity.class);
+        startActivity(intent);
+    }
+    public void openConnectionActivity(){
+        Intent intent = new Intent(this, ConnectionActivity.class);
+        startActivity(intent);
+    }
+
 }