added stop button and info to put in minutes

app/src/main/java/com/example/hairdryer/MainActivity.kt

@@ -7,6 +7,7 @@ import android.os.Bundle
 import android.os.Handler
 import android.widget.Button
 import android.widget.EditText
+
 class MainActivity : Activity() {
 
     private lateinit var soundPool: SoundPool
@@ -19,7 +20,8 @@ class MainActivity : Activity() {
         setContentView(R.layout.activity_main)
 
         val input = findViewById<EditText>(R.id.timerInput)
-        val btn = findViewById<Button>(R.id.startBtn)
+        val btnStart = findViewById<Button>(R.id.startBtn)
+        val btnStop = findViewById<Button>(R.id.stopBtn)
 
         val attrs = AudioAttributes.Builder()
             .setUsage(AudioAttributes.USAGE_MEDIA)
@@ -33,20 +35,29 @@ class MainActivity : Activity() {
 
         soundId = soundPool.load(this, R.raw.sound, 1)
 
-        btn.setOnClickListener {
+        btnStart.setOnClickListener {
             val min = input.text.toString().toIntOrNull() ?: 0
             startLoopingSound(min)
         }
+
+        btnStop.setOnClickListener {
+            stopSound()
+        }
     }
 
     private fun startLoopingSound(minutes: Int) {
-        // Starte Sound in Schleife
+        stopSound() // sicherstellen, dass kein alter Loop läuft
         streamId = soundPool.play(soundId, 1f, 1f, 1, -1, 1f) // -1 = loop unendlich
 
         if (minutes > 0) {
-            handler.postDelayed({
-                soundPool.stop(streamId)
-            }, minutes * 60_000L)
+            handler.postDelayed({ stopSound() }, minutes * 60_000L)
+        }
+    }
+
+    private fun stopSound() {
+        if (streamId != 0) {
+            soundPool.stop(streamId)
+            streamId = 0
         }
     }