fade out now exponential and optional when minutes set

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

@@ -10,6 +10,7 @@ import android.widget.EditText
 import android.widget.ProgressBar
 import android.widget.TextView
 import kotlin.math.pow
+import kotlin.math.max
 
 class MainActivity : Activity() {
 
@@ -18,11 +19,11 @@ class MainActivity : Activity() {
     private var streamId = 0
     private val handler = Handler()
     private var isPlaying = false
-    private var remainingMinutes = 0
+    private var fadeEnabled = false
-    private var countdownRunnable: Runnable? = null
-    private var fadeRunnable: Runnable? = null
     private var totalMillis: Long = 0
     private var startTime: Long = 0
+    private var fadeRunnable: Runnable? = null
+    private var countdownRunnable: Runnable? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -30,6 +31,7 @@ class MainActivity : Activity() {
 
         val status = findViewById<TextView>(R.id.statusText)
         val input = findViewById<EditText>(R.id.timerInput)
+        val fadeToggle = findViewById<TextView>(R.id.fadeToggle)
         val volumeBar = findViewById<ProgressBar>(R.id.volumeBar)
 
         val attrs = AudioAttributes.Builder()
@@ -44,14 +46,18 @@ class MainActivity : Activity() {
 
         soundId = soundPool.load(this, R.raw.sound, 1)
 
-        updateUI(status, volumeBar, "Ready", Color.LTGRAY, 1f)
+        updateUI(status, volumeBar, "Bereit", Color.LTGRAY, 1f)
+        fadeToggle.setOnClickListener {
+            fadeEnabled = !fadeEnabled
+            fadeToggle.text = "Fade-Out: " + if (fadeEnabled) "ON" else "OFF"
+        }
 
         status.setOnClickListener {
             if (isPlaying) {
                 stopSound(status, volumeBar)
             } else {
-                val min = input.text.toString().toIntOrNull() ?: 0
+                val minutes = input.text.toString().toIntOrNull() ?: 0
-                startSound(min, status, volumeBar)
+                startSound(minutes, status, volumeBar)
             }
         }
     }
@@ -63,59 +69,65 @@ class MainActivity : Activity() {
         startTime = System.currentTimeMillis()
 
         if (minutes > 0) {
-            remainingMinutes = minutes
             totalMillis = minutes * 60_000L
-            updateUI(status, volumeBar, "Runs for: $remainingMinutes min", Color.GREEN, 1f)
+            updateCountdown(minutes * 60, status)
-
+            // Countdown jede Sekunde
-            // Countdown jede Minute
             countdownRunnable = object : Runnable {
                 override fun run() {
-                    remainingMinutes--
+                    val elapsedSec = ((System.currentTimeMillis() - startTime) / 1000).toInt()
-                    if (remainingMinutes > 0) {
+                    val remainingSec = max(minutes * 60 - elapsedSec, 0)
-                        updateUI(status, volumeBar, "Runs for: $remainingMinutes min", Color.GREEN, currentVolume())
+                    updateCountdown(remainingSec, status)
-                        handler.postDelayed(this, 60_000L)
+                    if (remainingSec > 0) {
+                        handler.postDelayed(this, 1000L)
                     } else {
                         stopSound(status, volumeBar)
                     }
                 }
             }
-            handler.postDelayed(countdownRunnable!!, 60_000L)
+            handler.postDelayed(countdownRunnable!!, 1000L)
 
-            // Exponentieller Fade-Out alle 200 ms
+            // Fade-Out (optional)
-            fadeRunnable = object : Runnable {
+            if (fadeEnabled) {
-                override fun run() {
+                fadeRunnable = object : Runnable {
-                    if (!isPlaying) return
+                    override fun run() {
-                    val elapsed = System.currentTimeMillis() - startTime
+                        if (!isPlaying) return
-                    val progress = (elapsed.toFloat() / totalMillis).coerceIn(0f, 1f)
+                        val elapsed = System.currentTimeMillis() - startTime
-                    // exponentielles Absenken: volume = (1 - progress)^2
+                        val progress = (elapsed.toFloat() / totalMillis).coerceIn(0f, 1f)
-                    val volume = (1 - progress).pow(2)
+                        val volume = (1 - progress).pow(2) // exponentielles Fade
-                    soundPool.setVolume(streamId, volume, volume)
+                        soundPool.setVolume(streamId, volume, volume)
-                    volumeBar.progress = (volume * 100).toInt()
+                        volumeBar.progress = (volume * 100).toInt()
-                    if (progress < 1f) {
+                        if (progress < 1f) {
-                        handler.postDelayed(this, 200L)
+                            handler.postDelayed(this, 200L)
-                    } else {
+                        }
-                        stopSound(status, volumeBar)
                     }
                 }
+                handler.postDelayed(fadeRunnable!!, 200L)
+            } else {
+                volumeBar.progress = 100
             }
-            handler.postDelayed(fadeRunnable!!, 200L)
-
         } else {
             // unendlich
-            updateUI(status, volumeBar, "Runs: ∞", Color.GREEN, 1f)
+            updateUI(status, volumeBar, "Läuft: ∞", Color.GREEN, 1f)
             volumeBar.progress = 100
         }
     }
 
+    private fun updateCountdown(remainingSec: Int, status: TextView) {
+        val minutes = remainingSec / 60
+        val seconds = remainingSec % 60
+        status.text = String.format("Läuft: %02d:%02d", minutes, seconds)
+        status.setBackgroundColor(Color.GREEN)
+        status.setTextColor(Color.BLACK)
+    }
+
     private fun stopSound(status: TextView, volumeBar: ProgressBar) {
         if (isPlaying) {
             soundPool.stop(streamId)
             isPlaying = false
         }
-        remainingMinutes = 0
+        handler.removeCallbacks(countdownRunnable ?: Runnable {})
-        handler.removeCallbacks(countdownRunnable ?: Runnable { })
+        handler.removeCallbacks(fadeRunnable ?: Runnable {})
-        handler.removeCallbacks(fadeRunnable ?: Runnable { })
+        updateUI(status, volumeBar, "Gestoppt", Color.RED, 0f)
-        updateUI(status, volumeBar, "Stopped", Color.RED, 0f)
         volumeBar.progress = 0
     }
 
@@ -126,12 +138,6 @@ class MainActivity : Activity() {
         bar.progress = (volume * 100).toInt()
     }
 
-    private fun currentVolume(): Float {
-        val elapsed = System.currentTimeMillis() - startTime
-        val progress = (elapsed.toFloat() / totalMillis).coerceIn(0f, 1f)
-        return (1 - progress).pow(2)
-    }
-
     override fun onDestroy() {
         super.onDestroy()
         soundPool.release()

app/src/main/res/layout/activity_main.xml

@@ -38,6 +38,17 @@
         android:layout_height="wrap_content"
         android:layout_marginTop="20dp"/>
 
+    <TextView
+        android:id="@+id/fadeToggle"
+        android:text="Fade-Out: OFF"
+        android:gravity="center"
+        android:padding="12dp"
+        android:layout_marginTop="20dp"
+        android:background="#AAAAAA"
+        android:textColor="#000000"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"/>
+
     <ProgressBar
         android:id="@+id/volumeBar"
         style="@android:style/Widget.ProgressBar.Horizontal"