UX: seconds flash interval UI, hidden active controls, back-to-setup flow

app/src/main/java/com/mindmachine/mvp/MainActivity.kt

@@ -4,6 +4,7 @@ import android.app.Activity
 import android.content.pm.ActivityInfo
 import android.os.Bundle
 import androidx.activity.ComponentActivity
+import androidx.activity.compose.BackHandler
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
 import androidx.compose.foundation.background
@@ -41,6 +42,7 @@ import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.darkColorScheme
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.produceState
@@ -72,6 +74,9 @@ import com.mindmachine.mvp.session.FlashColor
 import com.mindmachine.mvp.session.MainViewModel
 import com.mindmachine.mvp.session.SplitFlashFrame
 import com.mindmachine.mvp.session.computeSplitFlashFrame
+import com.mindmachine.mvp.session.flashIntervalMsToSeconds
+import com.mindmachine.mvp.session.flashIntervalSecondsToMs
+import com.mindmachine.mvp.session.shouldShowActiveControlsByDefault
 import kotlin.math.roundToInt
 
 private val MindMachineColors = darkColorScheme(
@@ -174,7 +179,11 @@ fun App(vm: MainViewModel = viewModel()) {
             }, onHolder = { nav.navigate("holder") })
         }
         composable("active") {
-            ActiveSessionScreen(vm = vm, onFinish = { nav.navigate("complete") { popUpTo("setup") } })
+            ActiveSessionScreen(
+                vm = vm,
+                onFinish = { nav.navigate("complete") { popUpTo("setup") } },
+                onBackToSetup = { nav.popBackStack("setup", inclusive = false) }
+            )
         }
         composable("complete") {
             SimpleScreen(
@@ -250,13 +259,13 @@ fun SetupScreen(vm: MainViewModel, onStart: () -> Unit, onHolder: () -> Unit) {
                 )
             }
         }
-        Text("Flash interval: ${cfg.flashIntervalMs} ms", color = MaterialTheme.colorScheme.onBackground)
+        Text("Flash interval: ${"%.2f".format(flashIntervalMsToSeconds(cfg.flashIntervalMs))} s", color = MaterialTheme.colorScheme.onBackground)
         Slider(
-            value = cfg.flashIntervalMs.toFloat(),
-            onValueChange = { vm.setFlashIntervalMs(it.roundToInt()) },
-            valueRange = 50f..2000f
+            value = flashIntervalMsToSeconds(cfg.flashIntervalMs),
+            onValueChange = { vm.setFlashIntervalMs(flashIntervalSecondsToMs(it)) },
+            valueRange = 0.05f..2.0f
         )
-        Text("Controls how long each frame is shown (red/green/black pattern).", color = MaterialTheme.colorScheme.onBackground)
+        Text("Controls how long each frame is shown in the red/green/black pattern.", color = MaterialTheme.colorScheme.onBackground)
         Text("Carrier ${cfg.carrierFrequencyHz.roundToInt()} Hz", color = MaterialTheme.colorScheme.onBackground)
         Slider(value = cfg.carrierFrequencyHz, onValueChange = vm::setCarrier, valueRange = 80f..400f)
         Text("Difference ${cfg.binauralDifferenceHz} Hz", color = MaterialTheme.colorScheme.onBackground)
@@ -269,9 +278,14 @@ fun SetupScreen(vm: MainViewModel, onStart: () -> Unit, onHolder: () -> Unit) {
 }
 
 @Composable
-fun ActiveSessionScreen(vm: MainViewModel, onFinish: () -> Unit) {
+fun ActiveSessionScreen(vm: MainViewModel, onFinish: () -> Unit, onBackToSetup: () -> Unit) {
     val ui by vm.ui.collectAsStateWithLifecycle()
-    if (ui.runtimeState == RuntimeState.COMPLETED || ui.runtimeState == RuntimeState.STOPPED) onFinish()
+    if (ui.runtimeState == RuntimeState.COMPLETED) onFinish()
+
+    BackHandler {
+        vm.stop()
+        onBackToSetup()
+    }
 
     val isVisualMode = ui.config.mode != SessionMode.AUDIO_ONLY
     val context = LocalContext.current
@@ -288,7 +302,10 @@ fun ActiveSessionScreen(vm: MainViewModel, onFinish: () -> Unit) {
         }
     }
 
-    var showOverlay by remember { mutableStateOf(true) }
+    var showOverlay by remember(ui.runtimeState) { mutableStateOf(shouldShowActiveControlsByDefault(ui.runtimeState)) }
+    LaunchedEffect(ui.runtimeState) {
+        showOverlay = shouldShowActiveControlsByDefault(ui.runtimeState)
+    }
     val flashFrame by rememberSplitFlashFrame(
         isRunning = ui.runtimeState == RuntimeState.RUNNING,
         mode = ui.config.mode,
@@ -340,7 +357,7 @@ fun ActiveSessionScreen(vm: MainViewModel, onFinish: () -> Unit) {
                 } else {
                     Button(onClick = { vm.resume() }, modifier = Modifier.fillMaxWidth()) { Text("Resume") }
                 }
-                OutlinedButton(onClick = { vm.stop() }, modifier = Modifier.fillMaxWidth()) { Text("Stop") }
+                OutlinedButton(onClick = { vm.stop(); onFinish() }, modifier = Modifier.fillMaxWidth()) { Text("Stop") }
                 if (ui.interruptionReason != null) {
                     Text(ui.interruptionReason!!, color = Color.White)
                     if (ui.runtimeState == RuntimeState.INTERRUPTED) {

app/src/main/java/com/mindmachine/mvp/session/ActiveSessionUi.kt

@@ -0,0 +1,7 @@
+package com.mindmachine.mvp.session
+
+import com.mindmachine.mvp.domain.RuntimeState
+
+fun shouldShowActiveControlsByDefault(runtimeState: RuntimeState): Boolean {
+    return runtimeState != RuntimeState.RUNNING && runtimeState != RuntimeState.COUNTDOWN
+}

app/src/main/java/com/mindmachine/mvp/session/FlashIntervalUi.kt

@@ -0,0 +1,9 @@
+package com.mindmachine.mvp.session
+
+import kotlin.math.roundToInt
+
+private const val MILLIS_PER_SECOND = 1000f
+
+fun flashIntervalMsToSeconds(ms: Int): Float = ms / MILLIS_PER_SECOND
+
+fun flashIntervalSecondsToMs(seconds: Float): Int = (seconds * MILLIS_PER_SECOND).roundToInt()

app/src/main/java/com/mindmachine/mvp/session/SessionValidator.kt

@@ -6,7 +6,7 @@ import com.mindmachine.mvp.domain.SessionMode
 object SessionValidator {
     fun validate(config: SessionConfig, headsetAvailable: Boolean): String? {
         if (config.durationSec !in 60..(30 * 60)) return "Duration must be 1 to 30 minutes."
-        if (config.flashIntervalMs !in 50..2000) return "Flash interval must be 50 to 2000 ms."
+        if (config.flashIntervalMs !in 50..2000) return "Flash interval must be 0.05 to 2.00 seconds."
         if (config.carrierFrequencyHz !in 80f..400f) return "Carrier frequency must be 80 to 400 Hz."
         if (config.binauralDifferenceHz !in 0.5f..20f) return "Binaural difference must be 0.5 to 20 Hz."
         if (config.mode != SessionMode.VISUAL_ONLY && !headsetAvailable) {