refactor: handle MapView Lifecycle

app/src/main/java/com/geeksville/mesh/ui/map/MapFragment.kt

@@ -57,7 +57,7 @@ import com.geeksville.mesh.ui.map.components.CacheLayout
 import com.geeksville.mesh.ui.map.components.DownloadButton
 import com.geeksville.mesh.ui.map.components.EditWaypointDialog
 import com.geeksville.mesh.ui.components.IconButton
-import com.geeksville.mesh.util.EnableWakeLock
+import com.geeksville.mesh.ui.map.components.rememberMapViewWithLifecycle
 import com.geeksville.mesh.util.SqlTileWriterExt
 import com.geeksville.mesh.util.requiredZoomLevel
 import com.geeksville.mesh.util.formatAgo
@@ -147,13 +147,7 @@ fun MapView(model: UIViewModel = viewModel()) {
 
     val hasGps = context.hasGps()
 
-    EnableWakeLock(context)
-
-    val map = remember {
-        MapView(context).apply {
-            clipToOutline = true
-        }
-    }
+    val map = rememberMapViewWithLifecycle(context)
 
     fun toggleMyLocation() {
         if (context.gpsDisabled()) {

app/src/main/java/com/geeksville/mesh/ui/map/components/MapViewWithLifecycle.kt

@@ -0,0 +1,76 @@
+package com.geeksville.mesh.ui.map.components
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.os.PowerManager
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.LocalLifecycleOwner
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleEventObserver
+import com.geeksville.mesh.android.BuildUtils.errormsg
+import org.osmdroid.views.MapView
+
+@SuppressLint("WakelockTimeout")
+private fun PowerManager.WakeLock.safeAcquire() {
+    if (!isHeld) try {
+        acquire()
+    } catch (e: SecurityException) {
+        errormsg("WakeLock permission exception: ${e.message}")
+    } catch (e: IllegalStateException) {
+        errormsg("WakeLock acquire() exception: ${e.message}")
+    }
+}
+
+private fun PowerManager.WakeLock.safeRelease() {
+    if (isHeld) try {
+        release()
+    } catch (e: IllegalStateException) {
+        errormsg("WakeLock release() exception: ${e.message}")
+    }
+}
+
+@Composable
+fun rememberMapViewWithLifecycle(context: Context): MapView {
+    val mapView = remember {
+        MapView(context).apply {
+            clipToOutline = true
+        }
+    }
+    val lifecycle = LocalLifecycleOwner.current.lifecycle
+    DisposableEffect(lifecycle) {
+        val powerManager = context.getSystemService(Context.POWER_SERVICE) as PowerManager
+
+        @Suppress("DEPRECATION")
+        @SuppressLint("InvalidWakeLockTag")
+        val wakeLock = powerManager.newWakeLock(PowerManager.FULL_WAKE_LOCK, "ScreenLock")
+
+        wakeLock.safeAcquire()
+
+        val observer = LifecycleEventObserver { _, event ->
+            when (event) {
+                Lifecycle.Event.ON_PAUSE -> {
+                    wakeLock.safeRelease()
+                    mapView.onPause()
+                }
+
+                Lifecycle.Event.ON_RESUME -> {
+                    wakeLock.safeAcquire()
+                    mapView.onResume()
+                }
+
+                else -> {}
+            }
+        }
+
+        lifecycle.addObserver(observer)
+
+        onDispose {
+            lifecycle.removeObserver(observer)
+            wakeLock.safeRelease()
+            mapView.onDetach()
+        }
+    }
+    return mapView
+}