Enhance MapScreen with location permission handling and camera positioning

- Added functionality to request location permissions and navigate to the user's current location on the map.
- Integrated camera state management to animate the map view to the user's location.
- Updated UI to include a floating action button for accessing the user's location and refreshing zone data.

app/src/main/java/com/geozoner/app/ui/map/MapScreen.kt

@@ -1,9 +1,17 @@
 package com.geozoner.app.ui.map
 
+import android.Manifest
+import android.annotation.SuppressLint
+import android.content.pm.PackageManager
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.MyLocation
 import androidx.compose.material.icons.filled.Refresh
 import androidx.compose.material3.CircularProgressIndicator
 import androidx.compose.material3.MaterialTheme
@@ -13,21 +21,32 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.toArgb
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
+import androidx.core.content.ContextCompat
 import androidx.hilt.navigation.compose.hiltViewModel
 import com.geozoner.app.data.remote.dto.ZoneBriefResponse
-import com.geozoner.app.ui.theme.ZoneColors
+import com.google.android.gms.location.LocationServices
+import com.google.android.gms.location.Priority
+import com.google.android.gms.tasks.CancellationTokenSource
+import kotlinx.coroutines.launch
+import org.maplibre.compose.camera.CameraPosition
+import org.maplibre.compose.camera.rememberCameraState
 import org.maplibre.compose.expressions.dsl.const
 import org.maplibre.compose.layers.FillLayer
 import org.maplibre.compose.layers.LineLayer
 import org.maplibre.compose.map.MaplibreMap
 import org.maplibre.compose.sources.GeoJsonData
 import org.maplibre.compose.sources.rememberGeoJsonSource
+import org.maplibre.spatialk.geojson.Position
+import kotlin.time.Duration.Companion.seconds
 
 private const val OPENFREEMAP_STYLE = "https://tiles.openfreemap.org/styles/liberty"
 
@@ -36,6 +55,31 @@ fun MapScreen(
     viewModel: MapViewModel = hiltViewModel(),
 ) {
     val state by viewModel.uiState.collectAsState()
+    val context = LocalContext.current
+    val scope = rememberCoroutineScope()
+
+    val cameraState = rememberCameraState(
+        firstPosition = CameraPosition(
+            target = Position(latitude = 55.7558, longitude = 37.6173), // Moscow default
+            zoom = 12.0,
+        ),
+    )
+
+    var hasLocationPermission by remember {
+        mutableStateOf(
+            ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) ==
+                    PackageManager.PERMISSION_GRANTED
+        )
+    }
+
+    val permissionLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.RequestMultiplePermissions()
+    ) { permissions ->
+        hasLocationPermission = permissions[Manifest.permission.ACCESS_FINE_LOCATION] == true
+        if (hasLocationPermission) {
+            goToMyLocation(context, scope, cameraState)
+        }
+    }
 
     // Build GeoJSON strings for own and friend zones
     val myZoneGeoJson = remember(state.myZones) {
@@ -50,6 +94,7 @@ fun MapScreen(
         MaplibreMap(
             modifier = Modifier.fillMaxSize(),
             baseStyle = org.maplibre.compose.style.BaseStyle.Uri(OPENFREEMAP_STYLE),
+            cameraState = cameraState,
         ) {
             // Friend zones layer (rendered below own zones)
             if (friendZoneGeoJson.isNotEmpty()) {
@@ -115,22 +160,76 @@ fun MapScreen(
             )
         }
 
-        // Refresh button
-        SmallFloatingActionButton(
-            onClick = { viewModel.loadZones() },
+        // FABs column (top-end)
+        Column(
             modifier = Modifier
                 .align(Alignment.TopEnd)
                 .padding(top = 16.dp, end = 16.dp),
+            verticalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            // My Location button
+            SmallFloatingActionButton(
+                onClick = {
+                    if (hasLocationPermission) {
+                        goToMyLocation(context, scope, cameraState)
+                    } else {
+                        permissionLauncher.launch(
+                            arrayOf(
+                                Manifest.permission.ACCESS_FINE_LOCATION,
+                                Manifest.permission.ACCESS_COARSE_LOCATION,
+                            )
+                        )
+                    }
+                },
+                containerColor = MaterialTheme.colorScheme.surface,
+            ) {
+                Icon(Icons.Default.MyLocation, contentDescription = "My location")
+            }
+
+            // Refresh zones button
+            SmallFloatingActionButton(
+                onClick = { viewModel.loadZones() },
                 containerColor = MaterialTheme.colorScheme.surface,
             ) {
                 Icon(Icons.Default.Refresh, contentDescription = "Refresh zones")
             }
         }
+    }
+}
+
+/**
+ * Gets the current location and animates the camera to it.
+ */
+@SuppressLint("MissingPermission")
+private fun goToMyLocation(
+    context: android.content.Context,
+    scope: kotlinx.coroutines.CoroutineScope,
+    cameraState: org.maplibre.compose.camera.CameraState,
+) {
+    val fusedClient = LocationServices.getFusedLocationProviderClient(context)
+    val cancellationToken = CancellationTokenSource()
+
+    fusedClient.getCurrentLocation(Priority.PRIORITY_HIGH_ACCURACY, cancellationToken.token)
+        .addOnSuccessListener { location ->
+            if (location != null) {
+                scope.launch {
+                    cameraState.animateTo(
+                        finalPosition = CameraPosition(
+                            target = Position(
+                                latitude = location.latitude,
+                                longitude = location.longitude,
+                            ),
+                            zoom = 15.0,
+                        ),
+                        duration = 1.seconds,
+                    )
+                }
+            }
+        }
 }
 
 /**
  * Builds a GeoJSON FeatureCollection string from zone responses.
- * Each zone becomes a Feature with a Polygon geometry.
  */
 private fun buildZoneGeoJson(zones: List<ZoneBriefResponse>): String {
     if (zones.isEmpty()) return ""