feat: location button, and abstracting extInsets to common code

composeApp/src/commonMain/kotlin/moe/lava/banksia/App.kt

@@ -1,9 +1,18 @@
 package moe.lava.banksia
 
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.add
 import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.safeContent
+import androidx.compose.foundation.layout.safeDrawing
+import androidx.compose.foundation.layout.windowInsetsPadding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.LocationOn
 import androidx.compose.material3.BottomSheetScaffold
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.FloatingActionButton
+import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.SheetValue
 import androidx.compose.material3.rememberBottomSheetScaffoldState
@@ -12,12 +21,26 @@ import androidx.compose.runtime.Composable
 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.platform.LocalDensity
+import dev.icerock.moko.geo.compose.BindLocationTrackerEffect
+import dev.icerock.moko.geo.compose.LocationTrackerAccuracy
+import dev.icerock.moko.geo.compose.rememberLocationTrackerFactory
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.launch
 import moe.lava.banksia.api.ptv.PtvService
 import moe.lava.banksia.native.maps.Maps
+import moe.lava.banksia.native.maps.Point
+import moe.lava.banksia.native.maps.getScreenHeight
+import moe.lava.banksia.resources.Res
+import moe.lava.banksia.resources.my_location_24
 import moe.lava.banksia.ui.Searcher
+import org.jetbrains.compose.resources.painterResource
 import org.jetbrains.compose.ui.tooling.preview.Preview
+import kotlin.math.roundToInt
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
@@ -30,17 +53,43 @@ fun App() {
         )
     )
 
+    val locationFactory = rememberLocationTrackerFactory(LocationTrackerAccuracy.Best)
+    val locationTracker = remember { locationFactory.createLocationTracker() }
+    BindLocationTrackerEffect(locationTracker)
+    var lastLocation by remember { mutableStateOf(Point(-37.8136, 144.9631)) }
+    var newCameraPosition by remember { mutableStateOf<Point?>(Point(-37.8136, 144.9631)) }
     var searchTextState by remember { mutableStateOf("") }
     var searchExpandedState by remember { mutableStateOf(false) }
 
+    val sheetState = scaffoldState.bottomSheetState
+    val extInsets = if (
+        sheetState.currentValue != SheetValue.Hidden ||
+        sheetState.targetValue != SheetValue.Hidden
+    ) {
+        val scaffoldOffset = sheetState.requireOffset().roundToInt()
+        (getScreenHeight() - scaffoldOffset - WindowInsets.safeDrawing.getBottom(LocalDensity.current)).coerceAtLeast(0)
+    } else 0
+
+    var scope = rememberCoroutineScope()
+    scope.launch {
+        val flow = locationTracker.getLocationsFlow()
+        locationTracker.startTracking()
+        flow.distinctUntilChanged().collect {
+            lastLocation = Point(it.latitude, it.longitude)
+        }
+    }
+
     MaterialTheme {
         BottomSheetScaffold(
             scaffoldState = scaffoldState,
+            modifier = Modifier.fillMaxSize(),
             sheetContent = { Box(modifier = Modifier) },
         ) {
             Maps(
                 modifier = Modifier.fillMaxSize(),
-                sheetState = scaffoldState.bottomSheetState,
+                newCameraPosition = newCameraPosition,
+                cameraPositionUpdated = { newCameraPosition = null },
+                extInsets = extInsets,
             )
             Searcher(
                 ptvService = PtvService(),
@@ -50,6 +99,20 @@ fun App() {
                 onTextChange = { searchTextState = it },
                 onRouteChange = {}
             )
+
+            Box(
+                Modifier.windowInsetsPadding(WindowInsets.safeContent.add(WindowInsets(bottom = extInsets))),
+                contentAlignment = Alignment.BottomEnd
+            ) {
+                FloatingActionButton(
+                    containerColor = MaterialTheme.colorScheme.surfaceContainer,
+                    onClick = {
+                        newCameraPosition = lastLocation
+                    },
+                ) {
+                    Icon(painterResource(Res.drawable.my_location_24), "Move to current location")
+                }
+            }
         }
     }
 }

composeApp/src/commonMain/kotlin/moe/lava/banksia/native/maps/Maps.kt

@@ -5,17 +5,22 @@ import androidx.compose.material3.SheetState
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.Dp
 
 data class Marker(val name: String, val onClick: () -> Boolean)
 data class Point(val lat: Double, val lng: Double)
 data class Polyline(val points: List<Point>, val colour: Color)
 
+@Composable
+expect fun getScreenHeight(): Int
+
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 expect fun Maps(
     modifier: Modifier = Modifier,
     markers: List<Marker> = listOf(),
     polylines: List<Polyline> = listOf(),
-    cameraPosition: Point = Point(-37.8136, 144.9631),
-    sheetState: SheetState,
+    newCameraPosition: Point? = Point(-37.8136, 144.9631),
+    cameraPositionUpdated: () -> Unit,
+    extInsets: Int,
 )