Add support for min zoom level rendering

Signed-off-by: Kyle Corry <[email protected]>

Author: kylecorry31

app/src/main/java/com/kylecorry/trail_sense/shared/dem/map_layers/ContourGeoJsonSource.kt

@@ -20,7 +20,6 @@ import com.kylecorry.trail_sense.tools.paths.domain.LineStyle
 class ContourGeoJsonSource : GeoJsonSource {
 
     private val units = AppServiceRegistry.get<UserPreferences>().baseDistanceUnits
-    private val minZoomLevel = 13
     private val maxZoomLevel = 19
 
     var colorScale: ElevationColorMap = TrailSenseVibrantElevationColorMap()
@@ -73,10 +72,6 @@ class ContourGeoJsonSource : GeoJsonSource {
             (bounds.north + bounds.south) / 2
         ).coerceAtMost(maxZoomLevel)
 
-        if (zoomLevel < minZoomLevel) {
-            return null
-        }
-
         val interval = validIntervals[zoomLevel] ?: validIntervals.values.first()
         val contours = DEM.getContourLines(bounds, interval, validResolutions[zoomLevel]!!)
         var i = -10000L

app/src/main/java/com/kylecorry/trail_sense/shared/dem/map_layers/ContourLayer.kt

@@ -5,7 +5,7 @@ import com.kylecorry.trail_sense.shared.map_layers.MapLayerBackgroundTask
 import com.kylecorry.trail_sense.shared.map_layers.ui.layers.geojson.GeoJsonLayer
 
 class ContourLayer(taskRunner: MapLayerBackgroundTask = MapLayerBackgroundTask()) :
-    GeoJsonLayer<ContourGeoJsonSource>(ContourGeoJsonSource(), taskRunner) {
+    GeoJsonLayer<ContourGeoJsonSource>(ContourGeoJsonSource(), taskRunner, minZoomLevel = 13) {
 
     fun setPreferences(prefs: ContourMapLayerPreferences) {
         percentOpacity = prefs.opacity.get() / 100f

app/src/main/java/com/kylecorry/trail_sense/shared/map_layers/ui/layers/geojson/GeoJsonLayer.kt

@@ -5,14 +5,16 @@ import com.kylecorry.andromeda.core.units.PixelCoordinate
 import com.kylecorry.andromeda.geojson.GeoJsonFeature
 import com.kylecorry.andromeda.geojson.GeoJsonFeatureCollection
 import com.kylecorry.trail_sense.shared.map_layers.MapLayerBackgroundTask
+import com.kylecorry.trail_sense.shared.map_layers.tiles.TileMath
 import com.kylecorry.trail_sense.shared.map_layers.ui.layers.IAsyncLayer
 import com.kylecorry.trail_sense.shared.map_layers.ui.layers.IMapView
 import com.kylecorry.trail_sense.shared.map_layers.ui.layers.geojson.sources.GeoJsonSource
 import kotlinx.coroutines.CancellationException
 
 open class GeoJsonLayer<T : GeoJsonSource>(
     protected val source: T,
-    private val taskRunner: MapLayerBackgroundTask = MapLayerBackgroundTask()
+    private val taskRunner: MapLayerBackgroundTask = MapLayerBackgroundTask(),
+    private val minZoomLevel: Int? = null
 ) : IAsyncLayer {
 
     val renderer = GeoJsonRenderer()
@@ -23,6 +25,18 @@ open class GeoJsonLayer<T : GeoJsonSource>(
         taskRunner.addTask { bounds, metersPerPixel ->
             isInvalid = false
             try {
+                if (minZoomLevel != null) {
+                    val zoomLevel = TileMath.distancePerPixelToZoom(
+                        metersPerPixel.toDouble(),
+                        (bounds.north + bounds.south) / 2
+                    )
+
+                    if (zoomLevel < minZoomLevel) {
+                        renderer.setGeoJsonObject(GeoJsonFeatureCollection(emptyList()))
+                        return@addTask
+                    }
+                }
+
                 val obj =
                     source.load(bounds, metersPerPixel) ?: GeoJsonFeatureCollection(emptyList())
                 renderer.setGeoJsonObject(obj)

app/src/main/java/com/kylecorry/trail_sense/tools/signal_finder/map_layers/CellTowerGeoJsonSource.kt

@@ -8,27 +8,15 @@ import com.kylecorry.sol.science.geology.CoordinateBounds
 import com.kylecorry.trail_sense.R
 import com.kylecorry.trail_sense.shared.extensions.GEO_JSON_PROPERTY_SIZE_UNIT_METERS
 import com.kylecorry.trail_sense.shared.extensions.point
-import com.kylecorry.trail_sense.shared.map_layers.tiles.TileMath
 import com.kylecorry.trail_sense.shared.map_layers.ui.layers.geojson.sources.GeoJsonSource
 import com.kylecorry.trail_sense.tools.signal_finder.infrastructure.CellTowerModel
 
 class CellTowerGeoJsonSource : GeoJsonSource {
 
-    private val minZoomLevel = 10
-
     override suspend fun load(
         bounds: CoordinateBounds,
         metersPerPixel: Float
     ): GeoJsonObject? {
-        val zoomLevel = TileMath.distancePerPixelToZoom(
-            metersPerPixel.toDouble(),
-            (bounds.north + bounds.south) / 2
-        )
-
-        if (zoomLevel < minZoomLevel) {
-            return null
-        }
-
         val towers = CellTowerModel.getTowers(bounds)
         return GeoJsonFeatureCollection(
             towers.map {

app/src/main/java/com/kylecorry/trail_sense/tools/signal_finder/map_layers/CellTowerMapLayer.kt

@@ -14,7 +14,7 @@ import com.kylecorry.trail_sense.tools.navigation.infrastructure.Navigator
 
 class CellTowerMapLayer(
     private val onClick: (tower: ApproximateCoordinate) -> Boolean = { false }
-) : GeoJsonLayer<CellTowerGeoJsonSource>(CellTowerGeoJsonSource()) {
+) : GeoJsonLayer<CellTowerGeoJsonSource>(CellTowerGeoJsonSource(), minZoomLevel = 11) {
 
     fun setPreferences(prefs: CellTowerMapLayerPreferences) {
         percentOpacity = prefs.opacity.get() / 100f