Refactor map arguments

demo/src/jvmMain/kotlin/Main.kt

@@ -1,8 +1,6 @@
 // Copyright 2000-2021 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 import androidx.compose.desktop.ui.tooling.preview.Preview
-import androidx.compose.foundation.layout.Column
 import androidx.compose.material.MaterialTheme
-import androidx.compose.material.Text
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Home
 import androidx.compose.runtime.*
@@ -14,14 +12,19 @@ import androidx.compose.ui.window.application
 import centre.sciprog.maps.GeodeticMapCoordinates
 import centre.sciprog.maps.MapViewPoint
 import centre.sciprog.maps.compose.*
-import io.ktor.client.*
-import io.ktor.client.engine.cio.*
+import io.ktor.client.HttpClient
+import io.ktor.client.engine.cio.CIO
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import java.nio.file.Path
+import kotlin.math.PI
 import kotlin.random.Random
 
+private fun GeodeticMapCoordinates.toShortString(): String =
+    "${(latitude * 180.0 / PI).toString().take(6)}:${(longitude * 180.0 / PI).toString().take(6)}"
+
+
 @Composable
 @Preview
 fun App() {
@@ -42,48 +45,55 @@ fun App() {
             )
         }
 
-        var coordinates by remember { mutableStateOf<GeodeticMapCoordinates?>(null) }
+        var centerCoordinates by remember { mutableStateOf<GeodeticMapCoordinates?>(null) }
 
-        Column {
-            //display click coordinates
-            Text(coordinates?.toString() ?: "")
-            MapView(
-                mapTileProvider = mapTileProvider,
-                initialViewPoint = viewPoint,
-                onClick = { coordinates = focus },
-                config = MapViewConfig(inferViewBoxFromFeatures = true)
-            ) {
-                val pointOne = 55.568548 to 37.568604
-                val pointTwo = 55.929444 to 37.518434
-                val pointThree = 60.929444 to 37.518434
 
-                image(pointOne, Icons.Filled.Home)
+        MapView(
+            mapTileProvider = mapTileProvider,
+            initialViewPoint = viewPoint,
+            config = MapViewConfig(
+                inferViewBoxFromFeatures = true,
+                onViewChange = { centerCoordinates = focus }
+            )
+        ) {
+            val pointOne = 55.568548 to 37.568604
+            val pointTwo = 55.929444 to 37.518434
+            val pointThree = 60.929444 to 37.518434
 
-                //remember feature Id
-                val circleId: FeatureId = circle(
-                    centerCoordinates = pointTwo,
+            image(pointOne, Icons.Filled.Home)
+
+            //remember feature Id
+            val circleId: FeatureId = circle(
+                centerCoordinates = pointTwo,
+            )
+
+            custom(position = pointThree) {
+                drawRect(
+                    color = Color.Red,
+                    topLeft = Offset(-10f, -10f),
+                    size = Size(20f, 20f)
                 )
+            }
 
-                custom(position = pointThree) {
-                    drawRect(
-                        color = Color.Red,
-                        topLeft = Offset(-10f, -10f),
-                        size = Size(20f, 20f)
-                    )
+            line(pointOne, pointTwo)
+            text(pointOne, "Home")
+
+            centerCoordinates?.let {
+                group(id = "center") {
+                    circle(center = it, color = Color.Blue, size = 1f)
+                    text(position = it, it.toShortString(), color = Color.Blue)
                 }
-                line(pointOne, pointTwo)
-                text(pointOne, "Home")
+            }
 
-                scope.launch {
-                    while (isActive) {
-                        delay(200)
-                        //Overwrite a feature with new color
-                        circle(
-                            pointTwo,
-                            id = circleId,
-                            color = Color(Random.nextFloat(), Random.nextFloat(), Random.nextFloat())
-                        )
-                    }
+            scope.launch {
+                while (isActive) {
+                    delay(200)
+                    //Overwrite a feature with new color
+                    circle(
+                        pointTwo,
+                        id = circleId,
+                        color = Color(Random.nextFloat(), Random.nextFloat(), Random.nextFloat())
+                    )
                 }
             }
         }

maps-kt-compose/src/commonMain/kotlin/centre/sciprog/maps/compose/FeatureBuilder.kt

@@ -8,6 +8,7 @@ import androidx.compose.ui.graphics.drawscope.DrawScope
 import androidx.compose.ui.graphics.vector.ImageVector
 import androidx.compose.ui.unit.DpSize
 import androidx.compose.ui.unit.dp
+import centre.sciprog.maps.GeodeticMapCoordinates
 
 typealias FeatureId = String
 
@@ -34,6 +35,16 @@ internal class MapFeatureBuilder(initialFeatures: Map<FeatureId, MapFeature>) :
     override fun build(): SnapshotStateMap<FeatureId, MapFeature> = content
 }
 
+fun FeatureBuilder.circle(
+    center: GeodeticMapCoordinates,
+    zoomRange: IntRange = defaultZoomRange,
+    size: Float = 5f,
+    color: Color = Color.Red,
+    id: FeatureId? = null,
+) = addFeature(
+    id, MapCircleFeature(center, zoomRange, size, color)
+)
+
 fun FeatureBuilder.circle(
     centerCoordinates: Pair<Double, Double>,
     zoomRange: IntRange = defaultZoomRange,
@@ -59,6 +70,14 @@ fun FeatureBuilder.line(
     id: FeatureId? = null,
 ) = addFeature(id, MapLineFeature(aCoordinates.toCoordinates(), bCoordinates.toCoordinates(), zoomRange, color))
 
+fun FeatureBuilder.text(
+    position: GeodeticMapCoordinates,
+    text: String,
+    zoomRange: IntRange = defaultZoomRange,
+    color: Color = Color.Red,
+    id: FeatureId? = null,
+) = addFeature(id, MapTextFeature(position, text, zoomRange, color))
+
 fun FeatureBuilder.text(
     position: Pair<Double, Double>,
     text: String,

maps-kt-compose/src/commonMain/kotlin/centre/sciprog/maps/compose/MapView.kt

@@ -10,9 +10,14 @@ import kotlin.math.log2
 import kotlin.math.min
 
 
+//TODO consider replacing by modifier
 data class MapViewConfig(
     val zoomSpeed: Double = 1.0 / 3.0,
-    val inferViewBoxFromFeatures: Boolean = false
+    val inferViewBoxFromFeatures: Boolean = false,
+    val onClick: MapViewPoint.() -> Unit = {},
+    val onViewChange: MapViewPoint.() -> Unit = {},
+    val onSelect: (GmcBox) -> Unit = {},
+    val zoomOnSelect: Boolean = true
 )
 
 @Composable
@@ -20,8 +25,6 @@ expect fun MapView(
     mapTileProvider: MapTileProvider,
     computeViewPoint: (canvasSize: DpSize) -> MapViewPoint,
     features: Map<FeatureId, MapFeature>,
-    onClick: MapViewPoint.() -> Unit = {},
-    //TODO consider replacing by modifier
     config: MapViewConfig = MapViewConfig(),
     modifier: Modifier = Modifier.fillMaxSize(),
 )
@@ -31,14 +34,29 @@ fun MapView(
     mapTileProvider: MapTileProvider,
     initialViewPoint: MapViewPoint,
     features: Map<FeatureId, MapFeature> = emptyMap(),
-    onClick: MapViewPoint.() -> Unit = {},
     config: MapViewConfig = MapViewConfig(),
     modifier: Modifier = Modifier.fillMaxSize(),
     buildFeatures: @Composable (FeatureBuilder.() -> Unit) = {},
 ) {
     val featuresBuilder = MapFeatureBuilder(features)
     featuresBuilder.buildFeatures()
-    MapView(mapTileProvider, { initialViewPoint }, featuresBuilder.build(), onClick, config, modifier)
+    MapView(
+        mapTileProvider,
+        { initialViewPoint },
+        featuresBuilder.build(),
+        config,
+        modifier
+    )
+}
+
+internal fun GmcBox.getComputeViewPoint(mapTileProvider: MapTileProvider): (canvasSize: DpSize) -> MapViewPoint = { canvasSize ->
+    val zoom = log2(
+        min(
+            canvasSize.width.value / width,
+            canvasSize.height.value / height
+        ) * PI / mapTileProvider.tileSize
+    )
+    MapViewPoint(center, zoom)
 }
 
 @Composable
@@ -46,21 +64,17 @@ fun MapView(
     mapTileProvider: MapTileProvider,
     box: GmcBox,
     features: Map<FeatureId, MapFeature> = emptyMap(),
-    onClick: MapViewPoint.() -> Unit = {},
     config: MapViewConfig = MapViewConfig(),
     modifier: Modifier = Modifier.fillMaxSize(),
     buildFeatures: @Composable (FeatureBuilder.() -> Unit) = {},
 ) {
     val featuresBuilder = MapFeatureBuilder(features)
     featuresBuilder.buildFeatures()
-    val computeViewPoint: (canvasSize: DpSize) -> MapViewPoint = { canvasSize ->
-        val zoom = log2(
-            min(
-                canvasSize.width.value / box.width,
-                canvasSize.height.value / box.height
-            ) * PI / mapTileProvider.tileSize
-        )
-        MapViewPoint(box.center, zoom)
-    }
-    MapView(mapTileProvider, computeViewPoint, featuresBuilder.build(), onClick, config, modifier)
+    MapView(
+        mapTileProvider,
+        box.getComputeViewPoint(mapTileProvider),
+        featuresBuilder.build(),
+        config,
+        modifier
+    )
 }

maps-kt-compose/src/jvmMain/kotlin/centre/sciprog/maps/compose/MapViewJvm.kt

@@ -9,7 +9,6 @@ import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.geometry.Rect
-import androidx.compose.ui.geometry.Size
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.PathEffect
 import androidx.compose.ui.graphics.drawscope.*
@@ -55,7 +54,6 @@ actual fun MapView(
     mapTileProvider: MapTileProvider,
     computeViewPoint: (canvasSize: DpSize) -> MapViewPoint,
     features: Map<FeatureId, MapFeature>,
-    onClick: MapViewPoint.() -> Unit,
     config: MapViewConfig,
     modifier: Modifier,
 ) {
@@ -107,6 +105,8 @@ actual fun MapView(
     val canvasModifier = modifier.pointerInput(Unit) {
         forEachGesture {
             awaitPointerEventScope {
+                fun Offset.toDpOffset() = DpOffset(x.toDp(), y.toDp())
+
                 val event: PointerEvent = awaitPointerEvent()
                 event.changes.forEach { change ->
                     if (event.buttons.isPrimaryPressed) {
@@ -125,29 +125,32 @@ actual fun MapView(
                                 }
                             }
                             selectRect?.let { rect ->
-                                val (centerX, centerY) = rect.center
-                                val centerGmc = DpOffset(centerX.toDp(), centerY.toDp()).toGeodetic()
-
-                                val horizontalZoom: Float = log2(canvasSize.width.toPx() / rect.width)
-                                val verticalZoom: Float = log2(canvasSize.height.toPx() / rect.height)
-
-
-                                viewPointOverride = MapViewPoint(
-                                    centerGmc,
-                                    viewPoint.zoom + min(verticalZoom, horizontalZoom)
+                                //Use selection override if it is defined
+                                val gmcBox = GmcBox(
+                                    rect.topLeft.toDpOffset().toGeodetic(),
+                                    rect.bottomRight.toDpOffset().toGeodetic()
                                 )
+                                config.onSelect(gmcBox)
+                                if(config.zoomOnSelect) {
+                                    val newViewPoint = gmcBox.getComputeViewPoint(mapTileProvider).invoke(canvasSize)
+
+                                    config.onViewChange(newViewPoint)
+                                    viewPointOverride = newViewPoint
+                                }
                                 selectRect = null
                             }
                         } else {
                             val dragStart = change.position
                             val dpPos = DpOffset(dragStart.x.toDp(), dragStart.y.toDp())
-                            onClick(MapViewPoint(dpPos.toGeodetic(), viewPoint.zoom))
+                            config.onClick(MapViewPoint(dpPos.toGeodetic(), viewPoint.zoom))
                             drag(change.id) { dragChange ->
                                 val dragAmount = dragChange.position - dragChange.previousPosition
-                                viewPointOverride = viewPoint.move(
+                                val newViewPoint = viewPoint.move(
                                     -dragAmount.x.toDp().value / tileScale,
                                     +dragAmount.y.toDp().value / tileScale
                                 )
+                                config.onViewChange(newViewPoint)
+                                viewPointOverride = newViewPoint
                             }
                         }
                     }
@@ -159,7 +162,9 @@ actual fun MapView(
         val (xPos, yPos) = change.position
         //compute invariant point of translation
         val invariant = DpOffset(xPos.toDp(), yPos.toDp()).toGeodetic()
-        viewPointOverride = viewPoint.zoom(-change.scrollDelta.y.toDouble() * config.zoomSpeed, invariant)
+        val newViewPoint = viewPoint.zoom(-change.scrollDelta.y.toDouble() * config.zoomSpeed, invariant)
+        config.onViewChange(newViewPoint)
+        viewPointOverride = newViewPoint
     }.fillMaxSize()
 
 
@@ -241,7 +246,7 @@ actual fun MapView(
                 }
                 is MapDrawFeature -> {
                     val offset = feature.position.toOffset()
-                    translate (offset.x, offset.y) {
+                    translate(offset.x, offset.y) {
                         feature.drawFeature(this)
                     }
                 }