Fixed multi-drag issue. Added demo for bounded drag.

demo/maps/src/jvmMain/kotlin/Main.kt

@@ -45,8 +45,6 @@ fun App() {
         val pointTwo = 55.929444 to 37.518434
         val pointThree = 60.929444 to 37.518434
 
-        val dragPoint = 55.744 to 37.614
-
         MapView(
             mapTileProvider = mapTileProvider,
 //            initialViewPoint = MapViewPoint(
@@ -65,7 +63,27 @@ fun App() {
 
             image(pointOne, Icons.Filled.Home)
 
-            rectangle(dragPoint, id = "dragMe", size = DpSize(10.dp, 10.dp)).draggable()
+            var drag1 = Gmc.ofDegrees(55.744, 37.614)
+
+            var drag2 = Gmc.ofDegrees(55.8, 37.5)
+
+            fun updateLine() {
+                line(drag1, drag2, id = "connection", color = Color.Magenta)
+            }
+
+            rectangle(drag1, size = DpSize(10.dp, 10.dp)).draggable { _, _, end ->
+                drag1 = end.focus
+                updateLine()
+                true
+            }
+
+            rectangle(drag2, size = DpSize(10.dp, 10.dp)).draggable { _, _, end ->
+                drag2 = end.focus
+                updateLine()
+                true
+            }
+
+            updateLine()
 
             points(
                 points = listOf(

maps-kt-compose/src/commonMain/kotlin/center/sciprog/maps/compose/MapFeature.kt

@@ -18,10 +18,15 @@ import kotlin.math.floor
 public interface MapFeature {
     public val zoomRange: IntRange
     public fun getBoundingBox(zoom: Double): GmcRectangle?
-
 }
 
-public interface DraggableMapFeature : MapFeature {
+public interface SelectableMapFeature : MapFeature {
+    public operator fun contains(point: MapViewPoint): Boolean = getBoundingBox(point.zoom)?.let {
+        point.focus in it
+    } ?: false
+}
+
+public interface DraggableMapFeature : SelectableMapFeature {
     public fun withCoordinates(newCoordinates: GeodeticMapCoordinates): MapFeature
 }
 
@@ -118,8 +123,12 @@ public class MapLineFeature(
     public val b: GeodeticMapCoordinates,
     override val zoomRange: IntRange = defaultZoomRange,
     public val color: Color = Color.Red,
-) : MapFeature {
+) : SelectableMapFeature {
     override fun getBoundingBox(zoom: Double): GmcRectangle = GmcRectangle(a, b)
+
+    override fun contains(point: MapViewPoint): Boolean {
+        return super.contains(point)
+    }
 }
 
 /**

maps-kt-compose/src/commonMain/kotlin/center/sciprog/maps/compose/MapFeaturesState.kt

@@ -18,14 +18,14 @@ public object DraggableAttribute : MapFeaturesState.Attribute<DragHandle>
 
 public class MapFeaturesState internal constructor(
     private val features: MutableMap<FeatureId, MapFeature>,
-    private val attributes: MutableMap<FeatureId, SnapshotStateMap<Attribute<out Any?>, in Any?>>,
+    @PublishedApi internal val attributes: MutableMap<FeatureId, SnapshotStateMap<Attribute<out Any?>, in Any?>>,
 ) {
     public interface Attribute<T>
 
     //TODO use context receiver for that
     public fun FeatureId.draggable(
         //TODO add constraints
-        callback: DragHandle = DragHandle.BYPASS
+        callback: DragHandle = DragHandle.BYPASS,
     ) {
         val handle = DragHandle.withPrimaryButton { event, start, end ->
             val feature = features[this] as? DraggableMapFeature ?: return@withPrimaryButton true
@@ -72,7 +72,7 @@ public class MapFeaturesState internal constructor(
 //        }.keys
 //    }
 
-    public fun <T> forEachWithAttribute(key: Attribute<T>, block: (id: FeatureId, attributeValue: T) -> Unit) {
+    public inline fun <T> forEachWithAttribute(key: Attribute<T>, block: (id: FeatureId, attributeValue: T) -> Unit) {
         attributes.forEach { (id, attributeMap) ->
             attributeMap[key]?.let {
                 @Suppress("UNCHECKED_CAST")
@@ -126,6 +126,16 @@ public fun MapFeaturesState.circle(
     id, MapCircleFeature(centerCoordinates.toCoordinates(), zoomRange, size, color)
 )
 
+public fun MapFeaturesState.rectangle(
+    centerCoordinates: Gmc,
+    zoomRange: IntRange = defaultZoomRange,
+    size: DpSize = DpSize(5.dp, 5.dp),
+    color: Color = Color.Red,
+    id: FeatureId? = null,
+): FeatureId = addFeature(
+    id, MapRectangleFeature(centerCoordinates, zoomRange, size, color)
+)
+
 public fun MapFeaturesState.rectangle(
     centerCoordinates: Pair<Double, Double>,
     zoomRange: IntRange = defaultZoomRange,

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

@@ -146,11 +146,10 @@ public fun MapView(
     }
 
     val featureDrag: DragHandle = DragHandle.withPrimaryButton { event, start, end ->
-        var bypass = true
         featureState.forEachWithAttribute(DraggableAttribute) { _, handle ->
-            bypass = bypass and handle.handle(event, start, end)
+            if(!handle.handle(event, start, end)) return@withPrimaryButton false
         }
-        bypass
+        true
     }
 
 

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

@@ -116,20 +116,17 @@ public actual fun MapView(
                         val dpEnd = dragChange.position.toDpOffset()
 
                         //apply drag handle and check if it prohibits the drag even propagation
-                        if (
+                        if (selectionStart == null && !config.dragHandle.handle(
-                            !config.dragHandle.handle(
                                 event,
                                 MapViewPoint(dpStart.toGeodetic(), viewPoint.zoom),
                                 MapViewPoint(dpEnd.toGeodetic(), viewPoint.zoom)
                             )
                         ) {
-                            //clear selection just in case
-                            selectionStart = null
                             return@drag
                         }
 
                         if (event.buttons.isPrimaryPressed) {
-                            //Evaluating selection frame
+                            //If selection process is started, modify the frame
                             selectionStart?.let { start ->
                                 val offset = dragChange.position
                                 selectRect = Rect(
@@ -141,8 +138,8 @@ public actual fun MapView(
                                 return@drag
                             }
 
-                            config.onClick(MapViewPoint(dpPos.toGeodetic(), viewPoint.zoom), event)
+//                            config.onClick(MapViewPoint(dpPos.toGeodetic(), viewPoint.zoom), event)
-
+                            //If no selection, drag map
                             setViewPoint(
                                 viewPoint.move(
                                     -dragAmount.x.toDp().value / tileScale,