Minor code cleanup

base/src/jsMain/kotlin/jetbrains/datalore/base/event/dom/DomEventMapper.kt

@@ -44,84 +44,83 @@ class DomEventMapper(
  handle(DomEventType.MOUSE_MOVE) { state.onMouseEvent(DomEventType.MOUSE_MOVE, it) }
  }
 
- private fun handle(
- eventSpec: DomEventType<DomMouseEvent>,
- handler: (DomMouseEvent) -> Unit
- ) {
+ private fun handle(eventSpec: DomEventType<DomMouseEvent>, handler: (DomMouseEvent) -> Unit) {
  myEventTarget.on(eventSpec, consumer = {
- if (isHitOnTarget(it)) {
+ val needHandle = myTargetBounds?.contains(DoubleVector(it.offsetX, it.offsetY)) ?: true
+ if (needHandle) {
  handler(it)
  }
  })
  }
 
- private fun isHitOnTarget(event: DomMouseEvent): Boolean {
- val bbox = myTargetBounds ?: return true
- return bbox.contains(DoubleVector(event.offsetX, event.offsetY))
- }
-
- private fun dispatch(eventSpec: MouseEventSpec, mouseEvent: DomMouseEvent) {
- destMouseEventPeer.invoke(eventSpec, translate(mouseEvent))
- }
-
- private fun translate(event: DomMouseEvent): MouseEvent {
+ private fun dispatch(eventSpec: MouseEventSpec, domMouseEvent: DomMouseEvent) {
  val targetClientOrigin = myEventTarget.getBoundingClientRect().let { DoubleVector(it.x, it.y) }
- val eventClientCoord = DoubleVector(event.clientX.toDouble(), event.clientY.toDouble())
  val targetAbsoluteOrigin = myTargetBounds?.origin ?: DoubleVector.ZERO
-
+ val eventClientCoord = DoubleVector(domMouseEvent.clientX.toDouble(), domMouseEvent.clientY.toDouble())
  val eventTargetCoord = eventClientCoord.subtract(targetClientOrigin).subtract(targetAbsoluteOrigin)
- return MouseEvent(
+
+ val mouseEvent = MouseEvent(
  eventTargetCoord.x.toInt(),
  eventTargetCoord.y.toInt(),
- getButton(event),
- getModifiers(event)
+ getButton(domMouseEvent),
+ getModifiers(domMouseEvent)
  )
+
+ destMouseEventPeer.invoke(eventSpec, mouseEvent)
  }
 
- abstract inner class MouseState {
- abstract fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent)
+ private abstract inner class MouseState {
+ fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
+ log(type.name)
+ handleEvent(type, e)
+ }
+
+ abstract fun handleEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent)
+
  fun log(str: String) {
  if (ENABLE_DEBUG_LOG) {
  println("${this::class.simpleName}(${this@DomEventMapper.hashCode()}): $str")
  }
  }
  }
 
- open inner class HoverState : MouseState() {
- override fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
- log(type.name)
+ private inner class HoverState : MouseState() {
+ override fun handleEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
  if (type == DomEventType.MOUSE_DOWN) {
  dispatch(MouseEventSpec.MOUSE_PRESSED, e)
  state = ButtonDownState(eventCoord = DoubleVector(e.x, e.y))
  return
  }
 
- // Any event with already pressed button -> drag from another element, supress mouse events handling
+ // Any event with already pressed button -> drag from another element -> ignore events until buttons release
  if (e.buttons > 0) {
- state = InvalidDragging()
+ state = ForeignDragging()
  return
  }
 
  when (type) {
- DomEventType.CLICK -> dispatch(MouseEventSpec.MOUSE_CLICKED, e)
- DomEventType.DOUBLE_CLICK -> dispatch(MouseEventSpec.MOUSE_DOUBLE_CLICKED, e)
  DomEventType.MOUSE_MOVE -> dispatch(MouseEventSpec.MOUSE_MOVED, e)
  DomEventType.MOUSE_LEAVE -> dispatch(MouseEventSpec.MOUSE_LEFT, e)
  DomEventType.MOUSE_ENTER -> dispatch(MouseEventSpec.MOUSE_ENTERED, e)
+
+ DomEventType.DOUBLE_CLICK -> dispatch(MouseEventSpec.MOUSE_DOUBLE_CLICKED, e) // wish can handle in ButtonDownState
+ DomEventType.MOUSE_UP, DomEventType.CLICK -> {} // ignore to prevent ghost clicks on UI
  }
  }
  }
 
- inner class ButtonDownState(
+ private inner class ButtonDownState(
  private val eventCoord: DoubleVector,
  private val draggingTriggerDistance: Double = 3.0
  ) : MouseState() {
 
- override fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
- log(type.name)
+ override fun handleEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
  when (type) {
- DomEventType.MOUSE_UP -> {
- dispatch(MouseEventSpec.MOUSE_RELEASED, e)
+ DomEventType.MOUSE_UP -> { dispatch(MouseEventSpec.MOUSE_RELEASED, e) }
+
+ // It's safe to set HoverState on CLICK as DOM raises CLICK event exactly after MOUSE_UP,
+ DomEventType.CLICK -> {
+ dispatch(MouseEventSpec.MOUSE_CLICKED, e)
  state = HoverState()
  }
 
@@ -135,37 +134,34 @@ class DomEventMapper(
  }
  }
 
- inner class Dragging : MouseState() {
- // Listen for CLICK, not MOUSE_UP, as DRAG_END event consists of two events - MOUSE_UP and then MOUSE_CLICK.
- // MOUSE_CLICK event, if not handled properly, hits UI elements and triggers action.
+ private inner class Dragging : MouseState() {
  private var myDocumentMouseEventsRegistration = Registration.from(
  document.on(DomEventType.MOUSE_MOVE, ::onDocumentMouseMove),
- document.on(DomEventType.CLICK, ::onDocumentClick)
+ document.on(DomEventType.MOUSE_UP, ::onDocumentMouseUp)
  )
 
- // All required events handled by onDocumentMouseMove()
- override fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {}
-
  private fun onDocumentMouseMove(event: DomMouseEvent) {
  dispatch(MouseEventSpec.MOUSE_DRAGGED, event)
  }
 
- private fun onDocumentClick(e: DomMouseEvent) {
+ private fun onDocumentMouseUp(e: DomMouseEvent) {
  dispatch(MouseEventSpec.MOUSE_RELEASED, e)
  state = HoverState()
  myDocumentMouseEventsRegistration.dispose()
  }
- }
 
- inner class InvalidDragging : MouseState() {
- override fun onMouseEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
- log(type.name)
+ override fun handleEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
+ // All required events handled by onDocumentMouseMove()
+ }
+ }
 
-  if (e.buttons == 0.toShort() && type != DomEventType.MOUSE_UP) {
-  // Drag released outside the target - restore HoverState
-  // Yet don't set HoverState on MOUSE_UP as CLICK event will trigger UI elements
- state = HoverState()
+ private inner class ForeignDragging : MouseState() {
+ override fun handleEvent(type: DomEventType<DomMouseEvent>, e: DomMouseEvent) {
+ if (e.buttons > 0) {
+ return
  }
+
+ state = HoverState()
  }
  }
 }