Use marked positions to distinguish the cases to set the position

VimR/Context.swift

@@ -12,14 +12,17 @@ class StateContext {
   let actionEmitter = Emitter<Any>()
 
   init(_ initialState: AppState) {
-    self.appState = initialState
-    self.stateSource = self.stateSubject.asObservable()
-    let actionSource = self.actionEmitter.observable
-
     self.appDelegateTransformer = AppDelegateTransformer(baseServerUrl: initialState.baseServerUrl)
     self.previewTransformer = PreviewTransformer(baseServerUrl: initialState.baseServerUrl)
     self.httpServerService = HttpServerService(port: initialState.baseServerUrl.port ?? 0)
 
+    self.appState = initialState
+
+    self.stateSource = self.stateSubject.asObservable()
+    let actionSource = self.actionEmitter.observable/*.do(onNext: { _ in
+      self.appState.mainWindows.keys.forEach { self.appState.mainWindows[$0]?.resetInstantStates() }
+    })*/
+
     Observable
       .of(
         actionSource

VimR/MainWindowTransformer.swift

@@ -31,7 +31,7 @@ class MainWindowTransformer: Transformer {
         state.currentBuffer = buffer
 
       case let .scroll(to: position), let .setCursor(to: position):
-        state.cursorPosition = position
+        state.preview.editorPosition = Marked(position)
 
       case .close:
         state.isClosed = true

VimR/PreviewTool.swift

@@ -80,15 +80,18 @@ class PreviewTool: NSView, UiComponent, WKNavigationDelegate {
     source
       .observeOn(MainScheduler.instance)
       .subscribe(onNext: { [unowned self] state in
-        self.currentEditorPosition = state.cursorPosition
         self.automaticForwardMenuItem.boolState = state.previewTool.isForwardSearchAutomatically
         self.automaticReverseMenuItem.boolState = state.previewTool.isReverseSearchAutomatically
         self.refreshOnWriteMenuItem.boolState = state.previewTool.isRefreshOnWrite
 
-        if state.previewTool.isForwardSearchAutomatically {
-          self.forwardSearch(position: state.cursorPosition)
+        if state.previewTool.isForwardSearchAutomatically
+           && state.preview.editorPosition.mark != self.editorPosition.mark
+        {
+          self.forwardSearch(position: state.preview.editorPosition.payload)
         }
 
+        self.editorPosition = state.preview.editorPosition
+
         guard state.preview.updateDate > self.lastUpdateDate else { return }
         guard let serverUrl = state.preview.server else { return }
 
@@ -100,7 +103,7 @@ class PreviewTool: NSView, UiComponent, WKNavigationDelegate {
     self.webviewMessageHandler.source
       .throttle(0.75, latest: true, scheduler: self.scheduler)
       .subscribe(onNext: { [unowned self] position in
-        self.currentPreviewPosition = position
+        self.previewPosition = position
         self.emitter.emit(UuidAction(uuid: self.uuid, action: Action.reverseSearch(to: position)))
       })
       .addDisposableTo(self.disposeBag)
@@ -129,8 +132,8 @@ class PreviewTool: NSView, UiComponent, WKNavigationDelegate {
   fileprivate var isOpen = false
 
   fileprivate var lastUpdateDate = Date.distantPast
-  fileprivate var currentEditorPosition = Position(row: 1, column: 1)
-  fileprivate var currentPreviewPosition = Position(row: 1, column: 1)
+  fileprivate var editorPosition = Marked(Position(row: 1, column: 1))
+  fileprivate var previewPosition = Position(row: 1, column: 1)
 
   fileprivate let userContentController = WKUserContentController()
   fileprivate let webviewMessageHandler = WebviewMessageHandler()
@@ -160,11 +163,11 @@ extension PreviewTool {
   }
 
   func forwardSearchAction(_: Any?) {
-    self.forwardSearch(position: self.currentEditorPosition)
+    self.forwardSearch(position: self.editorPosition.payload)
   }
 
   func reverseSearchAction(_: Any?) {
-    self.emitter.emit(UuidAction(uuid: self.uuid, action: Action.reverseSearch(to: self.currentPreviewPosition)))
+    self.emitter.emit(UuidAction(uuid: self.uuid, action: Action.reverseSearch(to: self.previewPosition)))
   }
 
   func automaticForwardSearchAction(_ sender: NSMenuItem) {

VimR/PreviewToolTransformer.swift

@@ -13,6 +13,35 @@ class PreviewToolTransformer: Transformer {
   typealias Pair = StateActionPair<UuidState<MainWindow.State>, PreviewTool.Action>
 
   func transform(_ source: Observable<Pair>) -> Observable<Pair> {
-    return source
+    return source.map { pair in
+      var state = pair.state.payload
+
+      switch pair.action {
+
+      case .refreshNow:
+        return pair
+
+      case let .reverseSearch(to:position):
+        return pair
+
+      case .forwardSearch:
+        return pair
+
+      case let .scroll(to:position):
+        state.preview.previewPosition = Marked(position)
+
+      case let .setAutomaticReverseSearch(to:value):
+        return pair
+
+      case let .setAutomaticForwardSearch(to:value):
+        return pair
+
+      case let .setRefreshOnWrite(to:value):
+        return pair
+
+      }
+
+      return StateActionPair(state: UuidState(uuid: state.uuid, state: state), action: pair.action)
+    }
   }
 }

VimR/States.swift

@@ -71,6 +71,16 @@ class UuidState<S>: CustomStringConvertible {
   }
 }
 
+class Marked<T> {
+
+  let mark = Token()
+  let payload: T
+
+  init(_ payload: T) {
+    self.payload = payload
+  }
+}
+
 protocol Morpher {
 
   associatedtype In
@@ -132,21 +142,20 @@ struct PreviewState {
 
   var updateDate = Date.distantPast
 
-  var scrollPosition = Position(row: 1, column: 1)
+  var editorPosition = Marked(Position(row: 1, column: 1))
+  var previewPosition = Marked(Position(row: 1, column: 1))
 
   init(status: Status = .none,
        buffer: URL? = nil,
        html: URL? = nil,
        server: URL? = nil,
-       updateDate: Date = Date.distantPast,
-       scrollPosition: Position = Position(row: 1, column: 1))
+       updateDate: Date = Date.distantPast)
   {
     self.status = status
     self.buffer = buffer
     self.html = html
     self.server = server
     self.updateDate = updateDate
-    self.scrollPosition = scrollPosition
   }
 }
 
@@ -171,7 +180,6 @@ extension MainWindow {
     var currentBuffer: NeoVimBuffer?
     var buffers = [NeoVimBuffer]()
     var cwd = FileUtils.userHomeUrl
-    var cursorPosition = Position(row: 1, column: 1)
 
     var isDirty = false