Inform the user if there is a blocked window when quitting

NvimView/NvimView/NvimView+Api.swift

@@ -9,6 +9,10 @@ import MessagePack
 
 extension NvimView {
 
+  public func isBlocked() -> Single<Bool> {
+    return self.api.getMode().map { dict in dict["blocking"]?.boolValue ?? false }
+  }
+
   public func waitTillNvimExits() {
     self.nvimExitedCondition.wait(for: 5)
   }

VimR/VimR/AppDelegate.swift

@@ -167,7 +167,21 @@ extension AppDelegate {
   func applicationShouldTerminate(_ sender: NSApplication) -> NSApplication.TerminateReply {
     self.context.savePrefs()
 
-    if self.hasDirtyWindows && self.hasMainWindows {
+    guard self.hasMainWindows else {
+      self.uiRoot?.prepareQuit()
+      return .terminateNow
+    }
+
+    // check first whether there are blocked nvim instances, if so, abort and inform the user
+    if self.uiRoot?.hasBlockedWindows() == true {
+      let alert = NSAlert()
+      alert.messageText = "There are windows waiting for your input."
+      alert.alertStyle = .informational
+      alert.runModal()
+      return .terminateCancel
+    }
+
+    if self.hasDirtyWindows {
       let alert = NSAlert()
       alert.addButton(withTitle: "Cancel")
       let discardAndQuitButton = alert.addButton(withTitle: "Discard and Quit")
@@ -185,13 +199,8 @@ extension AppDelegate {
       return .terminateCancel
     }
 
-    if self.hasMainWindows {
-      self.updateMainWindowTemplateBeforeQuitting()
-      self.uiRoot?.prepareQuit()
-      return .terminateNow
-    }
-
-    // There are no open main window, then just quit.
+    self.updateMainWindowTemplateBeforeQuitting()
+    self.uiRoot?.prepareQuit()
     return .terminateNow
   }
 

VimR/VimR/UiRoot.swift

@@ -67,6 +67,15 @@ class UiRoot: UiComponent {
       .disposed(by: self.disposeBag)
   }
 
+  // The following should only be used when Cmd-Q'ing
+  func hasBlockedWindows() -> Bool {
+    for mainWin in self.mainWindows.values {
+      if mainWin.neoVimView.isBlocked().syncValue() == true { return true }
+    }
+
+    return false
+  }
+
   // The following should only be used when Cmd-Q'ing
   func prepareQuit() {
     self.mainWindows.values.forEach { $0.prepareClosing() }