Upgrade to TornadoFX 1.6.2.

tools/demobench/build.gradle

@@ -1,6 +1,6 @@
 buildscript {
     ext.kotlin_version = '1.0.6'
-    ext.tornadofx_version = '1.6.0'
+    ext.tornadofx_version = '1.6.2'
     ext.jna_version = '4.1.0'
     ext.purejavacomm_version = '0.0.17'
     ext.guava_version = '14.0.1'

tools/demobench/src/main/kotlin/net/corda/demobench/views/DemoBenchView.kt

@@ -94,6 +94,10 @@ class DemoBenchView : View("Corda Demo Bench") {
         addNodeButton.isDisable = false
     }
 
+    /**
+     * Ensures that DemoBench always has at least one instance NodeTabView.
+     * This method must NOT be called if DemoBench is shutting down.
+     */
     fun forceAtLeastOneTab() {
         if (nodeTabPane.tabs.isEmpty()) {
             addNodeButton.fire()

tools/demobench/src/main/kotlin/net/corda/demobench/views/NodeTabView.kt

@@ -169,9 +169,9 @@ class NodeTabView : Fragment() {
     init {
         INTEGER_FORMAT.isGroupingUsed = false
 
-        // Ensure that we close the terminal along with the tab.
+        // Ensure that we destroy the terminal along with the tab.
         nodeTab.setOnCloseRequest {
-            nodeTerminalView.close()
+            nodeTerminalView.destroy()
         }
 
         root.add(nodeConfigView)

tools/demobench/src/main/kotlin/net/corda/demobench/views/NodeTerminalView.kt

@@ -35,7 +35,7 @@ class NodeTerminalView : Fragment() {
     private val launchWebButton by fxid<Button>()
     private val launchExplorerButton by fxid<Button>()
 
-    private var isClosed: Boolean = false
+    private var isDestroyed: Boolean = false
     private val explorer = explorerController.explorer()
     private val webServer = webServerController.webServer()
     private val viewer = DBViewer()
@@ -143,14 +143,14 @@ class NodeTerminalView : Fragment() {
         }
     })
 
-    fun close() {
-        if (!isClosed) {
+    fun destroy() {
+        if (!isDestroyed) {
             webServer.close()
             explorer.close()
             viewer.close()
             rpc?.close()
             pty?.close()
-            isClosed = true
+            isDestroyed = true
         }
     }