Index: sources/gui/guiview.h
===================================================================
diff -u -r5194f3afffb28dac90a7ca4153b6a0ca2f239387 -r9a3ee027dbc33f39ee7df2a9dc5a7897c6b1854d
--- sources/gui/guiview.h	(.../guiview.h)	(revision 5194f3afffb28dac90a7ca4153b6a0ca2f239387)
+++ sources/gui/guiview.h	(.../guiview.h)	(revision 9a3ee027dbc33f39ee7df2a9dc5a7897c6b1854d)
@@ -15,9 +15,14 @@
 
 // Qt
 #include <QQuickItem>
+
 // Project
 #include "guiactions.h"
 
+// define
+// ...
+
+// namespace
 namespace Gui {
 
 class GuiView : public QQuickItem
@@ -27,11 +32,23 @@
 public:
     explicit GuiView(QQuickItem *parent = nullptr);
 
-public slots:
-    void notifyActionRequest(GuiAction vAction);
+private:
+    void connection();
 
+private slots:
+    void onActionConfirm (GuiActionType vAction, GuiActionInfo vInfo); // UI <= HD/DG
+    void onActionCommand (GuiActionType vAction                     ); // UI <= HD/DG
+
+public slots: // is public since will be used in the UI and is in the same thread.
+    void doActionRequest (GuiActionType vAction                     ); // UI => HD/DG
+    void doActionPerform (GuiActionType vAction, GuiActionInfo vInfo); // UI => HD/DG
+
 signals:
-    void actionEvaluated(GuiAction vAction, bool vAccepted);
-};
+    void didActionConfirm(GuiActionType vAction, GuiActionInfo vInfo); // UI <= HD/DG
+    void didActionCommand(GuiActionType vAction                     ); // UI <= HD/DG
 
+    void didActionRequest(GuiActionType vAction                     ); // UI => HD/DG
+    void didActionPerform(GuiActionType vAction, GuiActionInfo vInfo); // UI => HD/DG
+
+};
 }