wxGUI/console: Adding hint to command prompt (#2728)

gui/wxpython/gui_core/prompt.py

@@ -218,6 +218,9 @@ def __init__(self, parent, giface, menuModel, margin=False):
         self.SetSelBackground(True, selection_color)
         self.StyleClearAll()
 
+        # show hint
+        self._showHint()
+
         #
         # bindings
         #
@@ -228,6 +231,7 @@ def __init__(self, parent, giface, menuModel, margin=False):
         self.Bind(wx.EVT_LIST_ITEM_SELECTED, self.OnItemChanged)
         if sys.platform != "darwin":  # unstable on Mac with wxPython 3
             self.Bind(wx.EVT_KILL_FOCUS, self.OnKillFocus)
+            self.Bind(wx.EVT_SET_FOCUS, self.OnSetFocus)
 
         # signal which requests showing of a notification
         self.showNotification = Signal("GPromptSTC.showNotification")
@@ -322,11 +326,34 @@ def OnItemSelected(self, event):
             except IOError:
                 self.cmdDesc = None
 
+    def _showHint(self):
+        """Shows usability hint"""
+        self.StyleSetForeground(0, wx.SystemSettings.GetColour(wx.SYS_COLOUR_GRAYTEXT))
+        self.WriteText(_("Type command here and press Enter"))
+        self._hint_shown = True
+
+    def _hideHint(self):
+        """Hides usability hint"""
+        if self._hint_shown:
+            self.ClearAll()
+            self.StyleSetForeground(
+                0, wx.SystemSettings().GetColour(wx.SYS_COLOUR_WINDOWTEXT)
+            )
+            self._hint_shown = False
+
     def OnKillFocus(self, event):
-        """Hides autocomplete"""
+        """Hides autocomplete and shows hint"""
         # hide autocomplete
         if self.AutoCompActive():
             self.AutoCompCancel()
+        # show hint
+        if self.IsEmpty():
+            self._showHint()
+        event.Skip()
+
+    def OnSetFocus(self, event):
+        """Prepares prompt for entering commands."""
+        self._hideHint()
         event.Skip()
 
     def SetTextAndFocus(self, text):