Document entries parameter not supported qt for FileEditor/Director…

…yEditor (#1557)

* fix History_demo.py on wx backend

* better document that entries is only supported on wx not qt

docs/source/traitsui_user_manual/factories_basic.rst

@@ -591,10 +591,11 @@ the local system hierarchy. The styles of this editor are shown in Figure 31.
 
 The default version of the simply style displays a text box and a :guilabel:`Browse`
 button. Clicking :guilabel:`Browse` opens a platform-specific file selection dialog box.
-If you specify the *entries* keyword parameter with an integer value to the
+On the wx backend, if you specify the *entries* keyword parameter with an integer value to the
 factory function, the simple style is a combo box and a button labeled :guilabel:`...`.
 The user can type a file path in the combo box, or select one of *entries*
-previous values. Clicking the :guilabel:`...` button opens a browser panel similar to the
+previous values. Support for the *entries* parameter is yet to be implemented on
+the qt backend. Clicking the :guilabel:`...` button opens a browser panel similar to the
 custom style of editor. When the user selects a file in this browser, the panel
 collapses, and control is returned to the original editor widget, which is
 automatically populated with the new path string.

traitsui/editors/file_editor.py

@@ -65,7 +65,8 @@ class ToolkitEditorFactory(EditorFactory):
     enter_set = True
 
     #: The number of history entries to maintain:
-    #: FIXME: add support
+    #: FIXME: This is currently only supported on wx. Qt support needs to be
+    #: added
     entries = Int(10)
 
     #: The root path of the file tree view ('custom' style only, not supported

traitsui/wx/file_editor.py

@@ -86,7 +86,7 @@ def init(self, parent):
             pad = 8
 
         self._file_name = control
-        sizer.Add(control, 1, wx.EXPAND | wx.ALIGN_CENTER)
+        sizer.Add(control, 1, wx.EXPAND)
         sizer.Add(button, 0, wx.LEFT | wx.ALIGN_CENTER, pad)
         panel.Bind(wx.EVT_BUTTON, self.show_file_dialog, id=button.GetId())
         panel.SetDropTarget(FileDropTarget(self))