# HG changeset patch
# User Daniel J Sebald <daniel.sebald@ieee.org>
# Date 1523420523 18000
# Node ID 07bddddc58567e5960a77b8a79e0790cbb6a24d8
# Parent  164399071f4dc36c695cee6d727c81e8217fd011
Restore Variable Editor focusWidget lost in dock/undock transition (bug #53410)

* variable-editor.cc (variable_editor::variable_editor): Initialize new member
  variable m_variable_focus_widget to nullptr.
  (variable_editor::focusInEvent): If the m_main window's focusWidget() is
  nullptr, check if the recorded m_variable_focus_widget is still valid within
  the m_main container.  If so, use it as a valid pointer and restore its
  focus.
  (variable_editor::focusOutEvent): Record m_main's focusWidget() just prior
  to transition to/from docked state.

* variable-editor.h (variable_editor:octave_dock_widget): A class member
  variable m_variable_focus_widget to keep track of focusWidget().

diff -r 164399071f4d -r 07bddddc5856 libgui/src/variable-editor.cc
--- a/libgui/src/variable-editor.cc	Wed Apr 11 15:13:10 2018 -0400
+++ b/libgui/src/variable-editor.cc	Tue Apr 10 23:22:03 2018 -0500
@@ -990,7 +990,8 @@
       m_sel_font (),
       m_table_colors (),
       m_current_focus_vname (""),
-      m_hovered_focus_vname ("")
+      m_hovered_focus_vname (""),
+      m_variable_focus_widget (nullptr)
   {
     setObjectName ("VariableEditor");
     set_title (tr ("Variable Editor"));
@@ -1038,10 +1039,20 @@
   {
     octave_dock_widget::focusInEvent (ev);
 
-    // set focus to the current variable
+    // set focus to the current variable or most recent if still valid
     QWidget *fw = m_main->focusWidget ();
     if (fw != nullptr)
       fw->setFocus ();
+    else if (m_main->isAncestorOf (m_variable_focus_widget))
+      m_variable_focus_widget->setFocus ();
+  }
+
+  void variable_editor::focusOutEvent (QFocusEvent *ev)
+  {
+    // focusWidget() appears lost in transition to/from main window
+    m_variable_focus_widget = m_main->focusWidget ();
+
+    octave_dock_widget::focusOutEvent (ev);
   }
 
   // Add an action to a menu or the widget itself.
diff -r 164399071f4d -r 07bddddc5856 libgui/src/variable-editor.h
--- a/libgui/src/variable-editor.h	Wed Apr 11 15:13:10 2018 -0400
+++ b/libgui/src/variable-editor.h	Tue Apr 10 23:22:03 2018 -0500
@@ -338,6 +338,8 @@
 
     void focusInEvent (QFocusEvent *ev);
 
+    void focusOutEvent (QFocusEvent *ev);
+
   private:
 
     QAction * add_action (QMenu *menu, const QIcon& icon, const QString& text,
@@ -377,6 +379,8 @@
     QString m_current_focus_vname;
 
     QString m_hovered_focus_vname;
+
+    QWidget *m_variable_focus_widget;
   };
 }