eliminate global access to Octave interpreter in qt graphics classes Provide reference to interprerter to qt graphics classes to eliminate need for accessing it through a global variable. * qt-graphics-toolkit.cc (qt_graphics_toolkit::create_object): Pass m_interpreter to create functions for individual graphics objects. * BaseControl.h, BaseControl.cc, ButtonControl.h, ButtonControl.cc, ButtonGroup.h, ButtonGroup.cc, Canvas.h, Canvas.cc, CheckBoxControl.h, CheckBoxControl.cc, Container.h, Container.cc, ContextMenu.h, ContextMenu.cc, EditControl.h, EditControl.cc, Figure.h, Figure.cc, GLCanvas.h, GLCanvas.cc, ListBoxControl.h, ListBoxControl.cc, Menu.h, Menu.cc, Object.h, Object.cc, Panel.h, Panel.cc, PopupMenuControl.h, PopupMenuControl.cc, PushButtonControl.h, PushButtonControl.cc, PushTool.h, PushTool.cc, QtHandlesUtils.h, RadioButtonControl.h, RadioButtonControl.cc, SliderControl.h, SliderControl.cc, Table.h, Table.cc, TextControl.h, TextControl.cc, ToggleButtonControl.h, ToggleButtonControl.cc, ToggleTool.h, ToggleTool.cc, ToolBar.h, ToolBar.cc, ToolBarButton.h, ToolBarButton.cc: Accept reference to interpreter in create function and constructors for graphics objects. Eliminate global access to interpreter object and graphics_handle manager.

--- a/libgui/graphics/GLCanvas.h	Tue Nov 05 18:23:20 2019 -0500
+++ b/libgui/graphics/GLCanvas.h	Wed Nov 06 12:42:12 2019 -0500
@@ -56,8 +56,8 @@
   class GLCanvas : public OCTAVE_QT_OPENGL_WIDGET, public Canvas
   {
   public:
-    GLCanvas (octave::base_qobject& oct_qobj, const graphics_handle& handle,
-              QWidget *parent);
+    GLCanvas (octave::base_qobject& oct_qobj, octave::interpreter& interp,
+              const graphics_handle& handle, QWidget *parent);
     ~GLCanvas (void);
 
     void initializeGL (void);