interpreter-qobject.h

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////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2022 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
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////////////////////////////////////////////////////////////////////////
 
#if ! defined (octave_interpreter_qobject_h)
#define octave_interpreter_qobject_h 1
 
#include <QObject>
 
#include "qt-interpreter-events.h"
 
namespace octave
{
  class interpreter;
 
  class base_qobject;
 
  class interpreter_qobject : public QObject
  {
    Q_OBJECT
 
  public:
 
    interpreter_qobject (base_qobject& oct_qobj);
 
    ~interpreter_qobject (void) = default;
 
    qt_interpreter_events * qt_link (void);
 
    void interpreter_event (const fcn_callback& fcn);
 
    void interpreter_event (const meth_callback& meth);
 
    void interrupt (void);
 
    // Note: PAUSE, STOP, and RESUME are currently only used by the new
    // experimental terminal widget.
    void pause (void);
    void stop (void);
    void resume (void);
 
  signals:
 
    void ready (void);
 
    void shutdown_finished (int);
 
  public slots:
 
    // Programming Note: With the current design of the interpreter,
    // additional signals will not be noticed because the execute
    // function starts the Octave interpreter and it doesn't return
    // until the interpreter exits.  So the Qt event loop running in the
    // thread where the interpreter_qobject object lives never has a
    // chance to see another signal.  Changing the design of the
    // terminal widget as proposed and discussed here:
    //
    //   https://lists.gnu.org/archive/html/octave-maintainers/2019-05/msg00115.html
    //   https://lists.gnu.org/archive/html/octave-maintainers/2019-06/msg00009.html
    //
    // coulld solve that problem.  Briefly, instead of having the Octave
    // interpreter block and wait for keyboard input, the terminal
    // widget would be in charge of accepting keyboard events and use
    // readline in callback mode.  Then the terminal widget and the
    // interpreter will not block except when executing code.  Then we
    // could have the interpreter qobject directly accept signals.
 
    //! Initialize and execute the octave interpreter.
 
    void execute (void);
 
  private:
 
    base_qobject& m_octave_qobj;
 
    interpreter *m_interpreter;
  };
}
 
#endif