////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2014-2022 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
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QAction>
#include <QApplication>
#include <QCheckBox>
#include <QDebug>
#include <QDialogButtonBox>
#include <QFileDialog>
#include <QGridLayout>
#include <QHeaderView>
#include <QKeySequence>
#include <QLineEdit>
#include <QMessageBox>
#include <QPushButton>
#include <QVBoxLayout>
#include <QtCore>

#include "octave-qobject.h"
#include "shortcut-manager.h"
#include "gui-preferences-global.h"
#include "gui-preferences-sc.h"
#include "gui-settings.h"
#include "error.h"

namespace octave
{
  // enter_shortcut:
  // class derived from QLineEdit for directly entering key sequences which

  enter_shortcut::enter_shortcut (QWidget *p) : QLineEdit (p)
  {
    m_direct_shortcut = true;      // the shortcut is directly entered
    m_shift_modifier = false;      // the shift modifier is not added
  }

  // new keyPressEvent
  void enter_shortcut::keyPressEvent (QKeyEvent *e)
  {
    if (! m_direct_shortcut)
      {
        QLineEdit::keyPressEvent (e);
        return;
      }

    if (e->type () == QEvent::KeyPress)
      {
        int key = e->key ();

        if (key == Qt::Key_unknown || key == 0)
          return;

        Qt::KeyboardModifiers modifiers = QGuiApplication::keyboardModifiers (); //e->modifiers ();

        if (m_shift_modifier || (modifiers & Qt::ShiftModifier))
          key += Qt::SHIFT;
        if (modifiers & Qt::ControlModifier)
          key += Qt::CTRL;
        if (modifiers & Qt::AltModifier)
          key += Qt::ALT;
        if (modifiers & Qt::MetaModifier)
          key += Qt::META;

        setText (QKeySequence (key).toString ());
      }
  }

  // slot for checkbox whether the shortcut is directly entered or not
  void enter_shortcut::handle_direct_shortcut (int state)
  {
    if (state)
      m_direct_shortcut = true;  // the shortcut is directly entered
    else
      m_direct_shortcut = false; // the shortcut has to be written as text
  }

  // slot for checkbox whether the shift modifier should be added
  void enter_shortcut::handle_shift_modifier (int state)
  {
    if (state)
      m_shift_modifier = true;  // the shortcut is directly entered
    else
      m_shift_modifier = false; // the shortcut has to be written as text
  }


  shortcut_manager::shortcut_manager (base_qobject& oct_qobj)
    : m_octave_qobj (oct_qobj)
  {
    setObjectName ("Shortcut_Manager");

    // Mac: don't let Qt interpret CMD key ("Meta" in Qt terminology) as Ctrl
#if defined (Q_OS_MAC)
    QCoreApplication::setAttribute (Qt::AA_MacDontSwapCtrlAndMeta, true);
#endif
  }

  void shortcut_manager::init_data (void)
  {
    gui_settings settings;

    settings.setValue (sc_main_ctrld.key, false); // reset use fo ctrl-d

    // actions not related to specific menus or widgets

    // dock widgets
    init (tr ("Undock/Dock Widget"), sc_dock_widget_dock);
    init (tr ("Close Widget"), sc_dock_widget_close);

    // actions of the main window

    // file
    init (tr ("New File"), sc_main_file_new_file);
    init (tr ("New Function"), sc_main_file_new_function);
    init (tr ("New Figure"), sc_main_file_new_figure);
    init (tr ("Open File"), sc_main_file_open_file);
    init (tr ("Load Workspace"), sc_main_file_load_workspace);
    init (tr ("Save Workspace As"), sc_main_file_save_workspace);
    init (tr ("Exit Octave"), sc_main_file_exit);

    // edit
    init (tr ("Copy"), sc_main_edit_copy);
    init (tr ("Paste"), sc_main_edit_paste);
    init (tr ("Undo"), sc_main_edit_undo);
    init (tr ("Select All"), sc_main_edit_select_all);
    init (tr ("Clear Clipboard"), sc_main_edit_clear_clipboard);
    init (tr ("Find in Files"), sc_main_edit_find_in_files);
    init (tr ("Clear Command Window"), sc_main_edit_clear_command_window);
    init (tr ("Clear Command History"), sc_main_edit_clear_history);
    init (tr ("Clear Workspace"), sc_main_edit_clear_workspace);
    init (tr ("Set Path"), sc_main_edit_set_path);
    init (tr ("Preferences"), sc_main_edit_preferences);

    // debug
    init (tr ("Step"), sc_main_debug_step_over);
    init (tr ("Step Into"), sc_main_debug_step_into);
    init (tr ("Step Out"), sc_main_debug_step_out);
    init (tr ("Continue"), sc_main_debug_continue);
    init (tr ("Quit Debug Mode"), sc_main_debug_quit);

    // tools
    init (tr ("Start/Stop Profiler Session"), sc_main_tools_start_profiler);
    init (tr ("Resume Profiler Session"), sc_main_tools_resume_profiler);
    init (tr ("Show Profile Data"), sc_main_tools_show_profiler);

    // window
    init (tr ("Show Command Window"), sc_main_window_show_command);
    init (tr ("Show Command History"), sc_main_window_show_history);
    init (tr ("Show File Browser"), sc_main_window_show_file_browser);
    init (tr ("Show Workspace"), sc_main_window_show_workspace);
    init (tr ("Show Editor"), sc_main_window_show_editor);
    init (tr ("Show Documentation"), sc_main_window_show_doc);
    init (tr ("Show Variable Editor"), sc_main_window_show_variable_editor);
    init (tr ("Command Window"), sc_main_window_command);
    init (tr ("Command History"), sc_main_window_history);
    init (tr ("File Browser"), sc_main_window_file_browser);
    init (tr ("Workspace"), sc_main_window_workspace);
    init (tr ("Editor"), sc_main_window_editor);
    init (tr ("Documentation"), sc_main_window_doc);
    init (tr ("Variable Editor"), sc_main_window_variable_editor);
    init (tr ("Previous Widget"), sc_main_window_previous_dock);
    init (tr ("Reset Default Window Layout"), sc_main_window_reset);

    // help
    init (tr ("Show On-disk Documentation"), sc_main_help_ondisk_doc);
    init (tr ("Show Online Documentation"), sc_main_help_online_doc);
    init (tr ("Report Bug"), sc_main_help_report_bug);
    init (tr ("Octave Packages"), sc_main_help_packages);
    init (tr ("Contribute to Octave"), sc_main_help_contribute);
    init (tr ("Octave Developer Resources"), sc_main_help_developer);
    init (tr ("About Octave"), sc_main_help_about);

    // news
    init (tr ("Release Notes"), sc_main_news_release_notes);
    init (tr ("Community News"), sc_main_news_community_news);

    // Tab handling
    // The following shortcuts are moved into a separate tab.  The key names
    // are not changed, to preserve compatibility with older versions.
    init (tr ("Close Tab"), sc_edit_file_close);
    init (tr ("Close All Tabs"), sc_edit_file_close_all);
    init (tr ("Close Other Tabs"), sc_edit_file_close_other);
    init (tr ("Switch to Left Tab"), sc_edit_tabs_switch_left_tab);
    init (tr ("Switch to Right Tab"), sc_edit_tabs_switch_right_tab);
    init (tr ("Move Tab Left"), sc_edit_tabs_move_tab_left);
    init (tr ("Move Tab Right"), sc_edit_tabs_move_tab_right);

    // Zooming
    init (tr ("Zoom In"), sc_edit_view_zoom_in);
    init (tr ("Zoom Out"), sc_edit_view_zoom_out);
#if defined (Q_OS_MAC)
    init (tr ("Zoom Normal"), sc_edit_view_zoom_normal);
#else
    init (tr ("Zoom Normal"), sc_edit_view_zoom_normal);
#endif

    // actions of the editor

    // file
    init (tr ("Edit Function"), sc_edit_file_edit_function);
    init (tr ("Save File"), sc_edit_file_save);
    init (tr ("Save File As"), sc_edit_file_save_as);
    init (tr ("Print"), sc_edit_file_print);

    // edit
    init (tr ("Redo"), sc_edit_edit_redo);
    init (tr ("Cut"), sc_edit_edit_cut);
    init (tr ("Find and Replace"), sc_edit_edit_find_replace);
    init (tr ("Find Next"), sc_edit_edit_find_next);
    init (tr ("Find Previous"), sc_edit_edit_find_previous);
    init (tr ("Delete to Start of Word"), sc_edit_edit_delete_start_word);
    init (tr ("Delete to End of Word"), sc_edit_edit_delete_end_word);
    init (tr ("Delete to Start of Line"), sc_edit_edit_delete_start_line);
    init (tr ("Delete to End of Line"), sc_edit_edit_delete_end_line);
    init (tr ("Delete Line"), sc_edit_edit_delete_line);
    init (tr ("Copy Line"), sc_edit_edit_copy_line);
    init (tr ("Cut Line"), sc_edit_edit_cut_line);
    init (tr ("Duplicate Selection/Line"), sc_edit_edit_duplicate_selection);
    init (tr ("Transpose Line"), sc_edit_edit_transpose_line);
    init (tr ("Show Completion List"), sc_edit_edit_completion_list);

    init (tr ("Comment Selection"), sc_edit_edit_comment_selection);
    init (tr ("Uncomment Selection"), sc_edit_edit_uncomment_selection);
    init (tr ("Comment Selection (Choosing String)"), sc_edit_edit_comment_var_selection);
    init (tr ("Uppercase Selection"), sc_edit_edit_upper_case);
    init (tr ("Lowercase Selection"), sc_edit_edit_lower_case);

#if defined (Q_OS_MAC)
    init (tr ("Indent Selection Rigidly"), sc_edit_edit_indent_selection);
    init (tr ("Unindent Selection Rigidly"), sc_edit_edit_unindent_selection);
#else
    init (tr ("Indent Selection Rigidly"), sc_edit_edit_indent_selection);
    init (tr ("Unindent Selection Rigidly"), sc_edit_edit_unindent_selection);
#endif
    init (tr ("Indent Code"), sc_edit_edit_smart_indent_line_or_selection);

    init (tr ("Convert Line Endings to Windows"), sc_edit_edit_conv_eol_winows);
    init (tr ("Convert Line Endings to Unix"), sc_edit_edit_conv_eol_unix);
    init (tr ("Convert Line Endings to Mac"), sc_edit_edit_conv_eol_mac);

    init (tr ("Goto Line"), sc_edit_edit_goto_line);
    init (tr ("Move to Matching Brace"), sc_edit_edit_move_to_brace);
    init (tr ("Select to Matching Brace"), sc_edit_edit_select_to_brace);
    init (tr ("Toggle Bookmark"), sc_edit_edit_toggle_bookmark);
    init (tr ("Next Bookmark"), sc_edit_edit_next_bookmark);
    init (tr ("Previous Bookmark"), sc_edit_edit_previous_bookmark);
    init (tr ("Remove All Bookmark"), sc_edit_edit_remove_bookmark);

    init (tr ("Preferences"), sc_edit_edit_preferences);
    init (tr ("Styles Preferences"), sc_edit_edit_styles_preferences);

    // view
    init (tr ("Show Line Numbers"), sc_edit_view_show_line_numbers);
    init (tr ("Show Whitespace Characters"), sc_edit_view_show_white_spaces);
    init (tr ("Show Line Endings"), sc_edit_view_show_eol_chars);
    init (tr ("Show Indentation Guides"), sc_edit_view_show_ind_guides);
    init (tr ("Show Long Line Marker"), sc_edit_view_show_long_line);
    init (tr ("Show Toolbar"), sc_edit_view_show_toolbar);
    init (tr ("Show Statusbar"), sc_edit_view_show_statusbar);
    init (tr ("Show Horizontal Scrollbar"), sc_edit_view_show_hscrollbar);
    init (tr ("Sort Tabs Alphabetically"), sc_edit_view_sort_tabs);

    // debug
    init (tr ("Toggle Breakpoint"), sc_edit_debug_toggle_breakpoint);
    init (tr ("Next Breakpoint"), sc_edit_debug_next_breakpoint);
    init (tr ("Previous Breakpoint"), sc_edit_debug_previous_breakpoint);
    init (tr ("Remove All Breakpoints"), sc_edit_debug_remove_breakpoints);

    // run
    init (tr ("Run File"), sc_edit_run_run_file);
    init (tr ("Run Selection"), sc_edit_run_run_selection);

    // help
    init (tr ("Help on Keyword"), sc_edit_help_help_keyword);
    init (tr ("Document on Keyword"), sc_edit_help_doc_keyword);


    // Documentation browser
    init (tr ("Go to Homepage"), sc_doc_go_home);
    init (tr ("Go Back one Page"), sc_doc_go_back);
    init (tr ("Go Forward one Page"), sc_doc_go_next);
    init (tr ("Bookmark this Page"), sc_doc_bookmark);
  }

  // write one or all actual shortcut set(s) into a settings file
  void shortcut_manager::write_shortcuts (gui_settings& settings,
                                          bool closing)
  {
    bool sc_ctrld = false;

    QString sc_main = sc_main_file.mid (0, sc_main_file.indexOf ('_') + 1);

    for (int i = 0; i < m_sc.count (); i++)  // loop over all shortcuts
      {
        settings.setValue (sc_group + "/" + m_sc.at (i).m_settings_key,
                            m_sc.at (i).m_actual_sc.toString ());
        // special: check main-window for Ctrl-D (Terminal)
        if (m_sc.at (i).m_settings_key.startsWith (sc_main)
            && m_sc.at (i).m_actual_sc == QKeySequence (Qt::ControlModifier+Qt::Key_D))
          sc_ctrld = true;
      }

    settings.setValue (sc_main_ctrld.key, sc_ctrld);

    if (closing)
      {
        delete m_dialog;     // the dialog for key sequences can be removed now
        m_dialog = nullptr;  // make sure it is zero again
      }

    settings.sync ();      // sync the settings file
  }

  void shortcut_manager::set_shortcut (QAction *action, const sc_pref& scpref,
                                       bool enable)
  {
    if (! enable)
      {
        // Disable => remove existing shortcut from the action
        action->setShortcut (QKeySequence ());
        return;
      }

    // Enable: Is the given key known? If yes, get the value from the
    //         settings file and set it to the action
    int index;

    index = m_action_hash[scpref.key] - 1;

    if (index > -1 && index < m_sc.count ())
      {
        gui_settings settings;

        action->setShortcut (QKeySequence (settings.sc_value (scpref)));
      }
    else
      qDebug () << "Key: " << scpref.key << " not found in m_action_hash";
  }

  void shortcut_manager::shortcut (QShortcut *sc, const sc_pref& scpref)
  {
    int index;

    index = m_action_hash[scpref.key] - 1;

    if (index > -1 && index < m_sc.count ())
      {
        gui_settings settings;

        sc->setKey (QKeySequence (settings.sc_value (scpref)));
      }
    else
      qDebug () << "Key: " << scpref.key << " not found in m_action_hash";
  }

  void shortcut_manager::fill_treewidget (QTreeWidget *tree_view)
  {
    m_dialog = nullptr;
    m_level_hash.clear ();

    tree_view->header ()->setSectionResizeMode (QHeaderView::ResizeToContents);

    QTreeWidgetItem *main = new QTreeWidgetItem (tree_view);
    main->setText (0, tr ("Global"));
    main->setExpanded (true);
    QTreeWidgetItem *main_file = new QTreeWidgetItem (main);
    main_file->setText (0, tr ("File Menu"));
    QTreeWidgetItem *main_edit = new QTreeWidgetItem (main);
    main_edit->setText (0, tr ("Edit Menu"));
    QTreeWidgetItem *main_debug = new QTreeWidgetItem (main);
    main_debug->setText (0, tr ("Debug Menu"));
    QTreeWidgetItem *main_tools = new QTreeWidgetItem (main);
    main_tools->setText (0, tr ("Tools Menu"));
    QTreeWidgetItem *main_window = new QTreeWidgetItem (main);
    main_window->setText (0, tr ("Window Menu"));
    QTreeWidgetItem *main_help = new QTreeWidgetItem (main);
    main_help->setText (0, tr ("Help Menu"));
    QTreeWidgetItem *main_news = new QTreeWidgetItem (main);
    main_news->setText (0, tr ("News Menu"));
    QTreeWidgetItem *main_dock_widgets = new QTreeWidgetItem (main);
    main_dock_widgets->setText (0, tr ("Handling of Dock Widgets"));
    QTreeWidgetItem *main_tabs = new QTreeWidgetItem (main);
    main_tabs->setText (0, tr ("Tab Handling in Dock Widgets"));
    QTreeWidgetItem *main_find = new QTreeWidgetItem (main);
    main_find->setText (0, tr ("Find & Replace in Dock Widgets"));
    QTreeWidgetItem *main_zoom = new QTreeWidgetItem (main);
    main_zoom->setText (0, tr ("Zooming in Editor and Documentation"));

    m_level_hash[sc_main_file]   = main_file;
    m_level_hash[sc_main_edit]   = main_edit;
    m_level_hash[sc_main_debug]   = main_debug;
    m_level_hash[sc_main_tools]   = main_tools;
    m_level_hash[sc_main_window]   = main_window;
    m_level_hash[sc_main_help]   = main_help;
    m_level_hash[sc_main_news]   = main_news;
    m_level_hash[sc_dock_widget] = main_dock_widgets;
    m_level_hash[sc_edit_tabs]   = main_tabs;
    m_level_hash[sc_edit_find]   = main_find;
    m_level_hash[sc_edit_zoom]   = main_zoom;

    QTreeWidgetItem *editor = new QTreeWidgetItem (tree_view);
    editor->setText (0, tr ("Editor"));
    editor->setExpanded (true);
    QTreeWidgetItem *editor_file = new QTreeWidgetItem (editor);
    editor_file->setText (0, tr ("File Menu"));
    QTreeWidgetItem *editor_edit = new QTreeWidgetItem (editor);
    editor_edit->setText (0, tr ("Edit Menu"));
    QTreeWidgetItem *editor_view = new QTreeWidgetItem (editor);
    editor_view->setText (0, tr ("View Menu"));
    QTreeWidgetItem *editor_debug = new QTreeWidgetItem (editor);
    editor_debug->setText (0, tr ("Debug Menu"));
    QTreeWidgetItem *editor_run = new QTreeWidgetItem (editor);
    editor_run->setText (0, tr ("Run Menu"));
    QTreeWidgetItem *editor_help = new QTreeWidgetItem (editor);
    editor_help->setText (0, tr ("Help Menu"));

    m_level_hash[sc_edit_file] = editor_file;
    m_level_hash[sc_edit_edit] = editor_edit;
    m_level_hash[sc_edit_view] = editor_view;
    m_level_hash[sc_edit_debug] = editor_debug;
    m_level_hash[sc_edit_run] = editor_run;
    m_level_hash[sc_edit_help] = editor_help;

    QTreeWidgetItem *doc = new QTreeWidgetItem (tree_view);
    doc->setText (0, tr ("Documentation Viewer"));
    doc->setExpanded (true);

    QTreeWidgetItem *doc_browser = new QTreeWidgetItem (doc);
    doc_browser->setText (0, tr ("Browser"));

    m_level_hash[sc_doc] = doc_browser;

    connect (tree_view, &QTreeWidget::itemDoubleClicked,
             this, &shortcut_manager::handle_double_clicked);

    for (int i = 0; i < m_sc.count (); i++)
      {
        shortcut_t sc = m_sc.at (i);

        QTreeWidgetItem *section = m_level_hash[sc.m_settings_key.section (':', 0, 0)];

        // handle sections which have changed and do not correspond to the
        // previously defined keyname
        if (section == editor_file)
          {
            // Closing tabs now in global tab handling section
            if (sc.m_settings_key.contains (sc_edit_file_cl))
              section = main_tabs;
          }
        if (section == editor_edit)
          {
            // Find & replace now in global file & replace handling section
            if (sc.m_settings_key.contains (sc_edit_edit_find))
              section = main_find;
          }
        if (section == editor_view)
          {
            // Zooming now in global zoom handling section
            if (sc.m_settings_key.contains (sc_edit_view_zoom))
              section = main_zoom;
          }

        QTreeWidgetItem *tree_item = new QTreeWidgetItem (section);

        // set a slightly transparent foreground for default columns
        QColor fg = QColor (tree_item->foreground (1).color ());
        fg.setAlpha (128);
        tree_item->setForeground (1, QBrush (fg));

        // write the shortcuts
        tree_item->setText (0, sc.m_description);
        tree_item->setText (1, sc.m_default_sc.toString ());
        tree_item->setText (2, sc.m_actual_sc.toString ());

        m_item_index_hash[tree_item] = i + 1; // index+1 to avoid 0
        m_index_item_hash[i] = tree_item;
      }
  }

  // import or export of shortcut sets,
  // called from settings dialog when related buttons are clicked;
  // returns true on success, false otherwise
  bool
  shortcut_manager::import_export (int action)
  {
    // ask to save the current shortcuts, maybe abort import
    if (action == OSC_DEFAULT || action == OSC_IMPORT)
      {
        if (! overwrite_all_shortcuts ())
          return false;
      }

    // get the filename to read or write the shortcuts,
    // the default extension is .osc (octave shortcuts)
    if (action != OSC_DEFAULT)
      {
        QString file;

        // FIXME: Remove, if for all common KDE versions (bug #54607) is resolved.
        int opts = 0;  // No options by default.

        gui_settings settings;

        if (! settings.value (global_use_native_dialogs).toBool ())
          opts = QFileDialog::DontUseNativeDialog;

        if (action == OSC_IMPORT)
          file = QFileDialog::getOpenFileName (this,
                                               tr ("Import shortcuts from file..."), QString (),
                                               tr ("Octave Shortcut Files (*.osc);;All Files (*)"),
                                               nullptr, QFileDialog::Option (opts));
        else if (action == OSC_EXPORT)
          file = QFileDialog::getSaveFileName (this,
                                               tr ("Export shortcuts to file..."), QString (),
                                               tr ("Octave Shortcut Files (*.osc);;All Files (*)"),
                                               nullptr, QFileDialog::Option (opts));

        if (file.isEmpty ())
          return false;

        gui_settings osc_settings (file, QSettings::IniFormat);

        if (osc_settings.status () !=  QSettings::NoError)
          {
            qWarning () << tr ("Failed to open %1 as Octave shortcut file")
                        .arg (file);
            return false;
          }
        else
          {
            if (action == OSC_IMPORT)
              import_shortcuts (osc_settings);   // import (special action)
            else if (action == OSC_EXPORT)
              write_shortcuts (osc_settings, false); // export, (save settings)
          }
      }
    else
      reset_default_shortcuts ();

    return true;
  }

  void shortcut_manager::handle_double_clicked (QTreeWidgetItem *item, int col)
  {
    if (col != 2)
      return;

    int i = m_item_index_hash[item];
    if (i == 0)
      return;  // top-level-item clicked

    shortcut_dialog (i-1); // correct to index starting at 0
  }

  void shortcut_manager::shortcut_dialog_finished (int result)
  {
    if (result == QDialog::Rejected)
      return;

    // check for duplicate
    int double_index = m_shortcut_hash[m_edit_actual->text ()] - 1;

    if (double_index >= 0 && double_index != m_handled_index)
      {
        int ret = QMessageBox::warning (this, tr ("Double Shortcut"),
                                        tr ("The chosen shortcut\n  \"%1\"\n"
                                            "is already used for the action\n  \"%2\".\n"
                                            "Do you want to use the shortcut anyhow removing it "
                                            "from the previous action?")
                                        .arg (m_edit_actual->text ())
                                        .arg (m_sc.at (double_index).m_description),
                                        QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);

        if (ret == QMessageBox::Yes)
          {
            shortcut_t double_shortcut = m_sc.at (double_index);
            double_shortcut.m_actual_sc = QKeySequence ();
            m_sc.replace (double_index, double_shortcut);
            m_index_item_hash[double_index]->setText (2, QString ());
          }
        else
          return;
      }

    shortcut_t shortcut = m_sc.at (m_handled_index);
    if (! shortcut.m_actual_sc.isEmpty ())
      m_shortcut_hash.remove (shortcut.m_actual_sc.toString ());
    shortcut.m_actual_sc = m_edit_actual->text ();
    m_sc.replace (m_handled_index, shortcut);

    m_index_item_hash[m_handled_index]->setText (2, shortcut.m_actual_sc.toString ());

    if (! shortcut.m_actual_sc.isEmpty ())
      m_shortcut_hash[shortcut.m_actual_sc.toString ()] = m_handled_index + 1;
  }

  void shortcut_manager::shortcut_dialog_set_default (void)
  {
    m_edit_actual->setText (m_label_default->text ());
  }

  void shortcut_manager::init (const QString& description, const sc_pref& sc)
  {
    gui_settings settings;

    QKeySequence actual = QKeySequence (settings.sc_value (sc));

    // append the new shortcut to the list
    shortcut_t shortcut_info;
    shortcut_info.m_description = description;
    shortcut_info.m_settings_key = sc.key;
    shortcut_info.m_actual_sc = actual;
    shortcut_info.m_default_sc = settings.sc_def_value (sc);
    m_sc << shortcut_info;

    // insert shortcut in order to check for duplicates later
    if (! actual.isEmpty ())
      m_shortcut_hash[actual.toString ()] = m_sc.count ();
    m_action_hash[sc.key] = m_sc.count ();

    // check whether ctrl+d is used from main window, i.e. is a global shortcut
    QString main_group_prefix
      = sc_main_file.mid (0, sc_main_file.indexOf ('_') + 1);
    if (sc.key.startsWith (main_group_prefix)
        && actual == QKeySequence (Qt::ControlModifier+Qt::Key_D))
      settings.setValue (sc_main_ctrld.key, true);
  }

  void shortcut_manager::shortcut_dialog (int index)
  {
    if (! m_dialog)
      {
        m_dialog = new QDialog (this);

        m_dialog->setWindowTitle (tr ("Enter new Shortcut"));

        QVBoxLayout *box = new QVBoxLayout (m_dialog);
        box->setSpacing (2);
        box->setContentsMargins (12, 12, 12, 12);

        QLabel *help = new QLabel (tr ("Apply the desired shortcut or click "
                                       "on the right button to reset the "
                                       "shortcut to its default."));
        help->setWordWrap (true);
        box->addWidget (help);

        QCheckBox *direct
          = new QCheckBox (tr ("Enter shortcut directly by performing it"));

        QCheckBox *shift
          = new QCheckBox (tr ("Add Shift modifier\n"
                               "(allows one to enter number keys)"));

        shift->setStyleSheet
          ("QCheckBox::indicator { subcontrol-position: left top; }");

        connect (direct, &QCheckBox::clicked, shift, &QCheckBox::setEnabled);

        direct->setCheckState (Qt::Checked);

        box->addWidget (direct);
        box->addWidget (shift);

        box->addSpacing (15);

        QGridLayout *grid = new QGridLayout ();

        QLabel *actual = new QLabel (tr ("Actual shortcut"));
        m_edit_actual = new enter_shortcut (m_dialog);
        m_edit_actual->setAlignment (Qt::AlignHCenter);
        grid->addWidget (actual, 0, 0);
        grid->addWidget (m_edit_actual, 0, 1);

        QLabel *def = new QLabel (tr ("Default shortcut"));
        m_label_default = new QLabel (m_dialog);
        m_label_default->setAlignment (Qt::AlignHCenter);
        grid->addWidget (def, 1, 0);
        grid->addWidget (m_label_default, 1, 1);

        QPushButton *set_default = new QPushButton (tr ("Set to default"));
        grid->addWidget (set_default, 0, 2);
        connect (set_default, &QPushButton::clicked,
                 this, &shortcut_manager::shortcut_dialog_set_default);

        box->addLayout (grid);

        box->addSpacing (18);

        QDialogButtonBox *button_box = new QDialogButtonBox (QDialogButtonBox::Ok
                                                             | QDialogButtonBox::Cancel);
        QList<QAbstractButton *> buttons = button_box->buttons ();
        for (int i = 0; i < buttons.count (); i++)
          buttons.at (i)->setShortcut (QKeySequence ());
        connect (button_box, &QDialogButtonBox::accepted,
                 m_dialog, &QDialog::accept);
        connect (button_box, &QDialogButtonBox::rejected,
                 m_dialog, &QDialog::reject);
        box->addWidget (button_box);

        m_dialog->setLayout (box);

        connect (direct, &QCheckBox::stateChanged,
                 m_edit_actual, &enter_shortcut::handle_direct_shortcut);
        connect (shift, &QCheckBox::stateChanged,
                 m_edit_actual, &enter_shortcut::handle_shift_modifier);
        connect (m_dialog, &QDialog::finished,
                 this, &shortcut_manager::shortcut_dialog_finished);

      }

    m_edit_actual->setText (m_sc.at (index).m_actual_sc.toString ());
    m_label_default->setText (m_sc.at (index).m_default_sc.toString ());
    m_handled_index = index;

    m_edit_actual->setFocus ();
    m_dialog->setFocusProxy (m_edit_actual);
    m_dialog->exec ();
  }

  // import a shortcut set from a given settings file and refresh the
  // tree view
  void shortcut_manager::import_shortcuts (gui_settings& settings)
  {
    for (int i = 0; i < m_sc.count (); i++)
      {
        // update the list of all shortcuts

        // make a copy
        shortcut_t sc = m_sc.at (i);

        // get new shortcut from settings and use the old one as default
        sc.m_actual_sc = QKeySequence (settings.value (sc_group + sc.m_settings_key, sc.m_actual_sc).toString ());

        // replace the old with the new one
        m_sc.replace (i, sc);

        // update the tree view
        // get related tree item
        QTreeWidgetItem *tree_item = m_index_item_hash[i];

        // display new shortcut
        tree_item->setText (2, sc.m_actual_sc.toString ());
      }
  }

  // reset to the defaults and refresh the tree view
  void shortcut_manager::reset_default_shortcuts (void)
  {
    for (int i = 0; i < m_sc.count (); i++)
      {
        // update the list of all shortcuts

        // make a copy
        shortcut_t sc = m_sc.at (i);

        // get default shortcut
        sc.m_actual_sc = QKeySequence (sc.m_default_sc);

        // replace the old with the new one
        m_sc.replace (i, sc);

        // update the tree view
        // get related tree item
        QTreeWidgetItem *tree_item = m_index_item_hash[i];

        // display new shortcut
        tree_item->setText (2, sc.m_actual_sc.toString ());
      }
  }

  // ask the user whether to save the current shortcut set;
  // returns true to proceed with import action, false to abort it
  bool shortcut_manager::overwrite_all_shortcuts (void)
  {
    QMessageBox msg_box;
    msg_box.setWindowTitle (tr ("Overwriting Shortcuts"));
    msg_box.setIcon (QMessageBox::Warning);
    msg_box.setText (tr ("You are about to overwrite all shortcuts.\n"
                         "Would you like to save the current shortcut set or cancel the action?"));
    msg_box.setStandardButtons (QMessageBox::Save | QMessageBox::Cancel);
    QPushButton *discard = msg_box.addButton (tr ("Don't save"),
                                              QMessageBox::DestructiveRole);
    msg_box.setDefaultButton (QMessageBox::Save);

    int ret = msg_box.exec ();

    if (msg_box.clickedButton () == discard)
      return true;  // do not save and go ahead

    if (ret == QMessageBox::Save)
      {
        if (import_export (OSC_EXPORT))
          return true;  // go ahead
      }

    return false; // abort the import
  }
}