Warning, file /system/qtcurve/qt4/style/shortcuthandler.cpp was not indexed or was modified since last indexation (in which case cross-reference links may be missing, inaccurate or erroneous).

 /*****************************************************************************
  *   Copyright 2007 - 2010 Craig Drummond <craig.p.drummond@gmail.com>       *
  *   Copyright 2013 - 2015 Yichao Yu <yyc1992@gmail.com>                     *
  *                                                                           *
  *   This program is free software; you can redistribute it and/or modify    *
  *   it under the terms of the GNU Lesser General Public License as          *
  *   published by the Free Software Foundation; either version 2.1 of the    *
  *   License, or (at your option) version 3, or any later version accepted   *
  *   by the membership of KDE e.V. (or its successor approved by the         *
  *   membership of KDE e.V.), which shall act as a proxy defined in          *
  *   Section 6 of version 3 of the license.                                  *
  *                                                                           *
  *   This program 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       *
  *   Lesser General Public License for more details.                         *
  *                                                                           *
  *   You should have received a copy of the GNU Lesser General Public        *
  *   License along with this library. If not,                                *
  *   see <http://www.gnu.org/licenses/>.                                     *
  *****************************************************************************/
 
 #include "shortcuthandler.h"
 #include <QWidget>
 #include <QMenu>
 #include <QEvent>
 #include <QKeyEvent>
 #include <QMenuBar>
 
 namespace QtCurve {
 ShortcutHandler::ShortcutHandler(QObject *parent) : QObject(parent),
                                                     m_altDown(false)
 {
 }
 
 ShortcutHandler::~ShortcutHandler()
 {
 }
 
 bool ShortcutHandler::hasSeenAlt(const QWidget *widget) const
 {
     if (widget && !widget->isEnabled())
         return false;
 
     if (qobject_cast<const QMenu*>(widget)) {
         return m_openMenus.count() && m_openMenus.last()==widget;
         // const QWidget *w = widget;
         // while (w) {
         //     if (m_seenAlt.contains((QWidget*)w))
         //         return true;
         //     w = w->parentWidget();
         // }
     } else {
         return (m_openMenus.isEmpty() &&
                 m_seenAlt.contains((QWidget*)(widget->window())));
     }
     return false;
 }
 
 bool ShortcutHandler::showShortcut(const QWidget *widget) const
 {
     return m_altDown && hasSeenAlt(widget);
 }
 
 void ShortcutHandler::widgetDestroyed(QObject *o)
 {
     m_updated.remove(static_cast<QWidget *>(o));
     m_openMenus.removeAll(static_cast<QWidget *>(o));
 }
 
 void ShortcutHandler::updateWidget(QWidget *w)
 {
     if(!m_updated.contains(w))
     {
         m_updated.insert(w);
         w->update();
         connect(w, SIGNAL(destroyed(QObject *)), this, SLOT(widgetDestroyed(QObject *)));
     }
 }
 
 bool ShortcutHandler::eventFilter(QObject *o, QEvent *e)
 {
     if (!o->isWidgetType())
         return QObject::eventFilter(o, e);
 
     QWidget *widget = static_cast<QWidget*>(o);
     switch (e->type()) {
     case QEvent::KeyPress:
         if (Qt::Key_Alt == static_cast<QKeyEvent*>(e)->key()) {
             m_altDown = true;
             if (qobject_cast<QMenu*>(widget)) {
                 m_seenAlt.insert(widget);
                 updateWidget(widget);
                 if (widget->parentWidget() &&
                     widget->parentWidget()->window()) {
                     m_seenAlt.insert(widget->parentWidget()->window());
                 }
             } else {
                 widget = widget->window();
                 m_seenAlt.insert(widget);
                 QList<QWidget*> l = widget->findChildren<QWidget*>();
                 for (int pos = 0;pos < l.size();++pos) {
                     QWidget *w = l.at(pos);
                     if (!(w->isWindow() || !w->isVisible())) {
                         // || w->style()->styleHint(
                         //     QStyle::SH_UnderlineShortcut, 0, w)))
                         updateWidget(w);
                     }
                 }
                 QList<QMenuBar*> m = widget->findChildren<QMenuBar*>();
                 for (int i = 0; i < m.size(); ++i)
                     updateWidget(m.at(i));
             }
         }
         break;
     case QEvent::WindowDeactivate:
     case QEvent::KeyRelease:
         if (QEvent::WindowDeactivate == e->type() ||
             Qt::Key_Alt == static_cast<QKeyEvent*>(e)->key()) {
             m_altDown = false;
             foreach (QWidget *widget, m_updated) {
                 widget->update();
             }
             if (!m_updated.contains(widget))
                 widget->update();
             m_seenAlt.clear();
             m_updated.clear();
         }
         break;
     case QEvent::Show:
         if (qobject_cast<QMenu*>(widget)) {
             QWidget *prev = m_openMenus.count() ? m_openMenus.last() : 0L;
             m_openMenus.append(widget);
             if (m_altDown && prev)
                 prev->update();
             connect(widget, SIGNAL(destroyed(QObject*)),
                     this, SLOT(widgetDestroyed(QObject*)));
         }
         break;
     case QEvent::Hide:
         if (qobject_cast<QMenu*>(widget)) {
             m_seenAlt.remove(widget);
             m_updated.remove(widget);
             m_openMenus.removeAll(widget);
             if (m_altDown) {
                 if (m_openMenus.count()) {
                     m_openMenus.last()->update();
                 } else if (widget->parentWidget() &&
                            widget->parentWidget()->window())
                     widget->parentWidget()->window()->update();
             }
         }
         break;
     case QEvent::Close:
         // Reset widget when closing
         m_seenAlt.remove(widget);
         m_updated.remove(widget);
         m_seenAlt.remove(widget->window());
         m_openMenus.removeAll(widget);
         if (m_altDown) {
             if (m_openMenus.count()) {
                 m_openMenus.last()->update();
             } else if (widget->parentWidget() &&
                        widget->parentWidget()->window())
                 widget->parentWidget()->window()->update();
         }
         break;
     default:
         break;
     }
     return QObject::eventFilter(o, e);
 }
 
 }