src/screens/screen_switcher.h

   1 /***************************************************************************
   2  *   Copyright (C) 2008-2017 by Andrzej Rybczak                            *
   3  *   electricityispower@gmail.com                                          *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with this program; if not, write to the                         *
  17  *   Free Software Foundation, Inc.,                                       *
  18  *   51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.              *
  19  ***************************************************************************/
  20
  21 #ifndef NCMPCPP_SCREEN_SWITCHER_H
  22 #define NCMPCPP_SCREEN_SWITCHER_H
  23
  24 #include "global.h"
  25
  26 class SwitchTo
  27 {
  28         template <bool ToBeExecuted, typename ScreenT> struct TabbableAction_ {
  29                 static void execute(ScreenT *) { }
  30         };
  31         template <typename ScreenT> struct TabbableAction_<true, ScreenT> {
  32                 static void execute(ScreenT *screen) {
  33                         using Global::myScreen;
  34                         // it has to work only if both current and previous screens are Tabbable
  35                         if (dynamic_cast<Tabbable *>(myScreen))
  36                                 screen->setPreviousScreen(myScreen);
  37                 }
  38         };
  39
  40 public:
  41         template <typename ScreenT>
  42         static void execute(ScreenT *screen)
  43         {
  44                 using Global::myScreen;
  45                 using Global::myLockedScreen;
  46
  47                 const bool isScreenMergable = screen->isMergable() && myLockedScreen;
  48                 const bool isScreenTabbable = std::is_base_of<Tabbable, ScreenT>::value;
  49
  50                 assert(myScreen != screen);
  51                 if (isScreenMergable)
  52                         updateInactiveScreen(screen);
  53                 if (screen->hasToBeResized || isScreenMergable)
  54                         screen->resize();
  55                 TabbableAction_<isScreenTabbable, ScreenT>::execute(screen);
  56                 myScreen = screen;
  57         }
  58 };
  59
  60 #endif // NCMPCPP_SCREEN_SWITCHER_H