src/screen.h

   1 /***************************************************************************
   2  *   Copyright (C) 2008-2010 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 _SCREEN_H
  22 #define _SCREEN_H
  23
  24 #include "window.h"
  25 #include "menu.h"
  26 #include "mpdpp.h"
  27 #include "helpers.h"
  28 #include "settings.h"
  29 #include "status.h"
  30
  31 /// An interface for various instantiations of Screen template class. Since C++ doesn't like
  32 /// comparison of two different instantiations of the same template class we need the most
  33 /// basic class to be non-template to allow it.
  34 ///
  35 class BasicScreen
  36 {
  37         public:
  38                 /// Initializes all variables to zero
  39                 ///
  40                 BasicScreen() : hasToBeResized(0), isInitialized(0) { }
  41
  42                 virtual ~BasicScreen() { }
  43
  44                 /// @see Screen::ActiveWindow()
  45                 ///
  46                 virtual void *ActiveWindow() = 0;
  47
  48                 /// Method used for switching to screen
  49                 ///
  50                 virtual void SwitchTo() = 0;
  51
  52                 /// Method that should resize screen
  53                 /// if requested by hasToBeResized
  54                 ///
  55                 virtual void Resize() = 0;
  56
  57                 /// @return title of the screen
  58                 ///
  59                 virtual std::basic_string<my_char_t> Title() = 0;
  60
  61                 /// If the screen contantly has to update itself
  62                 /// somehow, it should be called by this function.
  63                 ///
  64                 virtual void Update() { }
  65
  66                 /// @see Screen::Refresh()
  67                 ///
  68                 virtual void Refresh() = 0;
  69
  70                 /// @see Screen::RefreshWindow()
  71                 ///
  72                 virtual void RefreshWindow() = 0;
  73
  74                 /// see Screen::ReadKey()
  75                 ///
  76                 virtual void ReadKey(int &key) = 0;
  77
  78                 /// @see Screen::Scroll()
  79                 ///
  80                 virtual void Scroll(Where where, const int key[2] = 0) = 0;
  81
  82                 /// Invoked after Enter was pressed
  83                 ///
  84                 virtual void EnterPressed() = 0;
  85
  86                 /// Invoked after Space was pressed
  87                 ///
  88                 virtual void SpacePressed() = 0;
  89
  90                 /// @see Screen::MouseButtonPressed()
  91                 ///
  92                 virtual void MouseButtonPressed(MEVENT) { }
  93
  94                 /// @return pointer to currently selected song in the screen
  95                 /// (if screen provides one) or null pointer otherwise.
  96                 ///
  97                 virtual MPD::Song *CurrentSong() { return 0; }
  98
  99                 /// @return true if the screen allows selecting items, false otherwise
 100                 ///
 101                 virtual bool allowsSelection() = 0;
 102
 103                 /// Reverses selection. Does nothing by default since pure
 104                 /// virtual allowsSelection() should remind of this function
 105                 /// to be defined
 106                 ///
 107                 virtual void ReverseSelection() { }
 108
 109                 /// Gets selected songs' positions from the screen
 110                 /// @param v vector to be filled with positions
 111                 ///
 112                 virtual void GetSelectedSongs(GNUC_UNUSED MPD::SongList &v) { }
 113
 114                 /// Applies a filter to the screen
 115                 virtual void ApplyFilter(GNUC_UNUSED const std::string &filter) { }
 116
 117                 /// @return pointer to instantiation of Menu template class
 118                 /// cast to List if available or null pointer otherwise
 119                 ///
 120                 virtual List *GetList() = 0;
 121
 122                 /// When this is overwritten with a function returning true, the
 123                 /// screen will be used in tab switching.
 124                 ///
 125                 virtual bool isTabbable() { return false; }
 126
 127                 /// Should be set to true each time screen needs resize
 128                 ///
 129                 bool hasToBeResized;
 130
 131         protected:
 132                 /// Since screens initialization is lazy, we don't want to do
 133                 /// this in the constructor. This function should be invoked
 134                 /// only once and after that isInitialized flag has to be set
 135                 /// to true to somehow avoid next attempt of initialization.
 136                 ///
 137                 virtual void Init() = 0;
 138
 139                 /// Flag that inditates whether the screen is initialized or not
 140                 ///
 141                 bool isInitialized;
 142 };
 143
 144 /// Class that all screens should derive from. It provides basic interface
 145 /// for the screen to be working properly and assumes that we didn't forget
 146 /// about anything vital.
 147 ///
 148 template <typename WindowType> class Screen : public BasicScreen
 149 {
 150         public:
 151                 Screen() : w(0) { }
 152                 virtual ~Screen() { }
 153
 154                 /// Since some screens contain more that one window
 155                 /// it's useful to determine the one that is being
 156                 /// active
 157                 /// @return address to window object cast to void *
 158                 ///
 159                 virtual void *ActiveWindow();
 160
 161                 /// @return pointer to currently active window
 162                 ///
 163                 WindowType *Main();
 164
 165                 /// Refreshes whole screen
 166                 ///
 167                 virtual void Refresh();
 168
 169                 /// Refreshes active window of the screen
 170                 ///
 171                 virtual void RefreshWindow();
 172
 173                 /// Reads a key from the screen
 174                 ///
 175                 virtual void ReadKey(int &key);
 176
 177                 /// Scrolls the screen by given amount of lines and
 178                 /// if fancy scrolling feature is disabled, enters the
 179                 /// loop that holds main loop until user releases the key
 180                 /// @param where indicates where one wants to scroll
 181                 /// @param key needed if fancy scrolling is disabled to
 182                 /// define the conditional for while loop
 183                 ///
 184                 virtual void Scroll(Where where, const int key[2] = 0);
 185
 186                 /// Invoked after there was one of mouse buttons pressed
 187                 /// @param me struct that contains coords of where the click
 188                 /// had its place and button actions
 189                 ///
 190                 virtual void MouseButtonPressed(MEVENT me);
 191
 192         protected:
 193                 /// Template parameter that should indicate the main type
 194                 /// of window used by the screen. What is more, it should
 195                 /// always be assigned to the currently active window (if
 196                 /// acreen contains more that one)
 197                 ///
 198                 WindowType *w;
 199 };
 200
 201 template <typename WindowType> void *Screen<WindowType>::ActiveWindow()
 202 {
 203         return w;
 204 }
 205
 206 template <typename WindowType> WindowType *Screen<WindowType>::Main()
 207 {
 208         return w;
 209 }
 210
 211 template <typename WindowType> void Screen<WindowType>::Refresh()
 212 {
 213         w->Display();
 214 }
 215
 216 template <typename WindowType> void Screen<WindowType>::RefreshWindow()
 217 {
 218         w->Display();
 219 }
 220
 221 template <typename WindowType> void Screen<WindowType>::ReadKey(int &key)
 222 {
 223         w->ReadKey(key);
 224 }
 225
 226 template <typename WindowType> void Screen<WindowType>::Scroll(Where where, const int key[2])
 227 {
 228         if (!Config.fancy_scrolling && key)
 229         {
 230                 int in = key[0];
 231                 w->SetTimeout(50);
 232                 while (Keypressed(in, key))
 233                 {
 234                         TraceMpdStatus();
 235                         w->Scroll(where);
 236                         w->Refresh();
 237                         ReadKey(in);
 238                 }
 239                 w->SetTimeout(ncmpcpp_window_timeout);
 240         }
 241         else
 242                 w->Scroll(where);
 243 }
 244
 245 template <typename WindowType> void Screen<WindowType>::MouseButtonPressed(MEVENT me)
 246 {
 247         if (me.bstate & BUTTON2_PRESSED)
 248         {
 249                 Scroll(wPageDown);
 250         }
 251         else if (me.bstate & BUTTON4_PRESSED)
 252         {
 253                 Scroll(wPageUp);
 254         }
 255 }
 256
 257 /// Specialization for Screen<Scrollpad>::MouseButtonPressed, that should
 258 /// not scroll whole page, but rather a few lines (the number of them is
 259 /// defined in the config)
 260 ///
 261 template <> inline void Screen<Scrollpad>::MouseButtonPressed(MEVENT me)
 262 {
 263         if (me.bstate & BUTTON2_PRESSED)
 264         {
 265                 for (size_t i = 0; i < Config.lines_scrolled; ++i)
 266                         Scroll(wDown);
 267         }
 268         else if (me.bstate & BUTTON4_PRESSED)
 269         {
 270                 for (size_t i = 0; i < Config.lines_scrolled; ++i)
 271                         Scroll(wUp);
 272         }
 273 }
 274
 275 #endif
 276