src/library/messagebuffer.cpp

   1 #include "messagebuffer.hpp"
   2
   3 messagebuffer::update_handler::~update_handler() throw()
   4 {
   5 }
   6
   7 messagebuffer::messagebuffer(size_t maxmessages, size_t windowsize) throw(std::bad_alloc, std::logic_error)
   8 {
   9         if(windowsize > maxmessages)
  10                 throw std::logic_error("Invalid window size");
  11         if(maxmessages == 0)
  12                 throw std::logic_error("Invalid max message count");
  13         first_present_message = 0;
  14         next_message_number = 0;
  15         window_start = 0;
  16         max_messages = maxmessages;
  17         window_size = windowsize;
  18         scroll_frozen = false;
  19         updates_frozen = false;
  20         window_start_at_freeze = 0;
  21         window_size_at_freeze = 0;
  22         next_message_number_at_freeze = 0;
  23 }
  24
  25 void messagebuffer::add_message(const std::string& msg) throw(std::bad_alloc, std::runtime_error)
  26 {
  27         messages_buf[next_message_number++] = msg;
  28         //If too many messages, erase one.
  29         if(messages_buf.size() > max_messages)
  30                 messages_buf.erase(first_present_message++);
  31         //Force scrolling if message in window got erased.
  32         if(window_start < first_present_message) {
  33                 window_start = first_present_message;
  34                 send_notifications();
  35         }
  36         //Autoscrolling at the end.
  37         if(!scroll_frozen && window_start + window_size + 1 == next_message_number) {
  38                 window_start++;
  39                 send_notifications();
  40         }
  41         send_notifications();
  42 }
  43
  44 const std::string& messagebuffer::get_message(size_t msgnum) throw(std::bad_alloc, std::logic_error)
  45 {
  46         if(!messages_buf.count(msgnum))
  47                 throw std::logic_error("Invalid message number");
  48         return messages_buf[msgnum];
  49 }
  50
  51 size_t messagebuffer::get_msg_first() throw()
  52 {
  53         return first_present_message;
  54 }
  55
  56 size_t messagebuffer::get_msg_count() throw()
  57 {
  58         return next_message_number - first_present_message;
  59 }
  60
  61 size_t messagebuffer::get_visible_first() throw()
  62 {
  63         return window_start;
  64 }
  65
  66 size_t messagebuffer::get_visible_count() throw()
  67 {
  68         if(window_start + window_size > next_message_number)
  69                 return next_message_number - window_start;
  70         else
  71                 return window_size;
  72 }
  73
  74 bool messagebuffer::is_more_messages() throw()
  75 {
  76         return (window_start + window_size < next_message_number);
  77 }
  78
  79 void messagebuffer::freeze_scrolling() throw()
  80 {
  81         scroll_frozen = true;
  82 }
  83
  84 void messagebuffer::unfreeze_scrolling() throw()
  85 {
  86         scroll_frozen = false;
  87 }
  88
  89 void messagebuffer::freeze_updates() throw()
  90 {
  91         updates_frozen = true;
  92         window_size_at_freeze = window_size;
  93         window_start_at_freeze = window_start;
  94         next_message_number_at_freeze = next_message_number;
  95 }
  96
  97 bool messagebuffer::unfreeze_updates() throw()
  98 {
  99         updates_frozen = false;
 100         if(window_start_at_freeze < first_present_message)
 101                 return true;
 102         uint64_t messages_visible_at_freeze;
 103         uint64_t messages_visible_now;
 104         if(window_start_at_freeze + window_size_at_freeze >= next_message_number_at_freeze)
 105                 messages_visible_at_freeze = next_message_number_at_freeze - window_start_at_freeze;
 106         else
 107                 messages_visible_at_freeze = window_size_at_freeze;
 108         messages_visible_now = get_visible_count();
 109         if(messages_visible_now != messages_visible_at_freeze)
 110                 return true;
 111         if(window_start_at_freeze != window_start)
 112                 return true;
 113         return false;
 114 }
 115
 116 void messagebuffer::scroll_beginning() throw(std::bad_alloc, std::runtime_error)
 117 {
 118         if(window_start == first_present_message)
 119                 return;
 120         window_start = first_present_message;
 121         send_notifications();
 122 }
 123
 124 void messagebuffer::scroll_up_page() throw(std::bad_alloc, std::runtime_error)
 125 {
 126         if(window_start == first_present_message)
 127                 return;
 128         if(window_start < first_present_message + window_size)
 129                 window_start = first_present_message;
 130         else
 131                 window_start -= window_size;
 132         send_notifications();
 133 }
 134
 135 void messagebuffer::scroll_up_line() throw(std::bad_alloc, std::runtime_error)
 136 {
 137         if(window_start == first_present_message)
 138                 return;
 139         window_start--;
 140         send_notifications();
 141 }
 142
 143 void messagebuffer::scroll_down_line() throw(std::bad_alloc, std::runtime_error)
 144 {
 145         if(window_start + window_size >= next_message_number)
 146                 return;
 147         window_start++;
 148         send_notifications();
 149 }
 150
 151 void messagebuffer::scroll_down_page() throw(std::bad_alloc, std::runtime_error)
 152 {
 153         if(window_start + window_size >= next_message_number)
 154                 return;
 155         window_start += window_size;
 156         if(window_start + window_size >= next_message_number)
 157                 window_start = next_message_number - window_size;
 158         send_notifications();
 159 }
 160
 161 void messagebuffer::scroll_end() throw(std::bad_alloc, std::runtime_error)
 162 {
 163         if(first_present_message + window_size > next_message_number)
 164                 return;
 165         window_start = next_message_number - window_size;
 166         send_notifications();
 167 }
 168
 169 void messagebuffer::register_handler(messagebuffer::update_handler& handler) throw(std::bad_alloc)
 170 {
 171         handlers.insert(&handler);
 172 }
 173
 174 void messagebuffer::unregister_handler(messagebuffer::update_handler& handler) throw()
 175 {
 176         handlers.erase(&handler);
 177 }
 178
 179 void messagebuffer::set_max_window_size(size_t windowsize) throw(std::bad_alloc, std::logic_error)
 180 {
 181         if(windowsize > max_messages)
 182                 throw std::logic_error("Invalid window size");
 183         if(window_size > windowsize) {
 184                 //Shrink window.
 185                 bool autoscrolling = !scroll_frozen && (window_start + window_size >= next_message_number);
 186                 if(autoscrolling && window_start + windowsize < next_message_number)
 187                         window_start = next_message_number - windowsize;
 188                 window_size = windowsize;
 189                 send_notifications();
 190         } else if(window_size < windowsize) {
 191                 //Enlarge window.
 192                 if(first_present_message + windowsize >= next_message_number)
 193                         window_start = first_present_message;
 194                 else if(window_start + windowsize >= next_message_number)
 195                         window_start = next_message_number - windowsize;
 196                 window_size = windowsize;
 197                 send_notifications();
 198         }
 199 }
 200
 201 size_t messagebuffer::get_max_window_size() throw()
 202 {
 203         return window_size;
 204 }
 205
 206 void messagebuffer::send_notifications()
 207 {
 208         if(updates_frozen)
 209                 return;
 210         for(auto i : handlers)
 211                 i->messagebuffer_update();
 212 }
 213
 214 std::string messagebuffer::get_last_message()
 215 {
 216         if(messages_buf.empty())
 217                 return "";
 218         return messages_buf.rbegin()->second;
 219 }