diff options
| -rw-r--r-- | news_gui.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/news_gui.c b/news_gui.c index de8a431e2..f6a10748c 100644 --- a/news_gui.c +++ b/news_gui.c @@ -29,6 +29,12 @@ * [O------------F-------------C---------L ] * | * forced + * + * Of course by using an array we can have situations like + * + * [----L O-----F---------C-----------------] + * This is where we have wrapped around the array and have + * (MAX_NEWS - O) + L news items */ #define MAX_NEWS 30 @@ -870,7 +876,7 @@ void DeleteVehicleNews(VehicleID vid, StringID news) { NewsID n; - for (n = _oldest_news; _latest_news != INVALID_NEWS && n != increaseIndex(_latest_news); n = increaseIndex(n)) { + for (n = _oldest_news; _latest_news != INVALID_NEWS; n = increaseIndex(n)) { const NewsItem *ni = &_news_items[n]; if (ni->flags & NF_VEHICLE && @@ -879,18 +885,32 @@ void DeleteVehicleNews(VehicleID vid, StringID news) Window *w; if (_forced_news == n || _current_news == n) MoveToNextItem(); + _total_news--; // If this is the last news item, invalidate _latest_news - if (_latest_news == _oldest_news) _latest_news = INVALID_NEWS; + if (_latest_news == _oldest_news) { + assert(_total_news == 0); + _latest_news = INVALID_NEWS; + } - if (n != _oldest_news) { + /* Since we only imitate a FIFO removing an arbitrary element does need + * some magic. Remove the item by shifting head towards the tail. eg + * oldest remove last + * | | | + * [------O--------n-----L--] + * will become (change dramatized to make clear) + * [---------O-----------L--] + * Also update the current news item in case it was pointing to the + * oldest, now shifted item */ + if (_total_news != 0) { NewsID i; for (i = n; i != _oldest_news; i = decreaseIndex(i)) { _news_items[i] = _news_items[decreaseIndex(i)]; } + + if (_current_news == _oldest_news) _current_news = increaseIndex(_current_news); _oldest_news = increaseIndex(_oldest_news); } - _total_news--; w = FindWindowById(WC_MESSAGE_HISTORY, 0); if (w != NULL) { @@ -898,5 +918,7 @@ void DeleteVehicleNews(VehicleID vid, StringID news) w->vscroll.count = _total_news; } } + + if (n == _latest_news) break; } } |