| 1 | /* |
| 2 | * This file is part of DisOrder |
| 3 | * Copyright (C) 2008 Richard Kettlewell |
| 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 3 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, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | /** @file lib/eventdist.c |
| 19 | * @brief Event distribution |
| 20 | */ |
| 21 | #include "common.h" |
| 22 | |
| 23 | #include "mem.h" |
| 24 | #include "eventdist.h" |
| 25 | #include "hash.h" |
| 26 | |
| 27 | struct event_data { |
| 28 | struct event_data *next; |
| 29 | const char *event; |
| 30 | event_handler *callback; |
| 31 | void *callbackdata; |
| 32 | }; |
| 33 | |
| 34 | static hash *events; |
| 35 | |
| 36 | /** @brief Register an event handler |
| 37 | * @param event Event type to handle |
| 38 | * @param callback Function to call when event occurs |
| 39 | * @param callbackdata Passed to @p callback |
| 40 | * @return Handle for this registration (for use with event_cancel()) |
| 41 | */ |
| 42 | event_handle event_register(const char *event, |
| 43 | event_handler *callback, |
| 44 | void *callbackdata) { |
| 45 | static const struct event_data *null; |
| 46 | struct event_data *ed = xmalloc(sizeof *ed), **head; |
| 47 | |
| 48 | if(!events) |
| 49 | events = hash_new(sizeof (struct event_data *)); |
| 50 | if(!(head = hash_find(events, event))) { |
| 51 | hash_add(events, event, &null, HASH_INSERT); |
| 52 | head = hash_find(events, event); |
| 53 | } |
| 54 | ed->next = *head; |
| 55 | ed->event = xstrdup(event); |
| 56 | ed->callback = callback; |
| 57 | ed->callbackdata = callbackdata; |
| 58 | *head = ed; |
| 59 | return ed; |
| 60 | } |
| 61 | |
| 62 | /** @brief Stop handling an event |
| 63 | * @param handle Registration to cancel (as returned from event_register()) |
| 64 | * |
| 65 | * @p handle is allowed to be NULL. |
| 66 | */ |
| 67 | void event_cancel(event_handle handle) { |
| 68 | struct event_data **head, **edp; |
| 69 | |
| 70 | if(!handle) |
| 71 | return; |
| 72 | assert(events); |
| 73 | head = hash_find(events, handle->event); |
| 74 | for(edp = head; *edp && *edp != handle; edp = &(*edp)->next) |
| 75 | ; |
| 76 | assert(*edp == handle); |
| 77 | *edp = handle->next; |
| 78 | } |
| 79 | |
| 80 | /** @brief Raise an event |
| 81 | * @param event Event type to raise |
| 82 | * @param eventdata Event-specific data |
| 83 | */ |
| 84 | void event_raise(const char *event, |
| 85 | void *eventdata) { |
| 86 | struct event_data *ed, **head; |
| 87 | if(!events) |
| 88 | return; |
| 89 | if(!(head = hash_find(events, event))) |
| 90 | return; |
| 91 | for(ed = *head; ed; ed = ed->next) |
| 92 | ed->callback(event, eventdata, ed->callbackdata); |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | Local Variables: |
| 97 | c-basic-offset:2 |
| 98 | comment-column:40 |
| 99 | fill-column:79 |
| 100 | indent-tabs-mode:nil |
| 101 | End: |
| 102 | */ |