8 #include "chimara-glk.h"
9 #include "chimara-glk-private.h"
11 extern GPrivate *glk_data_key;
13 #define EVENT_TIMEOUT_MICROSECONDS (3000000)
15 /* Internal function: push an event onto the event queue. If the event queue is
16 full, wait for max three seconds and then drop the event. If the event queue is
17 NULL, i.e. freed, then fail silently. */
19 event_throw(ChimaraGlk *glk, glui32 type, winid_t win, glui32 val1, glui32 val2)
21 ChimaraGlkPrivate *priv = CHIMARA_GLK_PRIVATE(glk);
23 if(!priv->event_queue)
27 g_get_current_time(&timeout);
28 g_time_val_add(&timeout, EVENT_TIMEOUT_MICROSECONDS);
30 g_mutex_lock(priv->event_lock);
32 /* Wait for room in the event queue */
33 while( g_queue_get_length(priv->event_queue) >= EVENT_QUEUE_MAX_LENGTH )
34 if( !g_cond_timed_wait(priv->event_queue_not_full, priv->event_lock, &timeout) )
36 /* Drop the event after 3 seconds */
37 g_mutex_unlock(priv->event_lock);
41 event_t *event = g_new0(event_t, 1);
46 g_queue_push_head(priv->event_queue, event);
48 /* Signal that there is an event */
49 g_cond_signal(priv->event_queue_not_empty);
51 g_mutex_unlock(priv->event_lock);
54 /* Helper function: Wait for an event in the event queue. If it is a forced
55 * input event, but no windows have an input request of that type, then wait
56 * for the next event and put the forced input event back on top of the queue.
59 get_appropriate_event(event_t *event)
61 ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
63 g_mutex_lock(glk_data->event_lock);
65 event_t *retrieved_event = NULL;
67 /* Wait for an event */
68 if( g_queue_is_empty(glk_data->event_queue) )
69 g_cond_wait(glk_data->event_queue_not_empty, glk_data->event_lock);
71 retrieved_event = g_queue_pop_tail(glk_data->event_queue);
73 /* Signal that the event queue is no longer full */
74 g_cond_signal(glk_data->event_queue_not_full);
76 g_mutex_unlock(glk_data->event_lock);
78 if(retrieved_event->type == evtype_ForcedCharInput)
80 /* Check for forced character input in the queue */
82 for(win = glk_window_iterate(NULL, NULL); win; win = glk_window_iterate(win, NULL))
83 if(win->input_request_type == INPUT_REQUEST_CHARACTER || win->input_request_type == INPUT_REQUEST_CHARACTER_UNICODE)
87 force_char_input_from_queue(win, event);
88 g_free(retrieved_event);
92 get_appropriate_event(event);
93 g_mutex_lock(glk_data->event_lock);
94 g_queue_push_tail(glk_data->event_queue, retrieved_event);
95 g_cond_signal(glk_data->event_queue_not_empty);
96 g_mutex_unlock(glk_data->event_lock);
99 else if(retrieved_event->type == evtype_ForcedLineInput)
101 /* Check for forced line input in the queue */
103 for(win = glk_window_iterate(NULL, NULL); win; win = glk_window_iterate(win, NULL))
104 if(win->input_request_type == INPUT_REQUEST_LINE || win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
108 force_line_input_from_queue(win, event);
109 g_free(retrieved_event);
113 get_appropriate_event(event);
114 g_mutex_lock(glk_data->event_lock);
115 g_queue_push_tail(glk_data->event_queue, retrieved_event);
116 g_cond_signal(glk_data->event_queue_not_empty);
117 g_mutex_unlock(glk_data->event_lock);
122 if(retrieved_event == NULL)
124 WARNING("Retrieved NULL event from non-empty event queue");
127 memcpy(event, retrieved_event, sizeof(event_t));
128 g_free(retrieved_event);
134 * @event: Pointer to an #event_t.
136 * Causes the program to wait for an event, and then store it in the structure
137 * pointed to by @event. Unlike most Glk functions that take pointers, the
138 * argument of glk_select() may not be %NULL.
140 * Most of the time, you only get the events that you request. However, there
141 * are some events which can arrive at any time. This is why you must always
142 * call glk_select() in a loop, and continue the loop until you get the event
146 glk_select(event_t *event)
148 g_return_if_fail(event != NULL);
150 /* Flush all window buffers */
152 for(win = glk_window_iterate(NULL, NULL); win != NULL; win = glk_window_iterate(win, NULL)) {
153 if(win->type == wintype_TextBuffer || win->type == wintype_TextGrid)
154 flush_window_buffer(win);
157 ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
159 get_appropriate_event(event);
161 /* Check for interrupt */
164 /* If the event was a line input event, the library must release the buffer */
165 if(event->type == evtype_LineInput && glk_data->unregister_arr)
167 if(event->win->input_request_type == INPUT_REQUEST_LINE_UNICODE)
168 (*glk_data->unregister_arr)(event->win->line_input_buffer_unicode, event->win->line_input_buffer_max_len, "&+#!Iu", event->win->buffer_rock);
170 (*glk_data->unregister_arr)(event->win->line_input_buffer, event->win->line_input_buffer_max_len, "&+#!Cn", event->win->buffer_rock);
173 /* If an abort event was generated, the thread should have exited by now */
174 g_assert(event->type != evtype_Abort);
179 * @event: Return location for an event.
181 * You can also inquire if an event is available, without stopping to wait for
184 * This checks if an internally-spawned event is available. If so, it stores it
185 * in the structure pointed to by @event. If not, it sets
186 * <code>@event->type</code> to %evtype_None. Either way, it returns almost
189 * The first question you now ask is, what is an internally-spawned event?
190 * glk_select_poll() does not check for or return %evtype_CharInput,
191 * %evtype_LineInput, %evtype_MouseInput, or %evtype_Hyperlink events. It is
192 * intended for you to test conditions which may have occurred while you are
193 * computing, and not interfacing with the player. For example, time may pass
194 * during slow computations; you can use glk_select_poll() to see if a
195 * %evtype_Timer event has occurred. (See <link
196 * linkend="chimara-Timer-Events">Timer Events</link>.)
198 * At the moment, glk_select_poll() checks for %evtype_Timer, %evtype_Arrange,
199 * %evtype_Redraw and %evtype_SoundNotify events. But see <link
200 * linkend="chimara-Other-Events">Other Events</link>.
202 * The second question is, what does it mean that glk_select_poll() returns
203 * <quote>almost immediately</quote>? In some Glk libraries, text that you send
204 * to a window is buffered; it does not actually appear until you request player
205 * input with glk_select(). glk_select_poll() attends to this buffer-flushing
206 * task in the same way. (Although it does not do the <quote><computeroutput>Hit
207 * any key to scroll down</computeroutput></quote> waiting which may be done in
208 * glk_select(); that's a player-input task.)
210 * Similarly, on multitasking platforms, glk_select() may yield time to other
211 * processes; and glk_select_poll() does this as well.
213 * The upshot of this is that you should not call glk_select_poll() very often.
214 * If you are not doing much work between player inputs, you should not need to
218 * For example, in a virtual machine interpreter, you should not call
219 * glk_select_poll() after every opcode.
222 * However, if you are doing intense computation, you may wish to call
223 * glk_select_poll() every so often to yield time to other processes. And if you
224 * are printing intermediate results during this computation, you should
225 * glk_select_poll() every so often, so that you can be certain your output will
226 * be displayed before the next glk_select().
229 * However, you should call glk_tick() often — once per opcode in a VM
230 * interpreter. See <link linkend="chimara-The-Tick-Thing">The Tick
235 glk_select_poll(event_t *event)
237 g_return_if_fail(event != NULL);
239 ChimaraGlkPrivate *glk_data = g_private_get(glk_data_key);
241 event->type = evtype_None;
243 g_mutex_lock(glk_data->event_lock);
245 if( !g_queue_is_empty(glk_data->event_queue) )
249 for(count = 0; (link = g_queue_peek_nth_link(glk_data->event_queue, count)) != NULL; count++)
251 glui32 type = ((event_t *)link->data)->type;
252 if(type != evtype_CharInput && type != evtype_LineInput && type != evtype_MouseInput && type != evtype_Hyperlink)
254 memcpy(event, link->data, sizeof(event_t));
256 g_queue_delete_link(glk_data->event_queue, link);
257 g_cond_signal(glk_data->event_queue_not_full);
263 g_mutex_unlock(glk_data->event_lock);
265 /* Check for interrupt */
268 /* If an abort event was generated, the thread should have exited by now */
269 g_assert(event->type != evtype_Abort);