Implement pause_on_output_change option (closes cmus#1139)

Doc/cmus.txt

@@ -1101,6 +1101,11 @@ mpris (true)
 output_plugin [roar, pulse, alsa, arts, oss, sndio, sun, coreaudio]
 	Name of output plugin.
 
+pause_on_output_change (false)
+    Pauses playback when the audio output changes.
+
+    Supported output plugins: none.
+
 pl_sort () [`Sort Keys`]
 	Sort keys for the playlist view (3). Empty value disables sorting and
 	enables manually moving tracks.

mixer.h

@@ -27,7 +27,9 @@
 
 enum {
     /* volume changes */
-    MIXER_FDS_VOLUME
+    MIXER_FDS_VOLUME,
+    /* output changes */
+    MIXER_FDS_OUTPUT
 };
 
 struct mixer_plugin_ops {

options.c

@@ -87,6 +87,7 @@ int start_view = TREE_VIEW;
 int stop_after_queue = 0;
 int tree_width_percent = 33;
 int tree_width_max = 0;
+int pause_on_output_change = 0;
 
 int colors[NR_COLORS] = {
 	-1,
@@ -1215,6 +1216,21 @@ static void toggle_stop_after_queue(void *data)
 	stop_after_queue ^= 1;
 }
 
+static void get_pause_on_output_change(void *data, char *buf, size_t size)
+{
+	strscpy(buf, bool_names[pause_on_output_change], size);
+}
+
+static void set_pause_on_output_change(void *data, const char *buf)
+{
+	parse_bool(buf, &pause_on_output_change);
+}
+
+static void toggle_pause_on_output_change(void *data)
+{
+	pause_on_output_change ^= 1;
+}
+
 /* }}} */
 
 /* special callbacks (id set) {{{ */
@@ -1465,6 +1481,7 @@ static const struct {
 	DT(stop_after_queue)
 	DN(tree_width_percent)
 	DN(tree_width_max)
+	DT(pause_on_output_change)
 	{ NULL, NULL, NULL, NULL, 0 }
 };
 

options.h

@@ -160,6 +160,7 @@ extern int start_view;
 extern int stop_after_queue;
 extern int tree_width_percent;
 extern int tree_width_max;
+extern int pause_on_output_change;
 
 extern const char * const aaa_mode_names[];
 extern const char * const view_names[NR_VIEWS + 1];

ui_curses.c

@@ -2140,6 +2140,7 @@ static void main_loop(void)
 		int poll_mixer = 0;
 		int i;
 		int nr_fds_vol = 0, fds_vol[NR_MIXER_FDS];
+		int nr_fds_out = 0, fds_out[NR_MIXER_FDS];
 		struct list_head *item;
 		struct client *client;
 
@@ -2186,6 +2187,12 @@ static void main_loop(void)
 			}
 		}
 
+		nr_fds_out = mixer_get_fds(MIXER_FDS_OUTPUT, fds_out);
+		for (i = 0; i < nr_fds_out; i++) {
+			BUG_ON(fds_out[i] <= 0);
+			SELECT_ADD_FD(fds_out[i]);
+		}
+
 		rc = select(fd_high + 1, &set, NULL, NULL, tv.tv_usec ? &tv : NULL);
 		if (poll_mixer) {
 			int ol = volume_l;
@@ -2215,6 +2222,16 @@ static void main_loop(void)
 				update_statusline();
 			}
 		}
+		for (i = 0; i < nr_fds_out; i++) {
+			if (FD_ISSET(fds_out[i], &set)) {
+				d_print("out changed\n");
+				if (pause_on_output_change) {
+					player_pause_playback();
+					update_statusline();
+				}
+				clear_pipe(fds_out[i], -1);
+			}
+		}
 		if (FD_ISSET(server_socket, &set))
 			server_accept();