events: Rework event subsystem (add_event, send_event) to be more versatile.

add_event_ex is added that takes an extra user_data pointer. This pointer is
passed to the callback (add_event and add_event_ex have slightly different
callbacks types). All callbacks also get the event id passed. Events added
with add_event_ex must be removed with remove_event_ex because the user_data
pointer must match in addition to the callback pointer.

On the other add_event is simplified to omit the oneshort parameter which
was almost always false (still there with add_event_ex).

As a side effect the ata_idle_notify callbacks are changed as well, they
do not take a data parameter anymore which was always NULL anyway.

This commit also adds some documentation to events.h

Change-Id: I13e29a0f88ef908f175b376d83550f9e0231f772

1 files changed, 10 insertions, 9 deletions

diff --git a/apps/scrobbler.c b/apps/scrobbler.c
index efd028327c..b8a95f85cb 100644
--- a/apps/scrobbler.c
+++ b/apps/scrobbler.c
@@ -150,9 +150,8 @@ static void write_cache(void)
     cache_pos = 0;
 }
 
-static void scrobbler_flush_callback(void *data)
+static void scrobbler_flush_callback(void)
 {
-    (void)data;
     if (scrobbler_initialised && cache_pos)
         write_cache();
 }
@@ -200,16 +199,17 @@ static void add_to_cache(const struct mp3entry *id)
 
 }
 
-static void scrobbler_change_event(void *data)
+static void scrobbler_change_event(unsigned short id, void *ev_data)
 {
-    struct mp3entry *id = ((struct track_event *)data)->id3;
+    (void)id;
+    struct mp3entry *id3 = ((struct track_event *)ev_data)->id3;
 
     /*  check if track was resumed > %50 played
         check for blank artist or track name */
-    if (id->elapsed > id->length / 2 || !id->artist || !id->title)
+    if (id3->elapsed > id3->length / 2 || !id3->artist || !id3->title)
     {
         pending = false;
-        logf("SCROBBLER: skipping file %s", id->path);
+        logf("SCROBBLER: skipping file %s", id3->path);
     }
     else
     {
@@ -219,8 +219,9 @@ static void scrobbler_change_event(void *data)
     }
 }
 
-static void scrobbler_finish_event(void *data)
+static void scrobbler_finish_event(unsigned short id, void *data)
 {
+    (void)id;
     struct track_event *te = (struct track_event *)data;
 
     /* add entry using the currently ending track */
@@ -254,8 +255,8 @@ int scrobbler_init(void)
 
     scrobbler_initialised = true;
 
-    add_event(PLAYBACK_EVENT_TRACK_CHANGE, false, scrobbler_change_event);
-    add_event(PLAYBACK_EVENT_TRACK_FINISH, false, scrobbler_finish_event);
+    add_event(PLAYBACK_EVENT_TRACK_CHANGE, scrobbler_change_event);
+    add_event(PLAYBACK_EVENT_TRACK_FINISH, scrobbler_finish_event);
 
     return 1;
 }