Implement Rewind across tracks functionality

Useful feature for audiobooks. To rewind from the end of the previous track - press rewind at the very beginning of the current track. So if you are in the middle of the track - first rewind till beginning then release and press rewind button again (Playback Settings -> Rewind Across Tracks option should be enabled)

Fixes FS#13290

Change-Id: I5d7f06f64ad76d1e8f7827fe594ccca5f621769d

8 files changed, 66 insertions, 20 deletions

diff --git a/apps/gui/wps.c b/apps/gui/wps.c
index 9d7a4c96f3..05a64370ac 100644
--- a/apps/gui/wps.c
+++ b/apps/gui/wps.c
@@ -202,7 +202,7 @@ static int skintouch_to_wps(struct wps_data *data)
 }
 #endif /* HAVE_TOUCHSCREEN */
 
-static bool ffwd_rew(int button)
+static bool ffwd_rew(int button, bool seek_from_end)
 {
     unsigned int step = 0;     /* current ff/rewind step */
     unsigned int max_step = 0; /* maximum ff/rewind step */
@@ -213,6 +213,7 @@ static bool ffwd_rew(int button)
     bool ff_rewind = false;
     const long ff_rw_accel = (global_settings.ff_rewind_accel + 3);
     struct wps_state *gstate = get_wps_state();
+    struct mp3entry *old_id3 = gstate->id3;
 
     if (button == ACTION_NONE)
     {
@@ -221,6 +222,16 @@ static bool ffwd_rew(int button)
     }
     while (!exit)
     {
+        struct mp3entry *id3 = gstate->id3;
+        if (id3 != old_id3)
+        {
+            ff_rewind = false;
+            ff_rewind_count = 0;
+            old_id3 = id3;
+        }
+        if (id3 && seek_from_end)
+            id3->elapsed = id3->length;
+
         switch ( button )
         {
             case ACTION_WPS_SEEKFWD:
@@ -232,16 +243,16 @@ static bool ffwd_rew(int button)
                     if (direction == 1)
                     {
                         /* fast forwarding, calc max step relative to end */
-                        max_step = (gstate->id3->length -
-                                    (gstate->id3->elapsed +
+                        max_step = (id3->length -
+                                    (id3->elapsed +
                                      ff_rewind_count)) *
                                      FF_REWIND_MAX_PERCENT / 100;
                     }
                     else
                     {
                         /* rewinding, calc max step relative to start */
-                        max_step = (gstate->id3->elapsed + ff_rewind_count) *
-                                    FF_REWIND_MAX_PERCENT / 100;
+                        max_step = (id3->elapsed + ff_rewind_count) *
+                                   FF_REWIND_MAX_PERCENT / 100;
                     }
 
                     max_step = MAX(max_step, MIN_FF_REWIND_STEP);
@@ -256,8 +267,7 @@ static bool ffwd_rew(int button)
                 }
                 else
                 {
-                    if ( (audio_status() & AUDIO_STATUS_PLAY) &&
-                          gstate->id3 && gstate->id3->length )
+                    if ((audio_status() & AUDIO_STATUS_PLAY) && id3 && id3->length )
                     {
                         audio_pre_ff_rewind();
                         if (direction > 0)
@@ -274,12 +284,12 @@ static bool ffwd_rew(int button)
                 }
 
                 if (direction > 0) {
-                    if ((gstate->id3->elapsed + ff_rewind_count) > gstate->id3->length)
-                        ff_rewind_count = gstate->id3->length - gstate->id3->elapsed;
+                    if ((id3->elapsed + ff_rewind_count) > id3->length)
+                        ff_rewind_count = id3->length - id3->elapsed;
                 }
                 else {
-                    if ((int)(gstate->id3->elapsed + ff_rewind_count) < 0)
-                        ff_rewind_count = -gstate->id3->elapsed;
+                    if ((int)(id3->elapsed + ff_rewind_count) < 0)
+                        ff_rewind_count = -id3->elapsed;
                 }
 
                 /* set the wps state ff_rewind_count so the progess info
@@ -296,8 +306,8 @@ static bool ffwd_rew(int button)
                 break;
 
             case ACTION_WPS_STOPSEEK:
-                gstate->id3->elapsed = gstate->id3->elapsed+ff_rewind_count;
-                audio_ff_rewind(gstate->id3->elapsed);
+                id3->elapsed = id3->elapsed + ff_rewind_count;
+                audio_ff_rewind(id3->elapsed);
                 gstate->ff_rewind_count = 0;
                 ff_rewind = false;
                 status_set_ffmode(0);
@@ -319,8 +329,9 @@ static bool ffwd_rew(int button)
             if (button == ACTION_TOUCHSCREEN)
                 button = skintouch_to_wps(skin_get_gwps(WPS, SCREEN_MAIN)->data);
 #endif
-            if (button != ACTION_WPS_SEEKFWD &&
-                button != ACTION_WPS_SEEKBACK)
+            if (button != ACTION_WPS_SEEKFWD
+                && button != ACTION_WPS_SEEKBACK
+                && button != 0)
                 button = ACTION_WPS_STOPSEEK;
         }
     }
@@ -733,7 +744,7 @@ long gui_wps_show(void)
                     }
                 }
                 else
-                    ffwd_rew(ACTION_WPS_SEEKFWD);
+                    ffwd_rew(ACTION_WPS_SEEKFWD, false);
                 last_right = last_left = 0;
                 break;
             /* fast rewind
@@ -752,9 +763,19 @@ long gui_wps_show(void)
                     {
                         change_dir(-1);
                     }
+                } else if (global_settings.rewind_across_tracks
+                           && get_wps_state()->id3->elapsed < DEFAULT_SKIP_THRESH
+                           && playlist_check(-1))
+                {
+                    if (!audio_paused)
+                        audio_pause();
+                    audio_prev();
+                    ffwd_rew(ACTION_WPS_SEEKBACK, true);
+                    if (!audio_paused)
+                        audio_resume();
                 }
                 else
-                    ffwd_rew(ACTION_WPS_SEEKBACK);
+                    ffwd_rew(ACTION_WPS_SEEKBACK, false);
                 last_left = last_right = 0;
                 break;
 
@@ -926,7 +947,7 @@ long gui_wps_show(void)
                 break;
             case ACTION_NONE: /* Timeout, do a partial update */
                 update = true;
-                ffwd_rew(button); /* hopefully fix the ffw/rwd bug */
+                ffwd_rew(button, false); /* hopefully fix the ffw/rwd bug */
                 break;
 #ifdef HAVE_RECORDING
             case ACTION_WPS_REC:
diff --git a/apps/lang/english.lang b/apps/lang/english.lang
index 31090aa861..29a2527bec 100644
--- a/apps/lang/english.lang
+++ b/apps/lang/english.lang
@@ -16388,3 +16388,17 @@
     clear_settings_on_hold, iriverh10: "Clear settings when reset button is held during startup"
   </voice>
 </phrase>
+<phrase>
+  id: LANG_REWIND_ACROSS_TRACKS
+  desc: in playback settings menu
+  user: core
+  <source>
+    *: "Rewind Across Tracks"
+  </source>
+  <dest>
+    *: "Rewind Across Tracks"
+  </dest>
+  <voice>
+    *: "Rewind across tracks"
+  </voice>
+</phrase>
diff --git a/apps/menus/playback_menu.c b/apps/menus/playback_menu.c
index 881a4b5a99..e4945be0b5 100644
--- a/apps/menus/playback_menu.c
+++ b/apps/menus/playback_menu.c
@@ -174,6 +174,7 @@ MAKE_MENU(unplug_menu, ID2P(LANG_HEADPHONE_UNPLUG), 0, Icon_NOICON,
 
 MENUITEM_SETTING(skip_length, &global_settings.skip_length, NULL);
 MENUITEM_SETTING(prevent_skip, &global_settings.prevent_skip, NULL);
+MENUITEM_SETTING(rewind_across_tracks, &global_settings.rewind_across_tracks, NULL);
 MENUITEM_SETTING(resume_rewind, &global_settings.resume_rewind, NULL);
 MENUITEM_SETTING(pause_rewind, &global_settings.pause_rewind, NULL);
 #ifdef HAVE_PLAY_FREQ
@@ -226,6 +227,7 @@ MAKE_MENU(playback_settings,ID2P(LANG_PLAYBACK),0,
          ,&unplug_menu
 #endif
          ,&skip_length, &prevent_skip
+          ,&rewind_across_tracks
 
           ,&resume_rewind
           ,&pause_rewind
diff --git a/apps/settings.h b/apps/settings.h
index 092c04a76b..37e546f6fc 100644
--- a/apps/settings.h
+++ b/apps/settings.h
@@ -613,7 +613,8 @@ struct user_settings
 #ifdef HAVE_ALBUMART
     int album_art; /* switch off album art display or choose preferred source */
 #endif
-    
+    bool rewind_across_tracks;
+
     /* playlist viewer settings */
     bool playlist_viewer_icons; /* display icons on viewer */
     bool playlist_viewer_indices; /* display playlist indices on viewer */
diff --git a/apps/settings_list.c b/apps/settings_list.c
index 6d01f5c6fc..f54738163a 100644
--- a/apps/settings_list.c
+++ b/apps/settings_list.c
@@ -2061,7 +2061,7 @@ const struct settings_list settings[] = {
                     tsc_is_changed, tsc_set_default),
 #endif
     OFFON_SETTING(0, prevent_skip, LANG_PREVENT_SKIPPING, false, "prevent track skip", NULL),
-
+    OFFON_SETTING(0, rewind_across_tracks, LANG_REWIND_ACROSS_TRACKS, false, "rewind across tracks", NULL),
 #ifdef HAVE_PITCHCONTROL
     OFFON_SETTING(0, pitch_mode_semitone, LANG_SEMITONE, false,
                   "Semitone pitch change", NULL),
diff --git a/docs/CREDITS b/docs/CREDITS
index 86e009c8a8..c2422e2367 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -712,6 +712,7 @@ Selami Dinçer
 Matej Golian
 James Le Cuirot
 Michael Landherr
+Roman Artiukhin
 
 The libmad team
 The wavpack team
diff --git a/manual/appendix/config_file_options.tex b/manual/appendix/config_file_options.tex
index bf231de46c..dc186e2d26 100644
--- a/manual/appendix/config_file_options.tex
+++ b/manual/appendix/config_file_options.tex
@@ -174,6 +174,8 @@
             90s, 2min, 3min, 5min, 10min, 15min & N/A\\
     prevent track skip
                     & on, off           & N/A\\
+    rewind across tracks
+                    & on, off           & N/A\\
     start in screen & previous, root, files, dB, wps, menu,
       \opt{recording}{recording, }
       \opt{radio}{radio, }
diff --git a/manual/configure_rockbox/playback_options.tex b/manual/configure_rockbox/playback_options.tex
index a2337439db..0c75315214 100644
--- a/manual/configure_rockbox/playback_options.tex
+++ b/manual/configure_rockbox/playback_options.tex
@@ -287,6 +287,11 @@ you to configure settings related to audio playback.
   if a track ends, which can be achieved by combining this option with
   \setting{Repeat} set to \setting{One}
 
+\section{Rewind Across Tracks}\index{Rewind Across Tracks}
+  Enables rewinding to the end of the previous track. When enabled pressing rewind
+  at the very beginning of the current track (first 3 seconds) skips to the end of
+  the previous track.
+
 \section{Rewind Before Resume}\index{Rewind Before Resume}
   When restarting a track or a bookmark, a short rewind can be done before the
   playback is started. This can be useful when listening to speech material,