From 3ec02b57cb3861d19f31810b582c507604d12fe6 Mon Sep 17 00:00:00 2001
From: Stephen Johnson <stephenjohnsonm@gmail.com>
Date: Sun, 27 Sep 2020 00:23:27 +0900
Subject: [PATCH] Guarantee previous track return where seek supported

---
 README.md          |   5 +++
 dbus/get_property  |   4 +-
 plugin/vimedia.vim | 108 +++++++++++++++++++++++++--------------------
 3 files changed, 67 insertions(+), 50 deletions(-)

diff --git a/README.md b/README.md
index b0a9d97..086b6a4 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,11 @@ for now I've just tried to cover those places that throw errors when unavailable
 Rhythmbox is an example of a fully-implemented player, while a player like chromium 
 is still very limited in terms of supported functionality.
 
+For players that support the `Seek` command, `Prev` will return to the previous
+track regardless of the position of the current track. If `Seek` is not
+supported, `Prev` will only return to the previous track if the command is
+called within the first few seconds of playback (default MPRIS behavior).
+
 ## Config
 To configure a default media player, add a line like the following to your
 vimrc dotfile:
diff --git a/dbus/get_property b/dbus/get_property
index 6a83b21..b698d3e 100755
--- a/dbus/get_property
+++ b/dbus/get_property
@@ -4,7 +4,7 @@ case $2 in
 "Volume")
     sed_pattern="/double/{s/[[:alpha:]-]//g;s/^\s*//g;p}"
     ;;
-"Shuffle")
+"Shuffle"|"CanSeek")
     sed_pattern="/boolean/{s/variant//g;s/boolean//g;s/^\s*//g;p}"
     ;;
 "Position")
@@ -22,4 +22,4 @@ dbus-send \
 /org/mpris/MediaPlayer2 \
 org.freedesktop.DBus.Properties.Get \
 string:'org.mpris.MediaPlayer2.Player' \
-string:$2 | sed -ne "$sed_pattern"
\ No newline at end of file
+string:$2 | sed -ne "$sed_pattern"
diff --git a/plugin/vimedia.vim b/plugin/vimedia.vim
index 1e87bbd..b1c3a68 100644
--- a/plugin/vimedia.vim
+++ b/plugin/vimedia.vim
@@ -52,7 +52,7 @@ fu! s:QuitCmd(player)
 endfu
 
 " *************************************************************************** "
-" **********************   D-Bus Command Callbacks   ************************ "
+" *************************   Command Callbacks   *************************** "
 " *************************************************************************** "
 
 fu! s:SetPlayerCallback(channel, msg)
@@ -96,6 +96,18 @@ fu! s:PauseAllCallback(channel, msg)
   call s:PauseAllPlayers(a:msg)
 endfu
 
+fu! s:PreviousCallback(channel, msg)
+  if a:msg == "true"
+    call job_start(s:SeekCmd(s:selected_player, -1 * s:ticker_microseconds), {"callback": function("s:SeekStartCallback")})
+  else
+    call job_start(s:ControlPlaybackCmd(s:selected_player, "Previous"))
+  endif
+endfu
+
+fu! s:SeekStartCallback(channel, msg)
+  call job_start(s:ControlPlaybackCmd(s:selected_player, "Previous"))
+endfu
+
 fu! s:MuteCallback(channel, msg)
   call s:SetVolumeAll(a:msg, 0.0)
 endfu
@@ -138,7 +150,7 @@ fu! s:QuitCallback(channel, msg)
 endfu
 
 " *************************************************************************** "
-" **************************   Timer Functions   **************************** "
+" *************************   Base Functionality   ************************** "
 " *************************************************************************** "
 
 fu! s:init_now_playing_config()
@@ -149,51 +161,6 @@ endfu
 
 call s:init_now_playing_config()
 
-fu! s:Refresh(timer)
-  if s:selected_player == "N/A"
-    return
-  endif
-
-  call job_start(s:GetPropertyCmd(s:selected_player, "Position"), {"out_cb": function("s:GetPositionCallback")})
-  call job_start(s:GetMetadataCmd(s:selected_player, "Title"), {"out_cb": function("s:GetTitleCallback")})
-  call job_start(s:GetMetadataCmd(s:selected_player, "Artist"), {"out_cb": function("s:GetArtistCallback")})
-endfu
-
-fu! NowPlayingText()
-  return s:current_track_name . " - " . s:current_artist_name
-endfu
-
-fu! PlaybackTicker()
-  let l:pos_seconds = s:ticker_microseconds / 1000000
-  let l:min = l:pos_seconds / 60
-  let l:sec = l:pos_seconds - (l:min * 60)
-  return l:min . ":" . (l:sec > 9 ? l:sec : ("0" . l:sec))
-endfu
-
-fu! s:UpdateStatusline(timer)
-  if g:vimedia_statusline_enabled == 0
-    return
-  endif
-
-  if s:selected_player == "N/A" || s:current_artist_name == "N/A" || s:current_track_name == "N/A"
-    return
-  endif
-
-  set statusline=
-  set statusline+=\%{NowPlayingText()}
-  set statusline+=%=
-  set statusline+=\%{PlaybackTicker()}
-endfu
-
-"" Refresh track/artist name and playback ticker every half-second
-let timer = timer_start(500, function('s:Refresh'), {'repeat':-1})
-"" Update the status line each second with the latest playback info 
-let timer = timer_start(1000, function('s:UpdateStatusline'), {'repeat':-1})
-
-" *************************************************************************** "
-" *************************   Base Functionality   ************************** "
-" *************************************************************************** "
-
 fu! s:init_player_config()
   let s:selected_player_abbrev = ""
 
@@ -240,7 +207,7 @@ fu! s:Skip() abort
 endfu
 
 fu! s:Previous() abort
-  call job_start(s:ControlPlaybackCmd(s:selected_player, "Previous"))
+  call job_start(s:GetPropertyCmd(s:selected_player, "CanSeek"), {"out_cb": function("s:PreviousCallback")})
 endfu
 
 fu! s:Seek(duration_seconds) abort
@@ -347,6 +314,51 @@ fu! s:CheckPlayer(fn, ...) abort
   endif
 endfu
 
+" *************************************************************************** "
+" **************************   Timer Functions   **************************** "
+" *************************************************************************** "
+
+fu! s:Refresh(timer)
+  if s:selected_player == "N/A"
+    return
+  endif
+
+  call job_start(s:GetPropertyCmd(s:selected_player, "Position"), {"out_cb": function("s:GetPositionCallback")})
+  call job_start(s:GetMetadataCmd(s:selected_player, "Title"), {"out_cb": function("s:GetTitleCallback")})
+  call job_start(s:GetMetadataCmd(s:selected_player, "Artist"), {"out_cb": function("s:GetArtistCallback")})
+endfu
+
+fu! NowPlayingText()
+  return s:current_track_name . " - " . s:current_artist_name
+endfu
+
+fu! PlaybackTicker()
+  let l:pos_seconds = s:ticker_microseconds / 1000000
+  let l:min = l:pos_seconds / 60
+  let l:sec = l:pos_seconds - (l:min * 60)
+  return l:min . ":" . (l:sec > 9 ? l:sec : ("0" . l:sec))
+endfu
+
+fu! s:UpdateStatusline(timer)
+  if g:vimedia_statusline_enabled == 0
+    return
+  endif
+
+  if s:selected_player == "N/A" || s:current_artist_name == "N/A" || s:current_track_name == "N/A"
+    return
+  endif
+
+  set statusline=
+  set statusline+=\%{NowPlayingText()}
+  set statusline+=%=
+  set statusline+=\%{PlaybackTicker()}
+endfu
+
+"" Refresh track/artist name and playback ticker every half-second
+let timer = timer_start(500, function('s:Refresh'), {'repeat':-1})
+"" Update the status line each second with the latest playback info
+let timer = timer_start(1000, function('s:UpdateStatusline'), {'repeat':-1})
+
 " *************************************************************************** "
 " ***************************   Command Bindngs   *************************** " 
 " *************************************************************************** "