Try to default to a video player that's available

Part of #136

aeidon/enums.py

@@ -19,6 +19,7 @@
 
 import aeidon
 import os
+import shutil
 import sys
 
 from aeidon.i18n import _
@@ -159,6 +160,7 @@ class PlayerMPlayer(aeidon.EnumerationItem):
         # http://www.mplayerhq.hu/DOCS/HTML/en/faq.html#idm5930
         command_utf_8 = "{} < /dev/null".format(command_utf_8)
 
+    found = shutil.which(_get_mplayer_executable()) is not None
     label = "MPlayer"
 
 class PlayerMPV(aeidon.EnumerationItem):
@@ -179,6 +181,7 @@ class PlayerMPV(aeidon.EnumerationItem):
                               "--sub-codepage=utf-8",
                               "$VIDEOFILE",))
 
+    found = shutil.which(_get_mpv_executable()) is not None
     label = "mpv"
 
 class PlayerVLC(aeidon.EnumerationItem):
@@ -193,6 +196,7 @@ class PlayerVLC(aeidon.EnumerationItem):
                               ":sub-file=$SUBFILE",
                               ":subsdec-encoding=UTF-8",))
 
+    found = shutil.which(_get_vlc_executable()) is not None
     label = "VLC"
 
 players = aeidon.Enumeration()

gaupol/config.py

@@ -143,10 +143,9 @@
     "preview": {
         "custom_command": "",
         "force_utf_8": True,
-        "offset": (5.0 if sys.platform == "win32" else 1.0),
-        "player": (aeidon.players.VLC if sys.platform == "win32"
-                   else aeidon.players.MPV),
-
+        # mpv is the only player that supports precise seek, others need a longer offset.
+        "offset": 1.0 if gaupol.util.get_default_player() == aeidon.players.MPV else 5.0,
+        "player": gaupol.util.get_default_player(),
         "use_custom_command": False,
     },
     "search": {

gaupol/util.py

@@ -69,6 +69,12 @@ def get_content_size(widget, font=None):
     raise ValueError("Unsupported container type: {!r}"
                      .format(type(widget)))
 
+def get_default_player():
+    """Return the default video player to use for preview."""
+    players = [aeidon.players.MPV, aeidon.players.MPLAYER, aeidon.players.VLC]
+    players = [x for x in players if x.found]
+    return players[0] if players else aeidon.players.MPV
+
 def get_font():
     """Return custom font or blank string."""
     return (gaupol.conf.editor.custom_font if