Import only the needed backend

The activity only open one tipe of file at time, but was importing
all the backends. Now import the needed backend after having the mimetype,
to have better startup times and lower memory use.

Signed-off-by: Gonzalo Odiard <gonzalo@laptop.org>

1 files changed, 6 insertions, 3 deletions

diff --git a/readactivity.py b/readactivity.py
index 201f90b..bfcedb1 100644
--- a/readactivity.py
+++ b/readactivity.py
@@ -28,6 +28,9 @@ import dbus
 from gi.repository import GObject
 from gi.repository import Gtk
 from gi.repository import Gdk
+
+GObject.threads_init()
+
 import telepathy
 
 from sugar3.activity import activity
@@ -51,9 +54,6 @@ from readtoolbar import SpeechToolbar
 from readsidebar import Sidebar
 from readtopbar import TopBar
 from readdb import BookmarkManager
-import epubadapter
-import evinceadapter
-import textadapter
 import speech
 from sugarmenuitem import SugarMenuItem
 
@@ -788,10 +788,13 @@ class ReadActivity(activity.Activity):
             return
         mimetype = mime.get_for_file(filepath)
         if mimetype == 'application/epub+zip':
+            import epubadapter
             self._view = epubadapter.EpubViewer()
         elif mimetype == 'text/plain' or mimetype == 'application/zip':
+            import textadapter
             self._view = textadapter.TextViewer()
         else:
+            import evinceadapter
             self._view = evinceadapter.EvinceViewer()
 
         self._view.setup(self)