[#2670] [GTKUI] optimize file trees according to pygtk tips

Use a context manager to wrap the common steps:

1) disconnect the treestore from the listview
2) disable treestore sorting
3) add rows (different in add dialog vs files tab)
4) enable treestore sorting
5) connect model to listview

deluge/ui/gtkui/addtorrentdialog.py

@@ -24,7 +24,7 @@ from deluge.configmanager import ConfigManager
 from deluge.httpdownloader import download_file
 from deluge.ui.client import client
 from deluge.ui.common import TorrentInfo
-from deluge.ui.gtkui.common import reparent_iter
+from deluge.ui.gtkui.common import listview_replace_treestore, reparent_iter
 from deluge.ui.gtkui.dialogs import ErrorDialog
 from deluge.ui.gtkui.path_chooser import PathChooser
 from deluge.ui.gtkui.torrentview_data_funcs import cell_data_size
@@ -275,17 +275,13 @@ class AddTorrentDialog(component.Component):
         self.save_torrent_options()
 
     def prepare_file_store(self, files):
-        self.listview_files.set_model(None)
-        self.files_treestore.clear()
+        with listview_replace_treestore(self.listview_files):
             split_files = {}
-        i = 0
-        for file in files:
+            for i, file in enumerate(files):
                 self.prepare_file(
                     file, file["path"], i, file["download"], split_files
                 )
-            i += 1
             self.add_files(None, split_files)
-        self.listview_files.set_model(self.files_treestore)
         self.listview_files.expand_row("0", False)
 
     def prepare_file(self, file, file_name, file_num, download, files_storage):

deluge/ui/gtkui/common.py

@@ -8,6 +8,7 @@
 #
 """Common functions for various parts of gtkui to use."""
 
+import contextlib
 import cPickle
 import logging
 import os
@@ -267,3 +268,29 @@ def load_pickled_state_file(filename):
         else:
             log.info("Successfully loaded %s: %s", filename, _filepath)
             return state
+
+
+@contextlib.contextmanager
+def listview_replace_treestore(listview):
+    """Prepare a listview's treestore to be entirely replaced.
+
+    Params:
+        listview: a listview backed by a treestore
+    """
+    # From http://faq.pygtk.org/index.py?req=show&file=faq13.043.htp
+    # "tips for improving performance when adding many rows to a Treeview"
+    listview.freeze_child_notify()
+    treestore = listview.get_model()
+    listview.set_model(None)
+    treestore.clear()
+    treestore.set_default_sort_func(lambda *args: 0)
+    original_sort = treestore.get_sort_column_id()
+    treestore.set_sort_column_id(-1, gtk.SORT_ASCENDING)
+
+    yield
+
+    if original_sort != (None, None):
+        treestore.set_sort_column_id(*original_sort)
+
+    listview.set_model(treestore)
+    listview.thaw_child_notify()

deluge/ui/gtkui/files_tab.py

@@ -18,7 +18,8 @@ import gtk.gdk
 import deluge.component as component
 from deluge.common import FILE_PRIORITY, open_file, show_file
 from deluge.ui.client import client
-from deluge.ui.gtkui.common import load_pickled_state_file, reparent_iter, save_pickled_state_file
+from deluge.ui.gtkui.common import (listview_replace_treestore, load_pickled_state_file, reparent_iter,
+                                    save_pickled_state_file)
 from deluge.ui.gtkui.torrentdetails import Tab
 from deluge.ui.gtkui.torrentview_data_funcs import cell_data_size
 
@@ -376,7 +377,7 @@ class FilesTab(Tab):
         return ret
 
     def update_files(self):
-        self.treestore.clear()
+        with listview_replace_treestore(self.listview):
             self.prepare_file_store(self.files_list[self.torrent_id])
         self.listview.expand_row("0", False)