Remove recreate tree method.

Removing and recreating tree isn't very efficient, so for operations
like adding new directory or removing items from the store, only
affected rows are changed (added or removed from the treestore).

gtkpass.py

@@ -163,12 +163,6 @@ class GTKPass(Gtk.Window):
                 child.show() if set_visible else child.hide()
         self.textview.show() if set_visible else self.textview.hide()
 
-    def recreate_tree_store(self):
-        self.passs.gather_pass_tree()
-        self.tree_store.clear()
-        self.add_nodes(self.passs.data, None)
-        self.refresh()
-
     def create_toolbar(self):
         toolbar = Gtk.Toolbar()
 
@@ -329,10 +323,8 @@ class GTKPass(Gtk.Window):
 
     def on_new_dir(self, button):
         if self._selected is None:
-            print('none selected')
             path = ''
         else:
-            print(f'{self._selected} selected')
             path = self._selected
 
         dialog = NewDirDialog(self, path)
@@ -340,7 +332,7 @@ class GTKPass(Gtk.Window):
         dirname = dialog.get_dirname()
         dialog.destroy()
 
-        if response != Gtk.ResponseType.OK:
+        if response != Gtk.ResponseType.OK or not dirname:
             return
 
         result, msg = self.passs.new_dir(os.path.join(path, dirname))
@@ -350,11 +342,22 @@ class GTKPass(Gtk.Window):
                                        message_type=Gtk.MessageType.INFO,
                                        buttons=Gtk.ButtonsType.CLOSE,
                                        text='There was an error')
+
             dialog.format_secondary_text(msg)
             dialog.run()
             dialog.destroy()
 
-        self.recreate_tree_store()
+        selection = self.treeview.get_selection()
+        if not selection:
+            return
+        tree_model_filter, tree_paths = selection.get_selected_rows()
+        tree_store = tree_model_filter.get_model()
+        tree_iter = tree_store.get_iter(tree_paths[0])
+
+        self.tree_store.append(tree_iter, [True, dirname,
+                                           Pango.Weight.NORMAL, "folder",
+                                           os.path.join(path, dirname), False])
+
 
     def on_delete(self, button):
         if not self._selected:
@@ -385,7 +388,16 @@ class GTKPass(Gtk.Window):
             dialog.format_secondary_text(msg)
             dialog.run()
             dialog.destroy()
-        self.recreate_tree_store()
+        self._selected = None
+
+        # remove selected branch/leaf from store
+        selection = self.treeview.get_selection()
+        tree_model_filter, tree_paths = selection.get_selected_rows()
+        tree_store = tree_model_filter.get_model()
+
+        for path in tree_paths:
+            tree_iter = tree_store.get_iter(path)
+            tree_store.remove(tree_iter)
 
     def on_key_press_event(self, widget, event):
         ctrl = (event.state & Gdk.ModifierType.CONTROL_MASK)