Remove custom drag-motion management

The GTK+ issue that needed this hack is fixed since 2.24.7
Also the hack did not manage the scroll nor the expand which is now managed by
GTK+ internals.

issue5026
review16671002

tryton/gui/window/view_form/view/list.py

@@ -600,20 +600,25 @@ class ViewTree(View):
         if not dnd:
             return
 
+        self.treeview.enable_model_drag_dest(
+            [('MY_TREE_MODEL_ROW', gtk.TARGET_SAME_WIDGET, 0)],
+            gtk.gdk.ACTION_MOVE)
+        self.treeview.enable_model_drag_source(
+            gtk.gdk.BUTTON1_MASK | gtk.gdk.BUTTON3_MASK,
+            [('MY_TREE_MODEL_ROW', gtk.TARGET_SAME_WIDGET, 0)],
+            gtk.gdk.ACTION_MOVE)
+        # XXX have to set manually because enable_model_drag_source
+        # does not set the mask
+        # https://bugzilla.gnome.org/show_bug.cgi?id=756177
         self.treeview.drag_source_set(
             gtk.gdk.BUTTON1_MASK | gtk.gdk.BUTTON3_MASK,
             [('MY_TREE_MODEL_ROW', gtk.TARGET_SAME_WIDGET, 0)],
             gtk.gdk.ACTION_MOVE)
-        self.treeview.drag_dest_set(gtk.DEST_DEFAULT_ALL,
-            [('MY_TREE_MODEL_ROW', gtk.TARGET_SAME_WIDGET, 0)],
-            gtk.gdk.ACTION_MOVE)
 
-        self.treeview.connect('drag-begin', self.drag_begin)
-        self.treeview.connect('drag-motion', self.drag_motion)
-        self.treeview.connect('drag-drop', self.drag_drop)
         self.treeview.connect("drag-data-get", self.drag_data_get)
         self.treeview.connect('drag-data-received',
             self.drag_data_received)
+        self.treeview.connect('drag-drop', self.drag_drop)
         self.treeview.connect('drag-data-delete', self.drag_data_delete)
 
     @property
@@ -760,27 +765,6 @@ class ViewTree(View):
         self.screen.current_record = record
         self.screen.display(set_cursor=True)
 
-    def drag_begin(self, treeview, context):
-        return True
-
-    def drag_motion(self, treeview, context, x, y, time):
-        try:
-            treeview.set_drag_dest_row(*treeview.get_dest_row_at_pos(x, y))
-        except TypeError:
-            treeview.set_drag_dest_row(len(treeview.get_model()) - 1,
-                gtk.TREE_VIEW_DROP_AFTER)
-        if context.get_source_widget() == treeview:
-            kind = gtk.gdk.ACTION_MOVE
-        else:
-            kind = gtk.gdk.ACTION_COPY
-        context.drag_status(kind, time)
-        return True
-
-    def drag_drop(self, treeview, context, x, y, time):
-        treeview.emit_stop_by_name('drag-drop')
-        treeview.drag_get_data(context, context.targets[-1], time)
-        return True
-
     def drag_data_get(self, treeview, context, selection, target_id,
             etime):
         treeview.emit_stop_by_name('drag-data-get')
@@ -856,6 +840,11 @@ class ViewTree(View):
             record.group.set_sequence(field=self.attributes['sequence'])
         return True
 
+    def drag_drop(self, treeview, context, x, y, time):
+        treeview.emit_stop_by_name('drag-drop')
+        treeview.drag_get_data(context, context.targets[-1], time)
+        return True
+
     def drag_data_delete(self, treeview, context):
         treeview.emit_stop_by_name('drag-data-delete')