fix several drag-and-drop usability issues

1) drag and drop of an item from the item pane "into" a menu item of the
item pane

2) moving a separator item from the item pane "into" a menu item of the
"menu pane"

3) dragging an item from the item pane to another position in the item
pane (between two other items)

https://bugzilla.gnome.org/show_bug.cgi?id=611278

2 files changed, 37 insertions, 13 deletions

diff --git a/Mozo/MainWindow.py b/Mozo/MainWindow.py
index c6fa109..b7c1ab6 100644
--- a/Mozo/MainWindow.py
+++ b/Mozo/MainWindow.py
@@ -431,6 +431,8 @@ class MainWindow:
 				elif item.get_type() == matemenu.TYPE_DIRECTORY:
 					if self.editor.moveMenu(item, new_parent) == False:
 						self.loadUpdates()
+				elif item.get_type() == matemenu.TYPE_SEPARATOR:
+					self.editor.moveSeparator(item, new_parent)
 				else:
 					context.finish(False, False, etime) 
 				context.finish(True, True, etime)
@@ -507,7 +509,9 @@ class MainWindow:
 
 	def on_item_tree_drag_data_received(self, treeview, context, x, y, selection, info, etime):
 		items = treeview.get_model()
-		types = (Gtk.TreeViewDropPosition.BEFORE,	Gtk.TreeViewDropPosition.INTO_OR_BEFORE)
+		types_before = (Gtk.TreeViewDropPosition.BEFORE, Gtk.TreeViewDropPosition.INTO_OR_BEFORE)
+		types_into = (Gtk.TreeViewDropPosition.INTO_OR_BEFORE, Gtk.TreeViewDropPosition.INTO_OR_AFTER)
+		types_after = (Gtk.TreeViewDropPosition.AFTER, Gtk.TreeViewDropPosition.INTO_OR_AFTER)
 		if str(selection.get_target()) == 'MOZO_ITEM_ROW':
 			drop_info = treeview.get_dest_row_at_pos(x, y)
 			before = None
@@ -515,22 +519,32 @@ class MainWindow:
 			if self.drag_data == None:
 				return False
 			item = self.drag_data
+			# by default we assume, that the items stays in the same menu
+			destination = item.get_parent()
 			if drop_info:
 				path, position = drop_info
-				if position in types:
-					before = items[path][3]
+				target = items[path][3]
+				# move the item to the directory, if the item was dropped into it
+				if (target.get_type() == matemenu.TYPE_DIRECTORY) and (position in types_into):
+					# append the selected item to the choosen menu
+					destination = target
+				elif position in types_before:
+					before = target
+				elif position in types_after:
+					after = target
 				else:
-					after = items[path][3]
+					# this does not happen
+					pass
 			else:
 				path = (len(items) - 1,)
 				after = items[path][3]
 			if item.get_type() == matemenu.TYPE_ENTRY:
-				self.editor.moveItem(item, item.get_parent(), before, after)
+				self.editor.moveItem(item, destination, before, after)
 			elif item.get_type() == matemenu.TYPE_DIRECTORY:
-				if self.editor.moveMenu(item, item.get_parent(), before, after) == False:
+				if self.editor.moveMenu(item, destination, before, after) == False:
 					self.loadUpdates()
 			elif item.get_type() == matemenu.TYPE_SEPARATOR:
-				self.editor.moveSeparator(item, item.get_parent(), before, after)
+				self.editor.moveSeparator(item, destination, before, after)
 			context.finish(True, True, etime)
 		elif str(selection.get_target()) == 'text/plain':
 			if selection.data == None:
diff --git a/Mozo/MenuEditor.py b/Mozo/MenuEditor.py
index af7ee4f..79aaf1e 100644
--- a/Mozo/MenuEditor.py
+++ b/Mozo/MenuEditor.py
@@ -343,8 +343,15 @@ class MenuEditor:
 		self.save()
 
 	def moveSeparator(self, separator, new_parent, before=None, after=None):
+		undo = []
+		# remove the original separator if its parent is not the new destination
+		if separator.get_parent() != new_parent:
+			self.deleteSeparator(separator)
+			undo.append(separator)
+		# this adds the new separator to the specified position
 		self.__positionItem(new_parent, separator, before, after)
-		self.__addUndo([self.__getMenu(new_parent),])
+		undo.append(self.__getMenu(new_parent))
+		self.__addUndo(undo)
 		self.save()
 
 	def deleteItem(self, item):
@@ -690,18 +697,21 @@ class MenuEditor:
 		self.__addXmlFilename(xml_parent, dom, file_id, 'Exclude')
 
 	def __positionItem(self, parent, item, before=None, after=None):
-		if not before and not after:
-			return
 		if after:
 			index = parent.contents.index(after) + 1
 		elif before:
 			index = parent.contents.index(before)
+		else:
+			# append the item to the list
+			index = len(parent.contents)
 		contents = parent.contents
 		#if this is a move to a new parent you can't remove the item
-		try:
+		if item in contents:
+			# decrease the destination index, if we shorten the list
+			if (before and (contents.index(item) < index)) \
+			    or (after and (contents.index(item) < index - 1)):
+				index -= 1
 			contents.remove(item)
-		except:
-			pass
 		contents.insert(index, item)
 		layout = self.__createLayout(contents)
 		dom = self.__getMenu(parent).dom