...

src/calibre/gui2/tag_view.py

@@ -398,14 +398,18 @@ class TagsView(QTreeView): # {{{
         index = self.indexAt(event.pos())
         if not index.isValid():
             return
+        src_is_tb = event.mimeData().hasFormat('application/calibre+from_tag_browser')
         item = index.internalPointer()
         flags = self._model.flags(index)
         if item.type == TagTreeItem.TAG and flags & Qt.ItemIsDropEnabled:
-            self.setDropIndicatorShown(True)
+            self.setDropIndicatorShown(not src_is_tb)
         else:
             if item.type == TagTreeItem.CATEGORY:
                 fm_dest = self.db.metadata_for_field(item.category_key)
                 if fm_dest['kind'] == 'user':
+                    if src_is_tb:
+                        self.setDropIndicatorShown(True)
+                        return
                     md = event.mimeData()
                     if hasattr(md, 'column_name'):
                         fm_src = self.db.metadata_for_field(md.column_name)
@@ -674,8 +678,17 @@ class TagsModel(QAbstractItemModel): # {{{
         for idx in indexes:
             if idx.isValid():
                 # get some useful serializable data
-                name = unicode(self.data(idx, Qt.DisplayRole).toString())
+                node = idx.internalPointer()
-                data.append(name)
+                if node.type == TagTreeItem.CATEGORY:
+                    d = (node.type, node.py_name, node.category_key)
+                else:
+                    t = node.tag
+                    p = node
+                    while p.type != TagTreeItem.CATEGORY:
+                        p = p.parent
+                    d = (node.type, p.category_key,
+                         getattr(t, 'original_name', t.name), t.category, t.id)
+                data.append(d)
             else:
                 data.append(None)
         raw = bytearray(cPickle.dumps(data, -1))
@@ -688,6 +701,53 @@ class TagsModel(QAbstractItemModel): # {{{
         if not fmts.intersection(set(self.mimeTypes())) or \
                 action != Qt.CopyAction:
             return False
+        if "application/calibre+from_library" in fmts:
+            return self.do_drop_from_library(md, action, row, column, parent)
+        elif 'application/calibre+from_tag_browser' in fmts:
+            return self.do_drop_from_tag_browser(md, action, row, column, parent)
+
+    def do_drop_from_tag_browser(self, md, action, row, column, parent):
+        if not parent.isValid():
+            return False
+        dest = parent.internalPointer()
+        if dest.type != TagTreeItem.CATEGORY:
+            return False
+        if not md.hasFormat('application/calibre+from_tag_browser'):
+            return False
+        data = str(md.data('application/calibre+from_tag_browser'))
+        src = cPickle.loads(data)
+        for s in src:
+            if s[0] != TagTreeItem.TAG:
+                return False
+        user_cats = self.db.prefs.get('user_categories', {})
+        for s in src:
+            src_parent, src_name, src_cat = s[1:4]
+            src_parent = src_parent[1:]
+            dest_key = dest.category_key[1:]
+            if dest_key not in user_cats:
+                continue
+            new_cat = []
+            # delete the item if the source is a user category
+            if src_parent in user_cats:
+                for tup in user_cats[src_parent]:
+                    if src_name == tup[0] and src_cat == tup[1]:
+                        continue
+                    new_cat.append(list(tup))
+                user_cats[src_parent] = new_cat
+            # Now add the item to the destination user category
+            add_it = True
+            for tup in user_cats[dest_key]:
+                if src_name == tup[0] and src_cat == tup[1]:
+                    add_it = False
+            if add_it:
+                user_cats[dest_key].append([src_name, src_cat, 0])
+        self.db.prefs.set('user_categories', user_cats)
+        path = self.path_for_index(parent)
+        self.tags_view.set_new_model()
+        self.tags_view.model().show_item_at_path(path)
+        return True
+
+    def do_drop_from_library(self, md, action, row, column, parent):
         idx = parent
         if idx.isValid():
             node = self.data(idx, Qt.UserRole)
@@ -1102,6 +1162,7 @@ class TagsModel(QAbstractItemModel): # {{{
         if index.isValid():
             node = self.data(index, Qt.UserRole)
             if node.type == TagTreeItem.TAG:
+                if getattr(node.tag, 'can_edit', True):
                     ans |= Qt.ItemIsDragEnabled
                 fm = self.db.metadata_for_field(node.tag.category)
                 if node.tag.category in \

src/calibre/manual/gui.rst

@@ -431,6 +431,8 @@ User categories can have sub-categories. For example, the user category Favorite
 
 It is also possible to create hierarchies inside some of the built-in categories (the text categories). These hierarchies show with the small triangle permitting the sub-items to be hidden. To use hierarchies in a category, you must first go to Preferences / Look & Feel and enter the category name(s) into the "Categories with hierarchical items" box. Once this is done, items in that category that contain periods will be shown using the small triangle. For example, assume you create a custom column called "Genre" and indicate that it contains hierarchical items. Once done, items such as Mystery.Thriller and Mystery.English will display as Mystery with the small triangle next to it. Clicking on the triangle will show Thriller and English as sub-items.
 
+You can drag and drop items in the Tag browser onto user categories to add them to that category.
+
 
 Jobs
 -----