Tag browser: Improve handling of hierarchical tags

Renaming a tag now renames it and all its children. Drag and drop of
hierarchical tags alters their hierarchy. Deleting a tag now deletes all
its children.

Fixes #1880264 [[Enhancement] Additional functionality for tag hierarchies](https://bugs.launchpad.net/calibre/+bug/1880264)

Merge branch 'master' of https://github.com/cbhaley/calibre

src/calibre/gui2/tag_browser/model.py

@@ -59,6 +59,8 @@ class TagTreeItem(object):  # {{{
         self.blank = QIcon()
         self.is_gst = False
         self.boxed = False
+        self.temporary = False
+        self.can_be_edited = False
         self.icon_state_map = list(icon_map)
         if self.parent is not None:
             self.parent.append(self)
@@ -113,9 +115,9 @@ class TagTreeItem(object):  # {{{
         if self.type == self.ROOT:
             return 'ROOT'
         if self.type == self.CATEGORY:
-            return 'CATEGORY(category_key={!r}, name={!r}, num_children={!r})'.format(
+            return 'CATEGORY(category_key={!r}, name={!r}, num_children={!r}, temp={!r})'.format(
-                self.category_key, self.name, len(self.children))
+                self.category_key, self.name, len(self.children), self.temporary)
-        return 'TAG(name=%r)'%self.tag.name
+        return 'TAG(name={!r}), temp={!r})'.format(self.tag.name, self.temporary)
 
     def row(self):
         if self.parent is not None:
@@ -390,6 +392,7 @@ class TagsModel(QAbstractItemModel):  # {{{
         del node  # Clear reference to node in the current frame
         self.node_map.clear()
         self.category_nodes = []
+        self.hierarchical_categories = {}
         self.root_item = self.create_node(icon_map=self.icon_state_map)
         self._rebuild_node_tree(state_map=state_map)
 
@@ -538,10 +541,7 @@ class TagsModel(QAbstractItemModel):  # {{{
             top_level_component = 'z' + data[key][0].original_name
 
             last_idx = -collapse
-            category_is_hierarchical = not (
+            category_is_hierarchical = self.is_key_a_hierarchical_category(key)
-                key in ['authors', 'publisher', 'news', 'formats', 'rating'] or
-                key not in self.db.prefs.get('categories_using_hierarchy', []) or
-                config['sort_tags_by'] != 'name')
 
             for idx,tag in enumerate(data[key]):
                 components = None
@@ -573,7 +573,13 @@ class TagsModel(QAbstractItemModel):  # {{{
                                 d['first'] = ct2
                             else:
                                 d = {'first': tag}
+                                # Some nodes like formats and identifiers don't
+                                # have sort set. Fix that so the template will work
+                                if d['first'].sort is None:
+                                    d['first'].sort = tag.name
                                 d['last'] = data[key][last]
+                                if d['last'].sort is None:
+                                    d['last'].sort = data[key][last].name
 
                             name = eval_formatter.safe_format(collapse_template,
                                                         d, '##TAG_VIEW##', None)
@@ -716,6 +722,22 @@ class TagsModel(QAbstractItemModel):  # {{{
             p = p.parent
         return p.tag.category.startswith('@')
 
+    def is_key_a_hierarchical_category(self, key):
+        result = self.hierarchical_categories.get(key)
+        if result is None:
+            result = not (
+                    key in ['authors', 'publisher', 'news', 'formats', 'rating'] or
+                    key not in self.db.prefs.get('categories_using_hierarchy', []) or
+                    config['sort_tags_by'] != 'name')
+            self.hierarchical_categories[key] = result
+        return result
+
+    def is_index_on_a_hierarchical_category(self, index):
+        if not index.isValid():
+            return False
+        p = self.get_node(index)
+        return self.is_key_a_hierarchical_category(p.tag.category)
+
     # Drag'n Drop {{{
     def mimeTypes(self):
         return ["application/calibre+from_library",
@@ -760,15 +782,46 @@ class TagsModel(QAbstractItemModel):  # {{{
         if not parent.isValid():
             return False
         dest = self.get_node(parent)
-        if dest.type != TagTreeItem.CATEGORY:
-            return False
         if not md.hasFormat('application/calibre+from_tag_browser'):
             return False
         data = bytes(md.data('application/calibre+from_tag_browser'))
         src = json_loads(data)
-        for s in src:
+        if len(src) == 1:
+            # Check to see if this is a hierarchical rename
+            s = src[0]
+            # This check works for both hierarchical and user categories.
+            # We can drag only tag items.
             if s[0] != TagTreeItem.TAG:
                 return False
+            src_index = self.index_for_path(s[5])
+            if src_index == parent:
+                # dropped on itself
+                return False
+            src_item = self.get_node(src_index)
+            dest_item = parent.data(Qt.UserRole)
+            # Here we do the real work. If src is a tag, src == dest, and src
+            # is hierarchical then we can do a rename.
+            if (src_item.type == TagTreeItem.TAG and
+                    src_item.tag.category == dest_item.tag.category and
+                    self.is_key_a_hierarchical_category(src_item.tag.category)):
+                key = s[1]
+                # work out the part of the source name to use in the rename
+                # It isn't necessarily a simple name but might be the remaining
+                # levels of the hierarchy
+                part = src_item.tag.original_name.rpartition('.')
+                src_simple_name = part[2]
+                # work out the new prefix, the destination node name
+                if dest.type == TagTreeItem.TAG:
+                    new_name = dest_item.tag.original_name + '.' + src_simple_name
+                else:
+                    new_name = src_simple_name
+                # In d&d renames always use the vl. This might be controversial.
+                src_item.use_vl = True
+                self.rename_item(src_item, key, new_name)
+                return True
+        # Should be working with a user category
+        if dest.type != TagTreeItem.CATEGORY:
+            return False
         return self.move_or_copy_item_to_user_category(src, dest, action)
 
     def move_or_copy_item_to_user_category(self, src, dest, action):
@@ -1134,7 +1187,6 @@ class TagsModel(QAbstractItemModel):  # {{{
             return True
 
         key = item.tag.category
-        name = item.tag.original_name
         # make certain we know about the item's category
         if key not in self.db.field_metadata:
             return False
@@ -1153,19 +1205,46 @@ class TagsModel(QAbstractItemModel):  # {{{
             item.tag.name = val
             self.search_item_renamed.emit()  # Does a refresh
         else:
-            self.use_position_based_index_on_next_recount = True
+            self.rename_item(item, key, val)
-            restrict_to_book_ids=self.get_book_ids_to_use() if item.use_vl else None
-            self.db.new_api.rename_items(key, {item.tag.id: val},
-                                         restrict_to_book_ids=restrict_to_book_ids)
-            self.tag_item_renamed.emit()
-            item.tag.name = val
-            item.tag.state = TAG_SEARCH_STATES['clear']
-            self.use_position_based_index_on_next_recount = True
-            if not restrict_to_book_ids:
-                self.rename_item_in_all_user_categories(name, key, val)
-            self.refresh_required.emit()
         return True
 
+    def rename_item(self, item, key, to_what):
+        def do_one_item(lookup_key, an_item, original_name, new_name, restrict_to_books):
+            self.use_position_based_index_on_next_recount = True
+            self.db.new_api.rename_items(lookup_key, {an_item.tag.id: new_name},
+                                         restrict_to_book_ids=restrict_to_books)
+            self.tag_item_renamed.emit()
+            an_item.tag.name = new_name
+            an_item.tag.state = TAG_SEARCH_STATES['clear']
+            self.use_position_based_index_on_next_recount = True
+            if not restrict_to_books:
+                self.rename_item_in_all_user_categories(original_name,
+                                                        lookup_key, new_name)
+
+        children = item.all_children()
+        restrict_to_book_ids=self.get_book_ids_to_use() if item.use_vl else None
+        if item.tag.is_editable and len(children) == 0:
+            # Leaf node, just do it.
+            do_one_item(key, item, item.tag.original_name, to_what, restrict_to_book_ids)
+        else:
+            # Middle node of a hierarchy
+            search_name = item.tag.original_name
+            # Clear any search icons on the original tag
+            if item.parent.type == TagTreeItem.TAG:
+                item.parent.tag.state = TAG_SEARCH_STATES['clear']
+            # It might also be a leaf
+            if item.tag.is_editable:
+                do_one_item(key, item, item.tag.original_name, to_what, restrict_to_book_ids)
+            # Now do the children
+            for child_item in children:
+                from calibre.utils.icu import startswith
+                if (child_item.tag.is_editable and
+                        startswith(child_item.tag.original_name, search_name)):
+                    new_name = to_what + child_item.tag.original_name[len(search_name):]
+                    do_one_item(key, child_item, child_item.tag.original_name,
+                                new_name, restrict_to_book_ids)
+        self.refresh_required.emit()
+
     def rename_item_in_all_user_categories(self, item_name, item_category, new_name):
         '''
         Search all User categories for items named item_name with category
@@ -1217,7 +1296,7 @@ class TagsModel(QAbstractItemModel):  # {{{
         if index.isValid():
             node = self.data(index, Qt.UserRole)
             if node.type == TagTreeItem.TAG:
-                if node.tag.is_editable:
+                if node.tag.is_editable or node.tag.is_hierarchical:
                     ans |= Qt.ItemIsDragEnabled
                 fm = self.db.metadata_for_field(node.tag.category)
                 if node.tag.category in \

src/calibre/gui2/tag_browser/ui.py

@@ -278,21 +278,46 @@ class TagBrowserMixin(object):  # {{{
                 self.do_tag_item_renamed()
                 self.tags_view.recount()
 
-    def do_tag_item_delete(self, category, item_id, orig_name, restrict_to_book_ids=None):
+    def do_tag_item_delete(self, category, item_id, orig_name,
+                           restrict_to_book_ids=None, children=[]):
         '''
         Delete an item from some category.
         '''
-        if restrict_to_book_ids:
+        tag_names = []
-            msg = _('%s will be deleted from books in the Virtual library. Are you sure?')%orig_name
+        for child in children:
+            if child.tag.is_editable:
+                tag_names.append(child.tag.original_name)
+        n = '\n   '.join(tag_names)
+        if n:
+            n = '%s:\n   %s\n%s:\n   %s'%(_('Item'), orig_name, _('Children'), n)
+        if n:
+            if restrict_to_book_ids:
+                msg = _('%s and its children will be deleted from books '
+                        'in the Virtual library. Are you sure?')%orig_name
+            else:
+                msg = _('%s and its children will be deleted from all books. '
+                        'Are you sure?')%orig_name
         else:
-            msg = _('%s will be deleted from all books. Are you sure?')%orig_name
+            if restrict_to_book_ids:
+                msg = _('%s will be deleted from books in the Virtual library. Are you sure?')%orig_name
+            else:
+                msg = _('%s will be deleted from all books. Are you sure?')%orig_name
+
         if not question_dialog(self.tags_view,
                     title=_('Delete item'),
                     msg='<p>'+ msg,
-                    skip_dialog_name='tag_item_delete',
+                    det_msg=n,
+                    # Change the skip name because functionality has greatly changed
+                    skip_dialog_name='tag_item_delete_hierarchical',
                     skip_dialog_msg=_('Show this confirmation again')):
             return
-        self.current_db.new_api.remove_items(category, (item_id,), restrict_to_book_ids=restrict_to_book_ids)
+        ids_to_remove = [item_id]
+        for child in children:
+            if child.tag.is_editable:
+                ids_to_remove.append(child.tag.id)
+
+        self.current_db.new_api.remove_items(category, ids_to_remove,
+                                             restrict_to_book_ids=restrict_to_book_ids)
         if restrict_to_book_ids is None:
             m = self.tags_view.model()
             m.delete_item_from_all_user_categories(orig_name, category)

src/calibre/gui2/tag_browser/view.py

@@ -153,7 +153,7 @@ class TagsView(QTreeView):  # {{{
     search_item_renamed     = pyqtSignal()
     drag_drop_finished      = pyqtSignal(object)
     restriction_error       = pyqtSignal()
-    tag_item_delete         = pyqtSignal(object, object, object, object)
+    tag_item_delete         = pyqtSignal(object, object, object, object, object)
     apply_tag_to_selected   = pyqtSignal(object, object, object)
 
     def __init__(self, parent=None):
@@ -320,6 +320,11 @@ class TagsView(QTreeView):  # {{{
         except:
             pass
 
+    def mousePressEvent(self, event):
+        if event.buttons() & Qt.LeftButton:
+            self.possible_drag_start = event.pos()
+        return QTreeView.mousePressEvent(self, event)
+
     def mouseMoveEvent(self, event):
         dex = self.indexAt(event.pos())
         if dex.isValid():
@@ -331,6 +336,11 @@ class TagsView(QTreeView):  # {{{
         if self.in_drag_drop or not dex.isValid():
             QTreeView.mouseMoveEvent(self, event)
             return
+        # don't start drag/drop until the mouse has moved a bit.
+        if ((event.pos() - self.possible_drag_start).manhattanLength() <
+                                    QApplication.startDragDistance()):
+            QTreeView.mouseMoveEvent(self, event)
+            return
         # Must deal with odd case where the node being dragged is 'virtual',
         # created to form a hierarchy. We can't really drag this node, but in
         # addition we can't allow drag recognition to notice going over some
@@ -345,7 +355,14 @@ class TagsView(QTreeView):  # {{{
         drag = QDrag(self)
         drag.setPixmap(pixmap)
         drag.setMimeData(md)
-        if self._model.is_in_user_category(dex):
+        if (self._model.is_in_user_category(dex) or
+                    self._model.is_index_on_a_hierarchical_category(dex)):
+            '''
+            Things break if we specify MoveAction as the default, which is
+            what we want for drag on hierarchical categories. Dragging user
+            categories stops working. Don't know why. To avoid the problem
+            we fix the action in dragMoveEvent.
+            '''
             drag.exec_(Qt.CopyAction|Qt.MoveAction, Qt.CopyAction)
         else:
             drag.exec_(Qt.CopyAction)
@@ -440,11 +457,17 @@ class TagsView(QTreeView):  # {{{
                 self.edit(index)
                 return
             if action == 'delete_item_in_vl':
-                self.tag_item_delete.emit(key, index.id, index.original_name,
+                tag = index.tag
-                                          self.model().get_book_ids_to_use())
+                children = index.child_tags()
+                self.tag_item_delete.emit(key, tag.id, tag.original_name,
+                                          self.model().get_book_ids_to_use(),
+                                          children)
                 return
             if action == 'delete_item_no_vl':
-                self.tag_item_delete.emit(key, index.id, index.original_name, None)
+                tag = index.tag
+                children = index.child_tags()
+                self.tag_item_delete.emit(key, tag.id, tag.original_name,
+                                          None, children)
                 return
             if action == 'open_editor':
                 self.tags_list_edit.emit(category, key, is_first_letter)
@@ -550,6 +573,8 @@ class TagsView(QTreeView):  # {{{
                 if len(n) > 45:
                     n = n[:45] + '...'
                 ans = "'" + n + "'"
+            elif tag.is_hierarchical and not tag.is_editable:
+                ans = tag.original_name
             if ans:
                 ans = ans.replace('&', '&&')
             return ans
@@ -582,8 +607,8 @@ class TagsView(QTreeView):  # {{{
                 if tag:
                     # If the user right-clicked on an editable item, then offer
                     # the possibility of renaming that item.
-                    if tag.is_editable:
+                    if tag.is_editable or tag.is_hierarchical:
-                        # Add the 'rename' items
+                        # Add the 'rename' items to both interior and leaf nodes
                         if self.model().get_in_vl():
                             self.context_menu.addAction(self.rename_icon,
                                                     _('Rename %s in Virtual library')%display_name(tag),
@@ -593,18 +618,19 @@ class TagsView(QTreeView):  # {{{
                                                 _('Rename %s')%display_name(tag),
                                 partial(self.context_menu_handler, action='edit_item_no_vl',
                                         index=index, category=key))
+                    if tag.is_editable:
                         if key in ('tags', 'series', 'publisher') or \
                                 self._model.db.field_metadata.is_custom_field(key):
                             if self.model().get_in_vl():
                                 self.context_menu.addAction(self.delete_icon,
                                                     _('Delete %s in Virtual library')%display_name(tag),
                                 partial(self.context_menu_handler, action='delete_item_in_vl',
-                                    key=key, index=tag))
+                                    key=key, index=tag_item))
 
                             self.context_menu.addAction(self.delete_icon,
                                                     _('Delete %s')%display_name(tag),
                                 partial(self.context_menu_handler, action='delete_item_no_vl',
-                                    key=key, index=tag))
+                                    key=key, index=tag_item))
                         if key == 'authors':
                             self.context_menu.addAction(_('Edit sort for %s')%display_name(tag),
                                     partial(self.context_menu_handler,
@@ -841,8 +867,20 @@ class TagsView(QTreeView):  # {{{
         item = index.data(Qt.UserRole)
         if item.type == TagTreeItem.ROOT:
             return
-        flags = self._model.flags(index)
+
-        if item.type == TagTreeItem.TAG and flags & Qt.ItemIsDropEnabled:
+        if src_is_tb:
+            src = json_loads(bytes(event.mimeData().data('application/calibre+from_tag_browser')))
+            if len(src) == 1:
+                src_item = self._model.get_node(self._model.index_for_path(src[0][5]))
+                if (src_item.type == TagTreeItem.TAG and
+                        src_item.tag.category == item.tag.category and
+                        not item.temporary and
+                        self._model.is_key_a_hierarchical_category(src_item.tag.category)):
+                    event.setDropAction(Qt.MoveAction)
+                    self.setDropIndicatorShown(True)
+                    return
+        if item.type == TagTreeItem.TAG and self._model.flags(index) & Qt.ItemIsDropEnabled:
+            event.setDropAction(Qt.CopyAction)
             self.setDropIndicatorShown(not src_is_tb)
             return
         if item.type == TagTreeItem.CATEGORY and not item.is_gst:
@@ -850,8 +888,7 @@ class TagsView(QTreeView):  # {{{
             if fm_dest['kind'] == 'user':
                 if src_is_tb:
                     if event.dropAction() == Qt.MoveAction:
-                        data = bytes(event.mimeData().data('application/calibre+from_tag_browser'))
+                        # src is initialized above
-                        src = json_loads(data)
                         for s in src:
                             if s[0] == TagTreeItem.TAG and \
                                     (not s[1].startswith('@') or s[2]):