Make the tag browser expand and collapse menu items consistent.

1) add separate lines to expand item and expand item and children
2) add collapse lines for all parent nodes, not just the immediate parent and the category root

src/calibre/gui2/tag_browser/view.py

@@ -806,19 +806,6 @@ class TagsView(QTreeView):  # {{{
                             _('Manage User categories'),
                             partial(self.context_menu_handler, action='manage_categories',
                                     category=None))
-
-                node_name = tag_item.tag.name
-                parent = tag_item.parent
-                if parent.type != TagTreeItem.ROOT:
-                    # We have an internal node. Find its immediate parent
-                    parent_index = self._model.parent(index)
-                    parent_node = parent
-                    parent_name = parent.tag.name
-                else:
-                    # We have a top-level node.
-                    parent_index = index
-                    parent_node = tag_item
-                    parent_name = tag_item.name
         if self.hidden_categories:
             if not self.context_menu.isEmpty():
                 self.context_menu.addSeparator()
@@ -850,47 +837,70 @@ class TagsView(QTreeView):  # {{{
             da.setToolTip('*')
             pa.setToolTip('*')
 
+        # Add expand menu items
+        node_name = self._model.get_node(index).tag.name
         self.context_menu.addSeparator()
-        if index.isValid() and self.model().rowCount(index) > 0:
+        if self.has_children(index) and not self.isExpanded(index):
-            if self.isExpanded(index):
-                self.context_menu.addAction(_("Collapse {0}").format(node_name),
-                                            partial(self.collapse_node, index))
-            else:
             self.context_menu.addAction(_('Expand {0}').format(node_name),
-                                            partial(self.expand_node_and_descendants, index))
+                                        partial(self.expand, index))
-        if parent_index is not None and parent_index != index:
+        if self.has_unexpanded_children(index):
-            if self.isExpanded(parent_index):
+            self.context_menu.addAction(_('Expand {0} and all children').format(node_name),
-                # Don't bother to collapse if it isn't expanded
+                                        partial(self.expand_node_and_children, index))
-                self.context_menu.addAction(_("Collapse {0}").format(parent_name),
+
-                                            partial(self.collapse_node, parent_index))
+        # Add menu items to collapse parent nodes
-            if parent_node.parent.type != TagTreeItem.ROOT:
+        idx = index
-                # Add the top level node if the current parent is an internal node
+        paths = []
-                while parent_node.parent.type != TagTreeItem.ROOT:
+        while True:
-                    parent_node = parent_node.parent
+            # First walk up the node tree getting the displayed names of
-                idx = self._model.index_for_category(parent_node.category_key)
+            # expanded parent nodes
-                self.context_menu.addAction(_("Collapse {0}").format(parent_node.name),
+            node = self._model.get_node(idx)
-                                            partial(self.collapse_node, idx))
+            if node.type == TagTreeItem.ROOT:
+                break
+            if self.has_children(idx):
+                # leaf nodes don't have children so can't be expanded.
+                paths.append((node.tag.name, idx))
+            idx = self._model.parent(idx)
+        for p in paths:
+            # Now add the menu items
+            self.context_menu.addAction(_("Collapse {0}").format(p[0]),
+                                                 partial(self.collapse_node, p[1]))
         self.context_menu.addAction(_('Collapse all'), self.collapseAll)
 
         if not self.context_menu.isEmpty():
             self.context_menu.popup(self.mapToGlobal(point))
         return True
 
-    def collapse_node(self, idx):
+    def has_children(self, idx):
-        def collapse_node_and_children(idx):
+        return self.model().rowCount(idx) > 0
+
+    def collapse_node_and_children(self, idx):
         self.collapse(idx)
         for r in range(self.model().rowCount(idx)):
-                collapse_node_and_children(idx.child(r, 0))
+            self.collapse_node_and_children(idx.child(r, 0))
-        collapse_node_and_children(idx)
+
+    def collapse_node(self, idx):
+        if not idx.isValid():
+            return
+        self.collapse_node_and_children(idx)
         self.setCurrentIndex(idx)
         self.scrollTo(idx)
 
-    def expand_node_and_descendants(self, index):
+    def expand_node_and_children(self, index):
         if not index.isValid():
             return
         self.expand(index)
         for r in range(self.model().rowCount(index)):
-            self.expand_node_and_descendants(index.child(r, 0))
+            self.expand_node_and_children(index.child(r, 0))
+
+    def has_unexpanded_children(self, index):
+        if not index.isValid():
+            return
+        if self.has_children(index) and not self.isExpanded(index):
+            return True
+        for r in range(self.model().rowCount(index)):
+            if self.has_unexpanded_children(index.child(r, 0)):
+                return True
+        return False
 
     def collapse_menu_hovered(self, action):
         tip = action.toolTip()