Content server: In the book list hovering over the library name now shows the total number of books in the library. Fixes #1881384 [[Enhancement - Content server] Show number of books in a library](https://bugs.launchpad.net/calibre/+bug/1881384)

src/calibre/db/cache.py

@@ -1027,6 +1027,12 @@ class Cache(object):
             return frozenset(self._search('', vl))
         return frozenset(self._search('', search_restriction))
 
+    @read_api
+    def number_of_books_in_virtual_library(self, vl=None, search_restriction=None):
+        if not vl and not search_restriction:
+            return len(self.fields['uuid'].table.book_col_map)
+        return len(self.books_in_virtual_library(vl, search_restriction))
+
     @api
     def get_categories(self, sort='name', book_ids=None, already_fixed=None,
                        first_letter_sort=False):

src/calibre/srv/ajax.py

@@ -539,8 +539,10 @@ def search_result(ctx, rd, db, query, num, offset, sort, sort_order, vl=''):
     ids = db.multisort(fields=multisort, ids_to_sort=ids)
     total_num = len(ids)
     ids = ids[offset:offset+num]
+    num_books = db.number_of_books_in_virtual_library(vl) if query else total_num
     ans = {
         'total_num': total_num, 'sort_order':sort_order,
+        'num_books_without_search': num_books,
         'offset':offset, 'num':len(ids), 'sort':sort,
         'base_url':ctx.url_for(search, library_id=db.server_library_id),
         'query': query,

src/pyj/book_list/top_bar.pyj

@@ -82,6 +82,13 @@ def set_title(container, text):
     for bar in bars:
         bar.firstChild.firstChild.nextSibling.textContent = text
 
+
+def set_title_tooltip(container, text):
+    bars = get_bars(container)
+    for bar in bars:
+        bar.firstChild.firstChild.nextSibling.title = text
+
+
 def create_top_bar(container, **kw):
     create_markup(container)
     set_left_data(container, **kw)

src/pyj/book_list/views.pyj

@@ -34,7 +34,7 @@ from book_list.router import back, home, push_state, update_window_title
 from book_list.search import (
     init as init_search_panel, set_apply_search, tb_config_panel_handler
 )
-from book_list.top_bar import add_button, create_top_bar
+from book_list.top_bar import add_button, create_top_bar, set_title_tooltip
 from book_list.ui import query_as_href, set_panel_handler, show_panel
 from dom import add_extra_css, build_rule, clear, ensure_id, set_css
 from modals import error_dialog
@@ -319,6 +319,8 @@ def check_for_books_loaded():
         )
         return
     create_books_list(container)
+    if library_data.search_result and jstype(library_data.search_result.num_books_without_search) is 'number':
+        set_title_tooltip(this, _('Total number of books: {}').format(library_data.search_result.num_books_without_search))
 
 
 def init(container_id):