E-book viewer: Add a clickable link to show the currently viewed book in the calibre library (Click Go to->Metadata in the viewer controls to access it). Fixes #2034905 [ebook-viewer enhancement: Show book in library](https://bugs.launchpad.net/calibre/+bug/2034905)

src/calibre/gui2/viewer/__init__.py

@@ -34,6 +34,23 @@ def link_prefix_for_location_links(add_open_at=True):
     return link_prefix
 
 
+def url_for_book_in_library():
+    cbd = get_current_book_data()
+    ans = library_id = None
+    if 'calibre_library_id' in cbd:
+        library_id = cbd['calibre_library_id']
+        book_id = cbd['calibre_book_id']
+    elif cbd.get('book_library_details'):
+        bld = cbd['book_library_details']
+        book_id = bld['book_id']
+        library_id = bld['library_id']
+    if library_id:
+        library_id = '_hex_-' + library_id.encode('utf-8').hex()
+        ans = f'calibre://show-book/{library_id}/{book_id}'
+    return ans
+
+
+
 class PerformanceMonitor:
 
     def __init__(self):

src/calibre/gui2/viewer/web_view.py

@@ -22,7 +22,7 @@ from calibre.constants import (
 from calibre.ebooks.metadata.book.base import field_metadata
 from calibre.ebooks.oeb.polish.utils import guess_type
 from calibre.gui2 import choose_images, config, error_dialog, safe_open_url
-from calibre.gui2.viewer import link_prefix_for_location_links, performance_monitor
+from calibre.gui2.viewer import link_prefix_for_location_links, performance_monitor, url_for_book_in_library
 from calibre.gui2.viewer.config import viewer_config_dir, vprefs
 from calibre.gui2.viewer.tts import TTS
 from calibre.gui2.webengine import RestartingWebEngineView
@@ -631,7 +631,10 @@ class WebView(RestartingWebEngineView):
     def start_book_load(self, initial_position=None, highlights=None, current_book_data=None, reading_rates=None):
         key = (set_book_path.path,)
         book_url = link_prefix_for_location_links(add_open_at=False)
-        self.execute_when_ready('start_book_load', key, initial_position, set_book_path.pathtoebook, highlights or [], book_url, reading_rates)
+        book_in_library_url = url_for_book_in_library()
+        self.execute_when_ready(
+            'start_book_load', key, initial_position, set_book_path.pathtoebook, highlights or [], book_url,
+            reading_rates, book_in_library_url)
 
     def execute_when_ready(self, action, *args):
         if self.bridge.ready:

src/pyj/read_book/overlay.pyj

@@ -751,7 +751,7 @@ class Overlay:
         self.hide_current_panel()
         from_read_book = short_uuid()
 
-        def show_metadata_overlay(mi, pathtoebook, lname, book_id, overlay, container):
+        def show_metadata_overlay(mi, pathtoebook, calibre_book_in_library_url, lname, book_id, overlay, container):
             container_id = ensure_id(container)
             container.appendChild(E.div(class_=BD_CLASS_NAME, style='padding: 1ex 1em'))
             table = E.table(class_='metadata')
@@ -808,12 +808,21 @@ class Overlay:
                         pathtoebook)
                     )
                 )
+            if calibre_book_in_library_url:
+                container.lastChild.appendChild(E.div(
+                    style='margin-top: 1ex; padding-top: 1ex;',
+                    E.a(
+                        href=calibre_book_in_library_url,
+                        class_='blue-link', title=_('Click to see this book in the main calibre program book list'),
+                        _('Show book in the main calibre program'))
+                    )
+                )
 
         book = self.view.book
         key = book.key or v'[null, 0]'
         lname, book_id = key
         book_id = int(book_id or 0)
-        panel = SimpleOverlay(self, show_metadata_overlay.bind(None, book.metadata, book.manifest.pathtoebook, lname, book_id), self.view.book.metadata.title)
+        panel = SimpleOverlay(self, show_metadata_overlay.bind(None, book.metadata, book.manifest.pathtoebook, book.calibre_book_in_library_url, lname, book_id), self.view.book.metadata.title)
         panel.from_read_book = from_read_book
         self.panels.push(panel)
         self.show_current_panel()

src/pyj/viewer-main.pyj

@@ -95,7 +95,7 @@ def show_error(title, msg, details):
     to_python.show_error(title, msg, details)
 
 
-def manifest_received(key, initial_position, pathtoebook, highlights, book_url, reading_rates, end_type, xhr, ev):
+def manifest_received(key, initial_position, pathtoebook, highlights, book_url, reading_rates, book_in_library_url, end_type, xhr, ev):
     nonlocal book
     end_type = workaround_qt_bug(xhr, end_type)
     if end_type is 'load':
@@ -107,6 +107,7 @@ def manifest_received(key, initial_position, pathtoebook, highlights, book_url,
         book.highlights = highlights
         book.stored_files = {}
         book.calibre_book_url = book_url
+        book.calibre_book_in_library_url = book_in_library_url
         book.saved_reading_rates = reading_rates
         book.is_complete = True
         v'delete book.manifest["metadata"]'
@@ -229,8 +230,8 @@ def show_home_page():
 
 
 @from_python
-def start_book_load(key, initial_position, pathtoebook, highlights, book_url, reading_rates):
+def start_book_load(key, initial_position, pathtoebook, highlights, book_url, reading_rates, book_in_library_url):
-    xhr = ajax('manifest', manifest_received.bind(None, key, initial_position, pathtoebook, highlights, book_url, reading_rates), ok_code=0)
+    xhr = ajax('manifest', manifest_received.bind(None, key, initial_position, pathtoebook, highlights, book_url, reading_rates, book_in_library_url), ok_code=0)
     xhr.responseType = 'json'
     xhr.send()