E-book viewer: Add a button to directly open the viewer help section in the calibre user manual to the viewer controls

imgsrc/srv/help.svg

@@ -0,0 +1 @@
+<svg height='300px' width='300px'  xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" viewBox="0 0 128 128"><g><path d="M64,1C29.3,1,1,29.3,1,64s28.3,63,63,63s63-28.3,63-63S98.7,1,64,1z M64,7c11.8,0,22.8,3.6,32,9.8L78.8,34   c-4.5-2.2-9.5-3.5-14.8-3.5S53.7,31.8,49.2,34L32,16.8C41.2,10.6,52.2,7,64,7z M91.5,64c0,15.2-12.3,27.5-27.5,27.5   S36.5,79.2,36.5,64S48.8,36.5,64,36.5S91.5,48.8,91.5,64z M16.8,96C10.6,86.8,7,75.8,7,64c0-12.4,4-23.9,10.7-33.2l17,17   C32,52.6,30.5,58.1,30.5,64c0,5.3,1.3,10.3,3.5,14.8L16.8,96z M64,121c-12.4,0-23.9-4-33.2-10.7l17-17c4.8,2.7,10.3,4.2,16.2,4.2   c5.9,0,11.4-1.5,16.2-4.2l17,17C87.9,117,76.4,121,64,121z M121,64c0,11.8-3.6,22.8-9.8,32L94,78.8c2.2-4.5,3.5-9.5,3.5-14.8   c0-5.9-1.5-11.4-4.2-16.2l17-17C117,40.1,121,51.6,121,64z"></path></g></svg>

src/calibre/gui2/viewer/web_view.py

@@ -36,6 +36,7 @@ from calibre.gui2.webengine import (
     secure_webengine, to_js
 )
 from calibre.srv.code import get_translations_data
+from calibre.utils.localization import localize_user_manual_link
 from calibre.utils.serialize import json_loads
 from calibre.utils.shared_file import share_open
 from polyglot.builtins import as_bytes, iteritems
@@ -275,6 +276,7 @@ class ViewerBridge(Bridge):
     tts = from_js(object, object)
     edit_book = from_js(object, object, object)
     show_book_folder = from_js()
+    show_help = from_js(object)
 
     create_view = to_js()
     start_book_load = to_js()
@@ -538,6 +540,7 @@ class WebView(RestartingWebEngineView):
         self.bridge.highlights_changed.connect(self.highlights_changed)
         self.bridge.edit_book.connect(self.edit_book)
         self.bridge.show_book_folder.connect(self.show_book_folder)
+        self.bridge.show_help.connect(self.show_help)
         self.bridge.open_url.connect(safe_open_url)
         self.bridge.speak_simple_text.connect(self.tts.speak_simple_text)
         self.bridge.tts.connect(self.tts.action)
@@ -744,5 +747,9 @@ class WebView(RestartingWebEngineView):
         path = os.path.dirname(os.path.abspath(set_book_path.pathtoebook))
         safe_open_url(QUrl.fromLocalFile(path))
 
+    def show_help(self, which):
+        if which == 'viewer':
+            safe_open_url(localize_user_manual_link('https://manual.calibre-ebook.com/viewer.html'))
+
     def repair_after_fullscreen_switch(self):
         self.execute_when_ready('repair_after_fullscreen_switch')

src/calibre/srv/code.py

@@ -27,7 +27,7 @@ from calibre.srv.utils import get_library_data, get_use_roman
 from calibre.utils.config import prefs, tweaks
 from calibre.utils.icu import numeric_sort_key, sort_key
 from calibre.utils.localization import (
-    get_lang, lang_map_for_ui, localize_website_link
+    get_lang, lang_map_for_ui, localize_website_link, lang_code_for_user_manual
 )
 from calibre.utils.search_query_parser import ParseException
 from calibre.utils.serialize import json_dumps
@@ -156,7 +156,8 @@ def basic_interface_data(ctx, rd):
         'search_the_net_urls': getattr(ctx, 'search_the_net_urls', None) or [],
         'num_per_page': rd.opts.num_per_page,
         'default_book_list_mode': rd.opts.book_list_mode,
-        'donate_link': localize_website_link('https://calibre-ebook.com/donate')
+        'donate_link': localize_website_link('https://calibre-ebook.com/donate'),
+        'lang_code_for_user_manual': lang_code_for_user_manual(),
     }
     ans['library_map'], ans['default_library_id'] = ctx.library_info(rd)
     return ans

src/calibre/utils/localization.py

@@ -528,12 +528,19 @@ def user_manual_stats():
     return stats
 
 
-def localize_user_manual_link(url):
+def lang_code_for_user_manual():
     lc = lang_as_iso639_1(get_lang())
     if lc == 'en':
-        return url
+        return ''
     stats = user_manual_stats()
     if stats.get(lc, 0) < 0.3:
+        return ''
+    return lc
+
+
+def localize_user_manual_link(url):
+    lc = lang_code_for_user_manual()
+    if not lc:
         return url
     from polyglot.urllib import urlparse, urlunparse
     parts = urlparse(url)

src/pyj/read_book/overlay.pyj

@@ -430,11 +430,19 @@ class MainOverlay:  # {{{
             E.div( # bottom bar
                   style='position: fixed; width: 100%; bottom: 0; display: flex; justify-content: space-between; align-items: center;'
                         'user-select: none; background-color: {}'.format(get_color('window-background')),
+                E.div(
+                    style='display: flex; justify-content: space-between; align-items: center;',
                     E.div(
                         style='display: flex; align-items: center; cursor: pointer; padding: 0.5ex 1rem', class_='main-overlay-button',
                         title=_('Close the viewer controls'),
                         svgicon('close', icon_size, icon_size), '\xa0', _('Close')
                     ),
+                    E.div(
+                        style='display: flex; align-items: center; cursor: pointer; padding: 0.5ex 1rem', class_='main-overlay-button',
+                        svgicon('help', icon_size, icon_size), '\xa0', _('Help'), onclick=def(ev):
+                            ui_operations.show_help('viewer')
+                    )
+                ),
                 E.div(style='padding: 0.5ex 1rem', '\xa0'), E.div(style='padding: 0.5ex 1rem', '\xa0'),
             ),
         )

src/pyj/read_book/ui.pyj

@@ -18,6 +18,7 @@ from read_book.db import get_db
 from read_book.globals import ui_operations
 from read_book.tts import Client
 from read_book.view import View
+from session import get_interface_data
 from utils import debounce, full_screen_element, human_readable, request_full_screen
 from widgets import create_button
 
@@ -92,6 +93,16 @@ class ReadUI:
         ui_operations.find_next = self.view.search_overlay.find_next
         ui_operations.open_url = def(url):
             window.open(url, '_blank')
+        ui_operations.show_help = def(which):
+            if which is 'viewer':
+                path = '/viewer.html'
+            else:
+                return
+            if get_interface_data().lang_code_for_user_manual:
+                path = f'/{get_interface_data().lang_code_for_user_manual}{path}'
+            url = 'https://manual.calibre-ebook.com' + path
+            window.open(url, '_blank')
+
         ui_operations.copy_selection = def(text, html):
             # try using document.execCommand which on chrome allows the
             # copy on non-secure origin if this is close to a user

src/pyj/session.pyj

@@ -241,6 +241,7 @@ default_interface_data = {
     'icon_path': '',
     'custom_list_template': None,
     'num_per_page': 50,
+    'lang_code_for_user_manual': '',
 }
 
 def get_interface_data():

src/pyj/viewer-main.pyj

@@ -429,6 +429,8 @@ if window is window.top:
         to_python.edit_book(spine_name, frac, selected_text or '')
     ui_operations.show_book_folder = def():
         to_python.show_book_folder()
+    ui_operations.show_help = def(which):
+        to_python.show_help(which)
 
     document.body.appendChild(E.div(id='view'))
     window.onerror = onerror