Viewer: Allow right clicking on the scrollbar to easily access commonly used scrolling shortcuts

src/calibre/gui2/viewer/ui.py

@@ -13,8 +13,8 @@ from hashlib import sha256
 from threading import Thread
 
 from PyQt5.Qt import (
-    QApplication, QDockWidget, QEvent, QMimeData, QModelIndex, QPixmap, QScrollBar,
-    Qt, QToolBar, QUrl, QVBoxLayout, QWidget, pyqtSignal
+    QApplication, QCursor, QDockWidget, QEvent, QMenu, QMimeData, QModelIndex,
+    QPixmap, Qt, QToolBar, QUrl, QVBoxLayout, QWidget, pyqtSignal
 )
 
 from calibre import prints
@@ -78,13 +78,6 @@ def path_key(path):
     return sha256(as_bytes(path)).hexdigest()
 
 
-class ScrollBar(QScrollBar):
-
-    def paintEvent(self, ev):
-        if self.isEnabled():
-            return QScrollBar.paintEvent(self, ev)
-
-
 class EbookViewer(MainWindow):
 
     msg_from_anotherinstance = pyqtSignal(object)
@@ -178,6 +171,7 @@ class EbookViewer(MainWindow):
         self.web_view.reset_interface.connect(self.reset_interface, type=Qt.QueuedConnection)
         self.web_view.quit.connect(self.quit, type=Qt.QueuedConnection)
         self.web_view.shortcuts_changed.connect(self.shortcuts_changed)
+        self.web_view.scrollbar_context_menu.connect(self.scrollbar_context_menu)
         self.actions_toolbar.initialize(self.web_view, self.search_dock.toggleViewAction())
         self.setCentralWidget(self.web_view)
         self.loading_overlay = LoadingOverlay(self)
@@ -193,14 +187,38 @@ class EbookViewer(MainWindow):
             rmap[v].append(k)
         self.actions_toolbar.set_tooltips(rmap)
 
-    def toggle_inspector(self):
-        visible = self.inspector_dock.toggleViewAction().isChecked()
-        self.inspector_dock.setVisible(not visible)
-
     def resizeEvent(self, ev):
         self.loading_overlay.resize(self.size())
         return MainWindow.resizeEvent(self, ev)
 
+    def scrollbar_context_menu(self, x, y, frac):
+        m = QMenu(self)
+        amap = {}
+
+        def a(text, name):
+            m.addAction(text)
+            amap[text] = name
+
+        a(_('Scroll here'), 'here')
+        m.addSeparator()
+        a(_('Start of book'), 'start_of_book')
+        a(_('End of book'), 'end_of_book')
+        m.addSeparator()
+        a(_('Previous section'), 'previous_section')
+        a(_('Next section'), 'next_section')
+        m.addSeparator()
+        a(_('Start of current file'), 'start_of_file')
+        a(_('End of current file'), 'end_of_file')
+
+        q = m.exec_(QCursor.pos())
+        if not q:
+            return
+        q = amap[q.text()]
+        if q == 'here':
+            self.web_view.goto_frac(frac)
+        else:
+            self.web_view.trigger_shortcut(q)
+
     # IPC {{{
     def handle_commandline_arg(self, arg):
         if arg:
@@ -246,6 +264,10 @@ class EbookViewer(MainWindow):
 
     # Docks (ToC, Bookmarks, Lookup, etc.) {{{
 
+    def toggle_inspector(self):
+        visible = self.inspector_dock.toggleViewAction().isChecked()
+        self.inspector_dock.setVisible(not visible)
+
     def toggle_toc(self):
         self.toc_dock.setVisible(not self.toc_dock.isVisible())
 

src/calibre/gui2/viewer/web_view.py

@@ -272,6 +272,7 @@ class ViewerBridge(Bridge):
     reset_interface = from_js()
     quit = from_js()
     customize_toolbar = from_js()
+    scrollbar_context_menu = from_js(object, object, object)
 
     create_view = to_js()
     start_book_load = to_js()
@@ -443,6 +444,7 @@ class WebView(RestartingWebEngineView):
     reset_interface = pyqtSignal()
     quit = pyqtSignal()
     customize_toolbar = pyqtSignal()
+    scrollbar_context_menu = pyqtSignal(object, object, object)
     shortcuts_changed = pyqtSignal(object)
     paged_mode_changed = pyqtSignal()
     standalone_misc_settings_changed = pyqtSignal(object)
@@ -491,6 +493,7 @@ class WebView(RestartingWebEngineView):
         self.bridge.reset_interface.connect(self.reset_interface)
         self.bridge.quit.connect(self.quit)
         self.bridge.customize_toolbar.connect(self.customize_toolbar)
+        self.bridge.scrollbar_context_menu.connect(self.scrollbar_context_menu)
         self.bridge.export_shortcut_map.connect(self.set_shortcut_map)
         self.shortcut_map = {}
         self.bridge.report_cfi.connect(self.call_callback)

src/pyj/read_book/iframe.pyj

@@ -116,6 +116,7 @@ class IframeBoss:
             'window_size': self.received_window_size,
             'overlay_visibility_changed': self.on_overlay_visibility_changed,
             'show_search_result': self.show_search_result,
+            'handle_navigation_shortcut': self.on_handle_navigation_shortcut,
         }
         self.comm = IframeClient(handlers)
         self.last_window_ypos = 0
@@ -458,6 +459,10 @@ class IframeBoss:
                 else:
                     self.send_message('handle_shortcut', name=sc_name)
 
+    def on_handle_navigation_shortcut(self, data):
+        self.handle_navigation_shortcut(data.name, data.key or {
+            'key': '', 'altKey': False, 'ctrlKey': False, 'shiftKey': False, 'metaKey': False})
+
     def oncontextmenu(self, evt):
         if self.content_ready:
             evt.preventDefault()

src/pyj/read_book/scrollbar.pyj

@@ -7,7 +7,7 @@ from elementmaker import E
 from book_list.globals import get_session_data
 from book_list.theme import cached_color_to_rgba
 from dom import unique_id
-
+from read_book.globals import ui_operations
 
 SIZE = 10
 
@@ -31,7 +31,7 @@ class BookScrollbar:
         return E.div(
             id=self.container_id,
             style=f'height: 100vh; background-color: #aaa; width: {SIZE}px; border-radius: 5px',
-            onclick=self.bar_clicked,
+            onclick=self.bar_clicked, oncontextmenu=self.context_menu,
             E.div(
                 style=f'position: relative; width: 100%; height: {int(2.2*SIZE)}px; background-color: #444; border-radius: 5px',
                 onmousedown=self.on_bob_mousedown,
@@ -41,6 +41,16 @@ class BookScrollbar:
             )
         )
 
+    def context_menu(self, ev):
+        if ui_operations.scrollbar_context_menu:
+            ev.preventDefault(), ev.stopPropagation()
+            c = self.container
+            bob = c.firstChild
+            height = c.clientHeight - bob.clientHeight
+            top = max(0, min(ev.clientY - bob.clientHeight, height))
+            frac = max(0, min(top / height, 1))
+            ui_operations.scrollbar_context_menu(ev.screenX, ev.screenY, frac)
+
     def bar_clicked(self, evt):
         if evt.button is 0:
             c = self.container

src/pyj/read_book/view.pyj

@@ -442,6 +442,8 @@ class View:
             self.toggle_autoscroll()
         elif data.name.startsWith('switch_color_scheme:'):
             self.switch_color_scheme(data.name.partition(':')[-1])
+        else:
+            self.iframe_wrapper.send_message('handle_navigation_shortcut', name=data.name)
 
     def on_selection_change(self, data):
         self.currently_showing.selected_text = data.text

src/pyj/viewer-main.pyj

@@ -403,6 +403,8 @@ if window is window.top:
         to_python.autoscroll_state_changed(active)
     ui_operations.search_result_not_found = def(sr):
         to_python.search_result_not_found(sr)
+    ui_operations.scrollbar_context_menu = def(x, y, frac):
+        to_python.scrollbar_context_menu(x, y, frac)
 
     document.body.appendChild(E.div(id='view'))
     window.onerror = onerror