Add an auto-scroll button to the viewer controls

imgsrc/srv/auto-scroll.svg

@@ -0,0 +1 @@
+<svg width="1792" height="1792" viewBox="0 0 1792 1792" xmlns="http://www.w3.org/2000/svg"><path d="M1395 864q0 13-10 23l-466 466q-10 10-23 10t-23-10l-466-466q-10-10-10-23t10-23l50-50q10-10 23-10t23 10l393 393 393-393q10-10 23-10t23 10l50 50q10 10 10 23zm0-384q0 13-10 23l-466 466q-10 10-23 10t-23-10l-466-466q-10-10-10-23t10-23l50-50q10-10 23-10t23 10l393 393 393-393q10-10 23-10t23 10l50 50q10 10 10 23z"/></svg>

src/pyj/read_book/flow_mode.pyj

@@ -141,6 +141,24 @@ def scroll_by_page(direction):
     window.scrollBy(0, h * direction)
 
 
+def is_auto_scroll_active():
+    return scroll_animator.auto and scroll_animator.is_running()
+
+
+def start_autoscroll():
+    scroll_animator.start(DIRECTION.Down, True)
+
+
+def toggle_autoscroll():
+    running = False
+    if is_auto_scroll_active():
+        cancel_scroll()
+    else:
+        start_autoscroll()
+        running = True
+    get_boss().send_message('autoscroll_state_changed', running=running)
+
+
 def handle_shortcut(sc_name, evt):
     if sc_name is 'down':
         scroll_animator.start(DIRECTION.Down, False)
@@ -173,10 +191,7 @@ def handle_shortcut(sc_name, evt):
         scroll_by_page(1)
         return True
     if sc_name is 'toggle_autoscroll':
-        if scroll_animator.auto and scroll_animator.is_running():
+        toggle_autoscroll()
-            cancel_scroll()
-        else:
-            scroll_animator.start(DIRECTION.Down, True)
         return True
 
     if sc_name.startsWith('scrollspeed_'):
@@ -190,7 +205,7 @@ def layout(is_single_page):
     set_css(document.body, margin='0', border_width='0', padding='0')
 
 
-def flow_auto_scroll_resume():
+def auto_scroll_resume():
     scroll_animator.wait = False
     scroll_animator.sync()
 
@@ -422,3 +437,17 @@ anchor_funcs = {
         return (a[0] - b[0]) or (a[1] - b[1])
     ,
 }
+
+
+def auto_scroll_action(action):
+    if action is 'toggle':
+        toggle_autoscroll()
+    elif action is 'start':
+        if not is_auto_scroll_active():
+            toggle_autoscroll()
+    elif action is 'stop':
+        if is_auto_scroll_active():
+            toggle_autoscroll()
+    elif action is 'resume':
+        auto_scroll_resume()
+    return is_auto_scroll_active()

src/pyj/read_book/iframe.pyj

@@ -10,10 +10,10 @@ from iframe_comm import IframeClient
 from read_book.cfi import scroll_to as scroll_to_cfi
 from read_book.extract import get_elements
 from read_book.flow_mode import (
-    anchor_funcs as flow_anchor_funcs, cancel_scroll as flow_cancel_auto_scroll,
+    anchor_funcs as flow_anchor_funcs, auto_scroll_action as flow_auto_scroll_action,
-    flow_auto_scroll_resume, flow_onwheel, flow_to_scroll_fraction,
+    flow_onwheel, flow_to_scroll_fraction, handle_gesture as flow_handle_gesture,
-    handle_gesture as flow_handle_gesture, handle_shortcut as flow_handle_shortcut,
+    handle_shortcut as flow_handle_shortcut, layout as flow_layout,
-    layout as flow_layout, scroll_by_page as flow_scroll_by_page
+    scroll_by_page as flow_scroll_by_page
 )
 from read_book.footnotes import is_footnote_link
 from read_book.globals import (
@@ -22,10 +22,11 @@ from read_book.globals import (
 )
 from read_book.mathjax import apply_mathjax
 from read_book.paged_mode import (
-    anchor_funcs as paged_anchor_funcs, calc_columns_per_screen, current_cfi,
+    anchor_funcs as paged_anchor_funcs,
-    handle_gesture as paged_handle_gesture, handle_shortcut as paged_handle_shortcut,
+    auto_scroll_action as paged_auto_scroll_action, calc_columns_per_screen,
-    jump_to_cfi as paged_jump_to_cfi, layout as paged_layout,
+    current_cfi, handle_gesture as paged_handle_gesture,
-    onwheel as paged_onwheel, paged_auto_scroll_resume,
+    handle_shortcut as paged_handle_shortcut, jump_to_cfi as paged_jump_to_cfi,
+    layout as paged_layout, onwheel as paged_onwheel,
     prepare_for_resize as paged_prepare_for_resize, progress_frac,
     reset_paged_mode_globals, resize_done as paged_resize_done,
     scroll_by_page as paged_scroll_by_page, scroll_to_elem,
@@ -106,27 +107,32 @@ class IframeBoss:
             'scroll_to_anchor': self.on_scroll_to_anchor,
             'scroll_to_frac': self.on_scroll_to_frac,
             'scroll_to_ref': self.on_scroll_to_ref,
-            'set_forward_keypresses': self.set_forward_keypresses,
             'set_reference_mode': self.set_reference_mode,
+            'toggle_autoscroll': self.toggle_autoscroll,
             'wheel_from_margin': self.wheel_from_margin,
             'window_size': self.received_window_size,
-            'overlay_shown': self.on_overlay_shown,
+            'overlay_visibility_changed': self.on_overlay_visibility_changed,
         }
         self.comm = IframeClient(handlers)
         self.last_window_ypos = 0
         self.length_before = None
 
-    def on_overlay_shown(self):
+    def on_overlay_visibility_changed(self, data):
-        if current_layout_mode() is 'flow':
+        if data.visible:
-            flow_cancel_auto_scroll()
+            self.forward_keypresses = True
+            if self.auto_scroll_action:
+                self.auto_scroll_active_before_overlay = self.auto_scroll_action('is_active')
+                self.auto_scroll_action('stop')
+        else:
+            self.forward_keypresses = False
+            if self.auto_scroll_active_before_overlay:
+                self.auto_scroll_active_before_overlay = undefined
+                self.auto_scroll_action('start')
 
     def modify_selection(self, data):
         sel = window.getSelection()
         sel.modify('extend', data.direction, data.granularity)
 
-    def set_forward_keypresses(self, data):
-        self.forward_keypresses = data.forward
-
     def initialize(self, data):
         scroll_viewport.update_window_size(data.width, data.height)
         window.addEventListener('error', self.onerror)
@@ -188,7 +194,7 @@ class IframeBoss:
             self.to_scroll_fraction = flow_to_scroll_fraction
             self.jump_to_cfi = scroll_to_cfi
             self.anchor_funcs = flow_anchor_funcs
-            self.auto_scroll_resume = flow_auto_scroll_resume
+            self.auto_scroll_action = flow_auto_scroll_action
         else:
             self.do_layout = paged_layout
             self.handle_wheel = paged_onwheel
@@ -197,7 +203,7 @@ class IframeBoss:
             self.jump_to_cfi = paged_jump_to_cfi
             self._handle_gesture = paged_handle_gesture
             self.anchor_funcs = paged_anchor_funcs
-            self.auto_scroll_resume = paged_auto_scroll_resume
+            self.auto_scroll_action = paged_auto_scroll_action
         update_settings(data.settings)
         self.keyboard_shortcut_map = create_shortcut_map(data.settings.keyboard_shortcuts)
         set_current_spine_item({
@@ -217,6 +223,9 @@ class IframeBoss:
     def on_scroll_to_frac(self, data):
         self.to_scroll_fraction(data.frac, False)
 
+    def toggle_autoscroll(self):
+        self.auto_scroll_action('toggle')
+
     def handle_gesture(self, gesture):
         if gesture.type is 'show-chrome':
             self.send_message('show_chrome')
@@ -317,7 +326,7 @@ class IframeBoss:
         self.onscroll()
         self.send_message('content_loaded', progress_frac=self.calculate_progress_frac(), file_progress_frac=progress_frac())
         self.last_cfi = None
-        self.auto_scroll_resume()
+        self.auto_scroll_action('resume')
         window.setTimeout(self.update_cfi, 0)
         window.setTimeout(self.update_toc_position, 0)
 

src/pyj/read_book/overlay.pyj

@@ -6,6 +6,7 @@ from elementmaker import E
 from gettext import gettext as _
 
 from book_list.book_details import CLASS_NAME as BD_CLASS_NAME, render_metadata
+from book_list.globals import get_session_data
 from book_list.library_data import sync_library_books
 from book_list.router import home
 from book_list.theme import get_color
@@ -230,6 +231,7 @@ class MainOverlay:  # {{{
     def show(self, container):
         self.container_id = container.getAttribute('id')
         icon_size = '3.5ex'
+        sd = get_session_data()
 
         def ac(text, tooltip, action, icon, is_text_button):
             if is_text_button:
@@ -296,6 +298,14 @@ class MainOverlay:  # {{{
                 full_screen_actions.push(
                     ac(text, _('Toggle full screen mode'), def(): self.overlay.hide(), ui_operations.toggle_full_screen();, 'full-screen')
                 )
+        if sd.get('read_mode') is 'flow':
+            asa = self.overlay.view.autoscroll_active
+            full_screen_actions.append(ac(
+                _('Stop auto scroll') if asa else _('Auto scroll'), _('Toggle auto-scrolling'), def():
+                    self.overlay.hide()
+                    window.setTimeout(self.overlay.view.toggle_autoscroll, 0)
+                , 'auto-scroll'))
+
         if full_screen_actions.length:
             actions_div.appendChild(E.ul(*full_screen_actions))
 
@@ -510,7 +520,6 @@ class Overlay:
         c.style.color = get_color('window-foreground')
         if c.style.display is not 'block':
             c.style.display = 'block'
-            self.view.overlay_visibility_changed(True)
         return c
 
     @property

src/pyj/read_book/paged_mode.pyj

@@ -563,10 +563,7 @@ def handle_shortcut(sc_name, evt):
         scroll_by_page(False, True)
         return True
     if sc_name is 'toggle_autoscroll':
-        get_boss().send_message('error', title=_('No auto scroll in paged mode'), msg=_(
+        auto_scroll_action('toggle')
-            'Switch to flow mode (Viewer preferences->Page layout) to enable auto'
-            ' scrolling')
-        )
         return True
     return False
 
@@ -655,5 +652,10 @@ def resize_done():
     resize_manager.end_resize()
 
 
-def paged_auto_scroll_resume():
+def auto_scroll_action(action):
-    pass
+    if action is 'toggle':
+        get_boss().send_message('error', title=_('No auto scroll in paged mode'), msg=_(
+            'Switch to flow mode (Viewer preferences->Page layout) to enable auto'
+            ' scrolling')
+        )
+    return False

src/pyj/read_book/view.pyj

@@ -201,6 +201,9 @@ class View:
             ),
         )
         handlers = {
+            'autoscroll_state_changed': def(data):
+                self.autoscroll_active = v'!!data.running'
+            ,
             'bump_font_size': self.bump_font_size,
             'content_loaded': self.on_content_loaded,
             'error': self.on_iframe_error,
@@ -339,9 +342,7 @@ class View:
 
     def overlay_visibility_changed(self, visible):
         if self.iframe_wrapper.send_message:
-            if visible:
+            self.iframe_wrapper.send_message('overlay_visibility_changed', visible=visible)
-                self.iframe_wrapper.send_message('overlay_shown')
-            self.iframe_wrapper.send_message('set_forward_keypresses', forward=v'!!visible')
         if ui_operations.overlay_visibility_changed:
             ui_operations.overlay_visibility_changed(visible)
 
@@ -429,6 +430,9 @@ class View:
         sd.set('read_mode', new_mode)
         ui_operations.redisplay_book()
 
+    def toggle_autoscroll(self):
+        self.iframe_wrapper.send_message('toggle_autoscroll')
+
     def toggle_toolbar(self):
         sd = get_session_data()
         misc = sd.get('standalone_misc_settings')