Start abstracting the scroll viewport

src/pyj/read_book/cfi.pyj

@@ -21,7 +21,7 @@ from __python__ import hash_literals
 #    scroll_to(cfi): which scrolls the browser to a point corresponding to the
 #                    given cfi, and returns the x and y co-ordinates of the point.
 
-from read_book.globals import window_width, window_height
+from read_book.globals import scroll_viewport
 
 # CFI escaping {{{
 escape_pat = /[\[\],^();~@!-]/g
@@ -540,7 +540,7 @@ def at_point(ox, oy):  # {{{
 
 def at_current():  # {{{
     winx, winy = window_scroll_pos()
-    winw, winh = window_width(), window_height()
+    winw, winh = scroll_viewport.width(), scroll_viewport.height()
     winw = max(winw, 400)
     winh = max(winh, 600)
     deltay = Math.floor(winh/50)

src/pyj/read_book/flow_mode.pyj

@@ -3,7 +3,7 @@
 from __python__ import hash_literals, bound_methods
 
 from dom import set_css
-from read_book.globals import get_boss, window_width, window_height
+from read_book.globals import get_boss, scroll_viewport
 from keycodes import get_key
 from utils import document_height, document_width, viewport_to_document
 
@@ -31,14 +31,14 @@ def flow_onwheel(evt):
         elif evt.deltaMode is evt.DOM_DELTA_LINE:
             dy = 15 * evt.deltaY
         if evt.deltaMode is evt.DOM_DELTA_PAGE:
-            dy = (window_height() - 30) * evt.deltaY
+            dy = (scroll_viewport.height() - 30) * evt.deltaY
     if evt.deltaX:
         if evt.deltaMode is evt.DOM_DELTA_PIXEL:
             dx = evt.deltaX
         elif evt.deltaMode is evt.DOM_DELTA_LINE:
             dx = 15 * evt.deltaX
         else:
-            dx = (window_width() - 30) * evt.deltaX
+            dx = (scroll_viewport.width() - 30) * evt.deltaX
     if dx:
         window.scrollBy(dx, 0)
     elif dy:
@@ -63,7 +63,7 @@ def goto_boundary(y):
 
 @check_for_scroll_end
 def scroll_by_page(backward):
-    h = window_height() - 10
+    h = scroll_viewport.height() - 10
     window.scrollBy(0, -h if backward else h)
 
 def flow_onkeydown(evt):
@@ -175,10 +175,10 @@ anchor_funcs = {
         y, x = pos
         if y < window.pageYOffset:
             return -1
-        if y < window.pageYOffset + window_height():
+        if y < window.pageYOffset + scroll_viewport.height():
             if x < window.pageXOffset:
                 return -1
-            if x < window.pageXOffset + window_width():
+            if x < window.pageXOffset + scroll_viewport.width():
                 return 0
         return 1
     ,

src/pyj/read_book/globals.pyj

@@ -39,6 +39,35 @@ class Messenger:
 messenger = Messenger()
 iframe_id = 'read-book-iframe'
 uid = 'calibre-' + hexlify(random_bytes(12))
+scroll_viewport = {}
+
+def flow_viewport_x():
+    return window.pageXOffset
+
+def flow_viewport_y():
+    return window.pageYOffset
+
+def flow_viewport_scroll_to(x, y):
+    window.scrollTo(x, y)
+
+scroll_viewport.x = flow_viewport_x
+scroll_viewport.y = flow_viewport_y
+scroll_viewport.scroll_to = flow_viewport_scroll_to
+
+if is_ios:
+    window_width = def ():
+        return window_width.from_parent or window.innerWidth
+    window_height = def():
+        return window_height.from_parent or window.innerHeight
+else:
+    window_width = def():
+        return window.innerWidth
+    window_height = def():
+        return window.innerHeight
+
+scroll_viewport.width = window_width
+scroll_viewport.height = window_height
+
 
 def current_layout_mode():
     return current_layout_mode.value
@@ -73,14 +102,3 @@ register_callback(def():
         scheme = default_color_schemes[key]
         scheme.name = gt(scheme.name)
 )
-
-if is_ios:
-    window_width = def ():
-        return window_width.from_parent or window.innerWidth
-    window_height = def():
-        return window_height.from_parent or window.innerHeight
-else:
-    window_width = def():
-        return window.innerWidth
-    window_height = def():
-        return window.innerHeight

src/pyj/read_book/paged_mode.pyj

@@ -6,7 +6,7 @@ from dom import set_css
 from elementmaker import E
 from keycodes import get_key
 from read_book.cfi import scroll_to as cfi_scroll_to, at_point as cfi_at_point, at_current as cfi_at_current
-from read_book.globals import get_boss, window_width, window_height
+from read_book.globals import get_boss, scroll_viewport
 from read_book.settings import opts
 import traceback
 from utils import get_elem_data, set_elem_data, viewport_to_document, document_width
@@ -112,19 +112,19 @@ def layout(is_single_page):
     body_style = window.getComputedStyle(document.body)
     first_layout = not _in_paged_mode
     cps = opts.columns_per_screen or {}
-    cps = cps.landscape if window_width() > window_height() else cps.portrait
+    cps = cps.landscape if scroll_viewport.width() > scroll_viewport.height() else cps.portrait
     try:
         cps = int(cps)
     except:
         cps = 0
     if not cps:
-        cps = int(Math.floor(window_width() / 500.0))
+        cps = int(Math.floor(scroll_viewport.width() / 500.0))
     cps = max(1, min(cps or 1, 20))
     if first_layout:
         handle_rtl_body(body_style)
         # Check if the current document is a full screen layout like
         # cover, if so we treat it specially.
-        single_screen = (document.body.scrollHeight < window_height() + 75)
+        single_screen = (document.body.scrollHeight < scroll_viewport.height() + 75)
         first_layout = True
         has_svg = document.getElementsByTagName('svg').length > 0
         imgs = document.getElementsByTagName('img')
@@ -149,7 +149,7 @@ def layout(is_single_page):
     n = cols_per_screen = cps
     # Calculate the column width so that cols_per_screen columns fit exactly in
     # the window width, with their separator margins
-    ww = col_width = screen_width = window_width()
+    ww = col_width = screen_width = scroll_viewport.width()
     gap = 0
     if n > 1:
         # Adjust the side margin so that the window width satisfies
@@ -158,7 +158,7 @@ def layout(is_single_page):
         gap = sm + ((ww + sm) % n)  # Ensure ww + gap is a multiple of n
         col_width = ((ww + gap) // n) - gap
 
-    screen_height = window_height()
+    screen_height = scroll_viewport.height()
     col_and_gap = col_width + gap
 
     set_css(document.body, column_gap=gap + 'px', column_width=col_width + 'px', column_rule='0px inset blue',
@@ -272,8 +272,8 @@ def column_location(elem):
     c = column_at(left)
     width = min(br.right, (c+1)*col_and_gap) - br.left
     if br.bottom < br.top:
-        br.bottom = window_height()
+        br.bottom = scroll_viewport.height()
-    height = min(br.bottom, window_height()) - br.top
+    height = min(br.bottom, scroll_viewport.height()) - br.top
     left -= c * col_and_gap
     return {'column':c, 'left':left, 'top':top, 'width':width, 'height':height}
 
@@ -304,7 +304,7 @@ def next_screen_location():
         cols_left = ncols - (current_col + cols_per_screen)
         if cols_left < cols_per_screen:
             return -1  # Only blank, dummy pages left
-    limit = document.body.scrollWidth - window_width()
+    limit = document.body.scrollWidth - scroll_viewport.width()
     if limit < col_and_gap:
         return -1
     if ans > limit:
@@ -332,7 +332,7 @@ def next_col_location():
         return -1
     cc = current_column_location()
     ans = cc + col_and_gap
-    limit = document.body.scrollWidth - window_width()
+    limit = document.body.scrollWidth - scroll_viewport.width()
     if ans > limit:
         ans = limit if current_scroll_offset() < limit else -1
     return ans
@@ -421,9 +421,9 @@ def current_cfi():
             if left < 0 or right > document.body.scrollWidth:
                 continue
             deltax = col_and_gap // 25
-            deltay = window_height() // 25
+            deltay = scroll_viewport.height() // 25
             cury = 0
-            while cury < window_height():
+            while cury < scroll_viewport.height():
                 curx = left
                 while curx < right - gap:
                     cfi = cfi_at_point(curx-current_scroll_offset(), cury-window.pageYOffset)
@@ -445,11 +445,11 @@ def current_cfi():
 def progress_frac(frac):
     # The current scroll position as a fraction between 0 and 1
     if in_paged_mode:
-        limit = document.body.scrollWidth - window_width()
+        limit = document.body.scrollWidth - scroll_viewport.width()
         if limit <= 0:
             return 0.0
         return current_scroll_offset() / limit
-    limit = document.body.scrollHeight - window_height()
+    limit = document.body.scrollHeight - scroll_viewport.height()
     if limit <= 0:
         return 0.0
     return window.pageYOffset / limit

src/pyj/read_book/toc.pyj

@@ -8,7 +8,7 @@ from elementmaker import E
 from gettext import gettext as _
 from modals import error_dialog
 from widgets import create_tree, find_text_in_tree, scroll_tree_item_into_view
-from read_book.globals import toc_anchor_map, set_toc_anchor_map, current_spine_item, current_layout_mode, current_book, window_width, window_height
+from read_book.globals import toc_anchor_map, set_toc_anchor_map, current_spine_item, current_layout_mode, current_book, scroll_viewport
 
 
 def update_visible_toc_nodes(visible_anchors):
@@ -137,7 +137,7 @@ def create_toc_panel(book, container, onclick):
 
 def current_toc_anchor_map(tam, anchor_funcs):
     current_map = toc_anchor_map()
-    if not (current_map and current_map.layout_mode is current_layout_mode() and current_map.width is window_width() and current_map.height is window_height()):
+    if not (current_map and current_map.layout_mode is current_layout_mode() and current_map.width is scroll_viewport.width() and current_map.height is scroll_viewport.height()):
         name = current_spine_item().name
         am = {}
         anchors = v'[]'
@@ -154,7 +154,7 @@ def current_toc_anchor_map(tam, anchor_funcs):
         # stable sort by position in document
         anchors.sort(def (a, b): return anchor_funcs.cmp(am[a], am[b]) or (pos_map[a] - pos_map[b]);)
 
-        current_map = {'layout_mode': current_layout_mode, 'width': window_width(), 'height': window_height(), 'pos_map': am, 'sorted_anchors':anchors}
+        current_map = {'layout_mode': current_layout_mode, 'width': scroll_viewport.width(), 'height': scroll_viewport.height(), 'pos_map': am, 'sorted_anchors':anchors}
         set_toc_anchor_map(current_map)
     return current_map
 

src/pyj/read_book/touch.pyj

@@ -2,7 +2,7 @@
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 from __python__ import hash_literals, bound_methods
 
-from read_book.globals import get_boss, window_width, window_height
+from read_book.globals import get_boss, scroll_viewport
 from book_list.globals import get_read_ui
 
 HOLD_THRESHOLD = 750  # milliseconds
@@ -240,10 +240,10 @@ class BookTouchHandler(TouchHandler):
                 return
             if not gesture.active:
                 if self.for_side_margin or not tap_on_link(gesture):
-                    if gesture.viewport_y < min(100, window_height() / 4):
+                    if gesture.viewport_y < min(100, scroll_viewport.height() / 4):
                         gesture.type = 'show-chrome'
                     else:
-                        if gesture.viewport_x < min(100, window_width() / 4):
+                        if gesture.viewport_x < min(100, scroll_viewport.width() / 4):
                             gesture.type = 'prev-page'
                         else:
                             gesture.type = 'next-page'