Do not reload book when changing color scheme

src/pyj/read_book/iframe.pyj

@@ -45,6 +45,7 @@ class IframeBoss:
             'scroll_to_anchor': self.on_scroll_to_anchor,
             'next_screen': self.on_next_screen,
             'change_font_size': self.change_font_size,
+            'change_color_scheme': self.change_color_scheme,
         }
         self.last_window_ypos = 0
 
@@ -148,6 +149,11 @@ class IframeBoss:
             opts.base_font_size = data.base_font_size
             self.apply_font_size()
 
+    def change_color_scheme(self, data):
+        if data.color_scheme and data.color_scheme.foreground and data.color_scheme.background:
+            opts.color_scheme = data.color_scheme
+            self.apply_colors()
+
     def content_loaded(self):
         document.documentElement.style.overflow = 'hidden'
         # document.body.appendChild(

src/pyj/read_book/prefs/colors.pyj

@@ -5,7 +5,7 @@ from __python__ import hash_literals, bound_methods
 from gettext import gettext as _
 from dom import svgicon, set_css, add_extra_css, build_rule, clear, unique_id
 from elementmaker import E
-from book_list.globals import get_session_data
+from book_list.globals import get_session_data, get_boss
 from read_book.globals import default_color_schemes
 from modals import error_dialog
 from widgets import create_button
@@ -34,6 +34,20 @@ add_extra_css(def():
 def get_container():
     return document.getElementById(CONTAINER)
 
+def resolve_color_scheme(current_color_scheme):
+    sd = get_session_data()
+    cs = current_color_scheme or sd.get('current_color_scheme') or 'white'
+    ucs = sd.get('user_color_schemes')
+    if default_color_schemes[cs]:
+        ans = default_color_schemes[cs]
+    elif ucs[cs] and ucs[cs].foreground and ucs[cs].background:
+        ans = ucs[cs]
+    else:
+        for sn in default_color_schemes:
+            ans = default_color_schemes[sn]
+            break
+    return ans
+
 def change_current_color(ev):
     ul = ev.currentTarget.parentNode
     for li in ul.childNodes:
@@ -152,6 +166,9 @@ def set_action_button_visibility():
 def create_colors_panel(container):
     container.appendChild(E.div(id=CONTAINER))
     container = container.lastChild
+    cs = resolve_color_scheme()
+    container.dataset.bg = cs.background
+    container.dataset.fg = cs.foreground
     container.appendChild(E.p(_('Choose a color scheme below'), style='margin:1ex 1em; padding: 1ex 0'))
     ul = E.ul(id=COLOR_LIST)
     container.appendChild(ul)
@@ -179,8 +196,9 @@ develop = create_colors_panel
 
 def commit_colors(onchange):
     ccs = current_color_scheme()
+    rcs = resolve_color_scheme(ccs)
+    c = get_container()
+    if rcs.foreground is not c.dataset.fg or rcs.background is not c.dataset.bg:
         sd = get_session_data()
-    if sd.get('current_color_scheme') is not ccs:
         sd.set('current_color_scheme', ccs)
-        onchange()
-
+        get_boss().read_ui.update_color_scheme()

src/pyj/read_book/ui.pyj

@@ -113,6 +113,9 @@ class ReadUI:
     def update_font_size(self):
         self.view.update_font_size()
 
+    def update_color_scheme(self):
+        self.view.update_color_scheme()
+
     @property
     def url_data(self):
         ans = {'book_id':self.base_url_data.book_id, 'fmt': self.base_url_data.fmt}

src/pyj/read_book/view.pyj

@@ -6,9 +6,10 @@ from book_list.globals import get_session_data, get_boss
 from dom import set_css, add_extra_css, build_rule, svgicon
 from elementmaker import E
 from gettext import gettext as _
-from read_book.globals import messenger, iframe_id, default_color_schemes
+from read_book.globals import messenger, iframe_id
 from read_book.resources import load_resources
 from read_book.overlay import Overlay
+from read_book.prefs.colors import resolve_color_scheme
 from book_list.theme import get_color
 from utils import parse_url_params, username_key
 
@@ -178,17 +179,7 @@ class View:
         self.ui.show_error((data.title or _('There was an error processing the book')), data.msg, data.details)
 
     def get_color_scheme(self, apply_to_margins):
-        sd = get_session_data()
-        cs = sd.get('current_color_scheme') or 'white'
-        ucs = sd.get('user_color_schemes')
-        if default_color_schemes[cs]:
-            ans = default_color_schemes[cs]
-        elif ucs[cs] and ucs[cs].foreground and ucs[cs].background:
-            ans = ucs[cs]
-        else:
-            for sn in default_color_schemes:
-                ans = default_color_schemes[sn]
-                break
+        ans = resolve_color_scheme()
         if apply_to_margins:
             for which in 'left top right bottom'.split(' '):
                 s = document.getElementById('book-{}-margin'.format(which)).style
@@ -324,3 +315,7 @@ class View:
 
     def update_font_size(self):
         self.send_message('change_font_size', base_font_size=get_session_data().get('base_font_size'))
+
+    def update_color_scheme(self):
+        cs = self.get_color_scheme(True)
+        self.send_message('change_color_scheme', color_scheme=cs)