use screen for UI color control

frontend/device/generic/device.lua

@@ -99,6 +99,13 @@ function Device:init()
     end
 
     self.screen.isColorScreen = self.hasColorScreen
+    self.screen.isColorEnabled = function()
+        if G_reader_settings:has("color_rendering") then
+            return G_reader_settings:isTrue("color_rendering")
+        else
+            return self.screen.isColorScreen()
+        end
+    end
 
     self.screen.isBGRFrameBuffer = self.hasBGRFrameBuffer
 

frontend/ui/elements/screen_color_menu_table.lua

@@ -7,11 +7,11 @@ local _ = require("gettext")
 return {
     text = _("Color rendering"),
     enabled_func = Screen.isColorScreen,
-    checked_func = function() return Runtimectl.is_color_rendering_enabled end,
+    checked_func = Screen.isColorEnabled,
     callback = function()
-        Runtimectl:setColorRenderingEnabled(not Runtimectl.is_color_rendering_enabled)
-        G_reader_settings:saveSetting(
-            "color_rendering", Runtimectl.is_color_rendering_enabled)
+        local new_val = Screen.isColorEnabled()
+        Runtimectl:setColorRenderingEnabled(new_val)
+        G_reader_settings:saveSetting("color_rendering", new_val)
         UIManager:broadcastEvent(Event:new("ColorRenderingUpdate"))
     end
 }

frontend/ui/widget/htmlboxwidget.lua

@@ -8,10 +8,10 @@ local Geom = require("ui/geometry")
 local GestureRange = require("ui/gesturerange")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local Mupdf = require("ffi/mupdf")
+local Screen = Device.screen
 local TimeVal = require("ui/timeval")
 local logger = require("logger")
 local util  = require("util")
-local Runtimectl = require("runtimectl")
 
 local HtmlBoxWidget = InputContainer:new{
     bb = nil,
@@ -83,7 +83,7 @@ function HtmlBoxWidget:_render()
     -- In pdfdocument.lua, color is activated only at the moment of
     -- rendering and then immediately disabled, for safety with kopt.
     -- We do the same here.
-    Mupdf.color = Runtimectl.is_color_rendering_enabled
+    Mupdf.color = Screen:isColorEnabled()
 
     local page = self.document:openPage(self.page_number)
     local dc = DrawContext.new()

frontend/ui/widget/textboxwidget.lua

@@ -361,11 +361,11 @@ function TextBoxWidget:_renderText(start_row_idx, end_row_idx)
     if self._bb then self._bb:free() end
     local bbtype = nil
     if self.line_num_to_image and self.line_num_to_image[start_row_idx] then
-        -- Whether Runtimectl.is_color_rendering_enabled or not, it's best to
+        -- Whether Screen:isColorEnabled or not, it's best to
         -- always use BBRGB32 and alphablitFrom() for the best display of
         -- various images:
         --   With greyscale screen TYPE_BB8 (the default, and
-        --   what we would have chosen when not Runtimectl.is_color_rendering_enabled):
+        --   what we would have chosen when not Screen:isColorEnabled):
         --     alphablitFrom: some images are all white (ex: flags on Milan,
         --     Ilkhanides on wiki.fr)
         --     blitFrom: some images have a black background (ex: RDA,