Allow disabling automagic image inversion in Nightmode in CRe (#5095)

* Allow disabling automagic image inversion in NightMode

Fix #4986

frontend/apps/reader/modules/readertypeset.lua

@@ -96,6 +96,14 @@ function ReaderTypeset:onReadSettings(config)
         self.smooth_scaling = (global == nil or global == 0) and 0 or 1
     end
     self:toggleImageScaling(self.smooth_scaling)
+
+    -- default to automagic nightmode-friendly handling of images
+    self.nightmode_images = config:readSetting("nightmode_images")
+    if self.nightmode_images == nil then
+        local global = G_reader_settings:readSetting("copt_nightmode_images")
+        self.nightmode_images = (global == nil or global == 1) and 1 or 0
+    end
+    self:toggleNightmodeImages(self.nightmode_images)
 end
 
 function ReaderTypeset:onSaveSettings()
@@ -105,6 +113,7 @@ function ReaderTypeset:onSaveSettings()
     self.ui.doc_settings:saveSetting("embedded_fonts", self.embedded_fonts)
     self.ui.doc_settings:saveSetting("render_dpi", self.render_dpi)
     self.ui.doc_settings:saveSetting("smooth_scaling", self.smooth_scaling)
+    self.ui.doc_settings:saveSetting("nightmode_images", self.nightmode_images)
 end
 
 function ReaderTypeset:onToggleEmbeddedStyleSheet(toggle)
@@ -122,6 +131,11 @@ function ReaderTypeset:onToggleImageScaling(toggle)
     return true
 end
 
+function ReaderTypeset:onToggleNightmodeImages(toggle)
+    self:toggleNightmodeImages(toggle)
+    return true
+end
+
 -- June 2018: epub.css has been cleaned to be more conforming to HTML specs
 -- and to not include class name based styles (with conditional compatiblity
 -- styles for previously opened documents). It should be usable on all
@@ -286,6 +300,17 @@ function ReaderTypeset:toggleImageScaling(toggle)
     self.ui:handleEvent(Event:new("UpdatePos"))
 end
 
+function ReaderTypeset:toggleNightmodeImages(toggle)
+    if toggle and (toggle == true or toggle == 1) then
+        self.nightmode_images = true
+        self.ui.document:setNightmodeImages(true)
+    else
+        self.nightmode_images = false
+        self.ui.document:setNightmodeImages(false)
+    end
+    self.ui:handleEvent(Event:new("UpdatePos"))
+end
+
 function ReaderTypeset:toggleFloatingPunctuation(toggle)
     -- for some reason the toggle value read from history files may stay boolean
     -- and there seems no more elegant way to convert boolean values to numbers

frontend/document/credocument.lua

@@ -23,6 +23,7 @@ local CreDocument = Document:new{
     _loaded = false,
     _view_mode = nil,
     _smooth_scaling = false,
+    _nightmode_images = true,
 
     line_space_percent = 100,
     default_font = "Noto Serif",
@@ -378,7 +379,7 @@ function CreDocument:drawCurrentView(target, x, y, rect, pos)
 
     -- local start_clock = os.clock()
     self._drawn_images_count, self._drawn_images_surface_ratio =
-        self._document:drawCurrentPage(self.buffer, self.render_color, Screen.night_mode, self._smooth_scaling, Screen.sw_dithering)
+        self._document:drawCurrentPage(self.buffer, self.render_color, Screen.night_mode and self._nightmode_images, self._smooth_scaling, Screen.sw_dithering)
     -- print(string.format("CreDocument:drawCurrentView: Rendering took %9.3f ms", (os.clock() - start_clock) * 1000))
 
     -- start_clock = os.clock()
@@ -736,6 +737,11 @@ function CreDocument:setImageScaling(toggle)
     self._smooth_scaling = toggle
 end
 
+function CreDocument:setNightmodeImages(toggle)
+    logger.dbg("CreDocument: set nightmode images", toggle)
+    self._nightmode_images = toggle
+end
+
 function CreDocument:setFloatingPunctuation(enabled)
     -- FIXME: occasional segmentation fault when toggling floating punctuation
     logger.dbg("CreDocument: set floating punctuation", enabled)

frontend/ui/data/creoptions.lua

@@ -427,6 +427,19 @@ Note that your selected font size is not affected by this setting.]]),
                 help_text = _([[- 'fast' uses a fast but inaccurate scaling algorithm when scaling images.
 - 'best' switches to a more costly but vastly more pleasing and accurate algorithm.]]),
             },
+            {
+                name = "nightmode_images",
+                name_text = S.NIGHTMODE_IMAGES,
+                toggle = {S.ON, S.OFF},
+                values = {1, 0},
+                default_value = 1,
+                args = {true, false},
+                default_arg = nil,
+                event = "ToggleNightmodeImages",
+                show_func = function() return Device.screen.night_mode end,
+                name_text_hold_callback = optionsutil.showValues,
+                help_text = _([[Disable the automagic inversion of images when nightmode is enabled. Useful if your book contains mainly inlined mathematical content or scene break art.]]),
+            },
         },
     },
 }

frontend/ui/data/strings.lua

@@ -40,6 +40,7 @@ S.FORCED_OCR = _("Forced OCR")
 S.HW_DITHERING = _("Dithering")
 S.INVERSE_READING_ORDER = _("Inverse Order")
 S.IMAGE_SCALING = _("Image Scaling")
+S.NIGHTMODE_IMAGES = _("Invert Images")
 
 S.ON = _("on")
 S.OFF = _("off")

frontend/ui/widget/configdialog.lua

@@ -196,7 +196,12 @@ function ConfigOption:init()
     for c = 1, #self.options do
         -- Ignore names of options that won't be shown
         local show_default = not self.options[c].advanced or show_advanced
-        if self.options[c].show ~= false and show_default then
+        local show = self.options[c].show
+        -- Prefer show_func over show if there's one
+        if self.options[c].show_func then
+            show = self.options[c].show_func()
+        end
+        if show ~= false and show_default then
             local name_font_face = self.options[c].name_font_face and self.options[c].name_font_face or "cfont"
             local name_font_size = self.options[c].name_font_size and self.options[c].name_font_size or default_name_font_size
             local text = self.options[c].name_text
@@ -225,7 +230,12 @@ function ConfigOption:init()
 
     for c = 1, #self.options do
         local show_default = not self.options[c].advanced or show_advanced
-        if self.options[c].show ~= false and show_default then
+        local show = self.options[c].show
+        -- Prefer show_func over show if there's one
+        if self.options[c].show_func then
+            show = self.options[c].show_func()
+        end
+        if show ~= false and show_default then
             local name_align = self.options[c].name_align_right and self.options[c].name_align_right or default_name_align_right
             local item_align = self.options[c].item_align_center and self.options[c].item_align_center or default_item_align_center
             local name_font_face = self.options[c].name_font_face and self.options[c].name_font_face or "cfont"
@@ -574,7 +584,7 @@ function ConfigOption:init()
             table.insert(self.config.layout, #self.config.layout,self:_itemGroupToLayoutLine(option_items_group))
             table.insert(horizontal_group, option_items_container)
             table.insert(vertical_group, horizontal_group)
-        end -- if self.options[c].show ~= false
+        end -- if show ~= false
     end -- for c = 1, #self.options
 
     table.insert(vertical_group, VerticalSpan:new{ width = default_option_vpadding })