Natural light configuration

frontend/device/kobo/device.lua

@@ -32,6 +32,7 @@ local Kobo = Generic:new{
     internal_storage_mount_point = "/mnt/onboard/",
     -- currently only Aura One has coloured frontlight
     hasNaturalLight = no,
+    frontlight_settings = {},
 }
 
 -- TODO: hasKeys for some devices?

frontend/device/kobo/powerd.lua

@@ -97,6 +97,12 @@ function KoboPowerD:init()
         -- If this device has natural light (currently only KA1)
         -- use the SysFS interface, and ioctl otherwise.
         if self.device.hasNaturalLight() then
+            local nl_config = G_reader_settings:readSetting("natural_light_config")
+            if nl_config then
+                for key,val in pairs(nl_config) do
+                    self.device.frontlight_settings[key] = val
+                end
+            end
             self.fl = SysfsLight:new(self.device.frontlight_settings)
             self.fl_warmth = 0
             self:_syncKoboLightOnStart()

frontend/device/kobo/sysfs_light.lua

@@ -17,6 +17,7 @@ local KoboSysfsLight = {
     white_offset = -25,
     red_offset = 0,
     green_offset = -65,
+    exponent = 0.25,
 }
 
 function KoboSysfsLight:new(o)
@@ -48,14 +49,28 @@ dbg:guard(KoboSysfsLight, 'setWarmth',
           end)
 
 function KoboSysfsLight:setNaturalBrightness(brightness, warmth)
-    -- On Nickel, the values for white/red/green are roughly linearly dependent
-    -- on the 4th root of brightness and warmth.
-    local white = math.min(self.white_gain * math.pow(brightness, 0.25) *
-                       math.pow(100 - warmth, 0.25) + self.white_offset, 255)
-    local red = math.min(self.red_gain * math.pow(brightness, 0.25) *
-                     math.pow(warmth, 0.25) + self.red_offset, 255)
-    local green = math.min(self.green_gain * math.pow(brightness, 0.25) *
-                       math.pow(warmth, 0.25) + self.green_offset, 255)
+    if not brightness then
+        brightness = self.current_brightness
+    end
+    if not warmth then
+        warmth = self.current_warmth
+    end
+
+    local red = 0
+    local green = 0
+    local white = 0
+    if brightness > 0 then
+        -- On Nickel, the values for white/red/green are roughly linearly dependent
+        -- on the 4th root of brightness and warmth.
+        white = math.min(self.white_gain * math.pow(brightness, self.exponent) *
+                             math.pow(100 - warmth, self.exponent) + self.white_offset, 255)
+    end
+    if warmth > 0 then
+        red = math.min(self.red_gain * math.pow(brightness, self.exponent) *
+                           math.pow(warmth, self.exponent) + self.red_offset, 255)
+        green = math.min(self.green_gain * math.pow(brightness, self.exponent) *
+                             math.pow(warmth, self.exponent) + self.green_offset, 255)
+    end
 
     white = math.max(white, 0)
     red = math.max(red, 0)

frontend/ui/widget/frontlightwidget.lua

@@ -11,6 +11,7 @@ local HorizontalGroup = require("ui/widget/horizontalgroup")
 local HorizontalSpan = require("ui/widget/horizontalspan")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local LineWidget = require("ui/widget/linewidget")
+local NaturalLight = require("ui/widget/naturallightwidget")
 local OverlapGroup = require("ui/widget/overlapgroup")
 local Size = require("ui/size")
 local TextBoxWidget = require("ui/widget/textboxwidget")
@@ -27,6 +28,8 @@ local FrontLightWidget = InputContainer:new{
     title_face = Font:getFace("x_smalltfont"),
     width = nil,
     height = nil,
+    -- This should stay active during natural light configuration
+    is_always_active = true,
 }
 
 function FrontLightWidget:init()
@@ -243,8 +246,21 @@ function FrontLightWidget:setProgress(num, step, num_warmth)
     table.insert(vertical_group,button_group_down)
     table.insert(vertical_group,padding_span)
     if self.natural_light then
-        -- If the device supports natural light, add the widgets for 'warmth'.
+        -- If the device supports natural light, add the widgets for 'warmth'
+        -- and a 'Configure' button
         self:addWarmthWidgets(num_warmth, step, vertical_group)
+        self.configure_button =  Button:new{
+            text = _("Configure"),
+            margin = Size.margin.small,
+            radius = 0,
+            width = self.screen_width * 0.20,
+            enabled = not self.nl_configure_open,
+            show_parent = self,
+            callback = function()
+                UIManager:show(NaturalLight:new{fl_widget = self})
+            end,
+        }
+        table.insert(vertical_group, self.configure_button)
     end
     table.insert(self.fl_container, vertical_group)
     -- Reset container height to what it actually contains
@@ -455,8 +471,11 @@ function FrontLightWidget:onAnyKeyPressed()
 end
 
 function FrontLightWidget:onTapCloseFL(arg, ges_ev)
-    if ges_ev.pos:notIntersectWith(self.light_frame.dimen) then
-        self:onClose()
+    -- Do not close when natural light configuration is open
+    if not self.nl_configure_open then
+        if ges_ev.pos:notIntersectWith(self.light_frame.dimen) then
+            self:onClose()
+        end
     end
     return true
 end
@@ -466,4 +485,26 @@ function FrontLightWidget:onClose()
     return true
 end
 
+-- This is called when natural light configuration is shown
+function FrontLightWidget:naturalLightConfigOpen()
+    -- Remove the close button
+    table.remove(self.light_bar)
+    -- Disable the 'configure' button
+    self.configure_button:disable()
+    self.nl_configure_open = true
+    -- Move to the bottom to make place for the new widget
+    self[1].align="bottom"
+    UIManager:setDirty("all", "ui")
+end
+
+function FrontLightWidget:naturalLightConfigClose()
+    table.insert(self.light_bar,
+                 CloseButton:new{window = self,
+                                 padding_top = Size.margin.title})
+    self.configure_button:enable()
+    self.nl_configure_open = false
+    self[1].align="center"
+    UIManager:setDirty("all", "ui")
+end
+
 return FrontLightWidget