frontlight on kobo: a few fixes (#3163)

* frontlight on kobo: a few fixes

Rewritten to not update NickelConf on every change, and never
if KOBO_SYNC_BRIGHTNESS_WITH_NICKEL = false.
Reintroduce global settings frontlight_intensity and
is_frontlight_on to keep level and state across koreader
sessions.
Fix a few of the remaining issues on kobo light.
Ensure settings are saved when rebooting/powering off from
File browser.

* Ensure untoggle works when starting with light off

defaults.lua

@@ -170,9 +170,10 @@ SEARCH_SERIES = true
 SEARCH_PATH = true
 
 -- Light parameter for Kobo
-KOBO_LIGHT_ON_START = -2           -- -1, -2 or 0-100. -1 leaves light as it
-                                   -- is, -2 uses 'Kobo eReader.conf', other
-                                   -- sets light on start/wake up
+KOBO_LIGHT_ON_START = -2           -- -1, -2 or 0-100.
+                                   -- -1 uses previous koreader session saved brightness
+                                   -- -2 uses 'Kobo eReader.conf' brighness,
+                                   -- other sets light on start to a fix brighness
 KOBO_SYNC_BRIGHTNESS_WITH_NICKEL = true  -- Save brightness set in KOreader
                                          -- with nickel's 'Kobo eReader.conf'
 

frontend/apps/filemanager/filemanager.lua

@@ -362,6 +362,7 @@ end
 
 function FileManager:onClose()
     logger.dbg("close filemanager")
+    G_reader_settings:flush()
     UIManager:close(self)
     if self.onExit then
         self:onExit()

frontend/device/generic/device.lua

@@ -166,6 +166,9 @@ function Device:initNetworkManager() end
 
 function Device:supportsScreensaver() return false end
 
+-- Device specific method if any setting needs being saved
+function Device:saveSettings() end
+
 --[[
 prepare for application shutdown
 --]]

frontend/device/kobo/device.lua

@@ -491,6 +491,11 @@ function Kobo:resume()
     end
 end
 
+function Kobo:saveSettings()
+    -- save frontlight state to G_reader_settings (and NickelConf if needed)
+    self.powerd:saveSettings()
+end
+
 function Kobo:powerOff()
     os.execute("poweroff")
 end

frontend/device/kobo/powerd.lua

@@ -4,6 +4,11 @@ local NickelConf = require("device/kobo/nickel_conf")
 local batt_state_folder =
         "/sys/devices/platform/pmic_battery.1/power_supply/mc13892_bat/"
 
+-- Here, we only deal with the real hw intensity.
+-- Dealing with toggling and remembering/restoring
+-- previous intensity when toggling/untoggling is done
+-- by BasePowerD.
+
 local KoboPowerD = BasePowerD:new{
     fl_min = 0, fl_max = 100,
     fl = nil,
@@ -14,28 +19,63 @@ local KoboPowerD = BasePowerD:new{
 
 -- TODO: Remove KOBO_LIGHT_ON_START
 function KoboPowerD:_syncKoboLightOnStart()
+    local new_intensity = nil
+    local is_frontlight_on = nil
     local kobo_light_on_start = tonumber(KOBO_LIGHT_ON_START)
     if kobo_light_on_start then
-        local new_intensity
-        local is_frontlight_on
         if kobo_light_on_start > 0 then
             new_intensity = math.min(kobo_light_on_start, 100)
             is_frontlight_on = true
         elseif kobo_light_on_start == 0 then
             new_intensity = 0
             is_frontlight_on = false
-        elseif kobo_light_on_start == -2 then
-            return
+        elseif kobo_light_on_start == -2 then -- get values from NickelConf
+            new_intensity = NickelConf.frontLightLevel.get()
+            is_frontlight_on = NickelConf.frontLightState:get()
+            if is_frontlight_on == nil then
+                -- this device does not support frontlight toggle,
+                -- we set the value based on frontlight intensity.
+                if new_intensity > 0 then
+                    is_frontlight_on = true
+                else
+                    is_frontlight_on = false
+                end
+            end
+            if is_frontlight_on == false and new_intensity == 0 then
+                -- frontlight was toggled off in nickel, and we have no
+                -- level-before-toggle-off (firmware without "FrontLightState"):
+                -- use the one from koreader settings
+                new_intensity = G_reader_settings:readSetting("frontlight_intensity")
+            end
         else -- if kobo_light_on_start == -1 or other unexpected value then
-            -- TODO(Hzj-jie): Read current frontlight states from OS.
-            return
+            -- As we can't read value from the OS or hardware, use last values
+            -- stored in koreader settings
+            new_intensity = G_reader_settings:readSetting("frontlight_intensity")
+            is_frontlight_on = G_reader_settings:readSetting("is_frontlight_on")
         end
-        NickelConf.frontLightLevel.set(new_intensity)
-        NickelConf.frontLightState.set(is_frontlight_on)
+    end
+
+    if new_intensity ~= nil then
+        self.hw_intensity = new_intensity
+    end
+    if is_frontlight_on ~= nil then
+        -- will only be used to give initial state to BasePowerD:_decideFrontlightState()
+        self.initial_is_fl_on = is_frontlight_on
+    end
+
+    -- In any case frontlight is off, ensure intensity is non-zero so untoggle works
+    if self.initial_is_fl_on == false and self.hw_intensity == 0 then
+        self.hw_intensity = 1
     end
 end
 
 function KoboPowerD:init()
+    -- Default values in case self:_syncKoboLightOnStart() does not find
+    -- any previously saved setting (and for unit tests where it will
+    -- not be called)
+    self.hw_intensity = 20
+    self.initial_is_fl_on = true
+
     if self.device.hasFrontlight() then
         local kobolight = require("ffi/kobolight")
         local ok, light = pcall(kobolight.open)
@@ -46,42 +86,59 @@ function KoboPowerD:init()
     end
 end
 
-function KoboPowerD:_syncIntensity(intensity)
-    if NickelConf.frontLightLevel.get() ~= intensity then
-        NickelConf.frontLightLevel.set(intensity)
-    end
-end
-
-function KoboPowerD:_syncNickelConf()
-    if not KOBO_SYNC_BRIGHTNESS_WITH_NICKEL then return end
-    if NickelConf.frontLightState.get() == nil then
-        self:_syncIntensity(self:frontlightIntensity())
-    else
-        if NickelConf.frontLightState.get() ~= self:isFrontlightOn() then
-            NickelConf.frontLightState.set(self:isFrontlightOn())
+function KoboPowerD:saveSettings()
+    -- Store BasePowerD values into settings (and not our hw_intensity, so
+    -- that if frontlight was toggled off, we save and restore the previous
+    -- untoggled intensity and toggle state at next startup)
+    local cur_intensity = self.fl_intensity
+    local cur_is_fl_on = self.is_fl_on
+    -- Save intensity to koreader settings
+    G_reader_settings:saveSetting("frontlight_intensity", cur_intensity)
+    G_reader_settings:saveSetting("is_frontlight_on", cur_is_fl_on)
+    -- And to "Kobo eReader.conf" if needed
+    if KOBO_SYNC_BRIGHTNESS_WITH_NICKEL then
+        if NickelConf.frontLightState.get() ~= nil then
+            if NickelConf.frontLightState.get() ~= cur_is_fl_on then
+                NickelConf.frontLightState.set(cur_is_fl_on)
+            end
+        else -- no support for frontlight state
+            if not cur_is_fl_on then -- if toggled off, save intensity as 0
+                cur_intensity = self.fl_min
+            end
+        end
+        if NickelConf.frontLightLevel.get() ~= cur_intensity then
+            NickelConf.frontLightLevel.set(cur_intensity)
         end
-        self:_syncIntensity(self.fl_intensity)
     end
 end
 
 function KoboPowerD:frontlightIntensityHW()
-    return NickelConf.frontLightLevel.get()
+    return self.hw_intensity
 end
 
 function KoboPowerD:isFrontlightOnHW()
-    local result = NickelConf.frontLightState.get()
-    if result == nil then
-        return self.fl_intensity > 0
+    if self.initial_is_fl_on ~= nil then -- happens only once after init()
+        -- give initial state to BasePowerD, which will
+        -- reset our self.hw_intensity to 0 if self.initial_is_fl_on is false
+        local ret = self.initial_is_fl_on
+        self.initial_is_fl_on = nil
+        return ret
     end
-    return result
+    return self.hw_intensity > 0
 end
 
-function KoboPowerD:turnOffFrontlightHW() self:_setIntensity(0) end
+function KoboPowerD:turnOffFrontlightHW()
+    self:_setIntensity(0) -- will call setIntensityHW(0)
+end
 
 function KoboPowerD:setIntensityHW(intensity)
     if self.fl == nil then return end
     self.fl:setBrightness(intensity)
-    self:_syncNickelConf()
+    self.hw_intensity = intensity
+    -- Now that we have set intensity, we need to let BasePowerD
+    -- know about possibly changed frontlight state (if we came
+    -- from light toggled off to some intensity > 0).
+    self:_decideFrontlightState()
 end
 
 function KoboPowerD:getCapacityHW()
@@ -94,16 +151,16 @@ end
 
 -- Turn off front light before suspend.
 function KoboPowerD:beforeSuspend()
-    self:turnOffFrontlightHW()
+    if self.fl == nil then return end
+    -- just turn off frontlight without remembering its state
+    self.fl:setBrightness(0)
 end
 
 -- Restore front light state after resume.
 function KoboPowerD:afterResume()
-    if KOBO_LIGHT_ON_START and tonumber(KOBO_LIGHT_ON_START) > -1 then
-        self:setIntensity(math.min(KOBO_LIGHT_ON_START, 100))
-    elseif self:isFrontlightOn() then
-        self:turnOnFrontlightHW()
-    end
+    if self.fl == nil then return end
+    -- just re-set it to self.hw_intensity that we haven't change on Suspend
+    self.fl:setBrightness(self.hw_intensity)
 end
 
 return KoboPowerD

frontend/ui/uimanager.lua

@@ -55,6 +55,7 @@ function UIManager:init()
         require("ui/screensaver"):show("poweroff", _("Powered off"))
         Screen:refreshFull()
         UIManager:nextTick(function()
+            Device:saveSettings()
             self:broadcastEvent(Event:new("Close"))
             Device:powerOff()
         end)
@@ -65,6 +66,7 @@ function UIManager:init()
         require("ui/screensaver"):show("reboot", _("Rebooting..."))
         Screen:refreshFull()
         UIManager:nextTick(function()
+            Device:saveSettings()
             self:broadcastEvent(Event:new("Close"))
             Device:reboot()
         end)

reader.lua

@@ -190,6 +190,9 @@ local function exitReader()
     local ReaderActivityIndicator =
         require("apps/reader/modules/readeractivityindicator")
 
+    -- Save any device settings before closing G_reader_settings
+    Device:saveSettings()
+
     G_reader_settings:close()
 
     -- Close lipc handles