fullscreen toggle for Jelly Bean devices

frontend/device/android/device.lua

@@ -1,5 +1,6 @@
 local Generic = require("device/generic/device")
 local A, android = pcall(require, "android")  -- luacheck: ignore
+local Geom = require("ui/geometry")
 local ffi = require("ffi")
 local C = ffi.C
 local lfs = require("libs/libkoreader-lfs")
@@ -132,6 +133,11 @@ function Device:init()
         android.setWakeLock(true)
     end
 
+    -- check if we disable fullscreen support
+    if G_reader_settings:isTrue("disable_android_fullscreen") then
+        self:toggleFullscreen()
+    end
+
     Generic.init(self)
 end
 
@@ -165,6 +171,34 @@ function Device:retrieveNetworkInfo()
     end
 end
 
+function Device:setViewport(x,y,w,h)
+    logger.info(string.format("Switching viewport to new geometry [x=%d,y=%d,w=%d,h=%d]",x, y, w, h))
+    local viewport = Geom:new{x=x, y=y, w=w, h=h}
+    self.screen:setViewport(viewport)
+end
+
+function Device:toggleFullscreen()
+    local api = android.app.activity.sdkVersion
+    if api >= 19 then
+        logger.dbg("ignoring fullscreen toggle, reason: always in immersive mode")
+    elseif api < 19 and api >= 17 then
+        local width = android.getScreenWidth()
+        local height = android.getScreenHeight()
+        local available_height = android.getScreenAvailableHeight()
+        local is_fullscreen = android.isFullscreen()
+        android.setFullscreen(not is_fullscreen)
+        G_reader_settings:saveSetting("disable_android_fullscreen", is_fullscreen)
+        is_fullscreen = android.isFullscreen()
+        if is_fullscreen then
+            self:setViewport(0, 0, width, height)
+        else
+            self:setViewport(0, 0, width, available_height)
+        end
+    else
+        logger.dbg("ignoring fullscreen toggle, reason: legacy api " .. api)
+    end
+end
+
 function Device:info()
     local is_eink, eink_platform = android.isEink()
 

frontend/ui/elements/common_settings_menu_table.lua

@@ -181,8 +181,8 @@ if Device:isAndroid() then
         }
     end
 
-    -- fullscreen toggle on devices with compatible fullscreen methods (apis 14-16)
-    if Device.firmware_rev <= 16 then
+    -- fullscreen toggle on devices with compatible fullscreen methods (apis 14-18)
+    if Device.firmware_rev < 19 then
         common_settings.fullscreen = {
             text = _("Fullscreen"),
             checked_func = function() return android.isFullscreen() end,

frontend/ui/elements/screen_android.lua

@@ -2,6 +2,7 @@ local isAndroid, android = pcall(require, "android")
 local Device = require("device")
 local Geom = require("ui/geometry")
 local logger = require("logger")
+local _ = require("gettext")
 local Input = Device.input
 local Screen = Device.screen
 
@@ -9,8 +10,23 @@ if not isAndroid then return end
 
 local ScreenHelper = {}
 
--- toggle android status bar visibility
 function ScreenHelper:toggleFullscreen()
+    local api = Device.firmware_rev
+
+    if api < 19 and api >= 17 then
+        Device:toggleFullscreen()
+        local UIManager = require("ui/uimanager")
+        local InfoMessage = require("ui/widget/infomessage")
+        UIManager:show(InfoMessage:new{
+            text = _("This will take effect on next restart.")
+        })
+    elseif api < 17 then
+        self:toggleFullscreenLegacy()
+    end
+end
+
+-- toggle android status bar visibility -- Legacy function for Apis 14 - 16
+function ScreenHelper:toggleFullscreenLegacy()
     -- toggle android status bar visibility
     local is_fullscreen = android.isFullscreen()
     android.setFullscreen(not is_fullscreen)