Implement keepalive plugin (#2456)

frontend/pluginloader.lua

@@ -20,10 +20,10 @@ function PluginLoader:loadPlugins()
             package.path = path.."/?.lua;"..package.path
             package.cpath = path.."/lib/?.so;"..package.cpath
             local ok, plugin_module = pcall(dofile, mainfile)
-            if not ok then
+            if not ok or not plugin_module then
                 DEBUG("Error when loading", mainfile, plugin_module)
             end
-            if not plugin_module.disabled and ok then
+            if ok and plugin_module and not plugin_module.disabled then
                 package.path = package_path
                 package.cpath = package_cpath
                 plugin_module.path = path

plugins/hello.koplugin/main.lua

@@ -16,7 +16,7 @@ end
 function Hello:addToMainMenu(tab_item_table)
     table.insert(tab_item_table.plugins, {
         text = _("Hello World"),
-        callback_func = function()
+        callback = function()
             UIManager:show(InfoMessage:new{
                 text = _("Hello, docless plugin world"),
             })

plugins/keepalive.koplugin/main.lua

@@ -0,0 +1,51 @@
+
+local ConfirmBox = require("ui/widget/confirmbox")
+local Device = require("device")
+local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local _ = require("gettext")
+
+local function showConfirmBox(disable)
+    UIManager:show(ConfirmBox:new{
+        text = _("The system won't sleep when this message is showing.\nPress \"Stay Alive\" if you prefer to keep system on even after closing this notification. *It will drain the battery.*\n\nIf for any reasons KOReader died before \"Close\" is pressed, please start and close KeepAlive plugin again to ensure settings are reset."),
+        ok_text = _("Close"),
+        ok_callback = disable,
+        cancel_text = _("Stay Alive"),
+    })
+end
+
+local menuItem = {
+    text = _("Keep Alive"),
+}
+
+if Device:isKobo() then
+    disable = function() UIManager:_startAutoSuspend() end
+    menuItem.callback = function()
+        UIManager:_stopAutoSuspend()
+        showConfirmBox(disable)
+    end
+elseif Device:isKindle() then
+    disable = function()
+        os.execute("lipc-set-prop com.lab126.powerd preventScreenSaver 0")
+    end
+    menuItem.callback = function()
+        os.execute("lipc-set-prop com.lab126.powerd preventScreenSaver 1")
+        showConfirmBox(disable)
+    end
+else
+    return { disabled = true, }
+end
+
+local KeepAlive = WidgetContainer:new{
+    name = "keepalive",
+}
+
+function KeepAlive:init()
+    self.ui.menu:registerToMainMenu(self)
+end
+
+function KeepAlive:addToMainMenu(tab_item_table)
+    table.insert(tab_item_table.plugins, menuItem)
+end
+
+return KeepAlive