SwitchPlugin and BackgroundTaskPlugin with tests (#3137)

frontend/ui/plugin/switch_plugin.lua

@@ -0,0 +1,111 @@
+--[[--
+SwitchPlugin creates a plugin with a switch to enable or disable it.
+See spec/unit/switch_plugin_spec.lua for the usage.
+]]
+
+local ConfirmBox = require("ui/widget/confirmbox")
+local DataStorage = require("datastorage")
+local LuaSettings = require("luasettings")
+local UIManager = require("ui/uimanager")
+local WidgetContainer = require("ui/widget/container/widgetcontainer")
+local logger = require("logger")
+local _ = require("gettext")
+
+local SwitchPlugin = WidgetContainer:new()
+
+function SwitchPlugin:extend(o)
+    o = o or {}
+    setmetatable(o, self)
+    self.__index = self
+    return o
+end
+
+function SwitchPlugin:new(o)
+    o = self:extend(o)
+    assert(type(o.name) == "string", "name is required");
+    o.settings = LuaSettings:open(DataStorage:getSettingsDir() .. "/" .. o.name .. ".lua")
+    o.settings_id = 0
+    SwitchPlugin._init(o)
+    return o
+end
+
+function SwitchPlugin:_init()
+    if self.default_enable then
+        self.enabled = self.settings:nilOrTrue("enable")
+    else
+        self.enabled = not self.settings:nilOrFalse("enable")
+    end
+    self.settings_id = self.settings_id + 1
+    logger.dbg("SwitchPlugin:_init() self.enabled: ", self.enabled, " with id ", self.settings_id)
+    if self.enabled then
+        self:_start()
+    else
+        self:_stop()
+    end
+end
+
+function SwitchPlugin:flipSetting()
+    if self.default_enable then
+        self.settings:flipNilOrTrue("enable")
+    else
+        self.settings:flipNilOrFalse("enable")
+    end
+    self:_init()
+end
+
+function SwitchPlugin:onFlushSettings()
+    self.settings:flush()
+end
+
+--- Show a ConfirmBox to ask for enabling or disabling this plugin.
+function SwitchPlugin:_showConfirmBox()
+    UIManager:show(ConfirmBox:new{
+        text = self:_confirmMessage(),
+        ok_text = self.enabled and _("Disable") or _("Enable"),
+        ok_callback = function()
+            self:flipSetting()
+        end,
+    })
+end
+
+function SwitchPlugin:_confirmMessage()
+    local result = ""
+    if type(self.confirm_message) == "string" then
+        result = self.confirm_message .. "\n"
+    elseif type(self.confirm_message) == "function" then
+        result = self.confirm_message() .. "\n"
+    end
+    if self.enabled then
+        result = result .. _("Do you want to disable it?")
+    else
+        result = result .. _("Do you want to enable it?")
+    end
+    return result
+end
+
+function SwitchPlugin:init()
+    if type(self.menu_item) == "string" and self.ui ~= nil and self.ui.menu ~= nil then
+        self.ui.menu:registerToMainMenu(self)
+    end
+end
+
+function SwitchPlugin:addToMainMenu(menu_items)
+    assert(type(self.menu_item) == "string",
+           "addToMainMenu should not be called without menu_item.")
+    assert(type(self.menu_text) == "string",
+           "Have you forgotten to set \"menu_text\"")
+    menu_items[self.menu_item] = {
+        text = self.menu_text,
+        callback = function()
+            self:_showConfirmBox()
+        end,
+        checked_func = function() return self.enabled end,
+    }
+end
+
+-- Virtual
+function SwitchPlugin:_start() end
+-- Virtual
+function SwitchPlugin:_stop() end
+
+return SwitchPlugin