add hidden file toggle

frontend/apps/filemanager/fm.lua

@@ -46,6 +46,7 @@ function FileManager:init()
 			end
 		end
 	}
+	self.file_chooser = file_chooser
 
 	function file_chooser:onFileSelect(file)
 		showReaderUI(file)
@@ -78,6 +79,9 @@ function FileManager:init()
 	self:handleEvent(Event:new("SetDimensions", self.dimen))
 end
 
+function FileManager:toggleHiddenFiles()
+	self.file_chooser:toggleHiddenFiles()
+end
 
 function FileManager:onClose()
 	UIManager:close(self)

frontend/apps/filemanager/fmmenu.lua

@@ -49,9 +49,17 @@ function FileManagerMenu:setUpdateItemTable()
 		widget:addToMainMenu(self.tab_item_table)
 	end
 
+	table.insert(self.tab_item_table.main, {
+		text = _("Toggle hidden files"),
+		callback = function()
+			self.ui:toggleHiddenFiles()
+		end
+	})
+
 	if Device:getFrontlight() ~= nil then
 		ReaderFrontLight:addToMainMenu(self.tab_item_table)
 	end
+
 	table.insert(self.tab_item_table.main, {
 		text = _("Help"),
 		callback = function()

frontend/ui/widget/filechooser.lua

@@ -55,6 +55,11 @@ function FileChooser:changeToPath(path)
 	self:swithItemTable(nil, self:genItemTableFromPath(path))
 end
 
+function FileChooser:toggleHiddenFiles()
+	self.show_hidden = not self.show_hidden
+	self:swithItemTable(nil, self:genItemTableFromPath(self.path))
+end
+
 function FileChooser:onMenuSelect(item)
 	if lfs.attributes(item.path, "mode") == "directory" then
 		self:changeToPath(item.path)