FileManager: Hold the "+" button to refresh content (#7559)

frontend/apps/filemanager/filemanager.lua

@@ -129,6 +129,13 @@ function FileManager:setupLayout()
         padding_right = Size.padding.large,
         padding_bottom = 0,
         callback = function() self:onShowPlusMenu() end,
+        hold_callback = function()
+            self:onRefresh()
+            UIManager:show(InfoMessage:new{
+                text = _("Content refreshed."),
+                timeout = 2,
+            })
+        end,
     }
 
     self.path_text = TextWidget:new{