Show full ToC entry on hold (#6729)

Fix #6728

frontend/apps/reader/modules/readertoc.lua

@@ -7,10 +7,12 @@ local Event = require("ui/event")
 local Font = require("ui/font")
 local GestureRange = require("ui/gesturerange")
 local Geom = require("ui/geometry")
+local InfoMessage = require("ui/widget/infomessage")
 local InputContainer = require("ui/widget/container/inputcontainer")
 local Menu = require("ui/widget/menu")
 local UIManager = require("ui/uimanager")
 local logger = require("logger")
+local util  = require("util")
 local _ = require("gettext")
 local Screen = Device.screen
 local T = require("ffi/util").template
@@ -582,6 +584,17 @@ function ReaderToc:onShowToc()
         end
     end
 
+    function toc_menu:onMenuHold(item)
+        -- Trim toc_indent
+        local trimmed_text = util.ltrim(item.text)
+        local infomessage = InfoMessage:new{
+            show_icon = false,
+            text = trimmed_text,
+        }
+        UIManager:show(infomessage)
+        return true
+    end
+
     toc_menu.close_callback = function()
         UIManager:close(menu_container)
     end