reader(fix): force draw info message before loading document

Since the doShowReader will run in nextTick, it will get picked up by
checkTask, which is in the beginning of next UI loop and blocks
UIManager from redrawing the screen for the info popup.

frontend/apps/reader/readerui.lua

@@ -12,7 +12,7 @@ local Device = require("device")
 local Screen = require("device").screen
 local Event = require("ui/event")
 local Cache = require("cache")
-local DEBUG = require("dbg")
+local dbg = require("dbg")
 local T = require("ffi/util").template
 local _ = require("gettext")
 
@@ -304,7 +304,7 @@ function ReaderUI:init()
     })
     -- koreader plugins
     for _,plugin_module in ipairs(PluginLoader:loadPlugins()) do
-        DEBUG("Loaded plugin", plugin_module.name, "at", plugin_module.path)
+        dbg("Loaded plugin", plugin_module.name, "at", plugin_module.path)
         self:registerModule(plugin_module.name, plugin_module:new{
             dialog = self.dialog,
             view = self.view,
@@ -313,7 +313,7 @@ function ReaderUI:init()
         })
     end
 
-    --DEBUG(self.doc_settings)
+    --dbg(self.doc_settings)
     -- we only read settings after all the widgets are initialized
     self:handleEvent(Event:new("ReadSettings", self.doc_settings))
 
@@ -328,20 +328,22 @@ function ReaderUI:init()
 end
 
 function ReaderUI:showReader(file)
-    DEBUG("show reader ui")
+    dbg("show reader ui")
     require("readhistory"):addItem(file)
     if lfs.attributes(file, "mode") ~= "file" then
         UIManager:show(InfoMessage:new{
-             text = T( _("File '%1' does not exist."), file)
+             text = T(_("File '%1' does not exist."), file)
         })
         return
     end
     UIManager:show(InfoMessage:new{
-        text = T( _("Opening file '%1'."), file),
+        text = T(_("Opening file '%1'."), file),
         timeout = 0.0,
     })
+    -- doShowReader might block for a long time, so force repaint here
+    UIManager:forceRePaint()
     UIManager:nextTick(function()
-        DEBUG("creating coroutine for showing reader")
+        dbg("creating coroutine for showing reader")
         local co = coroutine.create(function()
             self:doShowReader(file)
         end)
@@ -356,7 +358,7 @@ end
 
 local running_instance = nil
 function ReaderUI:doShowReader(file)
-    DEBUG("opening file", file)
+    dbg("opening file", file)
     -- keep only one instance running
     if running_instance then
         running_instance:onClose()
@@ -369,7 +371,7 @@ function ReaderUI:doShowReader(file)
         return
     end
     if document.is_locked then
-        DEBUG("document is locked")
+        dbg("document is locked")
         self._coroutine = coroutine.running() or self._coroutine
         self:unlockDocumentWithPassword(document)
         if coroutine.running() then
@@ -394,7 +396,7 @@ function ReaderUI:_getRunningInstance()
 end
 
 function ReaderUI:unlockDocumentWithPassword(document, try_again)
-    DEBUG("show input password dialog")
+    dbg("show input password dialog")
     self.password_dialog = InputDialog:new{
         title = try_again and _("Password is incorrect, try again?")
             or _("Input document password"),
@@ -482,10 +484,10 @@ function ReaderUI:notifyCloseDocument()
 end
 
 function ReaderUI:onClose()
-    DEBUG("closing reader")
+    dbg("closing reader")
     self:saveSettings()
     if self.document ~= nil then
-        DEBUG("closing document")
+        dbg("closing document")
         self:notifyCloseDocument()
     end
     UIManager:close(self.dialog, "full")

frontend/ui/uimanager.lua

@@ -521,6 +521,10 @@ function UIManager:_repaint()
     self.refresh_counted = false
 end
 
+function UIManager:forceRePaint()
+    self:_repaint()
+end
+
 function UIManager:setInputTimeout(timeout)
     self.INPUT_TIMEOUT = timeout or 200*1000
 end