Wikipedia Save as EPUB: fix some wiki links and speedup download (#3551)

- Fix links to wikipedia pages containing '?oldid=123', that
  wouldn't work when used back thru the API.
- Make external links to other wikipedias with a different langage
  work (they didn't work when non-ascii page titles)
- Speedup download of images by using a newly added 'fast_refresh'
  option to Trapper:info() to bypass UIManager.

frontend/ui/trapper.lua

@@ -105,14 +105,19 @@ steps of the work, to provide good responsiveness.
 Trapper:info() is a shortcut to get dismiss info while keeping
 the existing InfoMessage displayed.
 
+Optional fast_refresh parameter should only be used when
+displaying an InfoMessage over a previous InfoMessage of the
+exact same size.
+
 @string text text to display as an InfoMessage (or nil to keep existing one)
+@boolean fast_refresh[opt=false] true for faster refresh
 @treturn boolean true if InfoMessage was not dismissed, false if dismissed
 
 @usage
     Trapper:info("some text about step or progress")
     go_on = Trapper:info()
 ]]
-function Trapper:info(text)
+function Trapper:info(text, fast_refresh)
     local _coroutine = coroutine.running()
     if not _coroutine then
         logger.info("unwrapped info:", text)
@@ -181,23 +186,34 @@ function Trapper:info(text)
     -- events won't be considered action on the yet to be displayed
     -- widget
 
-    -- We're going to display a new widget, close previous one
-    if self.current_widget then
-        UIManager:close(self.current_widget)
-        -- no repaint here, we'll do that below when a new one is shown
-    end
+    -- If fast_refresh option, avoid UIManager refresh overhead
+    if fast_refresh and self.current_widget and self.current_widget.is_infomessage then
+        self.current_widget:free()
+        self.current_widget.text = text
+        self.current_widget:init()
+        local Screen = require("device").screen
+        self.current_widget:paintTo(Screen.bb, 0,0)
+        local d = self.current_widget[1][1].dimen
+        Screen.refreshUI(Screen, d.x, d.y, d.w, d.h)
+    else
+        -- We're going to display a new widget, close previous one
+        if self.current_widget then
+            UIManager:close(self.current_widget)
+            -- no repaint here, we'll do that below when a new one is shown
+        end
 
-    -- dismiss_callback will be checked for at start of next call
-    self.current_widget = InfoMessage:new{
-        text = text,
-        dismiss_callback = function()
-            coroutine.resume(_coroutine, false)
-        end,
-        is_infomessage = true -- flag on our InfoMessages
-    }
-    logger.dbg("Showing InfoMessage:", text)
-    UIManager:show(self.current_widget)
-    UIManager:forceRePaint()
+        -- dismiss_callback will be checked for at start of next call
+        self.current_widget = InfoMessage:new{
+            text = text,
+            dismiss_callback = function()
+                coroutine.resume(_coroutine, false)
+            end,
+            is_infomessage = true -- flag on our InfoMessages
+        }
+        logger.dbg("Showing InfoMessage:", text)
+        UIManager:show(self.current_widget)
+        UIManager:forceRePaint()
+    end
     return true
 end
 

frontend/ui/wikipedia.lua

@@ -685,7 +685,18 @@ time, abbr, sup {
     -- when we should have get "\xc3\xa7" ...
     -- We can avoid that by putting in the url plain unencoded UTF8
     local hex_to_char = function(x) return string.char(tonumber(x, 16)) end
+    -- Do that first (need to be done first) for full links to other language wikipedias
+    local fixEncodedOtherLangWikiPageTitle = function(wiki_lang, wiki_page)
+        -- First, remove any "?otherkey=othervalue" from url (a real "?" part of the wiki_page word
+        -- would be encoded as %3f), that could cause problem when used.
+        wiki_page = wiki_page:gsub("%?.*", "")
+        wiki_page = wiki_page:gsub("%%(%x%x)", hex_to_char)
+        return string.format([[href="https://%s.wikipedia.org/wiki/%s"]], wiki_lang, wiki_page)
+    end
+    html = html:gsub([[href="https?://([^%.]+).wikipedia.org/wiki/([^"]*)"]], fixEncodedOtherLangWikiPageTitle)
+    -- Now, do it for same wikipedia short urls
     local fixEncodedWikiPageTitle = function(wiki_page)
+        wiki_page = wiki_page:gsub("%?.*", "")
         wiki_page = wiki_page:gsub("%%(%x%x)", hex_to_char)
         return string.format([[href="%s/wiki/%s"]], wiki_base_url, wiki_page)
     end
@@ -747,6 +758,11 @@ time, abbr, sup {
 </html>
 ]], page_cleaned, page_htmltitle, lang:upper(), saved_on, see_online_version, html))
 
+    -- Force a GC to free the memory we used till now (the second call may
+    -- help reclaim more memory).
+    collectgarbage()
+    collectgarbage()
+
     -- ----------------------------------------------------------------
     -- OEBPS/images/*
     if include_images then
@@ -754,7 +770,8 @@ time, abbr, sup {
         for inum, img in ipairs(images) do
             -- Process can be interrupted at this point between each image download
             -- by tapping while the InfoMessage is displayed
-            local go_on = UI:info(T(_("Fetching image %1 / %2 …"), inum, nb_images))
+            -- We use the fast_refresh option from image #2 for a quicker download
+            local go_on = UI:info(T(_("Fetching image %1 / %2 …"), inum, nb_images), inum >= 2)
             if not go_on then
                 cancelled = true
                 break
@@ -810,6 +827,11 @@ time, abbr, sup {
     -- Finally move the .tmp to the final file
     os.rename(epub_path_tmp, epub_path)
     logger.info("successfully created:", epub_path)
+
+    -- Force a GC to free the memory we used (the second call may help
+    -- reclaim more memory).
+    collectgarbage()
+    collectgarbage()
     return true
 end