[CoverImage] Honor rotation after opening of a book (#11752)

If rotation changes, create a new cache entry and use that if necessary.

Fixes #11713.

frontend/apps/reader/modules/readerview.lua

@@ -781,7 +781,7 @@ function ReaderView:onSetRotationMode(rotation)
     if rotation ~= nil then
         local old_rotation = Screen:getRotationMode()
         if rotation == old_rotation then
-            return true
+            return
         end
 
         -- NOTE: We cannot rely on getScreenMode, as it actually checks the screen dimensions, instead of the rotation mode.
@@ -798,7 +798,7 @@ function ReaderView:onSetRotationMode(rotation)
             Screen:setRotationMode(rotation)
             UIManager:setDirty(self.dialog, "full")
             Notification:notify(T(_("Rotation mode set to: %1"), optionsutil:getOptionText("SetRotationMode", rotation)))
-            return true
+            return
         end
 
         Screen:setRotationMode(rotation)
@@ -810,7 +810,7 @@ function ReaderView:onSetRotationMode(rotation)
     self.ui:onScreenResize(new_screen_size)
     self.ui:handleEvent(Event:new("InitScrollPageStates"))
     Notification:notify(T(_("Rotation mode set to: %1"), optionsutil:getOptionText("SetRotationMode", rotation)))
-    return true
+    return
 end
 
 function ReaderView:onSetDimensions(dimensions)

plugins/coverimage.koplugin/main.lua

@@ -115,6 +115,7 @@ function CoverImage:createCoverImage(doc_settings)
         if cover_image then
             local cache_file = self:getCacheFile(custom_cover)
             if lfs.attributes(cache_file, "mode") == "file" then
+                logger.dbg("CoverImage: cache file already exists")
                 ffiutil.copyFile(cache_file, self.cover_image_path)
                 lfs.touch(cache_file) -- update date
                 return
@@ -124,6 +125,14 @@ function CoverImage:createCoverImage(doc_settings)
             local i_w, i_h = cover_image:getWidth(), cover_image:getHeight()
             local scale_factor = math.min(s_w / i_w, s_h / i_h)
 
+            if Screen:getRotationMode() == Screen.DEVICE_ROTATED_UPSIDE_DOWN
+                or Screen:getRotationMode() == Screen.DEVICE_ROTATED_CLOCKWISE then
+
+                local flipped_cover = cover_image:rotatedCopy(180)
+                cover_image:free()
+                cover_image = flipped_cover
+            end
+
             if self.cover_image_background == "none" or scale_factor == 1 then
                 local act_format = self.cover_image_format == "auto" and getExtension(self.cover_image_path) or self.cover_image_format
                 if not cover_image:writeToFile(self.cover_image_path, act_format, self.cover_image_quality, self.cover_image_grayscale) then
@@ -199,6 +208,11 @@ function CoverImage:onReaderReady(doc_settings)
     self:createCoverImage(doc_settings)
 end
 
+function CoverImage:onSetRotationMode(rotation)
+    logger.dbg("CoverImage: onSetRotationMode", rotation)
+    self:createCoverImage(self.ui.doc_settings)
+end
+
 function CoverImage:fallbackEnabled()
     return self.fallback and isFileOk(self.cover_image_fallback_path)
 end
@@ -217,6 +231,7 @@ function CoverImage:getCacheFile(custom_cover)
     -- use document_name here. Title may contain characters not allowed on every filesystem (esp. vfat on /sdcard)
     local key = document_name .. custom_cover_mtime .. self.cover_image_quality .. self.cover_image_stretch_limit
         .. self.cover_image_background .. self.cover_image_format .. tostring(self.cover_image_grayscale)
+        .. Screen:getRotationMode()
 
     return self.cover_image_cache_path .. self.cover_image_cache_prefix .. md5(key) .. "." .. getExtension(self.cover_image_path)
 end
@@ -470,7 +485,9 @@ function CoverImage:menuEntryCache()
                     end
                     return T(_("Maximum number of cached covers: %1"), number)
                 end,
-                help_text = _("If set to zero the number of cache files is unlimited.\nIf set to -1 the cache is disabled."),
+                help_text = string.format("%s\n\n%s",
+                    _("If set to zero the number of cache files is unlimited.\nIf set to -1 the cache is disabled."),
+                    _("Each screen orientation requires its own cache file.")),
                 checked_func = function()
                     return self.cover_image_cache_maxfiles >= 0
                 end,