Speedup initialization (needs to be done only once, and avoid
saving current mode to sqlite each time) and reader-to-filebrowser
switch, by doing a single rendering (instead of 2 or 3 previously).
ListMenu: cache sidecar file parsing results (page/percent
completed) for the browsing session duration.
Fix "No choice available" when on last page and changing
to a display mode with less pages.
This is done by/for kosync plugin at each opening, because
the docsettings was re-opened and saved for this, but later
overwritten by the current koreader docsettings - so it was
redone each time. This correctly adds this partial_md5_checksum
to the current koreader docsettings, which will be saved on
document closing - so it will not be redone next time.
Note: this partial_md5_checksum is not (yet) used by anything.
This gives the page position to these modules even in scroll mode.
Also, in readerrolling: don't query battery/charging status
when crengine does not need it (used only when it shows its top
progress bar).
We previously disabled cache, but that may cause excessive
memory usage with big books. We now use a temporary
cache directory, that we clean when no more needed.
Closes: #3236 and #3235
Details:
> Also, when looking in days, we see info how many hours we read. It would be great if we could tap a day, it opens info on book(s) we read that day with info pertaining to that day, and if we tap on book, we receive book info for that book.
> Statistics plugin is really great, I started to look in my reading statistics now much more, but all the time I can go only in one way. And I need to exit at lowest level of info. It would be great if I can use statistics plugin like part of menu, to go up and down within statistics data and exit at my wish, not when I have to.
Also added:
* new statistics book by week
* new statistics book by month
* last year by week now we can see days in selected week
Made the onHold buttons table similar to the one of File browser.
Added "Purge .sdr" and "Delete" to these buttons.
Moved the purgeSettings and removeFileFromHistoryIfWanted
logic into filemanagerutil functions.
Stay on the same page when manipulating history (previously, we were
always put back on first page).
Really keep deleted files in history (unless setting says otherwise).
Show deleted files in grey or dimmed in classic History and all
CoverBrowser display modes.
So an image file can have a cover in coverbrowser's display.
It also allows for an alternative viewer (ImageViewer widget)
when holding on file / View full size cover.
