Remove the Strength preferences setting.
Add a new left drawer menu item to set the current engine strength in
terms of Elo. Supported for all engines that implement the standard
UCI options UCI_LimitStrength and UCI_Elo.
Elo settings are remembered individually for each engine.
If both "Strength" and "UCI_Elo" is used, "UCI_Elo" tases precedence.
Internally UCI_Elo is converted to a Strength value using a lookup
table that was calculated by playing games against Stockfish 11 using
its UCI_Elo implementation. The time control was 60+0.6 on computers
where Stockfish bench reported about 1.73e6 NPS.
In many cases the pre-comment of one move is displayed at the same
position in the move text as the post-comment of the previous move.
When this is the case, don't make a distinction between pre and post
comments in the "Edit Comments" dialog.
The PGN standard does not allow the '}' character inside a comment,
because it is used to end the comment.
Therefore this character is now replaced with '｝' (fullwidth right
curly bracket) when editing comments. This does not look great but is
better than making the PGN data invalid.
This is needed to avoid problems when dragging one of the R/G/B
sliders. With the default Android conversion code, the other R/G/B
sliders sometimes move during dragging.
The following settings can now be changed using the OI file manager:
* Opening Book Settings -> Book Filename
* Endgame Tablebases -> GTB Directory
* Endgame Tablebases -> Syzygy Directory
For string UCI options containing "file" or "path" in their names, add
a button that opens a file browser to set the value of the option.
The browse button is only available if "OI file manager" or a
compatible app is installed. The button is not available for network
engines because there is no way to browse the remote filesystem where
the network engine runs.
