History browser: show color gutter based on timestamp

[simon04]

The history browser could show color gutter based on the timestamp of the corresponding versions:

Inspired by IntelliJ IDEA: ​https://www.jetbrains.com/help/idea/viewing-changes-information.html#annotations

[simon04]

In 17889/josm:

see #20880 - Extract class VersionTableCellRenderer

[simon04]

In 17890/josm:

fix #20880 - History browser: show color gutter based on timestamp

[simon04]

In 17892/josm:

see #20880 - Fix VersionTableCellRenderer

[gaben]

If the modifications not uploaded yet, the version number is messed up. After upload the since column becomes empty.

[gaben]

While testing, you will encounter #18697.

[skyper]

+1,
looking at the colors I would expect them to be the opposite from "cold" oldest version (dark blue) to "hot" newest version (dark red)

[skyper]

Replying to skyper:

+1,
looking at the colors I would expect them to be the opposite from "cold" oldest version (dark blue) to "hot" newest version (dark red)

I thought about the colors again and came to the conclusion, that it is too colorful. Using less different main colors and a clean distinction from dark (old) to bright (new) would be much better. I think about a color line: black - blue - silver - white. The two colors in the middle could be change like red - yellow or what you like.

If it really should be that colorful, the order of colors should be changed. It is a shame but I do not find the nice documentation about this problem but ​this article might help a bit, I hope.

[simon04]

Colour schemes of git blame in other applications:

• ​https://www.jetbrains.com/help/idea/investigate-changes.html#annotate_blame
• ​https://docs.github.com/en/github/managing-files-in-a-repository/managing-files-on-github/tracking-changes-in-a-file
• ​https://github.com/eamodio/vscode-gitlens#gutter-heatmap-

[skyper]

Actually, we already have several color settings for heatmaps in the gps track and point coloring settings. Why not offer all these for the clutter colors?