[PierreRaybaut]

Fix of an unreleased change of #454 (curve readability). Depends on DataLab-Platform/SigimaX#37, on the same branch name, which is cloned by the CI.

Problem

Since #454, SigimaX ignored stored curve styles at display time when they matched the automatic style cycle of DataLab 1.3 or earlier (tab10 colors with one of 4 line styles). A style chosen by the user among these 40 combinations, for example #1f77b4 with a solid line, was therefore:

• lost when reloading a workspace;
• removed from the metadata at the next save.

Change

SigimaX now always restores stored styles (DataLab-Platform/SigimaX#37). The automatic styles stored by older versions are therefore converted once, when DataLab loads their files.

Native HDF5 reader

• NativeH5Reader.saved_version: version that saved the file, decoded once whether it is stored as a string or as bytes. H5InputOutput now uses it, instead of its own private method.
• NativeH5Reader.has_legacy_curve_styles, based on is_legacy_style_version:
  • the file is considered legacy when its release number is lower than 1.4 (compared with packaging), so pre-releases of 1.4 are not legacy;
  • a missing or invalid version keeps the stored styles.

Signal loading

• SignalPanel.deserialize_object_from_hdf5 removes color and style when the file is legacy and the pair belongs to the old automatic cycle. The conversion happens before the plot items are created.
• This single point covers opening and appending workspaces, the headless mode, and .dlhist files, both when loaded into an empty workspace and when imported into a workspace in use.

Documentation

• View menu (Reset curve styles) and 1.4.0 release notes:
  • styles chosen with DataLab 1.3 that are identical to an automatic style of that version are also removed;
  • metadata imported from a file are applied as they are.
• French translations.

Tests

• curve_styles_unit_test.py:
  • a workspace whose DataLab_Version is rewritten to 1.3.0 is converted, while a legacy color with DotLine is kept;
  • the same file with the current version keeps its styles;
  • a .dlhist file dated 1.3 is converted when imported into a workspace in use;
  • #1f77b4 with SolidLine chosen by the user survives two HDF5 cycles;
  • version parsing (1.4.0rc1, 1.4.0.dev0, 1.10.0, invalid values, None).
• New native_reader_unit_test.py: saved_version stored as a string, as bytes, or invalid.
• test_open_file_headless_refreshes_reference_displays: its reader test double now provides saved_version, as the reader does.
• Without the conversion added to SignalPanel, both legacy loading tests fail.
• Local runs of the signal, hdf5, common, backbone, image, plugins and control suites: 1103 passed, 3 skipped.