Demos

The Datui demo animations are created using vhs, which lets you script and record keystrokes to a terminal app.

Prerequisites

VHS

See vhs install instructions.

JetBrainsMono Nerd Font

• Get it from nerdfonts.com and install it manually
• Get it from your distribution’s package manager
  • Arch Linux
  • Other distributions may have their own packages

Define Tapes

The vhs application uses .tape files to script keystrokes. See Datui’s here. Only tape files matching the {number}-{name}.tape format (e.g. 01-basic-navigation.tape) are included when generating all demos.

The home-screen demo records against a fixture

Every other tape opens a file it names. The home screen instead shows what is around you — recents, the working directory, configured directories, and the desktop’s recently-used list — so recording it on a developer’s machine would put that machine’s contents on screen. That is a privacy problem before it is anything else: the desktop’s list in particular holds whatever you last opened anywhere, which is regularly something you would not publish.

So 12-home-screen.tape records against a fixture, built by make-home-fixture.py, which the generator runs first:

• its own workspace of generated Parquet under /tmp/datui-demo, laid out like a real research tree — hive-partitioned by year, with related datasets — because the home screen’s whole point is what it can tell you about data before you open it, and that needs data with a shape;
• its own DATUI_CACHE_DIR, so Recent is seeded rather than inherited;
• its own XDG_CONFIG_HOME holding a config with use_desktop_recents = false, which is the line that matters: that list is the one input which can put a file from anywhere on the machine into the recording.

The tape exports those two variables itself, with Hide … Show around them, because VHS 0.11 has no Set Env.

The upshot is that regenerating this GIF gives the same result on any checkout, and shows nothing belonging to whoever ran it.

Generating the Animations

Run generate_demos.py to use vhs to generate an animated gif file for each matching tape. The script builds the debug binary, then runs VHS in parallel (one process per tape by default, using all available cores).

The script runs a debug build and uses that binary when creating the demos.

# Generate all demos (parallel, uses all cores)
python scripts/demos/generate_demos.py

Or if the script is executable:

scripts/demos/generate_demos.py

Useful command-line options

Examples:

# Generate only the second demo
python scripts/demos/generate_demos.py --number 2

# Generate all demos using 4 worker processes
python scripts/demos/generate_demos.py -n 4

The animations will be placed in the demos directory. A percentage bar shows progress as each tape finishes.

During the creation of the documentation, these animations are copied into a demos/ subdirectory of the generated site. From there, the files may be referenced from within the docs.