recording: query_and_hover (live readout follows the cursor)

[borisbat]

Seventh tutorial recording, and the last of the subject-interaction set. query_and_hover reads the cursor live: while the pointer is over the plot the example draws a vertical crosshair at the cursor x and an (x, y) label in data coords (GetPlotMousePos). The interaction it teaches is the hover — move the cursor and the readout follows, every frame. Driven with a real synthetic cursor glide (center → left → right), voiced and self-verifying: each beat waits for hovered to flip true, then asserts GetPlotMousePos resolved into the band the cursor was aimed at (and moved right between beats), so a dead hover or a frozen readout aborts at teardown.

Example tidy (from review)

The cursor label printed full double precision — (73.97119341563786, -0.19043977055449335). Formatted via fmt precision specifiers in the interpolation, "({mp.x:.1f}, {mp.y:.2f})", so it now reads (74.0, -0.19).

Note: format(...) is deprecated in favor of fmt, whose spec is :.1f (not printf %.1f), and it validates at runtime — so a bad spec passes compile/lint and only throws when the example runs. The driver's self-verification caught it (fmt error: invalid format string → recording aborted) before it could ship a broken clip.

Files

• examples/tutorial/query_and_hover.das — format the cursor label to 1–2 decimals (+ require strings for fmt).
• tests/integration/record_query_and_hover.das — the voiced driver (intro + glide left + glide right), each verifying hovered + mouse-plot-x in the aimed band.
• doc/source/tutorials/query_and_hover.rst — .. video:: query_and_hover.mp4; inline snippet + prose synced to the formatted label.
• doc/source/_static/tutorials/query_and_hover.mp4 — the recording (633 KB, 26.4 s, 695 frames, 0 dropped, Emma voice + −16 dB bed).

Verification

• ok:true, 695 frames, 0 dropped; all four gates pass (hovered + left band [8,40] + right band [60,92] + moved right).
• Eyeballed: crosshair + label track center → left (21.9, 0.20) → right (74.0, -0.19).

The headless guard is the existing test_query_and_hover.das.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Adds the final “subject-interaction” tutorial recording for query_and_hover, and tightens the example’s cursor readout formatting so the on-plot label is readable and consistent with the narrated walkthrough.

Changes:

• Add a new integration recording driver that glides a synthetic cursor and self-verifies hover + live GetPlotMousePos readout bands.
• Format the on-plot (x, y) cursor label to fixed decimals using fmt-style precision specifiers.
• Update the tutorial RST to include the walkthrough video and keep the inline snippet/prose in sync with the formatted label.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
tests/integration/record_query_and_hover.das	New voiced recording driver that hovers and glides the cursor while asserting live plot-mouse readout behavior.
examples/tutorial/query_and_hover.das	Formats the cursor label to 1–2 decimals and adds the required module import for formatting.
doc/source/tutorials/query_and_hover.rst	Updates snippet + prose to match the formatted label and adds a walkthrough video section.

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