Peek: support previewing midi file

[oxygen dioxide (oxygen-dioxide)]

Summary of the Pull Request

After this PR, users can preview midi (.mid) files as piano roll with peek.

PR Checklist

• Closes: Peek: Support previewing midi (and other symbolic music formats) #44493
• Communication: I've discussed this with core contributors already. If the work hasn't been agreed, this work might be rejected
• Tests: Added/updated and all pass
• Localization: All end-user-facing strings can be localized
• Dev docs: Added/updated
• New binaries: Added on the required places
  • JSON for signing for new binaries
  • WXS for installer for new binaries and localization folder
  • YML for CI pipeline for new test projects
  • YML for signed pipeline
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

When the user previews a midi file with peek, it will parse the midi file to get the positions, durations and pitches of musical notes, and plot them into a svg graph, where the X axis represents time, the Y axis represents pitch, and different colors represents different tracks. It will be shown in a webview2 where user can zoom and scroll.

Validation Steps Performed

Download this file and extract:
Oh_My_Darling_Clementine.mid.zip

Launch powertoys. Turn on peek. press Ctrl+Space on the midi file, and peek will show a window like this:

[leileizhang (lei9444)]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[Gordon Lam (yeelam-gordon)]

Thanks oxygen dioxide (@oxygen-dioxide) for the PR.
Since we use WebView2 for preview, we’re considering whether it would be simpler to create a miniView.html with a well-known JavaScript bundle that handles MIDI well, rather than implementing most of the logic in C#. This would also be the preferred direction for adding new file types.

leileizhang (@lei9444) and Niels Laute (@niels9001) here.

[oxygen dioxide (oxygen-dioxide)]

Sorry, I'm not farmiliar with html and js, so I'm not able to develop midi functionality on them

[Gordon Lam (yeelam-gordon)]

🔍 Automated PR Review Summary

Step	Severity	Finding
01-functionality	🟡 medium	CalculateRange() calls Min/Max on note collections without handling emp...
03-performance	🟡 medium	The new MIDI branch calls PianoRollHelper.PreviewTempFile(...) inside `Disp...
05-security	🟢 low	The MIDI parser is invoked directly on untrusted file content without an expl...
10-repo-patterns	🟡 medium	This PR introduces a new third-party dependency (Melanchall.DryWetMidi) but...
11-docs-automation	🟡 medium	A new third-party dependency (Melanchall.DryWetMidi) was added, but this PR...
12-code-comments	🟢 low	PianoRollHelper introduces public members (PianoRollHelper, MidiSvg) wi...

Review generated by pr-review skill. See Generated Files/prReview/44494/ for full details.

[Niels Laute (niels9001)]

Thanks oxygen dioxide (@oxygen-dioxide) for the PR. Since we use WebView2 for preview, we’re considering whether it would be simpler to create a miniView.html with a well-known JavaScript bundle that handles MIDI well, rather than implementing most of the logic in C#. This would also be the preferred direction for adding new file types.

leileizhang (@lei9444) and Niels Laute (@niels9001) here.

oxygen dioxide (@oxygen-dioxide) I agree with Gordon Lam (@yeelam-gordon); we want to keep Peek as light-weight as possible and would ideally like to use WebView2 to be the renderer of certain file previews so we don't need to maintain a lot.

I'm therefore closing this PR. We do very much appreciate the work - and thanks for taking the time! If we can support you in porting some of these things to the WebView2 approach please let us know!