Piano synth · deepseek-v4.1-flash

Let me start by checking the directory and the tone.min.js file.

Let me build the index.html. I'll design a playable piano with 13 keys C4-C5.

Notes: C4, C#4, D4, D#4, E4, F4, F#4, G4, G#4, A4, A#4, B4, C5
Keys: A W S E D F T G Y H U J K

Let me build white keys and black keys positioned correctly.

White keys: C D E F G A B C (8 white keys)
Black keys: C# D# F# G# A# (5 black keys)

Layout: white keys as flex, black keys absolutely positioned.

Let me write the HTML.

Voice: Tone.PolySynth with Tone.Synth and envelope ADSR. Use PolySynth to support multiple notes.

Audio activation: Start Tone context on user gesture.

Key handling: keydown with event.repeat guard, track active keys. keyup releases.

Pointer: pointerdown on key starts, pointerup/pointerleave/pointercancel; also window blur release all.

Let me write it.

Now let me test with the browser tool.

The piano renders well. Labels visible. Black keys positioned correctly. One issue: the black keys are a bit too wide perhaps, but it looks okay. Actually the black key labels are showing at bottom of black keys which is fine.

Let me test audio activation by clicking Start Audio and then playing keys. Let me click the start button.

Audio activated successfully. The click worked (button turned green, status says Audio active). Note there's still a warning about AudioContext not allowed to start, but that's from before the gesture. Let me check the console state now via inspect. Then play some keys using keyboard. Let me use key action.

Let me test keydown keyup. The browser tool has "key" action. I'll press and hold? Not sure if it supports holding. Let's test with key action. I want to verify active highlighting. Maybe I can use drag/click on a piano key. Let me use motion or inspect after key.

Let me try pressing "a" key. Actually the key action might do a full press+release. Let me check. I'll try key with text "a".

Actually to check highlight, I can dispatch pointerdown via click and screenshot. But click is a full press+release. Let me use a different approach: use inspect after keydown perhaps. Let me just test click on a key and check console for errors.

Let me first test click on C4 key. Coordinates: C4 white key center x~347, y~460 from screenshot. Click there.

The screenshot didn't include the highlight because click already released. Let me use the browser to dispatch a keydown and hold. The "key" action may support holding via text? Let me check what the type action does. Perhaps I can directly test handlers via inspect DOM. But the browser tool doesn't have eval. Let me try "key" action with text "a" and see if it holds. Actually let me test the drag action to simulate pointer hold on a key: drag from a key to same position might hold? Probably drag press at x,y then move, and release at to point? Unclear.

Let me just try key action.

The key press produced no console errors. It's a quick press-release so no highlight captured. The handlers appear fine. Let me verify by injecting a test via... I can't eval. But I can use DOM inspect only.

Actually the key action likely did a full press+release and no error occurred. Good enough.

Let me test a pointer hold by using "drag" action. Drag from a key to the same spot might not release until... unclear. Let me try drag from C4 to C5 and screenshot mid? The drag likely completes. 

Alternatively, I notice a potential bug: `document.addEventListener("pointerleave", ...)` fires when pointer leaves document, but also possibly on every element leave due to event bubbling? `pointerleave` doesn't bubble, but addEventListener on document could fire when leaving document. Should be fine.

Another concern: pointerdown pointer capture on piano. When setPointerCapture is called on piano, pointerup will target piano, fine. Window listener also catches.

Potential issue: `noteOn` calls `ensureAudio()` which calls Tone.start() from keydown gesture. Works.

However, there's a subtle bug: `Tone.start()` returns a promise. We set audioReady immediately. That's probably fine, but if called from keydown, the AudioContext resumes. In the test, Start Audio click already resumed. Good.

Now let me consider: the black keys are placed with width 8.6% and left = (index+1)*12.5 - 4.3. For C# between C and D: left = 12.5-4.3=8.2%. Good. That's centered over the boundary at 12.5%. Looks right in screenshot.

But visually the black keys look wider than typical and cover white key labels? No, labels at bottom.

Let me verify the black key width. In the screenshot, black keys look quite wide, nearly as wide as white keys. 8.6% of 560 = 48px, white = 70px. That's ~69%, reasonable actually. Screenshot perspective. Fine.

Let me do a final check: verify no console errors after interaction. The console only had Tone.js log and CSP worker error (from Tone's internal worker). The CSP worker error is pre-existing due to sandbox worker-src 'none'. Does Tone.js require the worker? It seems Tone.js tries to create a worker for some functionality (Tone.Ticker?). It falls back. The log says blocked. This could affect timing but notes still sound via fallback clock. It's unavoidable given CSP and no network. Actually Tone.js v14 uses a worker for the clock; if blocked, it falls back to the main thread clock. Should be fine.

Let me verify by checking whether audio actually produced sound — can't hear. But triggerAttack calls happened without errors.

One more thing: I should verify the "release held voices when pointer released outside key". Handled by window pointerup and document pointerleave.

Let me test drag to see highlight mid-press. Actually, let me try using "drag" to press and hold — maybe drag releases at destination. If I drag from C4 to C4 (no move), perhaps not. Not worth it.

I think it's done. Let me just double check the HTML has no syntax errors by running a quick node check? Can't easily. The browser loaded it fine.

Actually, let me verify active highlighting works by looking at the initial motion or using drag. Let me attempt a "motion" action which might capture frames during interaction. Or simply trust.

Let me do one more test: click and hold via drag from C4 to a point off the piano and inspect state? Hard.

Actually there's a way: the `type` action types text into focused element; not relevant.

I'll consider the task sufficiently verified. But let me test a keydown that's held by checking if "key" supports a hold. Let me look at the browser tool docs? Not available. I'll just report.

Actually, let me verify highlight programmatically is impossible. But I can verify through a quick temporary test: modify code? No.

One concern: In keydown handler, I check `if (n.el && n.el.classList.contains("active")) return;` in addition to e.repeat. Good against duplicate.

Let me also make sure pointerdown works on black keys since they're appended to piano, not white-row, and positioned absolutely. yes.

I think we're good. Let me also ensure the labels are visible: yes.

Final answer.

Wait — one potential real bug: the `document.addEventListener("pointerleave", ...)` handler releases all pointer notes when the pointer leaves the document. But `pointerleave` on document fires when moving from the document to outside; also, since white keys and black keys are children, moving between them shouldn't fire on document. Fine.

Also, when pointer is pressed on key and dragged off, pointerup on window releases. Good.

Let me do a final quick check with the drag tool to observe highlighting—I'll drag from C4 key to slightly below (off the key) while the screenshot after drag shows released. Not helpful.

I'll finalize. Let me quickly confirm that repeated keydown doesn't stack by reading code - done.

Let me report.

Everything looks in place. I'm confident. Final report.