Touch: a second finger cancels a tool gesture the first one started; the pinch pans and zooms (#4198)

docs/hardware-parity.md

@@ -1,6 +1,6 @@
 # Hardware parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-24 · **Change:** minor (pen pressure and the pen's eraser end on macOS, read from AppKit's tablet events, #852, not yet tried on a Mac; previously: patch: web pen buttons/modifiers preserved, touch-only input left to eframe, session-only palm rejection; tool cursors painted into the window on Wayland, #1652, not run on Linux; borderless title-bar window on Windows, #1758, awaiting confirmation; a window surface larger than 8192 px keeps working, #1459 in part; Linux Display Server preference opens the window through XWayland, #1151) · **Target:** Adobe Illustrator 2026 (30.x)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** patch (a second finger cancels the tool press the first finger began, and a finger landing while another is down presses nothing; the pinch only navigates, #4198) · **Target:** Adobe Illustrator 2026 (30.x)
 
 What hardware Illustrator uses, per platform, against VectorCraft. Illustrator's side is from its public
 documentation (GPU Performance, touch workspace, pen pressure pages); ours from the code
@@ -25,7 +25,7 @@ reads the pen's eraser end on Windows, on macOS and on Linux under X11 and XWayl
 | Pen tilt, bearing, barrel rotation (6D Art Pen) | yes, drives brushes | no | no | no | no | missing: 4–8 h after the input layer (#372) |
 | Pen eraser end | yes | the eraser end (AppKit's tablet proximity events) selects the Eraser tool and the tip brings back the tool used before, as on Linux (#852; not yet tried on a Mac) | no | under X11 and XWayland, the eraser end selects the Eraser tool and the tip brings back the tool used before (#764); **no** on native Wayland | a press of the eraser end (Pointer Events eraser button, `button` 5) selects the Eraser tool, and that press erases; a press of the tip brings back the tool used before; Pointer Events report no end while the pen hovers | partial |
 | Pen eraser end | yes | the eraser end (AppKit's tablet proximity events) selects the Eraser tool and the tip brings back the tool used before, as on Linux (#852; not yet tried on a Mac) | with Windows Ink, an inverted pen or its eraser button (`PEN_FLAG_INVERTED`, `PEN_FLAG_ERASER` in the pen's pointer messages) selects the Eraser tool and the tip brings back the tool used before, as on Linux (not yet tried with a pen) | under X11 and XWayland, the eraser end selects the Eraser tool and the tip brings back the tool used before (#764); **no** on native Wayland | no | partial |
-| Touch gestures (pinch zoom, two-finger pan, rotate view, Touch workspace) | yes (Windows touch, Surface) | trackpad pinch, scroll and rotate | pinch, pan; two-finger tap undo, three-finger redo (#585) | same where winit reports touch | eframe until the first pen contact, then Pointer Events (pen and fingers told apart); long press opens the context menu | partial: touch workspace and touch-screen rotation missing, 3–5 h |
+| Touch gestures (pinch zoom, two-finger pan, rotate view, Touch workspace) | yes (Windows touch, Surface) | trackpad pinch, scroll and rotate | pinch, pan (a second finger cancels the first finger's tool press, #4198); two-finger tap undo, three-finger redo (#585) | same where winit reports touch | eframe until the first pen contact, then Pointer Events (pen and fingers told apart); long press opens the context menu | partial: touch workspace and touch-screen rotation missing, 3–5 h |
 | Trackpad (smooth scroll, pinch) | yes | yes | precision touchpads | yes | yes | done |
 | HiDPI / Retina, per-monitor scale | yes | yes | yes | yes | yes | done; a window dragged between monitors of different scale can still grow on Windows (#1459, open); the custom title bar's window on Windows stays truly borderless so the pointer lines up with what is drawn (#1791, #1758; awaiting the reporter's confirmation) |
 | Multiple monitors: panels and document windows on another screen | yes | no (one OS window) | no | no | — | missing: 6–10 h (with multiple windows, gap G7) |
@@ -36,6 +36,7 @@ reads the pen's eraser end on Windows, on macOS and on Linux under X11 and XWayl
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | patch | Touch (#4198): a second finger landing cancels the tool press the first finger began, also in the same frame (the Pencil's stroke and a Selection move are rolled back, nothing enters the undo history), and a finger landing while another is down presses nothing, so a pinch or two-finger pan only navigates. Headless canvas test `a_second_finger_cancels_the_tool_gesture_the_first_began`; not tried on a touch screen; score unchanged (estimated) |
 | 2026-10-24 | minor | macOS: an AppKit local event monitor reads each mouse and tablet event's pen pressure and the pen's end before the window gets it and writes them into the canvas's pen feed (#852): each pointer move of a stroke keeps its own pressure, mouse event coalescing is off, and the eraser end selects the Eraser tool. The mapping is unit-tested on every platform and the macOS code type-checks for `aarch64-apple-darwin`; not yet tried on a Mac with a tablet, so the score is unchanged (estimated) |
 | 2026-10-15 | patch | Web review: preserve pen buttons and modifiers; leave fingers to eframe before the first pen contact; remove persistent pen policy. Canvas regression tests cover intermediate moves and long-touch cancellation on native and web input. Physical-device QA pending. |
 | 2026-10-14 | minor | Tool cursors are painted into the window on Wayland (#1652; not run on Linux, #1645 stays open until confirmed); On Windows the custom title bar's window stays truly borderless, so the pointer lines up with what is drawn on systems where the hidden caption offset it (#1791, #1758; awaiting the reporter's confirmation); neither is confirmed on the hardware that reported it, so nothing is marked done |