It collides with two-finger pull-to-refresh and needs count disambiguation

What it is

If an app also uses two fingers down as pull-to-refresh, the onset is almost the same as the system shortcut panel: two fingers, downward, from rest. Direction is already spent, so disambiguation has to use count, start location, and who claims first. One-finger refresh and a two-finger panel can coexist; two-finger refresh and a two-finger panel fight on one motion.

Why it happens

Count stabilizes earlier than direction. If the system splits on count in the status band, a two-finger refresh that starts near the top is stolen before the app sees it. Registering two-finger refresh anyway plants a second recognizer in a cell the system already owns. The stabler cut is: keep refresh as one-finger overscroll, and leave two fingers to the system; or fire refresh only from well inside the list, with a dead zone under the status bar. Location and count gates beat another velocity knob, because the two gestures share a speed distribution.

Studying it

From the status bar, the first row, and mid-list, pull with one and two fingers. Record whether the outcome is panel, notifications, refresh, or scroll. Factor the time gap between the two downs (0–80 ms). Split failures: system stole app refresh, versus app refresh blocked the panel. Do not test refresh only from mid-list—the clash is at the top.

Where it stops holding

On a device with no two-finger panel, two-finger refresh only fights two-finger pan, a different pair. One-finger refresh never enters this split. Custom web touch handlers may never see events the system already ate—“refresh is coded but dead” is a claim issue, not a threshold. This leaf does not argue whether the system should have reserved the cell.

Applying it

• Prefer one-finger overscroll for refresh; do not bind refresh to two-finger pulldown.
• If the product insists on two-finger refresh, start it away from the system top band, and fall back to one-finger scroll when the two downs are staggered.
• Two fingers from the very top should open the panel, not refresh; one finger from mid-first-row should refresh. If both fail, disambiguation is unfinished.

Related

• Same group: C3.27.1 Two-finger pulldown is reserved by some systems for a shortcut shade · C3.27.3 Once reserved, apps must not define a conflicting gesture in the same region · C3.27.4 The panel gesture has almost no visual preview
• Adjacent: C3.15 Pull to refresh · C3.19 Gesture conflicts and disambiguation
• Search: pull to refresh · finger count · gesture collision