Quantity stepper

v1.0.0·Added in 1.0.0

The minus, value, plus control of carts and product pages, with stock hints, hold to repeat, rolling digits and an Add to cart morph.

Tap or click minus and plus to change the quantity; the new number rolls in from below when it grows and from above when it shrinks. Hold a button and it repeats after 400ms, speeding up, and stops at the limit; on a phone a finger that starts to scroll never changes the value. Pressing past a limit shakes the control (and buzzes on a phone), and at the maximum a line under it says why. With removable, minus turns into a trash button at the minimum; with addToCart the control starts as an Add to cart button that morphs into the stepper and collapses back from the first step. Keyboard: Tab reaches the value (one stop), Up and Down step, Page Up and Page Down move 10 steps, Home and End jump to the minimum and maximum, Delete removes the line at the minimum when removable. With editable, type a number and press Enter or leave the field (Escape drops what was typed); it is snapped to the step and clamped, and pressing plus or minus right after typing steps from the typed number. While the cart syncs a spinner replaces the digits, and a failed save rolls back with a message.