smooth_dropdown 1.0.0

Smooth-motion dropdown widgets for Flutter: an expansion tile that reveals any content and a typed select. All open and close motion runs on the render layer.

Changelog

1.0.0

First stable release.

• SmoothExpansionTile shows any widget with a smooth open and close move. It also has a SmoothExpansionTile.text maker for a simple title and text.
• SmoothSelect lets a user open a list and tap one option to pick it. When the list fits without scrolling, the open list also carries the draggable SmoothHighlight.
• SmoothPicker is a draggable, spring-inertial selection list styled with SmoothHighlight. The velocity squash on the box is smoothed, teleport-guarded, and eased into its ceiling through a soft knee, so a brisk drag and a hard fling read differently instead of both pinning to SmoothHighlight.maxStretch, and its sides never snap; the overscroll pull is held inside SmoothHighlight.rubberBand.
• One highlight, and it is the single selection mark. At rest it sits on the picked option. The moment you drag, it lifts off under your finger and follows it exactly — no trailing offset, whether you grab from the top or the bottom — so the old row is never marked at the same time. On release it springs to the nearest option and comes to rest there, relaxing to a clean full-size box. It carries its own tick via SmoothHighlight.checkColor. A drag release or a tap commits the pick at once, with no wait for the spring to settle. Tapping a different option in an open list glides the highlight to it on the same spring — a soft accelerate, a small organic overshoot, and a clean settle — instead of jumping, so a tap and a drag land the box the same way.
• The highlight never hangs and never snaps. A value changed from outside while the box is still gliding re-aims the in-flight spring at the new pick, keeping its velocity, so it bends toward the new option instead of finishing to the old one and jumping. A spring that could never come to rest (a non-positive mass, stiffness, or damping) falls back to an instant move rather than driving a spring that would leave the box stuck mid-travel; SmoothHighlight exposes this as springSettles.
• SmoothExpansionController opens and closes a tile from your own code.
• Full theming with SmoothStyle, SmoothPalette, and SmoothMotionSpec.
• SmoothTheme shares one style with many widgets.
• All motion runs on the render layer. There is no setState and no AnimatedBuilder for the motion.
• The widgets respect the "reduce motion" setting.
• SmoothSelect is fully keyboard and switch operable, following the WCAG combobox pattern. It is one focus stop: Enter or Space opens the list and commits the highlighted option, the arrows and Home/End walk the options — driving the very same spring-glide highlight, so a keyboard walk looks like a drag — and Escape closes it. Focus stays on the field the whole time and never jumps into the list, so tab order stays sane; a disabled field drops out of the focus order. A focus ring shows only under keyboard focus, and every key path is dormant under touch, so touch behaviour is unchanged.
• Right-to-left is honoured throughout: the rising reveal text lays out in the ambient Directionality, and the traveling selection tick rides the trailing edge of the highlight — the left of the box in right-to-left.
• SmoothSelectItem gains a trailing slot for any widget (a badge, trailing text, a swatch), matching SmoothPickerItem.