Struct DragRecognizer 

pub struct DragRecognizer { /* private fields */ }

Drag gesture recognizer (INPUT-00 §5).

Sits upstream of TapRecognizer, consuming raw PointerDown/PointerMove/PointerUp. A contact that moves at least the start threshold (Euclidean, compared squared) away from its press origin becomes a drag: DragStart { x, y, origin_x, origin_y } is emitted once at the crossing, DragMove { x, y } for every subsequent move, and DragEnd { x, y } in place of the final PointerUp. While dragging, the raw move/up stream is consumed — combined with TapRecognizer::cancel at DragStart, a threshold-crossing contact can never also produce a PressRelease.

Sub-threshold contacts pass through untouched: taps with finger wander keep their existing debounce path. Non-pointer events always pass through unchanged.

Implementations

impl DragRecognizer

pub fn new() -> Self

Create a recognizer with the default DRAG_START_THRESHOLD_PX start threshold.

pub fn with_threshold(threshold_px: i32) -> Self

Create a recognizer with a custom start threshold in pixels. A threshold of 0 makes the first PointerMove start the drag.

pub fn is_dragging(&self) -> bool

Whether a drag is currently in progress (DragStart emitted, no DragEnd yet).

pub fn process(&mut self, event: &Event) -> Option<Event>

Process a raw input event. Returns the event to pass down the chain — either a drag event (the raw event was consumed) or the input itself (pass-through), None never escapes a pointer event silently.

Only PointerDown, PointerMove, and PointerUp participate; everything else passes through unchanged.

pub fn tick(&mut self) -> Option<Event>

Family-shape parity with the other recognizers. The drag state machine has no timers in v1; this always returns None and reserves the seam for long-press-to-drag (INPUT-00 §14).

Trait Implementations

impl Default for DragRecognizer

fn default() -> Self

Returns the “default value” for a type.