Struct TouchSequenceInfo 

pub struct TouchSequenceInfo {
    pub(crate) state: TouchSequenceState,
    active_touch_points: Vec<TouchPoint>,
    handling_touch_move: bool,
    pub prevent_click: bool,
    pub prevent_move: TouchMoveAllowed,
    pending_touch_move_actions: Vec<ScrollZoomEvent>,
    hit_test_result_cache: Option<HitTestResultCache>,
}

Fields

state: TouchSequenceState

touch sequence state

active_touch_points: Vec<TouchPoint>

touch sequence active touch points

handling_touch_move: bool

The script thread is already processing a touchmove operation.

We use this to skip sending the event to the script thread, to prevent overloading script.

prevent_click: bool

Do not perform a click action.

This happens when

• We had a touch move larger than the minimum distance OR
• We had multiple active touchpoints OR
• preventDefault() was called in a touch_down or touch_up handler

prevent_move: TouchMoveAllowed

Whether move is allowed, prevented or the result is still pending. Once the first move has been processed by script, we can transition to non-cancellable events, and directly perform the pan without waiting for script.

pending_touch_move_actions: Vec<ScrollZoomEvent>

Move operation waiting to be processed in the touch sequence.

This is only used while the first touch move is processed in script. Todo: It would be nice to merge this into the TouchSequenceState, but this requires some additional work to handle the merging of pending touch move events. Presumably if we keep a history of previous touch points, this would allow a better fling algorithm and easier merging of zoom events.

hit_test_result_cache: Option<HitTestResultCache>

Cache for the last touch hit test result.

Implementations

impl TouchSequenceInfo

fn touch_count(&self) -> usize

fn pinch_distance_and_center(&self) -> (f32, Point2D<f32, DevicePixel>)

fn add_pending_touch_move_action(&mut self, action: ScrollZoomEvent)

fn is_finished(&self) -> bool

Returns true when all touch events of a sequence have been received. This does not mean that all event handlers have finished yet.

fn update_hit_test_result_cache_pointer( &mut self, delta: Vector2D<f32, DevicePixel>, )