ReactFiberGestureScheduler.js — react Source File

Source Code

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 */

import type {FiberRoot} from './ReactInternalTypes';
import type {GestureOptions} from 'shared/ReactTypes';
import type {GestureTimeline, RunningViewTransition} from './ReactFiberConfig';
import type {TransitionTypes} from 'react/src/ReactTransitionType';
import type {Lane} from './ReactFiberLane';

import {
  GestureLane,
  markRootEntangled,
  markRootFinished,
  NoLane,
  NoLanes,
} from './ReactFiberLane';
import {
  ensureRootIsScheduled,
  requestTransitionLane,
} from './ReactFiberRootScheduler';
import {getCurrentGestureOffset, stopViewTransition} from './ReactFiberConfig';
import {pingGestureRoot, restartGestureRoot} from './ReactFiberWorkLoop';

// This type keeps track of any scheduled or active gestures.
export type ScheduledGesture = {
  provider: GestureTimeline,
  count: number, // The number of times this same provider has been started.
  rangeStart: number, // The percentage along the timeline where the "current" state starts.
  rangeEnd: number, // The percentage along the timeline where the "destination" state is reached.
  types: null | TransitionTypes, // Any addTransitionType call made during startGestureTransition.
  running: null | RunningViewTransition, // Used to cancel the running transition after we're done.
  commit: null | (() => void), // Callback to run to commit if there's a pending commit.
  committing: boolean, // If the gesture was released in a committed state and should actually commit.
  revertLane: Lane, // The Lane that we'll use to schedule the revert.
  prev: null | ScheduledGesture, // The previous scheduled gesture in the queue for this root.
  next: null | ScheduledGesture, // The next scheduled gesture in the queue for this root.
};

export function scheduleGesture(
  root: FiberRoot,
  provider: GestureTimeline,
): ScheduledGesture {
  let prev = root.pendingGestures;
  while (prev !== null) {
    if (prev.provider === provider) {
      // Existing instance found.
      return prev;
    }
    const next = prev.next;
    if (next === null) {
      break;
    }
    prev = next;
  }
// ... (198 more lines)