Get rid of the directional gesture options

It's just a start and end range now.

Author: sebmarkbage

fixtures/view-transition/src/components/SwipeRecognizer.js

@@ -38,9 +38,15 @@ export default function SwipeRecognizer({
       () => {
         gesture(direction);
       },
-      {
-        range: [0, direction === 'left' || direction === 'up' ? 100 : 0, 100],
-      }
+      direction === 'left' || direction === 'up'
+        ? {
+            rangeStart: 100,
+            rangeEnd: 0,
+          }
+        : {
+            rangeStart: 0,
+            rangeEnd: 100,
+          }
     );
   }
   function onScrollEnd() {

packages/react-reconciler/src/ReactFiberGestureScheduler.js

@@ -23,10 +23,8 @@ import {getCurrentGestureOffset, stopViewTransition} from './ReactFiberConfig';
 export type ScheduledGesture = {
   provider: GestureTimeline,
   count: number, // The number of times this same provider has been started.
-  direction: boolean, // false = previous, true = next
-  rangePrevious: number, // The end along the timeline where the previous state is reached.
-  rangeCurrent: number, // The starting offset along the timeline.
-  rangeNext: number, // The end along the timeline where the next state is reached.
+  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.
   running: null | RunningViewTransition, // Used to cancel the running transition after we're done.
   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.
@@ -51,10 +49,8 @@ export function scheduleGesture(
   const gesture: ScheduledGesture = {
     provider: provider,
     count: 0,
-    direction: false,
-    rangePrevious: -1,
-    rangeCurrent: -1,
-    rangeNext: -1,
+    rangeStart: 0, // Uninitialized
+    rangeEnd: 100, // Uninitialized
     running: null,
     prev: prev,
     next: null,
@@ -73,45 +69,24 @@ export function startScheduledGesture(
   gestureTimeline: GestureTimeline,
   gestureOptions: ?GestureOptions,
 ): null | ScheduledGesture {
-  const currentOffset = getCurrentGestureOffset(gestureTimeline);
-  const range = gestureOptions && gestureOptions.range;
-  const rangePrevious: number = range ? range[0] : 0; // If no range is provider we assume it's the starting point of the range.
-  const rangeCurrent: number = range ? range[1] : currentOffset;
-  const rangeNext: number = range ? range[2] : 100; // If no range is provider we assume it's the starting point of the range.
-  if (__DEV__) {
-    if (
-      (rangePrevious > rangeCurrent && rangeNext > rangeCurrent) ||
-      (rangePrevious < rangeCurrent && rangeNext < rangeCurrent)
-    ) {
-      console.error(
-        'The range of a gesture needs "previous" and "next" to be on either side of ' +
-          'the "current" offset. Both cannot be above current and both cannot be below current.',
-      );
-    }
-  }
-  const isFlippedDirection = rangePrevious > rangeNext;
-  const initialDirection =
-    // If a range is specified we can imply initial direction if it's not the current
-    // value such as if the gesture starts after it has already moved.
-    currentOffset < rangeCurrent
-      ? isFlippedDirection
-      : currentOffset > rangeCurrent
-        ? !isFlippedDirection
-        : // Otherwise, look for an explicit option.
-          gestureOptions
-          ? gestureOptions.direction === 'next'
-          : false;
-
+  const rangeStart =
+    gestureOptions && gestureOptions.rangeStart != null
+      ? gestureOptions.rangeStart
+      : getCurrentGestureOffset(gestureTimeline);
+  const rangeEnd =
+    gestureOptions && gestureOptions.rangeEnd != null
+      ? gestureOptions.rangeEnd
+      : rangeStart < 50
+        ? 100
+        : 0;
   let prev = root.pendingGestures;
   while (prev !== null) {
     if (prev.provider === gestureTimeline) {
       // Existing instance found.
       prev.count++;
       // Update the options.
-      prev.direction = initialDirection;
-      prev.rangePrevious = rangePrevious;
-      prev.rangeCurrent = rangeCurrent;
-      prev.rangeNext = rangeNext;
+      prev.rangeStart = rangeStart;
+      prev.rangeEnd = rangeEnd;
       return prev;
     }
     const next = prev.next;

packages/react-reconciler/src/ReactFiberWorkLoop.js

@@ -3932,10 +3932,8 @@ function commitGestureOnRoot(
   pendingViewTransition = finishedGesture.running = startGestureTransition(
     root.containerInfo,
     finishedGesture.provider,
-    finishedGesture.rangeCurrent,
-    finishedGesture.direction
-      ? finishedGesture.rangeNext
-      : finishedGesture.rangePrevious,
+    finishedGesture.rangeStart,
+    finishedGesture.rangeEnd,
     pendingTransitionTypes,
     flushGestureMutations,
     flushGestureAnimations,

packages/shared/ReactTypes.js

@@ -172,8 +172,8 @@ export type ReactFormState<S, ReferenceId> = [
 export type GestureProvider = any;
 
 export type GestureOptions = {
-  direction?: 'previous' | 'next',
-  range?: [/*previous*/ number, /*current*/ number, /*next*/ number],
+  rangeStart?: number,
+  rangeEnd?: number,
 };
 
 export type Awaited<T> = T extends null | void