1 files changed, 126 insertions, 0 deletions
diff --git a/src/view/com/util/gestures/HorzSwipe.tsx b/src/view/com/util/gestures/HorzSwipe.tsx
new file mode 100644
index 000000000..7ae1ee759
--- /dev/null
+++ b/src/view/com/util/gestures/HorzSwipe.tsx
@@ -0,0 +1,126 @@
+import React from 'react'
+import {
+  Animated,
+  GestureResponderEvent,
+  I18nManager,
+  PanResponder,
+  PanResponderGestureState,
+  useWindowDimensions,
+  View,
+} from 'react-native'
+import {clamp} from 'lodash'
+
+interface Props {
+  panX: Animated.Value
+  canSwipeLeft: boolean
+  canSwipeRight: boolean
+  swipeEnabled: boolean
+  onSwipeStart?: () => void
+  onSwipeEnd?: (dx: number) => void
+  children: React.ReactNode
+}
+
+export function HorzSwipe({
+  panX,
+  canSwipeLeft,
+  canSwipeRight,
+  swipeEnabled = true,
+  onSwipeStart,
+  onSwipeEnd,
+  children,
+}: Props) {
+  const winDim = useWindowDimensions()
+
+  const swipeVelocityThreshold = 35
+  const swipeDistanceThreshold = winDim.width / 1.75
+
+  const isMovingHorizontally = (
+    _: GestureResponderEvent,
+    gestureState: PanResponderGestureState,
+  ) => {
+    return (
+      Math.abs(gestureState.dx) > Math.abs(gestureState.dy * 1.5) &&
+      Math.abs(gestureState.vx) > Math.abs(gestureState.vy * 1.5)
+    )
+  }
+
+  const canMoveScreen = (
+    event: GestureResponderEvent,
+    gestureState: PanResponderGestureState,
+  ) => {
+    if (swipeEnabled === false) {
+      return false
+    }
+
+    const diffX = I18nManager.isRTL ? -gestureState.dx : gestureState.dx
+    return (
+      isMovingHorizontally(event, gestureState) &&
+      ((diffX > 0 && canSwipeLeft) || (diffX < 0 && canSwipeRight))
+    )
+  }
+
+  const startGesture = () => {
+    onSwipeStart?.()
+
+    // TODO
+    // if (keyboardDismissMode === 'on-drag') {
+    //   Keyboard.dismiss()
+    // }
+
+    panX.stopAnimation()
+    // @ts-expect-error: _value is private, but docs use it as well
+    panX.setOffset(panX._value)
+  }
+
+  const respondToGesture = (
+    _: GestureResponderEvent,
+    gestureState: PanResponderGestureState,
+  ) => {
+    const diffX = I18nManager.isRTL ? -gestureState.dx : gestureState.dx
+
+    if (
+      // swiping left
+      (diffX > 0 && !canSwipeLeft) ||
+      // swiping right
+      (diffX < 0 && !canSwipeRight)
+    ) {
+      return
+    }
+
+    panX.setValue(clamp(diffX / swipeDistanceThreshold, -1, 1) * -1)
+  }
+
+  const finishGesture = (
+    _: GestureResponderEvent,
+    gestureState: PanResponderGestureState,
+  ) => {
+    panX.flattenOffset()
+    panX.setValue(0)
+    if (
+      Math.abs(gestureState.dx) > Math.abs(gestureState.dy) &&
+      Math.abs(gestureState.vx) > Math.abs(gestureState.vy) &&
+      (Math.abs(gestureState.dx) > swipeDistanceThreshold / 3 ||
+        Math.abs(gestureState.vx) > swipeVelocityThreshold)
+    ) {
+      onSwipeEnd?.(((gestureState.dx / Math.abs(gestureState.dx)) * -1) | 0)
+    } else {
+      onSwipeEnd?.(0)
+    }
+  }
+
+  const panResponder = PanResponder.create({
+    onMoveShouldSetPanResponder: canMoveScreen,
+    onMoveShouldSetPanResponderCapture: canMoveScreen,
+    onPanResponderGrant: startGesture,
+    onPanResponderMove: respondToGesture,
+    onPanResponderTerminate: finishGesture,
+    onPanResponderRelease: finishGesture,
+    onPanResponderTerminationRequest: () => true,
+  })
+
+  return (
+    <View {...panResponder.panHandlers} style={{flex: 1}}>
+      {children}
+    </View>
+  )
+}