Unify dimensions cache between lightbox and feed (#6047)

* Remove useless memo

* Use explicit values when useImageAspectRatio doesn't know

It's not very good that you can't distingiush when we haven't loaded vs when we're certain. This shifts the burden of dealing with missing values to the caller.

* Check cache early

* Handle src change

* Rewrite image-sizes.fetch to avoid mixing async styles

* Make image-sizes LRU

Code is copy paste from useImageDimensions.ts

* Rm unused fields

* Derive aspect on the fly

* Factor useImageDimensions out of useImageAspectRatio

* Move useImageDimensions into image-sizes

* Make lightbox use the same cache

* Wire up known dimensions to the lightbox

* Handle division by zero in the hook

* Use safe aspect for lightbox calculations

2 files changed, 18 insertions, 15 deletions

diff --git a/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.android.tsx b/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.android.tsx
index 3de15b379..487acf931 100644
--- a/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.android.tsx
+++ b/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.android.tsx
@@ -12,8 +12,8 @@ import Animated, {
 } from 'react-native-reanimated'
 import {Image} from 'expo-image'
 
+import {useImageDimensions} from '#/lib/media/image-sizes'
 import type {Dimensions as ImageDimensions, ImageSource} from '../../@types'
-import useImageDimensions from '../../hooks/useImageDimensions'
 import {
   applyRounding,
   createTransform,
@@ -52,7 +52,10 @@ const ImageItem = ({
   isScrollViewBeingDragged,
 }: Props) => {
   const [isScaled, setIsScaled] = useState(false)
-  const imageDimensions = useImageDimensions(imageSrc)
+  const [imageAspect, imageDimensions] = useImageDimensions({
+    src: imageSrc.uri,
+    knownDimensions: imageSrc.dimensions,
+  })
   const committedTransform = useSharedValue(initialTransform)
   const panTranslation = useSharedValue({x: 0, y: 0})
   const pinchOrigin = useSharedValue({x: 0, y: 0})
@@ -119,12 +122,12 @@ const ImageItem = ({
     candidateTransform: TransformMatrix,
   ) {
     'worklet'
-    if (!imageDimensions) {
+    if (!imageAspect) {
       return [0, 0]
     }
     const [nextTranslateX, nextTranslateY, nextScale] =
       readTransform(candidateTransform)
-    const scaledDimensions = getScaledDimensions(imageDimensions, nextScale)
+    const scaledDimensions = getScaledDimensions(imageAspect, nextScale)
     const clampedTranslateX = clampTranslation(
       nextTranslateX,
       scaledDimensions.width,
@@ -248,7 +251,7 @@ const ImageItem = ({
     .numberOfTaps(2)
     .onEnd(e => {
       'worklet'
-      if (!imageDimensions) {
+      if (!imageDimensions || !imageAspect) {
         return
       }
       const [, , committedScale] = readTransform(committedTransform.value)
@@ -260,7 +263,6 @@ const ImageItem = ({
       }
 
       // Try to zoom in so that we get rid of the black bars (whatever the orientation was).
-      const imageAspect = imageDimensions.width / imageDimensions.height
       const screenAspect = SCREEN.width / SCREEN.height
       const candidateScale = Math.max(
         imageAspect / screenAspect,
@@ -363,11 +365,10 @@ const styles = StyleSheet.create({
 })
 
 function getScaledDimensions(
-  imageDimensions: ImageDimensions,
+  imageAspect: number,
   scale: number,
 ): ImageDimensions {
   'worklet'
-  const imageAspect = imageDimensions.width / imageDimensions.height
   const screenAspect = SCREEN.width / SCREEN.height
   const isLandscape = imageAspect > screenAspect
   if (isLandscape) {
diff --git a/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.ios.tsx b/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.ios.tsx
index f21953498..a96a1c913 100644
--- a/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.ios.tsx
+++ b/src/view/com/lightbox/ImageViewing/components/ImageItem/ImageItem.ios.tsx
@@ -19,8 +19,8 @@ import Animated, {
 import {Image} from 'expo-image'
 
 import {useAnimatedScrollHandler} from '#/lib/hooks/useAnimatedScrollHandler_FIXED'
-import {Dimensions as ImageDimensions, ImageSource} from '../../@types'
-import useImageDimensions from '../../hooks/useImageDimensions'
+import {useImageDimensions} from '#/lib/media/image-sizes'
+import {ImageSource} from '../../@types'
 
 const SWIPE_CLOSE_OFFSET = 75
 const SWIPE_CLOSE_VELOCITY = 1
@@ -47,7 +47,10 @@ const ImageItem = ({
   const scrollViewRef = useAnimatedRef<Animated.ScrollView>()
   const translationY = useSharedValue(0)
   const [scaled, setScaled] = useState(false)
-  const imageDimensions = useImageDimensions(imageSrc)
+  const [imageAspect, imageDimensions] = useImageDimensions({
+    src: imageSrc.uri,
+    knownDimensions: imageSrc.dimensions,
+  })
   const maxZoomScale = imageDimensions
     ? (imageDimensions.width / SCREEN.width) * MAX_ORIGINAL_IMAGE_ZOOM
     : 1
@@ -99,7 +102,7 @@ const ImageItem = ({
     const willZoom = !scaled
     if (willZoom) {
       nextZoomRect = getZoomRectAfterDoubleTap(
-        imageDimensions,
+        imageAspect,
         absoluteX,
         absoluteY,
       )
@@ -179,7 +182,7 @@ const styles = StyleSheet.create({
 })
 
 const getZoomRectAfterDoubleTap = (
-  imageDimensions: ImageDimensions | null,
+  imageAspect: number | undefined,
   touchX: number,
   touchY: number,
 ): {
@@ -188,7 +191,7 @@ const getZoomRectAfterDoubleTap = (
   width: number
   height: number
 } => {
-  if (!imageDimensions) {
+  if (!imageAspect) {
     return {
       x: 0,
       y: 0,
@@ -199,7 +202,6 @@ const getZoomRectAfterDoubleTap = (
 
   // First, let's figure out how much we want to zoom in.
   // We want to try to zoom in at least close enough to get rid of black bars.
-  const imageAspect = imageDimensions.width / imageDimensions.height
   const screenAspect = SCREEN.width / SCREEN.height
   const zoom = Math.max(
     imageAspect / screenAspect,