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Android bitmap snapshot capture and display (#56460)#56460

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zeyap wants to merge 5 commits intofacebook:mainfrom
zeyap:export-D99173446
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Android bitmap snapshot capture and display (#56460)#56460
zeyap wants to merge 5 commits intofacebook:mainfrom
zeyap:export-D99173446

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@zeyap zeyap commented Apr 15, 2026

Summary:

Changelog:

[Internal] [Added] - Android bitmap snapshot capture and display

Implement the Android side of view transition bitmap snapshots.

ViewTransitionSnapshotManager (new Kotlin class):
Manages the full snapshot lifecycle as a UIManagerListener. Captures bitmaps
on the UI thread, maps them from source to target pseudo-element tags,
re-applies after mount cycles (since views may be recreated), and self-cleans
when views are deleted.

JNI bridge:
FabricUIManagerBindingFabricMountingManagerFabricUIManager JNI
delegates to the snapshot manager.

SurfaceMountingManager.applyViewSnapshot: sets bitmap as view background
using the KTX Bitmap.toDrawable extension.

Reviewed By: sammy-SC, NickGerleman

Differential Revision: D99173446

@meta-cla meta-cla bot added the CLA Signed This label is managed by the Facebook bot. Authors need to sign the CLA before a PR can be reviewed. label Apr 15, 2026
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meta-codesync bot commented Apr 15, 2026

@zeyap has exported this pull request. If you are a Meta employee, you can view the originating Diff in D99173446.

zeyap added a commit to zeyap/react-native that referenced this pull request Apr 15, 2026
Summary:
Pull Request resolved: facebook#56460

## Changelog:

[Internal] [Added] - Android bitmap snapshot capture and display

Implement the Android side of view transition bitmap snapshots.

**`ViewTransitionSnapshotManager`** (new Kotlin class):
Manages the full snapshot lifecycle as a `UIManagerListener`. Captures bitmaps
on the UI thread, maps them from source to target pseudo-element tags,
re-applies after mount cycles (since views may be recreated), and self-cleans
when views are deleted.

**JNI bridge:**
`FabricUIManagerBinding` → `FabricMountingManager` → `FabricUIManager` JNI
delegates to the snapshot manager.

**`SurfaceMountingManager.applyViewSnapshot`:** sets bitmap as view background
using the KTX `Bitmap.toDrawable` extension.

Reviewed By: sammy-SC, NickGerleman

Differential Revision: D99173446
@meta-codesync meta-codesync bot changed the title Android bitmap snapshot capture and display Android bitmap snapshot capture and display (#56460) Apr 15, 2026
@zeyap zeyap force-pushed the export-D99173446 branch from fd4b60b to 795300a Compare April 15, 2026 18:22
Zeya Peng added 4 commits April 15, 2026 11:50
Summary:
Implement `createViewTransitionInstance`, which is invoked by the React reconciler to create pseudo-element shadow nodes that visually represent the old state of elements participating in a view transition.

Key changes:
- Add `createViewTransitionInstance` JSI binding in `UIManagerBinding`, accepting a transition name and pseudo-element tag
- Add virtual `createViewTransitionInstance` method to `UIManagerViewTransitionDelegate`
- Implement the method in `ViewTransitionModule`: creates an absolutely-positioned, non-interactive `View` shadow node matching the old element's layout metrics (position, size)
- Manage two pseudo-element node maps: `oldPseudoElementNodes_` for the current transition and `oldPseudoElementNodesForNextTransition_` for entering nodes that may exit in a future transition
- Update `getOldViewTransitionInstance` to return the pseudo-element's tag (instead of the original element's tag) when a pseudo-element exists
- Add `applySnapshotsOnPseudoElementShadowNodes` stub for future platform-level bitmap snapshot integration

`createViewTransitionInstance` is typically called after `applyViewTransitionName` in the React reconciler. See the diagram below for the full flow.

{F1987481080}

Differential Revision: D98981886
Summary:
Append view transition pseudo-element shadow nodes to the root's children at commit time (`shadowTreeWillCommit`), so they are committed into the shadow tree and rendered by the platform.

Key changes:
- Add `getPseudoElementNodes(surfaceId)` virtual method to `UIManagerViewTransitionDelegate`, returning pseudo-element shadow nodes filtered by surface ID
- Implement the method in `ViewTransitionModule`, iterating over `oldPseudoElementNodes_` and collecting nodes matching the given surface
- In `shadowTreeWillCommit`, when view transitions are enabled, query the delegate for pseudo-element nodes and insert them at the end of `rootChildren` before committing

This ensures pseudo-element nodes (created by `createViewTransitionInstance`) are included in the committed shadow tree and ultimately mounted as platform views that display old-element snapshots during transitions.

Differential Revision: D98982122
Summary:
Add `findPseudoElementShadowNodeByTag` to look up pseudo-element shadow nodes by tag from JS, and update the animation helper to connect animated nodes to pseudo-element shadow nodes for old-element animations.

Key changes:
- Add `findPseudoElementShadowNodeByTag(tag)` virtual method to `UIManagerViewTransitionDelegate` and implement in `ViewTransitionModule` (linear scan over `oldPseudoElementNodes_`)
- Expose the method via `NativeViewTransition` TurboModule so JS can resolve a pseudo-element's shadow node by its native tag
- Add `findPseudoElementShadowNodeByTag` to `NativeViewTransition.js` spec
- Update `ViewTransitionAnimationHelper.js`:
  - `animateInternal` accepts a new `pseudo` parameter (`'old'` | `'new'`)
  - When `pseudo === 'old'`, use `findPseudoElementShadowNodeByTag` instead of `findShadowNodeByTag_DEPRECATED` to connect animated nodes to the correct shadow node family
  - Pass `'new'` for enter animations and propagate `_pseudo` from pseudo-element objects for exit animations

Differential Revision: D98982251
Summary:
Wire view transition bitmap snapshot capture and display through the C++
delegate chain so platforms can implement snapshotting old-element views.

**ViewTransitionModule.cpp**: Call `uiManagerDidCaptureViewSnapshot(tag,
surfaceId)` in `applyViewTransitionName` to capture a bitmap of the old view
while it is still mounted, and `uiManagerDidSetViewSnapshot(sourceTag,
targetTag, surfaceId)` in `applySnapshotsOnPseudoElementShadowNodes` to map
captured bitmaps onto pseudo-element views.

**UIManagerDelegate / SchedulerDelegate**: Add pure virtual
`captureViewSnapshot` and `setViewSnapshot` methods.

**Scheduler**: Forward `UIManagerDelegate` calls to `SchedulerDelegate`.

**Platform stubs**: Empty implementations for iOS (`RCTScheduler.mm`),
CxxPlatform (`SchedulerDelegateImpl`), and Android JNI
(`FabricUIManagerBinding`) — Android implementation follows in D99173446.

Differential Revision: D98354659
zeyap added a commit to zeyap/react-native that referenced this pull request Apr 15, 2026
Summary:
Pull Request resolved: facebook#56460

## Changelog:

[Internal] [Added] - Android bitmap snapshot capture and display

Implement the Android side of view transition bitmap snapshots.

**`ViewTransitionSnapshotManager`** (new Kotlin class):
Manages the full snapshot lifecycle as a `UIManagerListener`. Captures bitmaps
on the UI thread, maps them from source to target pseudo-element tags,
re-applies after mount cycles (since views may be recreated), and self-cleans
when views are deleted.

**JNI bridge:**
`FabricUIManagerBinding` → `FabricMountingManager` → `FabricUIManager` JNI
delegates to the snapshot manager.

**`SurfaceMountingManager.applyViewSnapshot`:** sets bitmap as view background
using the KTX `Bitmap.toDrawable` extension.

Reviewed By: sammy-SC, NickGerleman

Differential Revision: D99173446
@zeyap zeyap force-pushed the export-D99173446 branch from 795300a to 3bf9f80 Compare April 15, 2026 19:01
Summary:
Pull Request resolved: facebook#56460

## Changelog:

[Internal] [Added] - Android bitmap snapshot capture and display

Implement the Android side of view transition bitmap snapshots.

**`ViewTransitionSnapshotManager`** (new Kotlin class):
Manages the full snapshot lifecycle as a `UIManagerListener`. Captures bitmaps
on the UI thread, maps them from source to target pseudo-element tags,
re-applies after mount cycles (since views may be recreated), and self-cleans
when views are deleted.

**JNI bridge:**
`FabricUIManagerBinding` → `FabricMountingManager` → `FabricUIManager` JNI
delegates to the snapshot manager.

**`SurfaceMountingManager.applyViewSnapshot`:** sets bitmap as view background
using the KTX `Bitmap.toDrawable` extension.

Reviewed By: sammy-SC, NickGerleman

Differential Revision: D99173446
@zeyap zeyap force-pushed the export-D99173446 branch from 3bf9f80 to ceab88c Compare April 15, 2026 20:30
@meta-codesync meta-codesync bot closed this in 2247778 Apr 16, 2026
@facebook-github-tools facebook-github-tools bot added the Merged This PR has been merged. label Apr 16, 2026
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meta-codesync bot commented Apr 16, 2026

This pull request has been merged in 2247778.

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