Skip to content

[Android] Align the alpha traversal gate with iOS #4513

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
m-bert merged 1 commit into from
Sep 14, 2026
+10 −3
Merged

[Android] Align the alpha traversal gate with iOS #4513

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 8 additions & 2 deletions ...ler/android/src/main/java/com/swmansion/gesturehandler/core/GestureHandlerOrchestrator.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -871,9 +871,11 @@ class GestureHandlerOrchestrator(
// A child view is handling touch, also extract handlers attached to this view
if (found) {
recordViewHandlersForPointer(view, coords, pointerId, event)
} else if (view is RNGestureHandlerDetectorView) {
} else if (view is RNGestureHandlerDetectorView && !allChildrenHidden(view)) {
// No child consumed the touch, but we still record the detector's own handlers so
// that `hitSlop` expansion keeps working. The detector's frame ignores
// that `hitSlop` expansion keeps working. Skipped when every child is hidden or
// below the alpha gate, otherwise the detector would stay tappable while its
// content is invisible. The detector's frame ignores
// child transforms, so for a single-child detector we check bounds in the child's
// transform-aware coordinate space - otherwise the detector would steal presses over
// areas its content has been moved away from.
Expand Down Expand Up @@ -911,6 +913,10 @@ class GestureHandlerOrchestrator(

private fun canReceiveEvents(view: View) = view.visibility == View.VISIBLE && view.alpha >= minimumAlphaForTraversal

// True when the group has children and none of them can receive events (hidden or below the alpha gate).
private fun allChildrenHidden(viewGroup: ViewGroup) =
viewGroup.childCount > 0 && (0 until viewGroup.childCount).none { canReceiveEvents(viewGroup.getChildAt(it)) }
Comment thread
m-bert marked this conversation as resolved.
Comment thread
coderabbitai[bot] marked this conversation as resolved.

// if view is not a view group it is clipping, otherwise we check for `getClipChildren` flag to
// be turned on and also confirm with the ViewConfigHelper implementation
private fun isClipping(view: View) = view !is ViewGroup || viewConfigHelper.isViewClippingChildren(view)
Expand Down
3 changes: 2 additions & 1 deletion ...er/android/src/main/java/com/swmansion/gesturehandler/react/RNGestureHandlerRootHelper.kt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -185,7 +185,8 @@ class RNGestureHandlerRootHelper(private val context: ReactContext, wrappedView:
}

companion object {
private const val MIN_ALPHA_FOR_TOUCH = 0.1f
// Same threshold as UIKit / RCTViewComponentView hit testing on iOS.
private const val MIN_ALPHA_FOR_TOUCH = 0.01f
private fun findRootViewTag(viewGroup: ViewGroup): ViewGroup {
UiThreadUtil.assertOnUiThread()
var parent: ViewParent? = viewGroup
Expand Down
Loading