[Android] Fix VerifyHybridWebViewWithShadow UI test regression on candidate branch#35013
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kubaflo merged 1 commit intoApr 17, 2026
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kubaflo
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Apr 21, 2026
…n on candidate branch (#35057) <!-- Please let the below note in for people that find this PR --> > [!NOTE] > Are you waiting for the changes in this PR to be merged? > It would be very helpful if you could [test the resulting artifacts](https://github.com/dotnet/maui/wiki/Testing-PR-Builds) from this PR and let us know in a comment if this change resolves your issue. Thank you! ### Root Cause The previous regression fix (PR #35013) set `ClipBounds = null` unconditionally in `OnSizeChanged` to resolve shadow clipping. While effective for shadows, this reintroduced the original full-screen flash issue (#31475) on slower devices. The underlying issue is that `ClipBounds = null` removes GPU-level rendering constraints. On slower devices, the hardware-accelerated WebView compositor renders a frame at full-screen size before Android layout bounds are enforced. Debug analysis showed that when Shadow/Border/Clip is applied, MAUI wraps the WebView inside a `WrapperView`. In this scenario, the wrapper constrains rendering, making `ClipBounds = null` safe. Without decorations, the WebView is hosted directly under `LayoutViewGroup` (with `ClipChildren = false`), requiring explicit bounds to prevent the flash. ### Description of Change Introduced a `UpdateClipBounds` method to dynamically determine the correct clipping strategy based on the parent: * **Parent is WrapperView (decorations applied):** Sets `ClipBounds = null` to allow shadow and visual overflow * **Parent is not WrapperView (no decorations):** Sets exact bounds to prevent full-screen flash on slower devices * **Zero size:** Applies empty bounds to block rendering when the view is collapsed Additionally, added an `OnAttachedToWindow` override to re-evaluate `ClipBounds` during runtime re-parenting (e.g., when shadow is toggled). This is required because re-parenting does not trigger `OnSizeChanged`. This approach aligns with existing MAUI patterns (e.g., `ContentViewGroup` handling parent checks in similar lifecycle hooks). ### Issues Fixed Fixes regression introduced by #35013 : `WebViewBackgroundColorShouldBeApplied` on Candidate branch. Tested the behaviour in the following platforms - [x] Android - [ ] Windows - [ ] iOS - [ ] Mac
Ahamed-Ali
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Apr 22, 2026
…ndidate branch (#35013) <!-- Please let the below note in for people that find this PR --> > [!NOTE] > Are you waiting for the changes in this PR to be merged? > It would be very helpful if you could [test the resulting artifacts](https://github.com/dotnet/maui/wiki/Testing-PR-Builds) from this PR and let us know in a comment if this change resolves your issue. Thank you! ### Root Cause Applying `ClipBounds = Rect(0, 0, width, height)` constrained the WebView strictly to its layout bounds, preventing shadows (rendered by the parent `WrapperView`) from drawing outside the view. This clipped the shadow and caused UI test failures due to visual mismatch with baseline snapshots. ### Description of Change Updated logic to set `ClipBounds = null` once the view has a valid size, restoring default Android behavior where layout bounds (not `ClipBounds`) control rendering. - Constructor still applies an empty clip to prevent pre-layout full-screen flash - Zero-size scenarios reapply the empty clip to maintain correctness - Aligns with existing handling in `LayoutViewGroup` [Ref](https://github.com/praveenkumarkarunanithi/maui/blob/main/src/Core/src/Platform/Android/LayoutViewGroup.cs#L161) when clipping is disabled ### Issues Fixed Fixes regression introduced by #33207 : `VerifyHybridWebViewWithShadow` on Candidate branch. Tested the behaviour in the following platforms - [x] Android - [ ] Windows - [ ] iOS - [ ] Mac
Ahamed-Ali
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Apr 22, 2026
…n on candidate branch (#35057) <!-- Please let the below note in for people that find this PR --> > [!NOTE] > Are you waiting for the changes in this PR to be merged? > It would be very helpful if you could [test the resulting artifacts](https://github.com/dotnet/maui/wiki/Testing-PR-Builds) from this PR and let us know in a comment if this change resolves your issue. Thank you! ### Root Cause The previous regression fix (PR #35013) set `ClipBounds = null` unconditionally in `OnSizeChanged` to resolve shadow clipping. While effective for shadows, this reintroduced the original full-screen flash issue (#31475) on slower devices. The underlying issue is that `ClipBounds = null` removes GPU-level rendering constraints. On slower devices, the hardware-accelerated WebView compositor renders a frame at full-screen size before Android layout bounds are enforced. Debug analysis showed that when Shadow/Border/Clip is applied, MAUI wraps the WebView inside a `WrapperView`. In this scenario, the wrapper constrains rendering, making `ClipBounds = null` safe. Without decorations, the WebView is hosted directly under `LayoutViewGroup` (with `ClipChildren = false`), requiring explicit bounds to prevent the flash. ### Description of Change Introduced a `UpdateClipBounds` method to dynamically determine the correct clipping strategy based on the parent: * **Parent is WrapperView (decorations applied):** Sets `ClipBounds = null` to allow shadow and visual overflow * **Parent is not WrapperView (no decorations):** Sets exact bounds to prevent full-screen flash on slower devices * **Zero size:** Applies empty bounds to block rendering when the view is collapsed Additionally, added an `OnAttachedToWindow` override to re-evaluate `ClipBounds` during runtime re-parenting (e.g., when shadow is toggled). This is required because re-parenting does not trigger `OnSizeChanged`. This approach aligns with existing MAUI patterns (e.g., `ContentViewGroup` handling parent checks in similar lifecycle hooks). ### Issues Fixed Fixes regression introduced by #35013 : `WebViewBackgroundColorShouldBeApplied` on Candidate branch. Tested the behaviour in the following platforms - [x] Android - [ ] Windows - [ ] iOS - [ ] Mac
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Are you waiting for the changes in this PR to be merged?
It would be very helpful if you could test the resulting artifacts from this PR and let us know in a comment if this change resolves your issue.
Thank you!
Root Cause
Applying
ClipBounds = Rect(0, 0, width, height)constrained the WebView strictly to its layout bounds, preventing shadows (rendered by the parentWrapperView) from drawing outside the view. This clipped the shadow and caused UI test failures due to visual mismatch with baseline snapshots.Description of Change
Updated logic to set
ClipBounds = nullonce the view has a valid size, restoring default Android behavior where layout bounds (notClipBounds) control rendering.LayoutViewGroupRef when clipping is disabledIssues Fixed
Fixes regression introduced by #33207 :
VerifyHybridWebViewWithShadowon Candidate branch.Tested the behaviour in the following platforms