Padding (and even children Margin) clips children on Android

[roubachof]

Current behavior

It seems that when setting Padding on a parent view, it clips children on android, whereas on other platform it does not clip the children.

Expected behavior

Padding and margin should behave consistently between platform hence android shouldn't clip child when using padding or child margin.

How to reproduce it (as minimally and precisely as possible)

Launch Uno toolkit winui sample, and select the ShadowContainer sample, from this branch:
unoplatform/uno.toolkit.ui#571

you will see that the first "Neumorphism" card is clipped by its parent padding

   <StackPanel Width="400"
                        Margin="0,32"
                        Padding="32"
                        Background="{StaticResource UnoColor}"
                        CornerRadius="30">
                <ui:ShadowContainer Shadows="{StaticResource NeumorphismRaising}">
                    <Grid Width="300"
                          Padding="20"
                          Background="{StaticResource UnoColor}"
                          CornerRadius="20">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="20" />
                            <RowDefinition Height="20" />
                        </Grid.RowDefinitions>

                        <TextBlock FontSize="15"
                                   Foreground="White"
                                   Text="Neumorphism" />
                        <TextBlock Grid.Row="1"
                                   FontSize="12"
                                   Foreground="White"
                                   Text="Raising element" />
                    </Grid>
                </ui:ShadowContainer>

on Windows and iOS, the children shadows are not clipped.

remark: Shadows are implement by a SKXamlCanvas .

Workaround

No response

Works on UWP/WinUI

None

Environment

No response

NuGet package version(s)

Uno.WinUI 4.7.37, 4.9.26
SkiaSharp.Views.Uno.WinUI 2.88.3

Affected platforms

No response

IDE

No response

IDE version

No response

Relevant plugins

No response

Anything else we need to know?

No response

[agneszitte]

@roubachof tested and said it was the same using latest Uno 5.0.0-dev.1380

[carldebilly]

@roubachof On Android, I'm having far worse result...

[roubachof]

Yup this is another issue: a regression on layout with uno 5, it also impact ios.
You can either try it with version < 5, or toggle the theming to force a new layout pass and have the correct result (with bad padding :).

[jeromelaban]

@roubachof could you create another issue with a before/after issue for that particular layout problem that is a regression? We're going to need to look at it separately. This issue may also still be blocked by the fact that we can't debug on android properly at this time.

[eriklimakc]

On WASM there is clipping as well, but it looks different from Android. Could it be related?

[eriklimakc]

About the WASM clipping, on SkiaSharp 2.88.4-preview.84 we get a better result:

[jeromelaban]

There's still a little bit of clipping, but it's a lot better for sure.

[roubachof]

This is in fact the same clipping, but since the fix I created for wasm was integrated in 2.88.4-preview (mono/SkiaSharp#2443), you have now the correct shadow color, which is softer and doesn't enlighten the wasm clipping so much.