Initial support for ThemeShadow

[MartinZikmund]

GitHub Issue (If applicable): part of #11115

PR Type

What kind of change does this PR introduce?

• Feature

What is the current behavior?

ThemeShadow not supported

What is the new behavior?

Basic support for WASM and Android

PR Checklist

Please check if your PR fulfills the following requirements:

• Docs have been added/updated which fit documentation template (for bug fixes / features)
• Unit Tests and/or UI Tests for the changes have been added (for bug fixes / features) (if applicable)
• Validated PR Screenshots Compare Test Run results.
• Contains NO breaking changes
• Associated with an issue (GitHub or internal) and uses the automatic close keywords.
• Commits must be following the Conventional Commits specification.

[gitpod-io]

[DierkDroth]

Happy New Year!

Curious, if this PR is merged: will ThemeShadow then be fully supported

• works on all target platforms (which ones?)
• in dark and light mode?
• works on WinUI/WindowsAppSdk as well?

[MartinZikmund]

@DierkDroth Support for ThemeShadow will be on all platforms, with slight appearance differences at first (this will be improved further) and it will work in both dark and light mode (although in dark mode it will be only slightly visible, similarly to UWP). The difference from UWP is that we can't (due to target platform's limitations) consider the ShadowReceviers, so the shadow is a simpler drop shadow. WinUI/WASDK support is handled directly by Microsoft, and I think ThemeShadow should be supported there already 👍 .

[DierkDroth]

@DierkDroth Support for ThemeShadow will be on all platforms, with slight appearance differences at first (this will be improved further) and it will work in both dark and light mode (although in dark mode it will be only slightly visible, similarly to UWP). The difference from UWP is that we can't (due to target platform's limitations) consider the ShadowReceviers, so the shadow is a simpler drop shadow. WinUI/WASDK support is handled directly by Microsoft, and I think ThemeShadow should be supported there already 👍 .

Thanks for your feedback @MartinZikmund
FYI I just read that DropShadow and the .Receivers property would soon be legacy anyway https://docs.microsoft.com/en-us/windows/apps/design/layout/depth-shadow

Z-depth and shadow for Windows apps - Windows apps

Z-depth, or relative depth, and shadow are two ways to incorporate depth into your app to help users focus naturally and efficiently.

[MartinZikmund]

@DierkDroth oh, that's actually good news, as Receivers were something that was kind of impossible to emulate 😀

[DierkDroth]

@MartinZikmund is ThemeShadow still being worked on? Is there an ETA available?

Also: when working it could be assigned e.g. to Border.Shadow and Border.Translation could be set to define the elevation, correct?

[DierkDroth]

@MartinZikmund FYI

I took the plunge and applied ElevatedView on WASM in theme XAML and code whereever shadow was missing. So, ThemeShadow on WASM no longer is of priority to me. Nevertheless, it would be great to see ThemeShadow support in UNO...

BTW I also tried to use ElevatedView on WindowsAppSDK (using latest Uno.WinUI bits) - since I actually find it nicer than the Windows default - but experienced a funny problem: after a few seconds and when moving the mouse around the shadow effect from ElevatedView vanishes and I 'only' saw the default shadow effect from WindowsAppSDK. Not sure if I did something wrong or if there really is an issue with ElevatedView on Windows...

[MartinZikmund]

@jeromelaban the merge is blocked by the conventional commits validation, can you force merge?