Implement AppThemeColor, AppThemeObject, and AppThemeResource

[jfversluis]

Still todo:

• Determine if we even want this (I think we do)
• Find the right place/namespace for it
• Add some samples for it
• Add code documentation
• Add conceptual docs: Add AppThemeColor and AppThemeResource docs MicrosoftDocs/CommunityToolkit#297

This adds the AppThemeColor and AppThemeResource objects that make it easier to work with colors and other resources in light/dark theme scenarios. This enables you to define colors (and resources) in resource dictionaries, making your XAML less verbose and more reusable.

Original PR on .NET MAUI by Dan Siegel: dotnet/maui#8839

[brminnick]

Hey Gerald! I've only done a partial review, but at first glance it looks like we can simplify AppThemeColor.cs a bit. What do you think?

[jfversluis]

@brminnick yep thanks! That was my outstanding comment on refactoring it to use the same code. Applied that now. There is one base AppThemeObject<T> and 2 convenience objects basically that inherit from it, but don't add anything except for making it easier to work with in both code and XAML: AppThemeResource which just uses an object and AppThemeColor which does the same for colors. What do you think?

I've left AppThemeObject<T> public on purpose, maybe people want to extend it for their own things?

[pictos]

This looks good in general, I've feel comments around the AppThemeObject class

[jfversluis]

OK I think I have all the feedback processed. Then the only question remains if we want to rename AppThemeExtension to anything.

If you start typing <Label TextColor="{AppTheme ... it will suggest the AppTheme type in .NET MAUI. Is that a problem? I think ideally we'd pick a different name to avoid collisions. On the other hand, people will most likely add the xmlns first and then type toolkit:AppTheme... and it will suggest the right one?

[jfversluis]

Similarly, Themed Resource would reference a resource.

A color is a resource though, even in this code, it literally just inherits from the resource. But this is more about it being clear to the consumer and not the technicalities I guess 😄

[jfversluis]

OK went with ThemeResourceExtension then you would write TextColor="{ThemeResource MyColor}" which is in line with StaticResource and DynamicResource was the idea.

[brminnick]

Hey Gang! I think we should the classes to Theme... now that we renamed ThemeResouceExtension:

• public class AppThemeResource -> public class ThemeResource
• public class AppThemeColor -> public class ThemeColor

Renaming will give us better consistency in XAML:

• Updated: <mct:ThemeResource ... />
  • Current <mct:AppThemeResource ... />
• Updated: <mct:ThemeColor ... />
  • Current: <mct:AppThemeColor ... />
• Current: {mct:ThemeResource ...}

[jfversluis]

@brminnick So yeah, funny story, now we're back to square 1.

The extension is called: ThemeResource and now we have an object ThemeResource... 😅

[brminnick]

Oh no!! 🙈🙃😭

Naming is so hard...

[IndianaGary]

😊 From: Brandon Minnick ***@***.***> Sent: Sunday, July 16, 2023 11:04 AM To: CommunityToolkit/Maui ***@***.***> Cc: Gary Lewis ***@***.***>; Mention ***@***.***> Subject: Re: [CommunityToolkit/Maui] Implement AppThemeColor and AppThemeResource (PR #1264) Oh no!! 🙈🙃😭 Naming is so hard... [image]<https://user-images.githubusercontent.com/13558917/253819702-98b18e0c-aa41-4dc0-9af5-e230c47bc46d.png> — Reply to this email directly, view it on GitHub<#1264 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ADFAH7BEE4KQ4RR4QEXM5WDXQQUHNANCNFSM6AAAAAAZRJDD4U>. You are receiving this because you were mentioned.Message ID: ***@***.******@***.***>>

[brminnick]

Thanks Gerald!! I think we finally got the naming:

public sealed class AppThemeColor : AppThemeObject<Color>;

public sealed class AppThemeObject : AppThemeObject<object>;

public abstract class AppThemeObject<T>;

public sealed class AppThemeResourceExtension : IMarkupExtension<BindingBase>;

I approve, and I'll defer to you to merge it to give you time to review the updates.

👇 Here's how these names look in the Sample app