Fluent2: Missing SystemAccentColorBrushes

[robert-abeo]

Description

For improved usability of the Fluent theme I think Light, Dark and HC need new brush resources:

    <SolidColorBrush
        x:Key="SystemAccentColorBrush"
        Color="{StaticResource SystemAccentColor}" />
    <SolidColorBrush
        x:Key="SystemAccentColorDark1Brush"
        Color="{StaticResource SystemAccentColorDark1}" />
    <SolidColorBrush
        x:Key="SystemAccentColorDark2Brush"
        Color="{StaticResource SystemAccentColorDark2}" />
    <SolidColorBrush
        x:Key="SystemAccentColorDark3Brush"
        Color="{StaticResource SystemAccentColorDark3}" />
    <SolidColorBrush
        x:Key="SystemAccentColorLight1Brush"
        Color="{StaticResource SystemAccentColorLight1}" />
    <SolidColorBrush
        x:Key="SystemAccentColorLight2Brush"
        Color="{StaticResource SystemAccentColorLight2}" />
    <SolidColorBrush
        x:Key="SystemAccentColorLight3Brush"
        Color="{StaticResource SystemAccentColorLight3}" />

Reproduction Steps

See above

Expected behavior

See above

Actual behavior

See above

Regression?

No response

Known Workarounds

No response

Impact

No response

Configuration

No response

Other information

No response

[miloush]

What is the usability improvement, that you type {StaticResource SystemAccentColorDark2Brush} instead of {x:Static SystemColors.AccentColorDark2Brush}?

Do you not need them to be dynamic?

[robert-abeo]

@miloush

What is the usability improvement

You misunderstand -- what are included right now are ONLY colors:

wpf/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Resources/Theme/Dark.xaml

Lines 131 to 139 in 9dea663

	<!-- AccentColor Brushes -->
	<DynamicResource x:Key="SystemAccentColor" ResourceKey="{x:Static SystemColors.AccentColorKey}" />
	<DynamicResource x:Key="SystemAccentColorLight1" ResourceKey="{x:Static SystemColors.AccentColorLight1Key}" />
	<DynamicResource x:Key="SystemAccentColorLight2" ResourceKey="{x:Static SystemColors.AccentColorLight2Key}" />
	<DynamicResource x:Key="SystemAccentColorLight3" ResourceKey="{x:Static SystemColors.AccentColorLight3Key}" />
	<DynamicResource x:Key="SystemAccentColorDark1" ResourceKey="{x:Static SystemColors.AccentColorDark1Key}" />
	<DynamicResource x:Key="SystemAccentColorDark2" ResourceKey="{x:Static SystemColors.AccentColorDark2Key}" />
	<DynamicResource x:Key="SystemAccentColorDark3" ResourceKey="{x:Static SystemColors.AccentColorDark3Key}" />

The vast majority of code we really need to use brushes instead (setting Background, Foreground, etc.). In fact the accent colors are listed under the brushes section so that's kind-of a mistake.

It is much easier to reference an existing brush than create a new SolidColorBrush every time an accent color is needed.

Do you not need them to be dynamic?

No, these are BASE resources. Base resources are completely swapped out for light/dark/hc. Only in the control styles would they need to be referenced as DynamicResource.

[miloush]

Well the colors are already DynamicResource, how are the brushes different? If the current system is to be followed, why not

 <DynamicResource x:Key="SystemAccentColorLight2Brush" ResourceKey="{x:Static SystemColors.AccentColorLight2BrushKey}" /> 

The accent color can change without theme change.

[robert-abeo]

The accent color can change without theme change.

Yes, I suppose that's true:

If the current system is to be followed, why not
<DynamicResource x:Key="SystemAccentColorLight2Brush" ResourceKey="{x:Static SystemColors.AccentColorLight2BrushKey}" />

I do NOT think we should include Brushes in the SystemColors class. Aside from the name mismatch with the class itself it violates convention here.

The following in the Dark/Light/HC resource XAML files is just fine:

<SolidColorBrush
        x:Key="SystemAccentColorBrush"
        Color="{DynamicResource SystemAccentColor}" />

[miloush]

I do NOT think we should include Brushes in the SystemColors class.

The SystemColors class already contains plenty of brushes corresponding to various system colors, so it is a convention to include brushes there and the accent brushes follow that convention and are already defined there (API review). I would have probably preferred separate SystemBrushes class but it's a bit late for that now.

If you lock the brush into a solid color brush, themes/users cannot replace it with different kind of brushes (like a gradient one).

[robert-abeo]

If you lock the brush into a solid color brush, themes/users cannot replace it with different kind of brushes (like a gradient one).

This is fine, all the other resources are done this way.