KeyboardFocus should be visually clearly indicated for better user experience, which is in Aero but Fluent regresses

[KotaroTONOIKE]

Summary

In recent WPF themes (e.g., Fluent), KeyboardFocus may be present but not visually indicated. This is a regression from older themes like Aero and Classic, which provided clear, predictable focus feedback.

Why this is a design flaw

• Users cannot determine which control will respond to the next key press.
• Aero provided a clear visual indicator via FocusVisualStyle and animation.
• Fluent omits this, leading to ambiguity and reduced accessibility.

Suggested Resolution

• Reinstate visual feedback for KeyboardFocus in default templates.
• Use FocusVisualStyle or IsKeyboardFocused triggers to provide consistent feedback.

Philosophical Note

A UI that accepts input without revealing its focus state violates the principle of explicit responsibility modeling. Aero got this right. Fluent regressed.