ThemeProvider gives widgets access to the current visual theme.

 

Concrete theme types (theme.Theme, material3.Theme) implement this

interface. The widget package defines only the interface to avoid

import cycles between widget and theme packages.

 

Widgets should use ThemeProvider for visual decisions (e.g., choosing

colors based on dark/light mode, default text color) rather than

importing a concrete theme package directly.

type ThemeProvider interface {
	// IsDark returns true if this is a dark theme.
	IsDark() bool

	// OnSurface returns the default color for text and icons on surface
	// backgrounds. Every design system (Material 3, Fluent, Cupertino)
	// defines an equivalent concept, making this a universal token.
	OnSurface() Color
}