Function system_icon_theme 

pub fn system_icon_theme() -> Result<String>

Detect the icon theme name for the current platform (cached).

Returns the name of the icon theme that provides the actual icon files:

• macOS / iOS: "sf-symbols" (no user-configurable icon theme)
• Windows: "segoe-fluent" (no user-configurable icon theme)
• Linux: DE-specific detection (e.g., "breeze-dark", "Adwaita")
• Other: an error; there is no icon theme to detect

On Linux, the detection method depends on the desktop environment:

• KDE: reads [Icons] Theme from kdeglobals, then from kdedefaults/kdeglobals
• GNOME/Budgie: gsettings get org.gnome.desktop.interface icon-theme
• Cinnamon: gsettings get org.cinnamon.desktop.interface icon-theme
• XFCE: xfconf-query -c xsettings -p /Net/IconThemeName
• MATE: gsettings get org.mate.interface icon-theme
• LXQt: reads icon_theme from ~/.config/lxqt/lxqt.conf
• Unknown: tries KDE, then GNOME gsettings

No theme stands in for one that cannot be detected: the error says why, and what to do without a theme is the caller’s decision.

Delegates to DetectionContext::icon_theme() which caches the outcome, a failure included, and supports per-field invalidation via invalidate_caches().

Errors

• Error::ReaderFailed with reader "icon-theme" on Linux when no source names a theme. Its message names each source tried and why it gave no name: the config directory could not be resolved ($XDG_CONFIG_HOME and $HOME both unset or empty), a file could not be read or lacks the key, or a command was not found, exited unsuccessfully or printed no name. On an unrecognised desktop it names both attempts, KDE’s and GNOME’s.
• Error::PlatformUnsupported on a platform other than Linux, macOS, iOS and Windows.

Examples

use native_theme::theme::system_icon_theme;

match system_icon_theme() {
    // On a KDE system with Breeze Dark: "breeze-dark"; on macOS: "sf-symbols"
    Ok(theme) => println!("icon theme: {theme}"),
    Err(e) => println!("no icon theme: {e}"),
}