1 files changed, 25 insertions, 0 deletions
diff --git a/third_party/rust/dbus/examples/unity_focused_window.rs b/third_party/rust/dbus/examples/unity_focused_window.rs
new file mode 100644
index 0000000000..a0e07d0372
--- /dev/null
+++ b/third_party/rust/dbus/examples/unity_focused_window.rs
@@ -0,0 +1,25 @@
+extern crate dbus;
+
+// Tracks currently focused window under the Unity desktop by listening to the
+// FocusedWindowChanged signal. The signal contains "window_id", "app_id" and "stage",
+// we print only "app_id". 
+
+use dbus::{Connection, BusType, ConnectionItem};
+
+fn focus_msg(ci: &ConnectionItem) -> Option<&str> {
+    let m = if let &ConnectionItem::Signal(ref s) = ci { s } else { return None };
+    if &*m.interface().unwrap() != "com.canonical.Unity.WindowStack" { return None };
+    if &*m.member().unwrap() != "FocusedWindowChanged" { return None };
+    let (_, app) = m.get2::<u32, &str>();
+    app
+}
+
+fn main() {
+    let c = Connection::get_private(BusType::Session).unwrap();
+    c.add_match("interface='com.canonical.Unity.WindowStack',member='FocusedWindowChanged'").unwrap();
+
+    for i in c.iter(1000) {
+        if let Some(app) = focus_msg(&i) { println!("{} has now focus.", app) };
+    }
+}
+