library: Ported Switch to Rust (#561)

src/Library/demos/Switch/code.rs

@@ -0,0 +1,21 @@
+use crate::workbench;
+use glib::clone;
+use gtk::glib;
+
+pub fn main() {
+    let switch_on: gtk::Switch = workbench::builder().object("switch_on").unwrap();
+    let label_on: gtk::Label = workbench::builder().object("label_on").unwrap();
+
+    let switch_off: gtk::Switch = workbench::builder().object("switch_off").unwrap();
+    let label_off: gtk::Label = workbench::builder().object("label_off").unwrap();
+
+    switch_on.connect_active_notify(clone!(@weak switch_off => move |switch_on| {
+        label_on.set_label(if switch_on.is_active() { "On" } else { "Off" });
+        switch_off.set_active(!switch_on.is_active());
+    }));
+
+    switch_off.connect_active_notify(move |switch_off| {
+        label_off.set_label(if switch_off.is_active() { "On" } else { "Off" });
+        switch_on.set_active(!switch_off.is_active());
+    });
+}