--- a/src/main.rs
+++ b/src/main.rs
@@ -14,182 +14,16 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-use gio::prelude::*;
-use glib::clone;
-use gtk::prelude::*;
-
-use std::env::args;
-use std::io::ErrorKind;
-use std::sync::Arc;
-use input_linux::Key;
-
+mod gtk;
 mod uinput;
 mod state;
-use state::State;
-
-const WIDTH: i32 = 320;
-const HEIGHT: i32 = 180;
 
 const MAX_X: i32 = 69920;
 const MAX_Y: i32 = 39980;
 
-fn build_main_menu(application: &gtk::Application) {
-    let quit = gio::SimpleAction::new("quit", None);
-    application.set_accels_for_action("app.quit", &["<Control>q"]);
-    application.add_action(&quit);
-    quit.connect_activate(clone!(@weak application => move |_, _| application.quit()));
-
-    let about = gio::SimpleAction::new("about", None);
-    application.add_action(&about);
-    about.connect_activate(|_, _| {
-        let about = gtk::AboutDialog::new();
-        about.set_program_name("TabletEmu");
-        about.set_logo_icon_name(Some("input-tablet"));
-        about.set_website(Some("https://hg.linkmauve.fr/tablet-emu"));
-        about.set_version(Some("0.1"));
-        about.set_license_type(gtk::License::Agpl30);
-        about.set_copyright(Some("© 2020 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>"));
-        about.run();
-        unsafe {
-            about.destroy();
-        }
-    });
-
-    let menu = gio::Menu::new();
-    {
-        let file = gio::Menu::new();
-        file.append(Some("_Quit"), Some("app.quit"));
-        menu.append_submenu(Some("_File"), &file);
-    }
-    {
-        let help = gio::Menu::new();
-        help.append(Some("_About"), Some("app.about"));
-        menu.append_submenu(Some("_Help"), &help);
-    }
-    application.set_menubar(Some(&menu));
-}
-
-fn build_ui(application: &gtk::Application) {
-    build_main_menu(application);
-
-    let state = match State::new() {
-        Ok(state) => state,
-        Err(err) => {
-            match err.kind() {
-                ErrorKind::NotFound => {
-                    eprintln!("Couldn’t find /dev/uinput: {}", err);
-                    eprintln!("Maybe you forgot to `modprobe uinput`?");
-                }
-                ErrorKind::PermissionDenied => {
-                    eprintln!("Couldn’t open /dev/uinput for writing: {}", err);
-                    eprintln!("Maybe you aren’t allowed to create input devices?");
-                }
-                _ => eprintln!("Couldn’t open /dev/uinput for writing: {}", err),
-            }
-            std::process::exit(1);
-        }
-    };
-
-    let window = gtk::ApplicationWindow::new(application);
-    window.set_title("tablet-emu");
-    window.set_position(gtk::WindowPosition::Center);
-
-    let hbox = gtk::Box::new(gtk::Orientation::Horizontal, 0);
-    let tools_box = gtk::Box::new(gtk::Orientation::Vertical, 0);
-
-    macro_rules! impl_tool {
-        ($tool:tt) => {
-            let tool = gtk::Button::with_mnemonic($tool);
-            let state_weak = Arc::downgrade(&state);
-            tool.connect_clicked(move |b| {
-                let state = state_weak.upgrade().unwrap();
-                let mut state = state.lock().unwrap();
-                let tool = match b.get_label().unwrap().as_str() {
-                    "_Pen" => Key::ButtonToolPen,
-                    "_Rubber" => Key::ButtonToolRubber,
-                    "_Brush" => Key::ButtonToolBrush,
-                    "P_encil" => Key::ButtonToolPencil,
-                    "_Airbrush" => Key::ButtonToolAirbrush,
-                    _ => unreachable!(),
-                };
-                state.select_tool(tool);
-            });
-            tools_box.add(&tool);
-        };
-    };
-    impl_tool!("_Pen");
-    impl_tool!("_Rubber");
-    impl_tool!("_Brush");
-    impl_tool!("P_encil");
-    impl_tool!("_Airbrush");
-
-    let drawing_area = gtk::DrawingArea::new();
-    drawing_area.set_size_request(WIDTH, HEIGHT);
-    drawing_area.set_hexpand(true);
-    drawing_area.set_events(
-        gdk::EventMask::BUTTON_PRESS_MASK
-            | gdk::EventMask::BUTTON_RELEASE_MASK
-            | gdk::EventMask::POINTER_MOTION_MASK,
-    );
-    let state_weak = Arc::downgrade(&state);
-    drawing_area.connect_configure_event(move |_, event| {
-        let state = state_weak.upgrade().unwrap();
-        let mut state = state.lock().unwrap();
-        state.set_size(event.get_size());
-        true
-    });
-    let state_weak = Arc::downgrade(&state);
-    drawing_area.connect_button_press_event(move |_, event| {
-        if event.get_button() != 1 {
-            return Inhibit(false);
-        }
-
-        let state = state_weak.upgrade().unwrap();
-        let mut state = state.lock().unwrap();
-        let (x, y) = event.get_position();
-        state.press(x, y).unwrap();
-        Inhibit(false)
-    });
-    let state_weak = Arc::downgrade(&state);
-    drawing_area.connect_button_release_event(move |_, event| {
-        if event.get_button() != 1 {
-            return Inhibit(false);
-        }
-
-        let state = state_weak.upgrade().unwrap();
-        let mut state = state.lock().unwrap();
-        let (x, y) = event.get_position();
-        state.release(x, y).unwrap();
-        Inhibit(false)
-    });
-    drawing_area.connect_motion_notify_event(move |_, event| {
-        let mut state = state.lock().unwrap();
-        let (x, y) = event.get_position();
-        state.motion(x, y).unwrap();
-        Inhibit(false)
-    });
-    drawing_area.connect_draw(move |_, ctx| {
-        //println!("drawing {}", drawing_area);
-        ctx.set_source_rgb(1., 0., 0.);
-        ctx.set_operator(cairo::Operator::Screen);
-        ctx.paint();
-        Inhibit(false)
-    });
-
-    hbox.add(&tools_box);
-    hbox.add(&drawing_area);
-
-    window.add(&hbox);
-
-    window.show_all();
-}
+const DEFAULT_WIDTH: i32 = 320;
+const DEFAULT_HEIGHT: i32 = 180;
 
 fn main() {
-    let application = gtk::Application::new(
-        Some("fr.linkmauve.TabletEmu"),
-        gio::ApplicationFlags::empty(),
-    )
-    .expect("Initialisation failed…");
-    application.connect_activate(build_ui);
-    application.run(&args().collect::<Vec<_>>());
+    gtk::main();
 }