Sync clipboard between X11 and Wayland

You would not believe how much work this was.
Closes #23

src/data_device.rs

@@ -0,0 +1,128 @@
+use crate::clientside::Globals;
+use smithay_client_toolkit::{
+    data_device_manager::{
+        data_device::DataDeviceHandler, data_offer::DataOfferHandler,
+        data_source::DataSourceHandler,
+    },
+    delegate_data_device,
+};
+delegate_data_device!(Globals);
+
+impl DataDeviceHandler for Globals {
+    fn selection(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        data_device: &wayland_client::protocol::wl_data_device::WlDataDevice,
+    ) {
+        self.selection = Some(data_device.clone());
+    }
+
+    fn drop_performed(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_device::WlDataDevice,
+    ) {
+    }
+
+    fn motion(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_device::WlDataDevice,
+    ) {
+    }
+
+    fn leave(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_device::WlDataDevice,
+    ) {
+    }
+
+    fn enter(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_device::WlDataDevice,
+    ) {
+    }
+}
+
+impl DataSourceHandler for Globals {
+    fn send_request(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+        mime: String,
+        fd: smithay_client_toolkit::data_device_manager::WritePipe,
+    ) {
+        self.selection_requests.push((mime, fd));
+    }
+
+    fn cancelled(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+    ) {
+        self.cancelled = true;
+    }
+
+    fn action(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+        _: wayland_client::protocol::wl_data_device_manager::DndAction,
+    ) {
+    }
+
+    fn dnd_finished(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+    ) {
+    }
+
+    fn dnd_dropped(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+    ) {
+    }
+
+    fn accept_mime(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &wayland_client::protocol::wl_data_source::WlDataSource,
+        _: Option<String>,
+    ) {
+    }
+}
+
+impl DataOfferHandler for Globals {
+    fn selected_action(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &mut smithay_client_toolkit::data_device_manager::data_offer::DragOffer,
+        _: wayland_client::protocol::wl_data_device_manager::DndAction,
+    ) {
+    }
+
+    fn source_actions(
+        &mut self,
+        _: &wayland_client::Connection,
+        _: &wayland_client::QueueHandle<Self>,
+        _: &mut smithay_client_toolkit::data_device_manager::data_offer::DragOffer,
+        _: wayland_client::protocol::wl_data_device_manager::DndAction,
+    ) {
+    }
+}