refactor: standardise error messages

src/clients/wayland/toplevel.rs

@@ -4,6 +4,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use tracing::trace;
 use wayland_client::{DispatchData, Main};
 use wayland_protocols::wlr::unstable::foreign_toplevel::v1::client::zwlr_foreign_toplevel_handle_v1::{Event, ZwlrForeignToplevelHandleV1};
+use crate::error;
 
 const STATE_ACTIVE: u32 = 2;
 const STATE_FULLSCREEN: u32 = 3;
@@ -144,7 +145,7 @@ impl Toplevel {
         handle.quick_assign(move |_handle, event, ddata| {
             let mut inner = inner
                 .write()
-                .expect("Failed to get write lock on toplevel inner state");
+                .expect(error::ERR_WRITE_LOCK);
             toplevel_implem(event, &mut inner, &mut callback, ddata);
         });