On X11, update keymap on XkbMapNotify

This is required to handle xmodmap.

Fixes #3338.

CHANGELOG.md

@@ -11,6 +11,7 @@ Unreleased` header.
 
 # Unreleased
 
+- On X11, keymap not updated from xmodmap.
 - On X11, reduce the amount of time spent fetching screen resources.
 - On Windows, macOS, X11, Wayland and Web, implement setting images as cursors. See the `custom_cursors.rs` example.
   - **Breaking:** Remove `Window::set_cursor_icon`

src/platform_impl/linux/x11/event_processor.rs

@@ -1282,6 +1282,21 @@ impl<T: 'static> EventProcessor<T> {
                                 unsafe { self.kb_state.init_with_x11_keymap() };
                             }
                         }
+                        ffi::XkbMapNotify => {
+                            let prev_mods = self.kb_state.mods_state();
+                            unsafe { self.kb_state.init_with_x11_keymap() };
+                            let new_mods = self.kb_state.mods_state();
+                            if prev_mods != new_mods {
+                                if let Some(window) = self.active_window {
+                                    callback(Event::WindowEvent {
+                                        window_id: mkwid(window),
+                                        event: WindowEvent::ModifiersChanged(
+                                            Into::<ModifiersState>::into(new_mods).into(),
+                                        ),
+                                    });
+                                }
+                            }
+                        }
                         ffi::XkbStateNotify => {
                             let xev =
                                 unsafe { &*(xev as *const _ as *const ffi::XkbStateNotifyEvent) };

src/platform_impl/linux/x11/mod.rs

@@ -365,7 +365,9 @@ impl<T: 'static> EventLoop<T> {
             .xconn
             .select_xkb_events(
                 0x100, // Use the "core keyboard device"
-                xkb::EventType::NEW_KEYBOARD_NOTIFY | xkb::EventType::STATE_NOTIFY,
+                xkb::EventType::NEW_KEYBOARD_NOTIFY
+                    | xkb::EventType::MAP_NOTIFY
+                    | xkb::EventType::STATE_NOTIFY,
             )
             .unwrap();