core: Allow pressing buttons with keyboard

This patch allows the keyboard to be used (Enter/Space) to press buttons.

core/src/player.rs

@@ -1125,6 +1125,25 @@ impl Player {
                 }
             }
 
+            // KeyPress events also take precedence over keyboard navigation.
+            // Note that keyboard navigation works only when the highlight is visible.
+            if !key_press_handled && context.focus_tracker.highlight().is_visible() {
+                if let Some(focus) = context.focus_tracker.get() {
+                    if matches!(
+                        event,
+                        PlayerEvent::KeyDown {
+                            key_code: KeyCode::Return,
+                            ..
+                        } | PlayerEvent::TextInput { codepoint: ' ' }
+                    ) {
+                        // The button/clip is pressed and then immediately released.
+                        // We do not have to wait for KeyUp.
+                        focus.handle_clip_event(context, ClipEvent::Press);
+                        focus.handle_clip_event(context, ClipEvent::Release);
+                    }
+                }
+            }
+
             Self::run_actions(context);
         });