Give touch-opened OnDemand layers keyboard focus

Remember and consume the opening interaction instead of depending on pointer focus. Revoke pending focus after another interaction, focus change, cancellation or unmapping, and retain lock and grab safeguards.

Fixes #54

compositor/src/input.rs

@@ -867,6 +867,7 @@ impl Ferese {
                 );
             }
             InputEvent::TouchCancel { .. } => {
+                self.pending_layer_focus = None;
                 self.consumed_touch_slots.clear();
                 let touch = self.seat.get_touch().expect("seat has touch capability");
                 touch.cancel(self);
@@ -1012,6 +1013,7 @@ impl Ferese {
     }
 
     fn focus_window_at(&mut self, position: Point<f64, Logical>, serial: Serial, raise: bool) {
+        self.pending_layer_focus = None;
         if self.input_capture.captures(1) {
             return;
         }
@@ -1044,6 +1046,14 @@ impl Ferese {
                 // release an expanded panel's focus too.
                 self.restore_keyboard_focus();
             }
+            if raise
+                && layer.cached_state().keyboard_interactivity
+                    == smithay::wayland::shell::wlr_layer::KeyboardInteractivity::None
+            {
+                // The client may enable OnDemand only after receiving this
+                // opening press. Touch does not establish pointer focus.
+                self.pending_layer_focus = Some((layer.wl_surface().clone(), std::time::Instant::now()));
+            }
             return;
         }