idle_inhibit: Ignore inhibitors when locked

When a session is locked, no views are visible and there is no way to
interact with the user session. This means that all inhibitors based on
visibility - with the exception being inhibitors on the session lock
surfaces themselves - become inert, allowing the session to go idle.

The only inhibitor type on normal views that one could argue should
remain active is INHIBIT_IDLE_OPEN, but for now we disable all view
inhibitors regardless of type.

sway/desktop/idle_inhibit_v1.c

@@ -1,5 +1,6 @@
 #include <stdlib.h>
 #include <wlr/types/wlr_idle_notify_v1.h>
+#include <wlr/types/wlr_session_lock_v1.h>
 #include "log.h"
 #include "sway/desktop/idle_inhibit_v1.h"
 #include "sway/input/seat.h"
@@ -103,6 +104,19 @@ void sway_idle_inhibit_v1_user_inhibitor_destroy(
 }
 
 bool sway_idle_inhibit_v1_is_active(struct sway_idle_inhibitor_v1 *inhibitor) {
+	if (server.session_lock.lock) {
+		// A session lock is active. In this case, only application inhibitors
+		// on the session lock surface can have any effect.
+		if (inhibitor->mode != INHIBIT_IDLE_APPLICATION) {
+			return false;
+		}
+		struct wlr_surface *wlr_surface = inhibitor->wlr_inhibitor->surface;
+		if (!wlr_session_lock_surface_v1_try_from_wlr_surface(wlr_surface)) {
+			return false;
+		}
+		return wlr_surface->mapped;
+	}
+
 	switch (inhibitor->mode) {
 	case INHIBIT_IDLE_APPLICATION:;
 		// If there is no view associated with the inhibitor, assume visible

sway/lock.c

@@ -239,6 +239,9 @@ static void handle_unlock(struct wl_listener *listener, void *data) {
 		struct sway_output *output = root->outputs->items[i];
 		arrange_layers(output);
 	}
+
+	// Views are now visible, so check if we need to activate inhibition again.
+	sway_idle_inhibit_v1_check_active();
 }
 
 static void handle_abandon(struct wl_listener *listener, void *data) {
@@ -302,6 +305,10 @@ static void handle_session_lock(struct wl_listener *listener, void *data) {
 
 	wlr_session_lock_v1_send_locked(lock);
 	server.session_lock.lock = sway_lock;
+
+	// The lock screen covers everything, so check if any active inhibition got
+	// deactivated due to lost visibility.
+	sway_idle_inhibit_v1_check_active();
 }
 
 static void handle_session_lock_destroy(struct wl_listener *listener, void *data) {

sway/tree/view.c

@@ -189,6 +189,10 @@ uint32_t view_configure(struct sway_view *view, double lx, double ly, int width,
 }
 
 bool view_inhibit_idle(struct sway_view *view) {
+	if (server.session_lock.lock) {
+		return false;
+	}
+
 	struct sway_idle_inhibitor_v1 *user_inhibitor =
 		sway_idle_inhibit_v1_user_inhibitor_for_view(view);