diff --git a/include/wlr/types/wlr_compositor.h b/include/wlr/types/wlr_compositor.h index 9331e8af6..fca325f53 100644 --- a/include/wlr/types/wlr_compositor.h +++ b/include/wlr/types/wlr_compositor.h @@ -127,6 +127,8 @@ struct wlr_surface_output { struct { struct wl_listener bind; struct wl_listener destroy; + + bool lazy_leave; } WLR_PRIVATE; }; @@ -399,6 +401,33 @@ void wlr_surface_send_enter(struct wlr_surface *surface, void wlr_surface_send_leave(struct wlr_surface *surface, struct wlr_output *output); +/** + * Queue a lazy wl_surface.leave event to be sent in a future call to + * wlr_surface_process_lazy_leaves(). + * + * If wlr_surface_send_enter() is called before wlr_surface_process_lazy_leaves() + * actually sends a leave event, the lazy leave mark is cleared. + */ +void wlr_surface_queue_lazy_leave(struct wlr_surface *surface, struct wlr_output *output); + +/** + * If at least one output would remain entered after all lazy leave events + * are sent, send all lazy leave events. Otherwise do nothing. + * + * This behavior helps the compositor implement the following recommended policy: + * + * 1. When a surface transitions from being visible on >0 outputs to being visible on 0 outputs + * don't send any leave events. + * + * 2. When a surface transitions from being visible on 0 outputs to being visible on >0 outputs + * send leave events for all entered outputs on which the surface is no longer visible as + * well as enter events for any outputs not already entered. + * + * This policy avoids sending redundant enter/leave events when a surface is hidden and then shown + * again without any change to the set of intersected outputs. + */ +void wlr_surface_process_lazy_leaves(struct wlr_surface *surface); + /** * Complete the queued frame callbacks for this surface. * diff --git a/types/wlr_compositor.c b/types/wlr_compositor.c index 6b31ab857..6b7e182b7 100644 --- a/types/wlr_compositor.c +++ b/types/wlr_compositor.c @@ -1084,6 +1084,7 @@ void wlr_surface_send_enter(struct wlr_surface *surface, wl_list_for_each(surface_output, &surface->current_outputs, link) { if (surface_output->output == output) { + surface_output->lazy_leave = false; return; } } @@ -1129,6 +1130,45 @@ void wlr_surface_send_leave(struct wlr_surface *surface, } } +void wlr_surface_queue_lazy_leave(struct wlr_surface *surface, struct wlr_output *output) { + struct wlr_surface_output *surface_output; + wl_list_for_each(surface_output, &surface->current_outputs, link) { + if (surface_output->output == output) { + surface_output->lazy_leave = true; + } + } +} + +void wlr_surface_process_lazy_leaves(struct wlr_surface *surface) { + // Only send leave events if at least one output would remain entered. + bool send_leave_events = false; + struct wlr_surface_output *surface_output; + wl_list_for_each(surface_output, &surface->current_outputs, link) { + if (!surface_output->lazy_leave) { + send_leave_events = true; + } + } + + if (!send_leave_events) { + return; + } + + struct wl_client *client = wl_resource_get_client(surface->resource); + struct wlr_surface_output *tmp; + wl_list_for_each_safe(surface_output, tmp, &surface->current_outputs, link) { + if (surface_output->lazy_leave) { + struct wl_resource *resource; + wl_resource_for_each(resource, &surface_output->output->resources) { + if (client == wl_resource_get_client(resource)) { + wl_surface_send_leave(surface->resource, resource); + } + } + surface_output_destroy(surface_output); + break; + } + } +} + void wlr_surface_send_frame_done(struct wlr_surface *surface, const struct timespec *when) { struct wl_resource *resource, *tmp;