Send output enter/leave events correctly

Previously we used a reparent event to detect when a view changes
parent, then sent an output enter/leave to the surfaces if needed. This
worked for tiling views but not floating views, as floating views can
intersect another output without changing parent.

The solution implemented for floating views also applies cleanly to
tiling views, so the previous method has been completely replaced and
the reparent event has been removed.

This introduces a new function container_discover_outputs. This function
compares the container's `current` position to the outputs, sends enter
and leave events as needed, and keeps track of which outputs it's
intersecting in a new `container->outputs` list. If it has entered a new
output with a different scale then the title and marks textures will
also be recreated at the new scale.

The function is called when a transaction applies. This is convenient as
it means we don't have to call it from various places.

There is imperfect rendering when a floating view overlaps two outputs
with different scales. It renders correctly for the most recently
entered output, but there is only one title texture so it renders
incorrectly on the old output.

Fixes #2482

1 files changed, 4 insertions, 54 deletions

diff --git a/sway/tree/view.c b/sway/tree/view.c
index b77a9bb2..4abf1abb 100644
--- a/sway/tree/view.c
+++ b/sway/tree/view.c
@@ -364,48 +364,6 @@ static void view_handle_surface_new_subsurface(struct wl_listener *listener,
 	view_subsurface_create(view, subsurface);
 }
 
-static void surface_send_enter_iterator(struct wlr_surface *surface,
-		int x, int y, void *data) {
-	struct wlr_output *wlr_output = data;
-	wlr_surface_send_enter(surface, wlr_output);
-}
-
-static void surface_send_leave_iterator(struct wlr_surface *surface,
-		int x, int y, void *data) {
-	struct wlr_output *wlr_output = data;
-	wlr_surface_send_leave(surface, wlr_output);
-}
-
-static void view_handle_container_reparent(struct wl_listener *listener,
-		void *data) {
-	struct sway_view *view =
-		wl_container_of(listener, view, container_reparent);
-	struct sway_container *old_parent = data;
-
-	struct sway_container *old_output = old_parent;
-	if (old_output != NULL && old_output->type != C_OUTPUT) {
-		old_output = container_parent(old_output, C_OUTPUT);
-	}
-
-	struct sway_container *new_output = view->swayc->parent;
-	if (new_output != NULL && new_output->type != C_OUTPUT) {
-		new_output = container_parent(new_output, C_OUTPUT);
-	}
-
-	if (old_output == new_output) {
-		return;
-	}
-
-	if (old_output != NULL) {
-		view_for_each_surface(view, surface_send_leave_iterator,
-			old_output->sway_output->wlr_output);
-	}
-	if (new_output != NULL) {
-		view_for_each_surface(view, surface_send_enter_iterator,
-			new_output->sway_output->wlr_output);
-	}
-}
-
 static bool view_has_executed_criteria(struct sway_view *view,
 		struct criteria *criteria) {
 	for (int i = 0; i < view->executed_criteria->length; ++i) {
@@ -567,9 +525,6 @@ void view_map(struct sway_view *view, struct wlr_surface *wlr_surface) {
 		&view->surface_new_subsurface);
 	view->surface_new_subsurface.notify = view_handle_surface_new_subsurface;
 
-	wl_signal_add(&view->swayc->events.reparent, &view->container_reparent);
-	view->container_reparent.notify = view_handle_container_reparent;
-
 	if (view->impl->wants_floating && view->impl->wants_floating(view)) {
 		view->border = config->floating_border;
 		view->border_thickness = config->floating_border_thickness;
@@ -587,15 +542,12 @@ void view_map(struct sway_view *view, struct wlr_surface *wlr_surface) {
 	view_update_title(view, false);
 	container_notify_subtree_changed(view->swayc->parent);
 	view_execute_criteria(view);
-
-	view_handle_container_reparent(&view->container_reparent, NULL);
 }
 
 void view_unmap(struct sway_view *view) {
 	wl_signal_emit(&view->events.unmap, view);
 
 	wl_list_remove(&view->surface_new_subsurface.link);
-	wl_list_remove(&view->container_reparent.link);
 
 	if (view->urgent_timer) {
 		wl_event_source_remove(view->urgent_timer);
@@ -937,10 +889,8 @@ void view_add_mark(struct sway_view *view, char *mark) {
 
 static void update_marks_texture(struct sway_view *view,
 		struct wlr_texture **texture, struct border_colors *class) {
-	struct sway_container *output = container_parent(view->swayc, C_OUTPUT);
-	if (!output) {
-		return;
-	}
+	struct sway_output *output =
+		view->swayc->outputs->items[view->swayc->outputs->length - 1];
 	if (*texture) {
 		wlr_texture_destroy(*texture);
 		*texture = NULL;
@@ -973,7 +923,7 @@ static void update_marks_texture(struct sway_view *view,
 	}
 	free(part);
 
-	double scale = output->sway_output->wlr_output->scale;
+	double scale = output->wlr_output->scale;
 	int width = 0;
 	int height = view->swayc->title_height * scale;
 
@@ -999,7 +949,7 @@ static void update_marks_texture(struct sway_view *view,
 	unsigned char *data = cairo_image_surface_get_data(surface);
 	int stride = cairo_format_stride_for_width(CAIRO_FORMAT_ARGB32, width);
 	struct wlr_renderer *renderer = wlr_backend_get_renderer(
-			output->sway_output->wlr_output->backend);
+			output->wlr_output->backend);
 	*texture = wlr_texture_from_pixels(
 			renderer, WL_SHM_FORMAT_ARGB8888, stride, width, height, data);
 	cairo_surface_destroy(surface);