Add xdg-positioner support

sway/desktop/xdg_shell.c

@@ -45,6 +45,53 @@ static void popup_handle_destroy(struct wl_listener *listener, void *data) {
 	view_child_destroy(&popup->child);
 }
 
+static void popup_unconstrain(struct sway_xdg_popup *popup) {
+	// get the output of the popup's positioner anchor point and convert it to
+	// the toplevel parent's coordinate system and then pass it to
+	// wlr_xdg_popup_unconstrain_from_box
+
+	struct sway_view *view = popup->child.view;
+	struct wlr_output_layout *output_layout =
+		root_container.sway_root->output_layout;
+	struct wlr_xdg_popup *wlr_popup = popup->wlr_xdg_surface->popup;
+
+	int anchor_lx, anchor_ly;
+	wlr_xdg_popup_get_anchor_point(wlr_popup, &anchor_lx, &anchor_ly);
+
+	int popup_lx, popup_ly;
+	wlr_xdg_popup_get_toplevel_coords(wlr_popup, wlr_popup->geometry.x,
+		wlr_popup->geometry.y, &popup_lx, &popup_ly);
+	popup_lx += view->x;
+	popup_ly += view->y;
+
+	anchor_lx += popup_lx;
+	anchor_ly += popup_ly;
+
+	double dest_x = 0, dest_y = 0;
+	wlr_output_layout_closest_point(output_layout, NULL, anchor_lx, anchor_ly,
+		&dest_x, &dest_y);
+
+	struct wlr_output *output =
+		wlr_output_layout_output_at(output_layout, dest_x, dest_y);
+	if (output == NULL) {
+		return;
+	}
+
+	int width = 0, height = 0;
+	wlr_output_effective_resolution(output, &width, &height);
+
+	// the output box expressed in the coordinate system of the toplevel parent
+	// of the popup
+	struct wlr_box output_toplevel_sx_box = {
+		.x = output->lx - view->x,
+		.y = output->ly - view->y,
+		.width = width,
+		.height = height
+	};
+
+	wlr_xdg_popup_unconstrain_from_box(wlr_popup, &output_toplevel_sx_box);
+}
+
 static struct sway_xdg_popup *popup_create(
 		struct wlr_xdg_popup *wlr_popup, struct sway_view *view) {
 	struct wlr_xdg_surface *xdg_surface = wlr_popup->base;
@@ -55,12 +102,15 @@ static struct sway_xdg_popup *popup_create(
 		return NULL;
 	}
 	view_child_init(&popup->child, &popup_impl, view, xdg_surface->surface);
+	popup->wlr_xdg_surface = xdg_surface;
 
 	wl_signal_add(&xdg_surface->events.new_popup, &popup->new_popup);
 	popup->new_popup.notify = popup_handle_new_popup;
 	wl_signal_add(&xdg_surface->events.destroy, &popup->destroy);
 	popup->destroy.notify = popup_handle_destroy;
 
+	popup_unconstrain(popup);
+
 	return popup;
 }
 

sway/desktop/xdg_shell_v6.c

@@ -44,6 +44,53 @@ static void popup_handle_destroy(struct wl_listener *listener, void *data) {
 	view_child_destroy(&popup->child);
 }
 
+static void popup_unconstrain(struct sway_xdg_popup_v6 *popup) {
+	// get the output of the popup's positioner anchor point and convert it to
+	// the toplevel parent's coordinate system and then pass it to
+	// wlr_xdg_popup_unconstrain_from_box
+
+	struct sway_view *view = popup->child.view;
+	struct wlr_output_layout *output_layout =
+		root_container.sway_root->output_layout;
+	struct wlr_xdg_popup_v6 *wlr_popup = popup->wlr_xdg_surface_v6->popup;
+
+	int anchor_lx, anchor_ly;
+	wlr_xdg_popup_v6_get_anchor_point(wlr_popup, &anchor_lx, &anchor_ly);
+
+	int popup_lx, popup_ly;
+	wlr_xdg_popup_v6_get_toplevel_coords(wlr_popup, wlr_popup->geometry.x,
+		wlr_popup->geometry.y, &popup_lx, &popup_ly);
+	popup_lx += view->x;
+	popup_ly += view->y;
+
+	anchor_lx += popup_lx;
+	anchor_ly += popup_ly;
+
+	double dest_x = 0, dest_y = 0;
+	wlr_output_layout_closest_point(output_layout, NULL, anchor_lx, anchor_ly,
+		&dest_x, &dest_y);
+
+	struct wlr_output *output =
+		wlr_output_layout_output_at(output_layout, dest_x, dest_y);
+	if (output == NULL) {
+		return;
+	}
+
+	int width = 0, height = 0;
+	wlr_output_effective_resolution(output, &width, &height);
+
+	// the output box expressed in the coordinate system of the toplevel parent
+	// of the popup
+	struct wlr_box output_toplevel_sx_box = {
+		.x = output->lx - view->x,
+		.y = output->ly - view->y,
+		.width = width,
+		.height = height
+	};
+
+	wlr_xdg_popup_v6_unconstrain_from_box(wlr_popup, &output_toplevel_sx_box);
+}
+
 static struct sway_xdg_popup_v6 *popup_create(
 		struct wlr_xdg_popup_v6 *wlr_popup, struct sway_view *view) {
 	struct wlr_xdg_surface_v6 *xdg_surface = wlr_popup->base;
@@ -54,12 +101,15 @@ static struct sway_xdg_popup_v6 *popup_create(
 		return NULL;
 	}
 	view_child_init(&popup->child, &popup_impl, view, xdg_surface->surface);
+	popup->wlr_xdg_surface_v6 = xdg_surface;
 
 	wl_signal_add(&xdg_surface->events.new_popup, &popup->new_popup);
 	popup->new_popup.notify = popup_handle_new_popup;
 	wl_signal_add(&xdg_surface->events.destroy, &popup->destroy);
 	popup->destroy.notify = popup_handle_destroy;
 
+	popup_unconstrain(popup);
+
 	return popup;
 }