[proof-of-concept] allow toplevel capture

Missing:
- xwayland child windows
- xwayland unmanaged windows, e.g. popups / menus / ...
- xdg child window positioning
- xdg subsurfaces (test-case: mate-terminal settings listboxes)
- xdg popup positioning

include/labwc.h

@@ -188,6 +188,13 @@ struct server {
 	struct wlr_xdg_toplevel_icon_manager_v1 *xdg_toplevel_icon_manager;
 	struct wl_listener xdg_toplevel_icon_set_icon;
 
+	struct {
+		struct wlr_ext_foreign_toplevel_image_capture_source_manager_v1 *manager;
+		struct {
+			struct wl_listener new_request;
+		} on;
+	} toplevel_capture;
+
 	struct wl_list views;
 	struct wl_list unmanaged_surfaces;
 

include/view.h

@@ -176,6 +176,11 @@ struct view {
 	char *title;
 	char *app_id; /* WM_CLASS for xwayland windows */
 
+	struct {
+		struct wlr_scene *scene;
+		struct wlr_ext_image_capture_source_v1 *source;
+	} capture;
+
 	bool mapped;
 	bool been_mapped;
 	enum lab_ssd_mode ssd_mode;
@@ -304,6 +309,7 @@ struct xdg_toplevel_view {
 	/* Events unique to xdg-toplevel views */
 	struct wl_listener set_app_id;
 	struct wl_listener request_show_window_menu;
+	struct wl_listener set_parent;
 	struct wl_listener new_popup;
 };
 

src/foreign-toplevel/ext-foreign.c

@@ -75,6 +75,9 @@ ext_foreign_toplevel_init(struct ext_foreign_toplevel *ext_toplevel,
 		return;
 	}
 
+	/* In support for ext-toplevel-capture */
+	ext_toplevel->handle->data = view;
+
 	/* Client side requests */
 	ext_toplevel->on.handle_destroy.notify = handle_handle_destroy;
 	wl_signal_add(&ext_toplevel->handle->events.destroy, &ext_toplevel->on.handle_destroy);

src/server.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #define _POSIX_C_SOURCE 200809L
 #include "config.h"
+#include <assert.h>
 #include <signal.h>
 #include <string.h>
 #include <sys/wait.h>
@@ -423,6 +424,25 @@ handle_renderer_lost(struct wl_listener *listener, void *data)
 	wlr_renderer_destroy(old_renderer);
 }
 
+static void
+handle_toplevel_capture_request(struct wl_listener *listener, void *data)
+{
+	struct server *server = wl_container_of(listener, server, toplevel_capture.on.new_request);
+	struct wlr_ext_foreign_toplevel_image_capture_source_manager_v1_request *request = data;
+	struct view *view = request->toplevel_handle->data;
+	assert(view);
+	wlr_log(WLR_INFO, "Got request to capture toplevel %s", view->app_id);
+
+	if (!view->capture.source) {
+		view->capture.source = wlr_ext_image_capture_source_v1_create_with_scene_node(
+			&view->capture.scene->tree.node, server->wl_event_loop,
+			server->allocator, server->renderer);
+	}
+	assert(view->capture.source);
+	wlr_ext_foreign_toplevel_image_capture_source_manager_v1_request_accept(
+		request, view->capture.source);
+}
+
 void
 server_init(struct server *server)
 {
@@ -656,6 +676,19 @@ server_init(struct server *server)
 	wlr_screencopy_manager_v1_create(server->wl_display);
 	wlr_ext_image_copy_capture_manager_v1_create(server->wl_display, 1);
 	wlr_ext_output_image_capture_source_manager_v1_create(server->wl_display, 1);
+
+	server->toplevel_capture.manager =
+		wlr_ext_foreign_toplevel_image_capture_source_manager_v1_create(
+			server->wl_display, 1);
+	if (server->toplevel_capture.manager) {
+		server->toplevel_capture.on.new_request.notify = handle_toplevel_capture_request;
+		wl_signal_add(&server->toplevel_capture.manager->events.new_request,
+			&server->toplevel_capture.on.new_request);
+	} else {
+		/* Allow safe removal on shutdown */
+		wl_list_init(&server->toplevel_capture.on.new_request.link);
+	}
+
 	wlr_data_control_manager_v1_create(server->wl_display);
 	wlr_ext_data_control_manager_v1_create(server->wl_display,
 		LAB_EXT_DATA_CONTROL_VERSION);
@@ -788,6 +821,8 @@ server_finish(struct server *server)
 		server->drm_lease_request.notify = NULL;
 	}
 
+	wl_list_remove(&server->toplevel_capture.on.new_request.link);
+
 	wlr_backend_destroy(server->backend);
 	wlr_allocator_destroy(server->allocator);
 

src/view.c

@@ -2570,6 +2570,8 @@ view_init(struct view *view)
 
 	view->title = xstrdup("");
 	view->app_id = xstrdup("");
+
+	view->capture.scene = wlr_scene_create();
 }
 
 void
@@ -2596,6 +2598,8 @@ view_destroy(struct view *view)
 	zfree(view->title);
 	zfree(view->app_id);
 
+	wlr_scene_node_destroy(&view->capture.scene->tree.node);
+
 	if (view->foreign_toplevel) {
 		foreign_toplevel_destroy(view->foreign_toplevel);
 		view->foreign_toplevel = NULL;

src/xdg-popup.c

@@ -166,4 +166,6 @@ xdg_popup_create(struct view *view, struct wlr_xdg_popup *wlr_popup)
 		wlr_scene_xdg_surface_create(parent_tree, wlr_popup->base);
 	node_descriptor_create(wlr_popup->base->surface->data,
 		LAB_NODE_XDG_POPUP, view, /*data*/ NULL);
+
+	wlr_scene_xdg_surface_create(&view->capture.scene->tree, wlr_popup->base);
 }

src/xdg.c

@@ -28,6 +28,8 @@
 #define LAB_XDG_SHELL_VERSION 6
 #define CONFIGURE_TIMEOUT_MS 100
 
+static struct view *xdg_toplevel_view_get_root(struct view *view);
+
 static struct xdg_toplevel_view *
 xdg_toplevel_view_from_view(struct view *view)
 {
@@ -377,6 +379,7 @@ handle_destroy(struct wl_listener *listener, void *data)
 	/* Remove xdg-shell view specific listeners */
 	wl_list_remove(&xdg_toplevel_view->set_app_id.link);
 	wl_list_remove(&xdg_toplevel_view->request_show_window_menu.link);
+	wl_list_remove(&xdg_toplevel_view->set_parent.link);
 	wl_list_remove(&xdg_toplevel_view->new_popup.link);
 	wl_list_remove(&view->commit.link);
 
@@ -488,6 +491,23 @@ handle_request_show_window_menu(struct wl_listener *listener, void *data)
 	menu_open_root(menu, cursor->x, cursor->y);
 }
 
+static void
+handle_set_parent(struct wl_listener *listener, void *data)
+{
+	struct xdg_toplevel_view *xdg_toplevel_view = wl_container_of(
+		listener, xdg_toplevel_view, set_parent);
+	struct view *view = &xdg_toplevel_view->base;
+	struct view *view_root = xdg_toplevel_view_get_root(view);
+	if (view_root == view) {
+		return;
+	}
+	struct wlr_scene_node *node, *tmp;
+	wl_list_for_each_safe(node, tmp, &view->capture.scene->tree.children, link) {
+		wlr_log(WLR_INFO, "moving capture scene node to view_root");
+		wlr_scene_node_reparent(node, &view_root->capture.scene->tree);
+	}
+}
+
 static void
 handle_set_title(struct wl_listener *listener, void *data)
 {
@@ -1050,6 +1070,9 @@ handle_new_xdg_toplevel(struct wl_listener *listener, void *data)
 
 	view_connect_map(view, xdg_surface->surface);
 
+	struct view *root_view = xdg_toplevel_view_get_root(view);
+	wlr_scene_xdg_surface_create(&root_view->capture.scene->tree, xdg_surface);
+
 	struct wlr_xdg_toplevel *toplevel = xdg_surface->toplevel;
 	CONNECT_SIGNAL(toplevel, view, destroy);
 	CONNECT_SIGNAL(toplevel, view, request_move);
@@ -1063,6 +1086,7 @@ handle_new_xdg_toplevel(struct wl_listener *listener, void *data)
 	/* Events specific to XDG toplevel views */
 	CONNECT_SIGNAL(toplevel, xdg_toplevel_view, set_app_id);
 	CONNECT_SIGNAL(toplevel, xdg_toplevel_view, request_show_window_menu);
+	CONNECT_SIGNAL(toplevel, xdg_toplevel_view, set_parent);
 	CONNECT_SIGNAL(xdg_surface, xdg_toplevel_view, new_popup);
 
 	wl_list_insert(&server->views, &view->link);

src/xwayland.c

@@ -844,6 +844,7 @@ xwayland_view_map(struct view *view)
 			return;
 		}
 		view->content_tree = tree;
+		wlr_scene_subsurface_tree_create(&view->capture.scene->tree, view->surface);
 	}
 
 	/*