support screenshare of single windows

Supersedes https://codeberg.org/dwl/dwl/pulls/1157.

Co-authored-by: Zuki Air <zukirust@gmail.com>

dwl.c

@@ -121,6 +121,12 @@ typedef struct {
 	} surface;
 	struct wlr_xdg_toplevel_decoration_v1 *decoration;
 	struct wlr_ext_foreign_toplevel_handle_v1 *foreign_toplevel_handle;
+	struct wlr_scene *image_capture_scene;
+	struct wlr_ext_image_capture_source_v1 *image_capture_source;
+	union {
+		struct wlr_scene_tree *image_capture_tree;
+		struct wlr_scene_surface *image_capture_scene_surface;
+	} capture;
 	struct wl_listener commit;
 	struct wl_listener map;
 	struct wl_listener maximize;
@@ -251,6 +257,7 @@ static void arrangelayer(Monitor *m, struct wl_list *list,
 static void arrangelayers(Monitor *m);
 static void axisnotify(struct wl_listener *listener, void *data);
 static void buttonpress(struct wl_listener *listener, void *data);
+static void capturerequest(struct wl_listener *listener, void *data);
 static void chvt(const Arg *arg);
 static void checkidleinhibitor(struct wlr_surface *exclude);
 static void cleanup(void);
@@ -386,6 +393,7 @@ static struct wlr_virtual_pointer_manager_v1 *virtual_pointer_mgr;
 static struct wlr_cursor_shape_manager_v1 *cursor_shape_mgr;
 static struct wlr_output_power_manager_v1 *power_mgr;
 static struct wlr_ext_foreign_toplevel_list_v1 *foreign_toplevel_list;
+static struct wlr_ext_foreign_toplevel_image_capture_source_manager_v1 *ext_foreign_toplevel_image_capture_source_manager_v1;
 
 static struct wlr_pointer_constraints_v1 *pointer_constraints;
 static struct wlr_relative_pointer_manager_v1 *relative_pointer_mgr;
@@ -440,6 +448,7 @@ static struct wl_listener request_set_cursor_shape = {.notify = setcursorshape};
 static struct wl_listener request_start_drag = {.notify = requeststartdrag};
 static struct wl_listener start_drag = {.notify = startdrag};
 static struct wl_listener new_session_lock = {.notify = locksession};
+static struct wl_listener new_foreign_toplevel_capture_request = {.notify = capturerequest};
 
 #ifdef XWAYLAND
 static void activatex11(struct wl_listener *listener, void *data);
@@ -688,6 +697,23 @@ buttonpress(struct wl_listener *listener, void *data)
 			event->time_msec, event->button, event->state);
 }
 
+void
+capturerequest(struct wl_listener *listener, void *data)
+{
+	struct wlr_ext_foreign_toplevel_image_capture_source_manager_v1_request *request = data;
+	Client *view = request->toplevel_handle->data;
+
+	if (!view->image_capture_source) {
+		view->image_capture_source = wlr_ext_image_capture_source_v1_create_with_scene_node(
+				&view->image_capture_scene->tree.node, event_loop, alloc, drw);
+		if (!view->image_capture_source)
+			return;
+	}
+
+	wlr_ext_foreign_toplevel_image_capture_source_manager_v1_request_accept(
+		request, view->image_capture_source);
+}
+
 void
 chvt(const Arg *arg)
 {
@@ -800,6 +826,7 @@ cleanuplisteners(void)
 	wl_list_remove(&request_start_drag.link);
 	wl_list_remove(&start_drag.link);
 	wl_list_remove(&new_session_lock.link);
+	wl_list_remove(&new_foreign_toplevel_capture_request.link);
 #ifdef XWAYLAND
 	wl_list_remove(&new_xwayland_surface.link);
 	wl_list_remove(&xwayland_ready.link);
@@ -1838,6 +1865,14 @@ mapnotify(struct wl_listener *listener, void *data)
 	c->foreign_toplevel_handle = wlr_ext_foreign_toplevel_handle_v1_create(
 			foreign_toplevel_list, &foreign_toplevel_state);
 	c->foreign_toplevel_handle->data = c;
+	c->image_capture_scene = wlr_scene_create();
+	if (c->type == XDGShell)
+		c->capture.image_capture_tree = wlr_scene_xdg_surface_create(&c->image_capture_scene->tree, c->surface.xdg);
+#ifdef XWAYLAND
+	else
+		c->capture.image_capture_scene_surface = wlr_scene_surface_create(&c->image_capture_scene->tree, c->surface.xwayland->surface);
+#endif
+
 
 	/* Set initial monitor, tags, floating status, and focus:
 	 * we always consider floating, clients that have parent and thus
@@ -2630,6 +2665,10 @@ setup(void)
 	wlr_scene_node_set_enabled(&locked_bg->node, 0);
 
 	foreign_toplevel_list = wlr_ext_foreign_toplevel_list_v1_create(dpy,1);
+	ext_foreign_toplevel_image_capture_source_manager_v1 =
+            wlr_ext_foreign_toplevel_image_capture_source_manager_v1_create(dpy, 1);
+	wl_signal_add(&ext_foreign_toplevel_image_capture_source_manager_v1->events.new_request,
+			&new_foreign_toplevel_capture_request);
 
 	/* Use decoration protocols to negotiate server-side decorations */
 	wlr_server_decoration_manager_set_default_mode(
@@ -2898,6 +2937,14 @@ unmapnotify(struct wl_listener *listener, void *data)
 		wlr_ext_foreign_toplevel_handle_v1_destroy(c->foreign_toplevel_handle);
 		c->foreign_toplevel_handle = NULL;
 	}
+#ifdef XWAYLAND
+	if (c->type != XDGShell && c->capture.image_capture_scene_surface) {
+		wlr_scene_node_destroy(&c->capture.image_capture_scene_surface->buffer->node);
+		c->capture.image_capture_scene_surface = NULL;
+	}
+#endif
+
+	wlr_scene_node_destroy(&c->image_capture_scene->tree.node);
 	wlr_scene_node_destroy(&c->scene->node);
 	client_surface(c)->data = NULL;
 	printstatus();