Add debug_dump_scene()

Dump view_tree and osd_tree on calling debug-action. Example bind:

<keybind key="A-F12">
  <action name="Debug"></action>
</keybind>

include/debug.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __DEBUG_H
+#define __DEBUG_H
+
+struct server;
+
+void debug_dump_scene(struct server *server);
+
+#endif /* __DEBUG_H */

include/labwc.h

@@ -173,6 +173,7 @@ struct server {
 	struct view *cycle_view;
 
 	struct theme *theme;
+
 	struct menu *rootmenu;
 	struct menu *windowmenu;
 };
@@ -476,6 +477,7 @@ void server_start(struct server *server);
 void server_finish(struct server *server);
 
 /* update onscreen display 'alt-tab' buffer */
+void osd_finish(struct server *server);
 void osd_update(struct server *server);
 
 /*

src/action.c

@@ -3,6 +3,7 @@
 #include <wlr/util/log.h>
 #include "common/spawn.h"
 #include "common/zfree.h"
+#include "debug.h"
 #include "labwc.h"
 #include "menu/menu.h"
 #include "ssd.h"
@@ -161,7 +162,7 @@ action(struct view *activator, struct server *server, struct wl_list *actions, u
 			}
 			break;
 		case ACTION_TYPE_DEBUG:
-			/* nothing */
+			debug_dump_scene(server);
 			break;
 		case ACTION_TYPE_EXECUTE:
 			{

src/debug.c

@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <wlr/types/wlr_scene.h>
+#include "buffer.h"
+#include "labwc.h"
+
+#define INDENT_SIZE (3)
+
+static char *
+get_node_type(enum wlr_scene_node_type type)
+{
+	switch (type) {
+	case WLR_SCENE_NODE_ROOT:
+		return "root";
+	case WLR_SCENE_NODE_TREE:
+		return "tree";
+	case WLR_SCENE_NODE_SURFACE:
+		return "surface";
+	case WLR_SCENE_NODE_RECT:
+		return "rect";
+	case WLR_SCENE_NODE_BUFFER:
+		return "buffer";
+	}
+	return "error";
+}
+
+static void
+dump_tree(struct wlr_scene_node *node, int pos, int x, int y)
+{
+	char *type = get_node_type(node->type);
+
+	if (pos) {
+		printf("%*c+-- ", pos, ' ');
+	}
+	printf("%s (%d,%d) [%p]\n", type, x, y, node);
+
+	struct wlr_scene_node *child;
+	wl_list_for_each(child, &node->state.children, state.link) {
+		dump_tree(child, pos + INDENT_SIZE, x + child->state.x,
+			y + child->state.y);
+	}
+}
+
+void
+debug_dump_scene(struct server *server)
+{
+	struct wlr_scene_node *node;
+
+	printf(":: view_tree ::\n");
+	node = &server->view_tree->node;
+	dump_tree(node, 0, node->state.x, node->state.y);
+
+	printf(":: osd_tree ::\n");
+	node = &server->osd_tree->node;
+	dump_tree(node, 0, node->state.x, node->state.y);
+}

src/meson.build

@@ -3,6 +3,7 @@ labwc_sources = files(
   'buffer.c',
   'cursor.c',
   'damage.c',
+  'debug.c',
   'desktop.c',
   'foreign.c',
   'interactive.c',