desktop: don't use LAB_NODE_LAYER_SUBSURFACE node type

Instead, set ctx.type = LAB_NODE_LAYER_SURFACE for both layer-surfaces
and layer-subsurfaces.

This patch preserves the existing behaviors:
- Pressing a subsurface of an on-demand layer-surface gives pointer
  focus to the subsurface, but gives keyboard focus to the parent
  layer-surface (related: a5fcbfaf).
- Pressing a subsurface of a layer-surface doesn't close a popup
  (related: a89bcc3c).

include/common/node-type.h

@@ -49,7 +49,6 @@ enum lab_node_type {
 	LAB_NODE_MENUITEM,
 	LAB_NODE_OSD,
 	LAB_NODE_LAYER_SURFACE,
-	LAB_NODE_LAYER_SUBSURFACE,
 	LAB_NODE_UNMANAGED,
 	LAB_NODE_ALL,
 

include/common/surface-helpers.h

@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-#ifndef LABWC_SURFACE_HELPERS_H
-#define LABWC_SURFACE_HELPERS_H
-
-struct wlr_surface;
-struct wlr_layer_surface_v1;
-
-/**
- * subsurface_parent_layer() - Get wlr_layer_surface from layer-subsurface
- * @wlr_surface: The wlr_surface of the wlr_subsurface for which to get the
- *               layer-surface.
- */
-struct wlr_layer_surface_v1 *subsurface_parent_layer(
-	struct wlr_surface *wlr_surface);
-
-#endif /* LABWC_SURFACE_HELPERS_H */

src/common/meson.build

@@ -17,7 +17,6 @@ labwc_sources += files(
   'parse-double.c',
   'scene-helpers.c',
   'set.c',
-  'surface-helpers.c',
   'spawn.c',
   'string-helpers.c',
   'xml.c',

src/common/surface-helpers.c

@@ -1,27 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-#include "common/surface-helpers.h"
-#include <wlr/types/wlr_layer_shell_v1.h>
-#include <wlr/types/wlr_subcompositor.h>
-#include <wlr/util/log.h>
-
-struct wlr_layer_surface_v1 *
-subsurface_parent_layer(struct wlr_surface *wlr_surface)
-{
-	struct wlr_subsurface *subsurface =
-		wlr_subsurface_try_from_wlr_surface(wlr_surface);
-	if (!subsurface) {
-		return NULL;
-	}
-	struct wlr_surface *parent = subsurface->parent;
-	if (!parent) {
-		wlr_log(WLR_DEBUG, "subsurface %p has no parent", subsurface);
-		return NULL;
-	}
-	struct wlr_layer_surface_v1 *wlr_layer_surface =
-		wlr_layer_surface_v1_try_from_wlr_surface(parent);
-	if (wlr_layer_surface) {
-		return wlr_layer_surface;
-	}
-	/* Recurse in case there are nested sub-surfaces */
-	return subsurface_parent_layer(parent);
-}

src/desktop.c

@@ -9,7 +9,6 @@
 #include <wlr/types/wlr_subcompositor.h>
 #include <wlr/types/wlr_xdg_shell.h>
 #include "common/scene-helpers.h"
-#include "common/surface-helpers.h"
 #include "dnd.h"
 #include "labwc.h"
 #include "layers.h"
@@ -312,9 +311,8 @@ get_cursor_context(struct server *server)
 				}
 				return ret;
 			case LAB_NODE_LAYER_SURFACE:
-				ret.node = node;
 				ret.type = LAB_NODE_LAYER_SURFACE;
-				ret.surface = get_surface_from_layer_node(node);
+				ret.surface = lab_wlr_surface_from_node(ret.node);
 				return ret;
 			case LAB_NODE_LAYER_POPUP:
 				ret.node = node;
@@ -374,29 +372,6 @@ get_cursor_context(struct server *server)
 			}
 		}
 
-		/* Edge-case nodes without node-descriptors */
-		if (node->type == WLR_SCENE_NODE_BUFFER) {
-			struct wlr_surface *surface = lab_wlr_surface_from_node(node);
-
-			/*
-			 * Handle layer-shell subsurfaces
-			 *
-			 * These don't have node-descriptors, but need to be
-			 * able to receive pointer actions so we have to process
-			 * them here.
-			 *
-			 * Test by running `gtk-layer-demo -k exclusive`, then
-			 * open the 'set margin' dialog and try setting the
-			 * margin with the pointer.
-			 */
-			if (surface && wlr_subsurface_try_from_wlr_surface(surface)
-					&& subsurface_parent_layer(surface)) {
-				ret.surface = surface;
-				ret.type = LAB_NODE_LAYER_SUBSURFACE;
-				return ret;
-			}
-		}
-
 		/* node->parent is always a *wlr_scene_tree */
 		node = node->parent ? &node->parent->node : NULL;
 	}

src/input/cursor.c

@@ -19,7 +19,6 @@
 #include "action.h"
 #include "common/macros.h"
 #include "common/mem.h"
-#include "common/surface-helpers.h"
 #include "config/mousebind.h"
 #include "config/rcxml.h"
 #include "dnd.h"
@@ -1075,6 +1074,25 @@ process_press_mousebinding(struct server *server, struct cursor_context *ctx,
 	return consumed_by_frame_context;
 }
 
+static struct wlr_layer_surface_v1 *
+get_root_layer(struct wlr_surface *wlr_surface)
+{
+	assert(wlr_surface);
+	struct wlr_subsurface *subsurface =
+		wlr_subsurface_try_from_wlr_surface(wlr_surface);
+	if (subsurface) {
+		if (subsurface->parent) {
+			return get_root_layer(subsurface->parent);
+		} else {
+			/* never reached? */
+			wlr_log(WLR_ERROR, "subsurface without parent");
+			return NULL;
+		}
+	} else {
+		return wlr_layer_surface_v1_try_from_wlr_surface(wlr_surface);
+	}
+}
+
 static uint32_t press_msec;
 
 bool
@@ -1107,16 +1125,8 @@ cursor_process_button_press(struct seat *seat, uint32_t button, uint32_t time_ms
 	 * the Focus action (used for normal views) does not work.
 	 */
 	if (ctx.type == LAB_NODE_LAYER_SURFACE) {
-		wlr_log(WLR_DEBUG, "press on layer-surface");
-		struct wlr_layer_surface_v1 *layer =
-			wlr_layer_surface_v1_try_from_wlr_surface(ctx.surface);
-		if (layer && layer->current.keyboard_interactive) {
-			layer_try_set_focus(seat, layer);
-		}
-	} else if (ctx.type == LAB_NODE_LAYER_SUBSURFACE) {
-		wlr_log(WLR_DEBUG, "press on layer-subsurface");
-		struct wlr_layer_surface_v1 *layer =
-			subsurface_parent_layer(ctx.surface);
+		wlr_log(WLR_DEBUG, "press on layer-(sub)surface");
+		struct wlr_layer_surface_v1 *layer = get_root_layer(ctx.surface);
 		if (layer && layer->current.keyboard_interactive) {
 			layer_try_set_focus(seat, layer);
 		}
@@ -1127,7 +1137,7 @@ cursor_process_button_press(struct seat *seat, uint32_t button, uint32_t time_ms
 #endif
 	}
 
-	if (ctx.type != LAB_NODE_CLIENT && ctx.type != LAB_NODE_LAYER_SUBSURFACE
+	if (ctx.type != LAB_NODE_CLIENT && ctx.type != LAB_NODE_LAYER_SURFACE
 			&& wlr_seat_pointer_has_grab(seat->seat)) {
 		/*
 		 * If we have an active popup grab (an open popup) we want to