From 467805da202e76f472b8db2d522fe225e3c0ecaa Mon Sep 17 00:00:00 2001
From: lkn <lkn@localhost>
Date: Tue, 23 Jun 2026 17:32:10 +0200
Subject: [PATCH] render DnD drag icon surface following cursor

When a client starts a drag with an icon surface, create a
wlr_scene_subsurface_tree in the overlay layer and position it
at the cursor. Update position on drag motion, destroy on end.
---
 src/backend/wayland/wl_dnd.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/backend/wayland/wl_dnd.c b/src/backend/wayland/wl_dnd.c
index 678f3e4..d8a40e3 100644
--- a/src/backend/wayland/wl_dnd.c
+++ b/src/backend/wayland/wl_dnd.c
@@ -7,12 +7,14 @@
 #include <wayland-server-core.h>
 #include <wlr/types/wlr_seat.h>
 #include <wlr/types/wlr_data_device.h>
+#include <wlr/types/wlr_scene.h>
 #include "wl_types.h"
 #include <WINGs/WINGsP.h>
 
 
 /* Currently active external wlr_drag (NULL if none). */
 struct wlr_drag *wl_current_drag = NULL;
+static struct wlr_scene_tree *drag_icon_tree = NULL;
 
 void handle_drag_motion(struct wl_listener *listener, void *data);
 void handle_drag_drop(struct wl_listener *listener, void *data);
@@ -35,6 +37,17 @@ handle_seat_request_start_drag(struct wl_listener *listener, void *data)
     wl_signal_add(&ev->drag->events.motion, &wl_drag_motion_listener);
     wl_signal_add(&ev->drag->events.drop, &wl_drag_drop_listener);
     wl_signal_add(&ev->drag->events.destroy, &wl_drag_destroy_listener);
+
+    /* Render the drag icon surface if provided */
+    if (ev->drag->icon && ev->drag->icon->surface && wl_state.scene) {
+        struct wlr_scene_tree *parent = wl_state.level_trees[WL_LAYER_OVERLAY]
+            ? wl_state.level_trees[WL_LAYER_OVERLAY] : &wl_state.scene->tree;
+        drag_icon_tree = wlr_scene_subsurface_tree_create(parent,
+            ev->drag->icon->surface);
+        if (drag_icon_tree)
+            wlr_scene_node_set_position(&drag_icon_tree->node,
+                (int)wl_state.pointer_x, (int)wl_state.pointer_y);
+    }
 }
 
 void
@@ -47,6 +60,11 @@ handle_drag_motion(struct wl_listener *listener, void *data)
     if (!wl_current_drag)
         return;
 
+    /* Update drag icon position */
+    if (drag_icon_tree)
+        wlr_scene_node_set_position(&drag_icon_tree->node,
+            (int)wl_state.pointer_x, (int)wl_state.pointer_y);
+
     /* Hit-test at current pointer position */
     struct wl_frame_buf *fb = frame_buf_hit(wl_state.pointer_x,
                                             wl_state.pointer_y);
@@ -140,5 +158,9 @@ handle_drag_destroy(struct wl_listener *listener, void *data)
     (void)listener;
     (void)data;
     wwarning("wl_backend: external DND finished");
+    if (drag_icon_tree) {
+        wlr_scene_node_destroy(&drag_icon_tree->node);
+        drag_icon_tree = NULL;
+    }
     wl_current_drag = NULL;
 }