From a63c97638d216b6ee2db4e35e2d71b91c29171c9 Mon Sep 17 00:00:00 2001
From: lkn <lkn@localhost>
Date: Sun, 7 Jun 2026 13:31:16 +0200
Subject: [PATCH] wclient_wl: fix cross-surface motion/release during implicit
 grab

When a popup menu is opened during a button-held drag, the compositor
changes pointer focus to the popup surface as the pointer enters it.
But pointer_handle_motion always delivered events to the originally
grabbed view (wlc_ptr_grab), never hit-testing inside the popup.
This meant wpopupbutton.c received motion events targeted at the
main button view with coordinates relative to that view, not the menu.

Fix: in both pointer_handle_motion and pointer_handle_button (release),
check whether the grab target is within the currently focused toplevel.
If not (the pointer entered a different surface), use wlc_hit_test
against wlc_ptr_focused to find the correct child view with proper
local coordinates.

Also enable enter/leave synthesis during grabs when target changes,
so child views receive proper WME_ENTER/WME_LEAVE as the pointer
moves between them across the cross-surface boundary.
---
 WINGs/wclient_wl.c | 63 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 46 insertions(+), 17 deletions(-)

diff --git a/WINGs/wclient_wl.c b/WINGs/wclient_wl.c
index 508805d..78f86a0 100644
--- a/WINGs/wclient_wl.c
+++ b/WINGs/wclient_wl.c
@@ -758,22 +758,39 @@ pointer_handle_motion(void *data, struct wl_pointer *p, uint32_t time,
     int lx, ly;
     W_View *target;
 
-    /* During implicit grab (button held), deliver to grabbed view */
+    /* During implicit grab (button held), deliver to grabbed view.
+     * If the pointer has entered a different toplevel surface (e.g. a
+     * popup menu opened during the drag), hit-test against the focused
+     * surface instead so motion events reach the correct child view
+     * (e.g. menuView) with proper local coordinates. */
     if (wlc_ptr_grab) {
-        target = wlc_ptr_grab;
-        int ox = 0, oy = 0;
-        for (W_View *v = target; v && v != wlc_ptr_focused->view; v = v->parent) {
-            ox += v->pos.x;
-            oy += v->pos.y;
+        /* Check if grab target is within the currently focused toplevel */
+        int grab_in_focused = 0;
+        for (W_View *v = wlc_ptr_grab; v; v = v->parent) {
+            if (v == wlc_ptr_focused->view) {
+                grab_in_focused = 1;
+                break;
+            }
+        }
+        if (grab_in_focused) {
+            target = wlc_ptr_grab;
+            int ox = 0, oy = 0;
+            for (W_View *v = target; v && v != wlc_ptr_focused->view; v = v->parent) {
+                ox += v->pos.x;
+                oy += v->pos.y;
+            }
+            lx = (int)wlc_ptr_x - ox;
+            ly = (int)wlc_ptr_y - oy;
+        } else {
+            /* Pointer entered a different toplevel — hit-test there */
+            target = wlc_hit_test(wlc_ptr_focused, (int)wlc_ptr_x, (int)wlc_ptr_y, &lx, &ly);
         }
-        lx = (int)wlc_ptr_x - ox;
-        ly = (int)wlc_ptr_y - oy;
     } else {
         target = wlc_hit_test(wlc_ptr_focused, (int)wlc_ptr_x, (int)wlc_ptr_y, &lx, &ly);
     }
 
     /* Synthesize enter/leave when pointer moves between child views */
-    if (!wlc_ptr_grab && target != wlc_ptr_child_focus) {
+    if (target != wlc_ptr_child_focus) {
         if (wlc_ptr_child_focus) {
             WMEvent lev;
             memset(&lev, 0, sizeof(lev));
@@ -859,17 +876,29 @@ pointer_handle_button(void *data, struct wl_pointer *p, uint32_t serial,
         target = wlc_hit_test(wlc_ptr_focused, (int)wlc_ptr_x, (int)wlc_ptr_y, &lx, &ly);
         wlc_ptr_grab = target;
     } else {
-        /* Deliver release to the grabbed view */
+        /* Deliver release to the grabbed view.  If the pointer has moved
+         * to a different toplevel (e.g. popup menu), hit-test there. */
         target = wlc_ptr_grab;
         if (target) {
-            /* Compute local coords relative to grabbed view */
-            int ox = 0, oy = 0;
-            for (W_View *v = target; v && v != wlc_ptr_focused->view; v = v->parent) {
-                ox += v->pos.x;
-                oy += v->pos.y;
+            int grab_in_focused = 0;
+            for (W_View *v = target; v; v = v->parent) {
+                if (v == wlc_ptr_focused->view) {
+                    grab_in_focused = 1;
+                    break;
+                }
+            }
+            if (grab_in_focused) {
+                int ox = 0, oy = 0;
+                for (W_View *v = target; v && v != wlc_ptr_focused->view; v = v->parent) {
+                    ox += v->pos.x;
+                    oy += v->pos.y;
+                }
+                lx = (int)wlc_ptr_x - ox;
+                ly = (int)wlc_ptr_y - oy;
+            } else {
+                /* Release on a different surface — hit-test there */
+                target = wlc_hit_test(wlc_ptr_focused, (int)wlc_ptr_x, (int)wlc_ptr_y, &lx, &ly);
             }
-            lx = (int)wlc_ptr_x - ox;
-            ly = (int)wlc_ptr_y - oy;
         } else {
             target = wlc_hit_test(wlc_ptr_focused, (int)wlc_ptr_x, (int)wlc_ptr_y, &lx, &ly);
         }