From ac8b22f2bba8f502097bc358166d89f6049cc62f Mon Sep 17 00:00:00 2001
From: Julian Orth <ju.orth@gmail.com>
Date: Wed, 10 Jul 2024 20:03:20 +0200
Subject: [PATCH] toplevel-drag: correctly update surface positions

---
 src/ifs/wl_seat/event_handling.rs | 14 ++++++++++++--
 src/ifs/xdg_toplevel_drag_v1.rs   | 17 +++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/src/ifs/wl_seat/event_handling.rs b/src/ifs/wl_seat/event_handling.rs
index f64ab341..51bcb5a4 100644
--- a/src/ifs/wl_seat/event_handling.rs
+++ b/src/ifs/wl_seat/event_handling.rs
@@ -410,6 +410,16 @@ impl WlSeatGlobal {
         }
     }
 
+    fn set_pointer_cursor_position(&self, x: Fixed, y: Fixed) -> (Fixed, Fixed) {
+        let (x, y) = self.pointer_cursor.set_position(x, y);
+        if let Some(td) = self.pointer_owner.toplevel_drag() {
+            let x_int = x.round_down();
+            let y_int = y.round_down();
+            td.move_(x_int, y_int);
+        }
+        (x, y)
+    }
+
     fn connector_position_event(
         self: &Rc<Self>,
         time_usec: u64,
@@ -424,7 +434,7 @@ impl WlSeatGlobal {
         let pos = output.global.pos.get();
         x += Fixed::from_int(pos.x1());
         y += Fixed::from_int(pos.y1());
-        (x, y) = self.pointer_cursor.set_position(x, y);
+        (x, y) = self.set_pointer_cursor_position(x, y);
         if let Some(c) = self.constraint.get() {
             if c.ty == ConstraintType::Lock || !c.contains(x.round_down(), y.round_down()) {
                 c.deactivate();
@@ -484,7 +494,7 @@ impl WlSeatGlobal {
                 dy_unaccelerated,
             );
         });
-        self.pointer_cursor.set_position(x, y);
+        self.set_pointer_cursor_position(x, y);
         self.cursor_moved(time_usec);
     }
 
diff --git a/src/ifs/xdg_toplevel_drag_v1.rs b/src/ifs/xdg_toplevel_drag_v1.rs
index f6f062cd..df34ec09 100644
--- a/src/ifs/xdg_toplevel_drag_v1.rs
+++ b/src/ifs/xdg_toplevel_drag_v1.rs
@@ -9,6 +9,7 @@ use {
         object::{Object, Version},
         rect::Rect,
         renderer::Renderer,
+        tree::ToplevelNode,
         utils::clonecell::CloneCell,
         wire::{xdg_toplevel_drag_v1::*, XdgToplevelDragV1Id},
     },
@@ -52,6 +53,18 @@ impl XdgToplevelDragV1 {
         }
     }
 
+    fn move2(&self, x: i32, y: i32) {
+        if let Some(tl) = self.toplevel.get() {
+            let extents = tl.xdg.absolute_desired_extents.get();
+            let extents = extents.at_point(x - self.x_off.get(), y - self.y_off.get());
+            tl.clone().tl_change_extents(&extents);
+        }
+    }
+
+    pub fn move_(&self, x: i32, y: i32) {
+        self.move2(x, y);
+    }
+
     pub fn render(&self, renderer: &mut Renderer<'_>, cursor_rect: &Rect, x: i32, y: i32) {
         if let Some(tl) = self.toplevel.get() {
             if tl.xdg.surface.buffer.get().is_some() {
@@ -107,6 +120,10 @@ impl XdgToplevelDragV1 {
         };
         tl.prepare_toplevel_drag();
         self.client.state.tree_changed();
+        if let Some(seat) = self.source.data.seat.get() {
+            let (x, y) = seat.pointer_cursor().position_int();
+            self.move2(x, y)
+        }
     }
 
     pub fn finish_drag(&self, seat: &Rc<WlSeatGlobal>) {