Don't snap after DnD scroll if view position didn't change

Otherwise, any DnD breaks temporarily centered columns.

src/layout/mod.rs

@@ -1105,7 +1105,7 @@ impl<W: LayoutElement> Layout<W> {
 
                         // Unlock the view on the workspaces.
                         for ws in self.workspaces_mut() {
-                            ws.view_offset_gesture_end(false, None);
+                            ws.dnd_scroll_gesture_end();
                         }
 
                         return Some(RemovedTile {
@@ -3853,7 +3853,7 @@ impl<W: LayoutElement> Layout<W> {
                     let moved_tile_was_active =
                         ws.active_window().is_some_and(|win| *win.id() == window_id);
 
-                    ws.view_offset_gesture_end(false, None);
+                    ws.dnd_scroll_gesture_end();
 
                     if moved_tile_was_active {
                         ws.activate_window(&window_id);
@@ -3876,7 +3876,7 @@ impl<W: LayoutElement> Layout<W> {
         // Unlock the view on the workspaces.
         if !move_.is_floating {
             for ws in self.workspaces_mut() {
-                ws.view_offset_gesture_end(false, None);
+                ws.dnd_scroll_gesture_end();
             }
         }
 
@@ -4050,7 +4050,7 @@ impl<W: LayoutElement> Layout<W> {
         self.dnd = None;
 
         for ws in self.workspaces_mut() {
-            ws.view_offset_gesture_end(false, None);
+            ws.dnd_scroll_gesture_end();
         }
     }
 
@@ -4459,7 +4459,7 @@ impl<W: LayoutElement> Layout<W> {
                             if is_scrolling {
                                 ws.dnd_scroll_gesture_begin();
                             } else {
-                                ws.view_offset_gesture_end(false, None);
+                                ws.dnd_scroll_gesture_end();
                             }
                         } else {
                             // Cancel the view offset gesture after workspace switches, moves, etc.

src/layout/scrolling.rs

@@ -3232,6 +3232,26 @@ impl<W: LayoutElement> ScrollingSpace<W> {
         true
     }
 
+    pub fn dnd_scroll_gesture_end(&mut self) {
+        let ViewOffset::Gesture(gesture) = &mut self.view_offset else {
+            return;
+        };
+
+        if gesture.dnd_last_event_time.is_some() && gesture.tracker.pos() == 0. {
+            // DnD didn't scroll anything, so preserve the current view position (rather than
+            // snapping the window).
+            self.view_offset = ViewOffset::Static(gesture.delta_from_tracker);
+
+            if !self.columns.is_empty() {
+                // Just in case, make sure the active window remains on screen.
+                self.animate_view_offset_to_column(None, self.active_column_idx, None);
+            }
+            return;
+        }
+
+        self.view_offset_gesture_end(false, None);
+    }
+
     pub fn interactive_resize_begin(&mut self, window: W::Id, edges: ResizeEdge) -> bool {
         if self.interactive_resize.is_some() {
             return false;

src/layout/workspace.rs

@@ -1650,6 +1650,10 @@ impl<W: LayoutElement> Workspace<W> {
         self.scrolling.dnd_scroll_gesture_scroll(delta);
     }
 
+    pub fn dnd_scroll_gesture_end(&mut self) {
+        self.scrolling.dnd_scroll_gesture_end();
+    }
+
     pub fn interactive_resize_begin(&mut self, window: W::Id, edges: ResizeEdge) -> bool {
         if self.floating.has_window(&window) {
             self.floating.interactive_resize_begin(window, edges)