1 files changed, 25 insertions, 8 deletions

diff --git a/src/window/mapped.rs b/src/window/mapped.rs
index 8263c078..6b539e46 100644
--- a/src/window/mapped.rs
+++ b/src/window/mapped.rs
@@ -3,7 +3,7 @@ use std::time::Duration;
 
 use niri_config::{Color, CornerRadius, GradientInterpolation, WindowRule};
 use smithay::backend::renderer::element::surface::render_elements_from_surface_tree;
-use smithay::backend::renderer::element::{Id, Kind};
+use smithay::backend::renderer::element::Kind;
 use smithay::backend::renderer::gles::GlesRenderer;
 use smithay::desktop::space::SpaceElement as _;
 use smithay::desktop::{PopupManager, Window};
@@ -26,6 +26,7 @@ use crate::layout::{
 };
 use crate::niri_render_elements;
 use crate::render_helpers::border::BorderRenderElement;
+use crate::render_helpers::offscreen::OffscreenData;
 use crate::render_helpers::renderer::NiriRenderer;
 use crate::render_helpers::snapshot::RenderSnapshot;
 use crate::render_helpers::solid_color::{SolidColorBuffer, SolidColorRenderElement};
@@ -70,10 +71,10 @@ pub struct Mapped {
     /// resizes immediately, without waiting for a 1 second throttled callback.
     needs_frame_callback: bool,
 
-    /// Id of the offscreen element rendered in place of this window.
+    /// Data of the offscreen element rendered in place of this window.
     ///
     /// If `None`, then the window is not offscreened.
-    offscreen_element_id: RefCell<Option<Id>>,
+    offscreen_data: RefCell<Option<OffscreenData>>,
 
     /// Whether this window has the keyboard focus.
     is_focused: bool,
@@ -192,7 +193,7 @@ impl Mapped {
             need_to_recompute_rules: false,
             needs_configure: false,
             needs_frame_callback: false,
-            offscreen_element_id: RefCell::new(None),
+            offscreen_data: RefCell::new(None),
             is_focused: false,
             is_active_in_column: true,
             is_floating: false,
@@ -257,8 +258,8 @@ impl Mapped {
         self.credentials.as_ref()
     }
 
-    pub fn offscreen_element_id(&self) -> Ref<Option<Id>> {
-        self.offscreen_element_id.borrow()
+    pub fn offscreen_data(&self) -> Ref<Option<OffscreenData>> {
+        self.offscreen_data.borrow()
     }
 
     pub fn is_focused(&self) -> bool {
@@ -751,8 +752,24 @@ impl LayoutElement for Mapped {
         self.window.output_leave(output)
     }
 
-    fn set_offscreen_element_id(&self, id: Option<Id>) {
-        self.offscreen_element_id.replace(id);
+    fn set_offscreen_data(&self, data: Option<OffscreenData>) {
+        let Some(data) = data else {
+            self.offscreen_data.replace(None);
+            return;
+        };
+
+        let mut offscreen_data = self.offscreen_data.borrow_mut();
+        match &mut *offscreen_data {
+            None => {
+                *offscreen_data = Some(data);
+            }
+            Some(existing) => {
+                // Replace the id, amend existing element states. This is necessary to handle
+                // multiple layers of offscreen (e.g. resize animation + alpha animation).
+                existing.id = data.id;
+                existing.states.states.extend(data.states.states);
+            }
+        }
     }
 
     fn set_activated(&mut self, active: bool) {