Implement place-within-backdrop layer rule

1 files changed, 18 insertions, 0 deletions

diff --git a/src/layer/mapped.rs b/src/layer/mapped.rs
index 5e62d033..78cfadbf 100644
--- a/src/layer/mapped.rs
+++ b/src/layer/mapped.rs
@@ -6,6 +6,7 @@ use smithay::backend::renderer::element::surface::{
 use smithay::backend::renderer::element::Kind;
 use smithay::desktop::{LayerSurface, PopupManager};
 use smithay::utils::{Logical, Point, Scale, Size};
+use smithay::wayland::shell::wlr_layer::{ExclusiveZone, Layer};
 
 use super::ResolvedLayerRules;
 use crate::layout::shadow::Shadow;
@@ -96,6 +97,23 @@ impl MappedLayer {
         true
     }
 
+    pub fn place_within_backdrop(&self) -> bool {
+        if !self.rules.place_within_backdrop {
+            return false;
+        }
+
+        if self.surface.layer() != Layer::Background {
+            return false;
+        }
+
+        let state = self.surface.cached_state();
+        if state.exclusive_zone != ExclusiveZone::DontCare {
+            return false;
+        }
+
+        true
+    }
+
     pub fn render<R: NiriRenderer>(
         &self,
         renderer: &mut R,