@@ -878,14 +878,27 @@ impl<'a> WindowContext<'a> {
pub(crate) fn was_top_layer_under_active_drag(
&self,
point: &Point<Pixels>,
- level: &StackingOrder,
+ layer: &StackingOrder,
) -> bool {
- for (opaque_level, _, bounds) in self.window.rendered_frame.depth_map.iter() {
- if level >= opaque_level {
- break;
+ // Precondition: the depth map is ordered from topmost to bottomost.
+
+ for (opaque_layer, _, bounds) in self.window.rendered_frame.depth_map.iter() {
+ if layer >= opaque_layer {
+ // The queried layer is either above or is the same as the this opaque layer.
+ // Anything after this point is guaranteed to be below the queried layer.
+ return true;
+ }
+
+ if !bounds.contains(point) {
+ // This opaque layer is above the queried layer but it doesn't contain
+ // the given position, so we can ignore it even if it's above.
+ continue;
}
- if opaque_level
+ // All normal content is rendered with a base z-index of 0, we know that if the root of this opaque layer
+ // equals `ACTIVE_DRAG_Z_INDEX` then it must be the drag layer and we can ignore it as we are
+ // looking to see if the queried layer was the topmost underneath the drag layer.
+ if opaque_layer
.first()
.map(|c| c.z_index == ACTIVE_DRAG_Z_INDEX)
.unwrap_or(false)
@@ -893,10 +906,21 @@ impl<'a> WindowContext<'a> {
continue;
}
- if bounds.contains(point) {
+ // At this point, we've established that this opaque layer is on top of the queried layer
+ // and contains the position:
+ // - If the opaque layer is an extension of the queried layer, we don't want
+ // to consider the opaque layer to be on top and so we ignore it.
+ // - Else, we will bail early and say that the queried layer wasn't the top one.
+ let opaque_layer_is_extension_of_queried_layer = opaque_layer.len() >= layer.len()
+ && opaque_layer
+ .iter()
+ .zip(layer.iter())
+ .all(|(a, b)| a.z_index == b.z_index);
+ if !opaque_layer_is_extension_of_queried_layer {
return false;
}
}
+
true
}