Rework how StackingContexts are dynamically added to layers

StackingContexts are added to layers when it is necessary to maintain
their ordering on top of other layered StackingContexts. Instead of
tracking the information about a layer scattered around into different
structs, combine it all into LayerInfo. LayerInfo will be used in the
future to hold layer information for DisplayItems that are layerized
independently of StackingContexts.
This commit is contained in:
Martin Robinson 2015-10-01 15:42:24 -07:00
parent ba2714f4f6
commit 553f1fc192
5 changed files with 162 additions and 115 deletions

View file

@ -50,9 +50,9 @@ pub struct LayerId(
LayerType,
/// The identifier for this layer's fragment, derived from the fragment memory address.
usize,
/// Whether or not this layer is a companion layer, synthesized to ensure that
/// An index for identifying companion layers, synthesized to ensure that
/// content on top of this layer's fragment has the proper rendering order.
bool
usize
);
impl Debug for LayerId {
@ -65,30 +65,23 @@ impl Debug for LayerId {
LayerType::AfterPseudoContent => "-AfterPseudoContent",
};
let companion_string = if companion {
"-companion"
} else {
""
};
write!(f, "{}{}{}", id, type_string, companion_string)
write!(f, "{}{}-{}", id, type_string, companion)
}
}
impl LayerId {
/// FIXME(#2011, pcwalton): This is unfortunate. Maybe remove this in the future.
pub fn null() -> LayerId {
LayerId(LayerType::FragmentBody, 0, false)
LayerId(LayerType::FragmentBody, 0, 0)
}
pub fn new_of_type(layer_type: LayerType, fragment_id: usize) -> LayerId {
LayerId(layer_type, fragment_id, false)
LayerId(layer_type, fragment_id, 0)
}
pub fn companion_layer_id(&self) -> LayerId {
let LayerId(layer_type, id, companion) = *self;
assert!(!companion);
LayerId(layer_type, id, true)
LayerId(layer_type, id, companion + 1)
}
}
@ -172,7 +165,7 @@ pub enum ScriptToCompositorMsg {
}
/// Subpage (i.e. iframe)-specific information about each layer.
#[derive(Clone, Copy, Deserialize, Serialize, HeapSizeOf)]
#[derive(Clone, Copy, Debug, Deserialize, Serialize, HeapSizeOf)]
pub struct SubpageLayerInfo {
/// The ID of the pipeline.
pub pipeline_id: PipelineId,