Struct StackingContext 

pub struct StackingContext {
    pub(crate) fragment: StackingContextFragments,
    pub(crate) context_type: StackingContextType,
    pub(crate) children: Vec<StackingContext>,
    pub(crate) containing_block_origin: PhysicalPoint<Au>,
    pub(crate) scroll_tree_node_id: ScrollTreeNodeId,
    pub(crate) clip_id: ClipId,
    pub(crate) z_index: i32,
    pub(crate) text_decorations: Rc<Vec<FragmentTextDecoration>>,
    pub(crate) container_timing_roots: Option<Rc<ContainerTimingRootChain>>,
    pub(crate) reference_frame_info: Option<StackingContextReferenceFrameInfo>,
    pub(crate) participates_in_a_3d_rendering_context: bool,
}

Either a stacking context or a stacking container, per the definitions in https://drafts.csswg.org/css-position-4/#painting-order.

We use the term “real stacking context” in situations that call for a stacking context but not a stacking container. Only positioned stacking containers every get a StackingContext. The rest are handled inline during the PaintTraversal.

Fields

fragment: StackingContextFragments

The BoxFragment that established this stacking context. This is used to paint this StackingContext and traverse its descendants for painting.

This is None for the root stacking context.

context_type: StackingContextType

The StackingContextType of this [StackingContet], which determines if it a stacking context or a stacking container.

children: Vec<StackingContext>

Child StackingContexts of this StackingContext.

containing_block_origin: PhysicalPoint<Au>

The offset of the containing block, used to properly paint child fragments of this stacking context or stacking container.

scroll_tree_node_id: ScrollTreeNodeId

The spatial id of this StackingContext.

clip_id: ClipId

The clip id of this StackingContext if it has one.

z_index: i32

The z-index of this StackingContext. Note that auto is represented as 0.

text_decorations: Rc<Vec<FragmentTextDecoration>>

The text decorations that apply to this StackingContext propagated via the box tree.

container_timing_roots: Option<Rc<ContainerTimingRootChain>>

The Container Timing roots that enclose this StackingContext in tree order, not including its own root fragment. Stacking contexts are painted out of tree order, so these are captured while building the stacking context tree.

reference_frame_info: Option<StackingContextReferenceFrameInfo>

If this StackingContext also created a WebRender reference frame, this field holds information about that reference frame.

participates_in_a_3d_rendering_context: bool

Whether or not this StackingContext participates in a 3D rendering context. See https://www.w3.org/TR/css-transforms-2/#3d-rendering-contexts

Implementations

impl StackingContext

fn root(scroll_tree_node_id: ScrollTreeNodeId) -> Self

fn create_descendant( &self, context_type: StackingContextType, containing_block_offset: PhysicalPoint<Au>, spatial_id: ScrollTreeNodeId, clip_id: ClipId, initializing_fragment: Arc<BoxFragment>, reference_frame_info: Option<StackingContextReferenceFrameInfo>, parent_info: &StackingContextParentInfo, ) -> Self

pub(crate) fn fragment(&self) -> Option<&Arc<BoxFragment>>

fn sort(&mut self)

fn print(&self, tree: &mut PrintTree)

Trait Implementations

impl MallocSizeOf for StackingContext

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.