Struct ViewTree 

pub struct ViewTree {
    pub stats: TreeStats,
    pub removed_ids: Vec<NodeId>,
    /* private fields */
}

A persistent view tree that supports incremental updates.

Fields

stats: TreeStats

Statistics from the last reconcile operation.

removed_ids: Vec<NodeId>

Nodes removed during the last update (needed to sync external systems like Taffy).

Implementations

impl ViewTree

pub fn new() -> Self

Create a new empty tree.

pub fn set_subcompose_scope(&mut self, scope: SubcomposeScope)

Set the constraints that will be passed to any SubcomposeLayout content closures during the next update call. The scope is read once per reconcile of a SubcomposeLayout node; if you need different scopes at different depths, the closure itself is responsible for narrowing the values it receives.

pub fn subcompose_scope(&self) -> SubcomposeScope

Get the currently-set subcompose scope.

pub fn invalidate_subcompose_cache(&mut self, node_id: NodeId)

Drop the cached subcomposed view for a single node. Call this when the SubcomposeLayout’s modifier or identity changes so the next reconciliation re-invokes the closure.

pub fn generation(&self) -> u64

Get the current generation.

pub fn root(&self) -> Option<NodeId>

Get the root node ID.

pub fn get(&self, id: NodeId) -> Option<&TreeNode>

Get a node by ID.

pub fn get_mut(&mut self, id: NodeId) -> Option<&mut TreeNode>

Get a mutable node by ID.

pub fn get_by_view_id(&self, view_id: ViewId) -> Option<&TreeNode>

Get a node by ViewId.

pub fn len(&self) -> usize

Get the number of nodes in the tree.

pub fn is_empty(&self) -> bool

Check if the tree is empty.

pub fn is_dirty(&self, id: NodeId) -> bool

Check if a node is marked dirty.

pub fn dirty_nodes(&self) -> &FxHashSet<NodeId>

Get the set of dirty nodes.

pub fn clear_dirty(&mut self)

Clear the dirty set (after layout).

pub fn mark_dirty(&mut self, id: NodeId)

Mark a node as needing re-layout.

pub fn update(&mut self, new_root: &View) -> NodeId

Update the tree from a new View, performing incremental reconciliation. Returns the root NodeId.

pub fn set_layout( &mut self, id: NodeId, rect: Rect, screen_rect: Rect, constraints: LayoutConstraints, )

Set cached layout for a node.

pub fn iter(&self) -> impl Iterator<Item = &TreeNode>

Iterate over all nodes (parent before children).

pub fn iter_with_ids(&self) -> impl Iterator<Item = (NodeId, &TreeNode)>

Iterate over all nodes with their IDs.

pub fn walk<F>(&self, f: F)

where F: FnMut(&TreeNode, u32) -> bool,

Walk the tree from root, calling f for each node. Returns early if f returns false.

pub fn children(&self, id: NodeId) -> Option<&[NodeId]>

Get children of a node.

Trait Implementations

impl Default for ViewTree

fn default() -> Self

Returns the “default value” for a type.