Hosanna UI API v1.30.2-next
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    Class NodePool

    NodePool manages reusable SceneGraph nodes for performance and memory efficiency. Implements the INodePool interface.

    Implements

    Index

    Constructors

    constructor

    Properties

    createdCounts holder inUseByType pool pristineConfig pristineConfigResolved pristineDefaults retainedNodesByParentId

    Methods

    buildNodeDebugInfo capturePristineDefaults cleanupRetainedNodesForParent clearRetainedNode get getDanglingRowsForDebug getInUseSnapshotForDebug getNodePoolPristineDefaultOverrides getPoolCounts hydratePristineDefaultsFromLoadedConfig prepopulate registerInUse release resolvePristineConfig trackRetainedNode unregisterInUse validatePristineConfigOrThrow getRetainedNodeKey isRequiredPristineField subtypeStringForDebug

    Constructors

    Properties

    createdCounts: { [componentType: string]: number } = {}

    Tracks the number of created nodes for each component type.

    holder: ISGNGroup = ...

    The hidden holder group for storing pooled nodes off-screen.

    inUseByType: Record<string, Record<string, ISGNNode>> = {}

    Nodes currently checked out (not in free list), keyed by subtype then stable key.

    pool: { [componentType: string]: ISGNNode[] } = {}

    The pool of reusable nodes, keyed by component type.

    pristineConfig: undefined | INodePoolPristineDefaults

    Cached nodePoolPristineDefaults section from app config. Populated lazily the first time resolvePristineConfig() succeeds, then sticky. undefined before AppConfig is wired (unit tests, early boot). Shape: { '*': { field: value, ... }, <subtype>: { ... } }.

    pristineConfigResolved: boolean = false
    pristineDefaults: { [componentType: string]: IStyleDictionary } = {}

    Pristine default field values captured from the first freshly-created node of each type. Used to reset pooled nodes to a known-good state before reuse.

    retainedNodesByParentId: Record<string, Record<string, ISGNNode>> = {}

    Nodes released to the pool while intentionally remaining attached to their parent.

    Methods

    • Parameters

      Returns INodePoolDebugInfo

    • Captures the default field values from a freshly-created node (once per component type). Uses node.Keys() for the key list and node[key] for direct property access.

      This is the single point at which pooled-node reset state is defined. The resulting snapshot is replayed via node.update(...) on every get(), so any field that needs a specific "fresh" value on reuse must end up in this snapshot.

      Object-valued (non-array) fields cannot round-trip safely on Roku (roAssociativeArray handles often can't be written back verbatim — e.g. clippingRect's "uninitialized" marker activates the field as a real 0x0 clip rect on replay). To keep pooled reset semantics deterministic across all targets (web, Roku, mobile), NodePool treats object-valued fields uniformly. For those fields:

      • If the merged nodePoolPristineDefaults map (wildcard + subtype bucket) has an entry for the field, the configured value is stored in the snapshot so the next checkout starts clean.
      • If the field is required by schema and the merged map has no value, NodePool throws to prevent stale state leakage once config is loaded.
      • Otherwise the field is skipped.

      Scoping safety: the snapshot is built from node.Keys(), so only fields the subtype actually exposes land in the snapshot. Stray keys in a subtype bucket in app config can't pollute unrelated subtypes.

      Parameters

      Returns void

    • Removes retained-parent nodes that were released for a specific parent.

      Parameters

      • parent: ISGNNode

        Parent whose retained released nodes should be detached.

      Returns void

    • Retrieves a node of the specified component type from the pool, or creates a new one if none are available. Optionally applies an initial state to the node.

      Type Parameters

      Parameters

      • componentType: string

        The type of node to retrieve.

      • OptionalinitialState: IStyleDictionary

        Optional initial state to apply to the node.

      Returns T

      The node instance.

    • Debug-only: nodes that look incorrectly parented while checked out.

      Returns INodePoolDebugInfo[]

    • Debug-only: in-use nodes per subtype (plain objects).

      Returns Record<string, INodePoolDebugInfo[]>

    • Builds the merged wildcard + subtype defaults map for a subtype. Subtype bucket wins so a subtype can override or extend the wildcard. Called only from pristine snapshot capture.

      Parameters

      Returns IStyleDictionary

    • Applies loaded app-config pristine overrides to already-captured subtype snapshots and keeps the updated snapshots cached.

      Returns void

    • Prepopulates the pool with a specified number of nodes of the given component type. Nodes are created off-screen and added to the pool.

      Parameters

      • componentType: string

        The type of node to prepopulate.

      • count: number

        The number of nodes to create.

      Returns void

    • Releases a node back into the pool for reuse. Removes the node from its parent and appends it to the holder group.

      Parameters

      • node: ISGNNode

        The node to release.

      • removeFromParent: boolean = true

      Returns void

    • Resolves nodePoolPristineDefaults.

      Two-phase behavior:

      • Bootstrap (config not yet loaded): fallback-only operation.
      • Loaded config: strict validation and fail-fast on missing required defaults.

      Returns undefined | INodePoolPristineDefaults

    • Parameters

      Returns string

    • Parameters

      • componentType: string
      • field: string

      Returns boolean

    • Parent may be a partial mock (e.g. tests) without subtype().

      Parameters

      Returns undefined | string

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