import { AbstractChart } from "../chart-base";
import type { ColumnDataMap } from "../../data/view-reader";
import { NodeStore } from "./node-store";
import { LazyTooltip } from "../../interaction/lazy-tooltip";
/**
 * Sentinel fallback for the Size slot when the user hasn't picked one:
 * use the first non-metadata column in the incoming view. Tree charts
 * still need *some* numeric-ish column to size geometry.
 */
export declare function firstNonMetadataColumn(columns: ColumnDataMap): string;
/**
 * Shared state for hierarchical charts (treemap, sunburst). Holds the
 * tree store + streaming-insert scaffolding + per-row tooltip data
 * buffers. Concrete chart classes extend this and add their own
 * layout / render / interact state.
 *
 * Fields are `public` so the `tree-data.ts` helpers and per-chart
 * layout modules can read/write them without friction.
 */
export declare abstract class TreeChartBase extends AbstractChart {
    _sizeName: string;
    _colorName: string;
    /**
     * Color-slot semantics.
     * - `"empty"`: no Color slot → single palette[0], legend suppressed.
     * - `"numeric"`: Color column is float / integer / date / datetime →
     *   continuous gradient via `colorValueToT`.
     * - `"series"`: Color column is any other type → discrete series
     *   palette keyed by the composite of group_by level values.
     */
    _colorMode: "empty" | "numeric" | "series";
    _nodeStore: NodeStore;
    _rootId: number;
    _currentRootId: number;
    _breadcrumbIds: number[];
    /**
     * Per-parent `Map<childName, childId>` for O(1) find-or-create
     * during streaming tree insertion. Rebuilt on each dataset reset.
     */
    _childLookup: Map<number, Map<string, number>>;
    _rowCount: number;
    _colorMin: number;
    _colorMax: number;
    _uniqueColorLabels: Map<string, number>;
    _visibleNodeIds: Int32Array | null;
    _visibleNodeCount: number;
    /**
     * Lazy-tooltip cache. `lines` is `null` until the async row fetch
     * resolves; the controller's serial dance drops stale results so
     * rapid mouse motion doesn't paint out-of-date text. The render
     * path consults `hoveredTarget` to verify cached lines belong to
     * the currently hovered node before painting.
     */
    _lazyTooltip: LazyTooltip<number>;
}