import { CollectionView } from './CollectionView';
import { GroupDisplayRow } from './GroupRowModel';
/**
 * Read-only window over the grid's items. Everything reads rows through this
 * class instead of touching the source array. It is backed by a
 * {@link CollectionView}, so edits routed through {@link applyEdit} are tracked
 * when the view has trackChanges enabled.
 *
 * When the view is grouped, the grid renders a flattened list of display rows
 * (group headers interleaved with data rows). This class maps a display-row
 * index to the underlying leaf item and reports which rows are group headers.
 */
export declare class DataView<T = Record<string, unknown>> {
    private view;
    private groupModel;
    constructor(source?: T[] | CollectionView<T>);
    get collectionView(): CollectionView<T>;
    /** Rebuild the display-row list from the view's current group tree. */
    refreshGroups(): void;
    get grouped(): boolean;
    /** Number of rows the grid renders (data rows plus visible group headers). */
    get length(): number;
    /** The leaf item at a display-row index, or undefined for group-header rows. */
    item(index: number): T;
    rowType(index: number): 'group' | 'data';
    /** The group-header descriptor at a display-row index, or null for data rows. */
    groupRow(index: number): GroupDisplayRow<T> | null;
    /** Map a display-row index to a leaf index in the view, or -1 for group rows. */
    dataIndexAt(index: number): number;
    toggleGroup(pathKey: string): void;
    collapseAllGroups(): void;
    expandAllGroups(): void;
    /** Path keys of the currently collapsed groups. */
    collapsedGroups(): string[];
    /** Restore the collapsed groups from saved path keys. */
    setCollapsedGroups(keys: string[]): void;
    setItems(items: T[]): void;
    /** Run a mutation inside an edit transaction so the change view can record it. */
    applyEdit(item: T, mutate: () => void): void;
}