import type { Event, Disposable, MaybePromise } from '@difizen/mana-common';
import { Emitter, DisposableCollection } from '@difizen/mana-common';
import type { Tree, TreeNode } from './tree';
import type { TreeViewDecorationData } from './tree-view-decoration';
/**
 * The {@link TreeDecorator} allows adapting the look and the style of the tree items within a widget. Changes are reflected in
 * the form of `decoration data`. This `decoration data` is a map storing {@link TreeDecoration.Data} for affected tree nodes (using the unique node id as key).
 * It is important to notice that there is no common contribution point for `TreeDecorators`. Instead, each {@link TreeDecoratorService} is
 * supposed to declare its own contribution provider for `TreeDecorators`.
 *
 * ### Example usage
 * A simple tree decorator that changes the background color of each tree node to `red`.
 *
 * ```typescript
 * @singleton()
 * export class MyTreeDecorator implements TreeDecorator {
 *     id = 'myTreeDecorator';
 *
 *     protected readonly emitter = new Emitter<(tree: Tree) => Map<string, TreeDecoration.Data>>();
 *
 *     get onDidChangeDecorations(): Event<(tree: Tree) => Map<string, TreeDecoration.Data>> {
 *         return this.emitter.event;
 *     }
 *
 *     decorations(tree: Tree): MaybePromise<Map<string, TreeDecoration.Data>> {
 *         const result = new Map();
 *
 *         if (tree.root === undefined) {
 *             return result;
 *         }
 *         for (const treeNode of new DepthFirstTreeIterator(tree.root)) {
 *             result.set(treeNode.id,<TreeDecoration.Data>{backgroundColor:'red'})
 *         }
 *         return result;
 *     }
 * }
 * ```
 */
export type TreeDecorator = {
    /**
     * The unique identifier of the decorator. Ought to be unique in the application.
     */
    readonly id: string;
    /**
     * Fired when this decorator has calculated all the `decoration data` for the tree nodes.
     */
    readonly onDidChangeDecorations: Event<(tree: Tree) => Map<string, TreeViewDecorationData>>;
    /**
     * Computes the current `decoration data` for the given tree. Might return a promise if the computation is handled asynchronously.
     *
     * @param tree the tree to decorate.
     *
     * @returns (a promise of) a map containing the current {@linkTreeDecoration.Data} for each node. Keys are the unique identifier of the tree nodes.
     */
    decorations: (tree: Tree) => MaybePromise<Map<string, TreeViewDecorationData>>;
};
export declare const TreeDecoratorService: unique symbol;
/**
 * The {@link TreeDecoratorService} manages a set of known {link TreeDecorator}s and emits events when
 * any of the known decorators has changes. Typically, a `TreeDecoratorService` provides a contribution point that can be used to
 * register {@link TreeDecorator}s exclusively for this service.
 *
 * ### Example usage
 * ```typescript
 * export const MyTreeDecorator = Symbol('MyTreeDecorator');
 *
 * @singleton()
 * export class MyDecorationService extends AbstractTreeDecoratorService {
 *     constructor(@contrib(MyTreeDecorator) protected readonly contributions: ContributionProvider<TreeDecorator>) {
 *         super(contributions.getContributions());
 *     }
 * }
 * ```
 */
export type TreeDecoratorService = {
    /**
     * Fired when any of the available tree decorators has changes.
     */
    readonly onDidChangeDecorations: Event<void>;
    /**
     * Computes the decorations for the tree based on the actual state of this decorator service.
     *
     * @param tree the tree to decorate
     *
     * @returns (a promise of) the computed `decoration data`
     */
    getDecorations: (tree: Tree) => MaybePromise<Map<string, TreeViewDecorationData[]>>;
    /**
     * Transforms the `decoration data` into an object, so that it can be safely serialized into JSON.
     * @param decorations the `decoration data` that should be deflated
     *
     * @returns the `decoration data` as serializable JSON object
     */
    deflateDecorators: (decorations: Map<string, TreeViewDecorationData[]>) => object;
    /**
     * Counterpart of the [deflateDecorators](#deflateDecorators) method. Restores the argument into a Map
     * of tree node IDs and the corresponding decorations data array (`decoration data`).
     *
     * @returns the deserialized `decoration data
     */
    inflateDecorators: (state: any) => Map<string, TreeViewDecorationData[]>;
} & Disposable;
/**
 * The default tree decorator service. Does nothing at all. One has to rebind to a concrete implementation
 * if decorators have to be supported in the tree widget.
 */
export declare class NoopTreeDecoratorService implements TreeDecoratorService {
    protected readonly emitter: Emitter<void>;
    readonly onDidChangeDecorations: Event<void>;
    dispose(): void;
    getDecorations(): Map<any, any>;
    deflateDecorators(): object;
    inflateDecorators(): Map<string, TreeViewDecorationData[]>;
}
/**
 * Abstract decorator service implementation which emits events from all known tree decorators and caches the current state.
 */
export declare abstract class AbstractTreeDecoratorService implements TreeDecoratorService {
    protected readonly onDidChangeDecorationsEmitter: Emitter<void>;
    readonly onDidChangeDecorations: Event<void>;
    protected readonly toDispose: DisposableCollection;
    protected readonly decorators: readonly TreeDecorator[];
    constructor(decorators: readonly TreeDecorator[]);
    dispose(): void;
    getDecorations(tree: Tree): Promise<Map<string, TreeViewDecorationData[]>>;
    deflateDecorators(decorations: Map<string, TreeViewDecorationData[]>): object;
    inflateDecorators(state: any): Map<string, TreeViewDecorationData[]>;
}
export type DecoratedTreeNode = {
    /**
     * The additional tree decoration data attached to the tree node itself.
     */
    readonly decorationData: TreeViewDecorationData;
} & TreeNode;
export declare namespace DecoratedTreeNode {
    /**
     * Type-guard for decorated tree nodes.
     */
    function is(node: TreeNode | undefined): node is DecoratedTreeNode;
}
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