import { utils } from "pixi.js";
import { DBaseStateSet } from "./d-base-state-set";
export interface DFocusableMightBe {
    parent: DFocusableContainer | null;
    visible: boolean;
}
export interface DFocusableContainer extends DFocusableMightBe {
    children: DFocusableMightBe[];
}
export interface DFocusable extends DFocusableMightBe {
    readonly state: DBaseStateSet;
}
export interface DControllerFocus extends utils.EventEmitter {
    focus(focusable: DFocusable | null): DFocusable | null;
    blur(focusable: DFocusable): DFocusable | null;
    clear(): DFocusable | null;
    set(focusable: DFocusable | null, isFocused: boolean): DFocusable | null;
    get(): DFocusable | null;
    /**
     * Searches a focusable and returns a firstly-found focusable.
     * If no focusable is found, returns null.
     * The search starts from the given target in the depth-first manner.
     * If the root is given, the search will be limited to the root's children.
     * The root itself will not be checked.
     * This method assumes the root is the one of the parents of the given target.
     *
     * @param target a target where a search starts at
     * @param includesTarget true to check the target itself
     * @param includesTargetChildren true to check the target's children
     * @param direction true to search in the descending order
     * @param root a root of a search
     */
    find(target: DFocusableMightBe, includesTarget: boolean, includesTargetChildren: boolean, direction: boolean, root?: unknown): DFocusable | null;
    /**
     * Returns the closest focusable parent of the specified target.
     * If the specified target is focusable, returns the specified target.
     *
     * @param mightBeFocusable the node a search starts from
     */
    findParent(mightBeFocusable: DFocusableMightBe | null): DFocusable | null;
}