import type { Identifier, Unsubscribe } from 'dnd-core';
export interface XYCoord {
    x: number;
    y: number;
}
export interface HandlerManager {
    receiveHandlerId: (handlerId: Identifier | null) => void;
    getHandlerId: () => Identifier | null;
}
export interface DragSourceMonitor<DragObject = unknown, DropResult = unknown> extends HandlerManager, MonitorEventEmitter {
    /**
     * Returns true if no drag operation is in progress, and the owner's canDrag() returns true or is not defined.
     */
    canDrag(): boolean;
    /**
     *  Returns true if a drag operation is in progress, and either the owner initiated the drag, or its isDragging() is defined and returns true.
     */
    isDragging(): boolean;
    /**
     * Returns a string or a symbol identifying the type of the current dragged item. Returns null if no item is being dragged.
     */
    getItemType(): Identifier | null;
    /**
     * Returns a plain object representing the currently dragged item. Every drag source must specify it by returning an object from its beginDrag() method.
     * Returns null if no item is being dragged.
     */
    getItem<T = DragObject>(): T;
    /**
     * Returns a plain object representing the last recorded drop result. The drop targets may optionally specify it by returning an object from their
     * drop() methods. When a chain of drop() is dispatched for the nested targets, bottom up, any parent that explicitly returns its own result from drop()
     * overrides the child drop result previously set by the child. Returns null if called outside endDrag().
     */
    getDropResult<T = DropResult>(): T | null;
    /**
     *  Returns true if some drop target has handled the drop event, false otherwise. Even if a target did not return a drop result, didDrop() returns true.
     * Use it inside endDrag() to test whether any drop target has handled the drop. Returns false if called outside endDrag().
     */
    didDrop(): boolean;
    /**
     * Returns the { x, y } client offset of the pointer at the time when the current drag operation has started. Returns null if no item is being dragged.
     */
    getInitialClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } client offset of the drag source component's root DOM node at the time when the current drag operation has started.
     * Returns null if no item is being dragged.
     */
    getInitialSourceClientOffset(): XYCoord | null;
    /**
     * Returns the last recorded { x, y } client offset of the pointer while a drag operation is in progress. Returns null if no item is being dragged.
     */
    getClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } difference between the last recorded client offset of the pointer and the client offset when the current drag operation has started.
     * Returns null if no item is being dragged.
     */
    getDifferenceFromInitialOffset(): XYCoord | null;
    /**
     * Returns the projected { x, y } client offset of the drag source component's root DOM node, based on its position at the time when the current drag operation has
     * started, and the movement difference. Returns null if no item is being dragged.
     */
    getSourceClientOffset(): XYCoord | null;
    /**
     * Returns the ids of the potential drop targets.
     */
    getTargetIds(): Identifier[];
}
export interface MonitorEventEmitter {
    subscribeToStateChange(fn: () => void, options?: {
        handlerIds?: Identifier[];
    }): Unsubscribe;
}
export interface DropTargetMonitor<DragObject = unknown, DropResult = unknown> extends HandlerManager, MonitorEventEmitter {
    /**
     * Returns true if there is a drag operation in progress, and the owner's canDrop() returns true or is not defined.
     */
    canDrop(): boolean;
    /**
     * Returns true if there is a drag operation in progress, and the pointer is currently hovering over the owner.
     * You may optionally pass { shallow: true } to strictly check whether only the owner is being hovered, as opposed
     * to a nested target.
     */
    isOver(options?: {
        shallow?: boolean;
    }): boolean;
    /**
     * Returns a string or a symbol identifying the type of the current dragged item. Returns null if no item is being dragged.
     */
    getItemType(): Identifier | null;
    /**
     * Returns a plain object representing the currently dragged item. Every drag source must specify it by returning an object from
     * its beginDrag() method. Returns null if no item is being dragged.
     */
    getItem<T = DragObject>(): T;
    /**
     * Returns a plain object representing the last recorded drop result. The drop targets may optionally specify it by returning an
     * object from their drop() methods. When a chain of drop() is dispatched for the nested targets, bottom up, any parent that explicitly
     * returns its own result from drop() overrides the drop result previously set by the child. Returns null if called outside drop().
     */
    getDropResult<T = DropResult>(): T | null;
    /**
     *  Returns true if some drop target has handled the drop event, false otherwise. Even if a target did not return a drop result,
     * didDrop() returns true. Use it inside drop() to test whether any nested drop target has already handled the drop. Returns false
     * if called outside drop().
     */
    didDrop(): boolean;
    /**
     * Returns the { x, y } client offset of the pointer at the time when the current drag operation has started. Returns null if no item
     * is being dragged.
     */
    getInitialClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } client offset of the drag source component's root DOM node at the time when the current drag operation has started.
     * Returns null if no item is being dragged.
     */
    getInitialSourceClientOffset(): XYCoord | null;
    /**
     * Returns the last recorded { x, y } client offset of the pointer while a drag operation is in progress. Returns null if no item is being dragged.
     */
    getClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } difference between the last recorded client offset of the pointer and the client offset when current the drag operation has
     * started. Returns null if no item is being dragged.
     */
    getDifferenceFromInitialOffset(): XYCoord | null;
    /**
     * Returns the projected { x, y } client offset of the drag source component's root DOM node, based on its position at the time when the current
     * drag operation has started, and the movement difference. Returns null if no item is being dragged.
     */
    getSourceClientOffset(): XYCoord | null;
}
export interface DragLayerMonitor<DragObject = unknown> {
    /**
     * Returns true if a drag operation is in progress. Returns false otherwise.
     */
    isDragging(): boolean;
    /**
     * Returns a string or a symbol identifying the type of the current dragged item.
     * Returns null if no item is being dragged.
     */
    getItemType(): Identifier | null;
    /**
     * Returns a plain object representing the currently dragged item.
     * Every drag source must specify it by returning an object from its beginDrag() method.
     * Returns null if no item is being dragged.
     */
    getItem<T = DragObject>(): T;
    /**
     * Returns the { x, y } client offset of the pointer at the time when the current drag operation has started.
     * Returns null if no item is being dragged.
     */
    getInitialClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } client offset of the drag source component's root DOM node at the time when the current
     * drag operation has started. Returns null if no item is being dragged.
     */
    getInitialSourceClientOffset(): XYCoord | null;
    /**
     * Returns the last recorded { x, y } client offset of the pointer while a drag operation is in progress.
     * Returns null if no item is being dragged.
     */
    getClientOffset(): XYCoord | null;
    /**
     * Returns the { x, y } difference between the last recorded client offset of the pointer and the client
     * offset when current the drag operation has started. Returns null if no item is being dragged.
     */
    getDifferenceFromInitialOffset(): XYCoord | null;
    /**
     * Returns the projected { x, y } client offset of the drag source component's root DOM node, based on its
     * position at the time when the current drag operation has started, and the movement difference.
     * Returns null if no item is being dragged.
     */
    getSourceClientOffset(): XYCoord | null;
}