@ng-dnd/core/src/drop-target-specification.d.ts

Drag and Drop for Angular

import { DropTargetMonitor } from './target-monitor';
/**
 * The spec passed to {@link DndService#dropTarget}.
 *
 * Note the two type parameters. Both must represent plain JS objects. See the extended
 * discussion of these type parameters at {@link DragSourceSpec}.
 */
export interface DropTargetSpec<Item = unknown, DropResult = unknown> {
    /**
     * Queries your component to determine whether an item can be dropped on this target.
     *
     * **NOTE: runs outside Angular change detection.** This is for performance
     * reasons. You shouldn't be making changes to your component here anyway. If
     * you do change your component inside this callback, it may not appear
     * immediately, and if you use `NgZone.run()` then you may experience
     * performance degradation.
     *
     * Default, when not specified, is `true`.
     */
    canDrop?(monitor: DropTargetMonitor<Item, DropResult>): boolean;
    /**
     * Called frequently while the mouse hovers over the owner drop target while
     * dragging a relevant item.
     */
    hover?(monitor: DropTargetMonitor<Item, DropResult>): void;
    /**
     * Called when a compatible item is dropped on the target. You may either
     * return nothing, or a plain object.
     *
     * If you return an object, it is going to become the drop result and will be
     * available to the drag source in its {@link DragSourceSpec#endDrag} method as
     * {@link DropTargetMonitor#getDropResult}. This is useful in case you want the
     * source to perform different actions depending on which target received the
     * drop. Otherwise, it is simpler to handle the dropped item here.
     *
     * If you have nested drop targets, you can test whether a nested target has
     * already handled drop by checking {@link DropTargetMonitor#didDrop}. Both this
     * method and the source's `endDrag()` method are good places to fire
     * `@ngrx/store` actions.
     *
     * This method will not be called if `canDrop()` is defined and returns `false`.
     */
    drop?(monitor: DropTargetMonitor<Item, DropResult>): DropResult | void;
}