Files
blockly/core/drag_target.ts
Beka Westberg abfbbbc299 fix!: various drag-adjacent interfaces (#7975)
* fix: ISelectable and IDeletable interfaces

* fix: switch everything over to use new draggable interface

* fix: exports
2024-03-29 21:00:56 +00:00

98 lines
2.6 KiB
TypeScript

/**
* @license
* Copyright 2021 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* The abstract class for a component with custom behaviour when a
* block or bubble is dragged over or dropped on top of it.
*
* @class
*/
// Former goog.module ID: Blockly.DragTarget
import type {IDragTarget} from './interfaces/i_drag_target.js';
import type {IDraggable} from './interfaces/i_draggable.js';
import type {Rect} from './utils/rect.js';
/**
* Abstract class for a component with custom behaviour when a block or bubble
* is dragged over or dropped on top of it.
*/
export class DragTarget implements IDragTarget {
/**
* The unique id for this component that is used to register with the
* ComponentManager.
*/
// TODO(b/109816955): remove '!', see go/strict-prop-init-fix.
id!: string;
/**
* Constructor for DragTarget. It exists to add the id property and should not
* be called directly, only by a subclass.
*/
constructor() {}
/**
* Handles when a cursor with a block or bubble enters this drag target.
*
* @param _dragElement The block or bubble currently being dragged.
*/
onDragEnter(_dragElement: IDraggable) {
// no-op
}
/**
* Handles when a cursor with a block or bubble is dragged over this drag
* target.
*
* @param _dragElement The block or bubble currently being dragged.
*/
onDragOver(_dragElement: IDraggable) {
// no-op
}
/**
* Handles when a cursor with a block or bubble exits this drag target.
*
* @param _dragElement The block or bubble currently being dragged.
*/
onDragExit(_dragElement: IDraggable) {
// no-op
}
/**
* Handles when a block or bubble is dropped on this component.
* Should not handle delete here.
*
* @param _dragElement The block or bubble currently being dragged.
*/
onDrop(_dragElement: IDraggable) {
// no-op
}
/**
* Returns the bounding rectangle of the drag target area in pixel units
* relative to the Blockly injection div.
*
* @returns The component's bounding box. Null if drag target area should be
* ignored.
*/
getClientRect(): Rect | null {
return null;
}
/**
* Returns whether the provided block or bubble should not be moved after
* being dropped on this component. If true, the element will return to where
* it was when the drag started.
*
* @param _dragElement The block or bubble currently being dragged.
* @returns Whether the block or bubble provided should be returned to drag
* start.
*/
shouldPreventMove(_dragElement: IDraggable): boolean {
return false;
}
}