Class HTML5BackendImpl

packages/backend-html5/src/HTML5BackendImpl.ts:29–758

type RootNode = Node & { __isReactDndBackendSetUp: boolean | undefined }

export class HTML5BackendImpl implements Backend {
	private options: OptionsReader

	// React-Dnd Components
	private actions: DragDropActions
	private monitor: DragDropMonitor
	private registry: HandlerRegistry

	// Internal State
	private enterLeaveCounter: EnterLeaveCounter

	private sourcePreviewNodes: Map<string, Element> = new Map()
	private sourcePreviewNodeOptions: Map<string, any> = new Map()
	private sourceNodes: Map<string, Element> = new Map()
	private sourceNodeOptions: Map<string, any> = new Map()

	private dragStartSourceIds: string[] | null = null
	private dropTargetIds: string[] = []
	private dragEnterTargetIds: string[] = []
	private currentNativeSource: NativeDragSource | null = null
	private currentNativeHandle: Identifier | null = null
	private currentDragSourceNode: Element | null = null
	private altKeyPressed = false
	private mouseMoveTimeoutTimer: number | null = null
	private asyncEndDragFrameId: number | null = null
	private dragOverTargetIds: string[] | null = null

	private lastClientOffset: XYCoord | null = null
	private hoverRafId: number | null = null

	public constructor(
		manager: DragDropManager,
		globalContext?: HTML5BackendContext,
		options?: HTML5BackendOptions,
	) {
		this.options = new OptionsReader(globalContext, options)
		this.actions = manager.getActions()
		this.monitor = manager.getMonitor()
		this.registry = manager.getRegistry()
		this.enterLeaveCounter = new EnterLeaveCounter(this.isNodeInDocument)
	}

	/**
	 * Generate profiling statistics for the HTML5Backend.
	 */
	public profile(): Record<string, number> {
		return {
			sourcePreviewNodes: this.sourcePreviewNodes.size,
			sourcePreviewNodeOptions: this.sourcePreviewNodeOptions.size,
			sourceNodeOptions: this.sourceNodeOptions.size,
			sourceNodes: this.sourceNodes.size,
			dragStartSourceIds: this.dragStartSourceIds?.length || 0,
			dropTargetIds: this.dropTargetIds.length,
			dragEnterTargetIds: this.dragEnterTargetIds.length,
			dragOverTargetIds: this.dragOverTargetIds?.length || 0,
		}
	}