konva/src/PointerEvents.ts

import { KonvaEventObject } from './types';

import { Shape } from './Shape';
import { Stage } from './Stage';

const Captures = new Map<number, Shape | Stage>();

export interface KonvaPointerEvent extends KonvaEventObject<PointerEvent> {
  pointerId: number;
}

let implicitRelease = null;

export function getCapturedShape(pointerId: number) {
  return Captures.get(pointerId);
}

export function createEvent(evt: PointerEvent): KonvaPointerEvent {
  return {
    evt,
    pointerId: evt.pointerId
  } as any;
}

export function hasPointerCapture(pointerId: number, shape: Shape | Stage) {
  return Captures.get(pointerId) === shape;
}

export function setPointerCapture(pointerId: number, shape: Shape | Stage) {
  releaseCapture(pointerId);

  const { content } = shape.getStage();

  content.setPointerCapture(pointerId);

  Captures.set(pointerId, shape);

  shape._fire(
    'gotpointercapture',
    createEvent(new PointerEvent('gotpointercapture'))
  );
}

export function releaseCapture(pointerId: number, target?: Shape | Stage) {
  const shape = Captures.get(pointerId);

  if (!shape) return;

  const { content } = shape.getStage();

  content.releasePointerCapture(pointerId);

  Captures.delete(pointerId);

  shape._fire(
    'lostpointercapture',
    createEvent(new PointerEvent('lostpointercapture'))
  );
}