Angular Konva Simple Animations Tutorial

Konva provides two main animation tools: node.to() for simple transitions and Konva.Animation for frame-by-frame updates.

This example uses Konva.Animation directly to move a circle in a sine wave after the view initializes.

Instructions: The demo continuously animates the red circle left and right.

For more details, see the Animation docs and the Node API Reference.

Simple Animation Example

import { Component, ViewChild, OnInit, OnDestroy } from '@angular/core';
import { StageConfig } from 'konva/lib/Stage';
import { CircleConfig } from 'konva/lib/shapes/Circle';
import Konva from 'konva';

import {
  CoreShapeComponent,
  StageComponent,
} from 'ng2-konva';

@Component({
  selector: 'app-root',
  standalone: true,
  template: `
    <ko-stage [config]="configStage">
      <ko-layer>
        <ko-circle #circle [config]="configCircle"></ko-circle>
      </ko-layer>
    </ko-stage>
  `,
  imports: [StageComponent, CoreShapeComponent],
})
export default class App implements OnInit, OnDestroy {
  @ViewChild('circle') circle!: any;
  private animation: any = null;

  public configStage: StageConfig = {
    width: window.innerWidth,
    height: window.innerHeight,
  };
  public configCircle: CircleConfig = {
    x: 100,
    y: 100,
    radius: 50,
    fill: 'red',
    stroke: 'black',
    strokeWidth: 4
  };

  ngAfterViewInit() {
    const circle = this.circle.getNode();
    this.animation = new Konva.Animation((frame: any) => {
      const time = frame.time;
      const x = 100 + Math.sin(time / 1000) * 100;
      circle.x(x);
    }, circle.getLayer());

    this.animation.start();
  }

  ngOnDestroy() {
    if (this.animation) {
      this.animation.stop();
    }
  }
}