HTML5 Canvas Select Shape by Name Tutorial

To select shapes by name with Konva, we can use the find() method using the . selector. The find() method returns an array of nodes that match the selector string.

Vanilla

import Konva from 'konva';

const stage = new Konva.Stage({
  container: 'container',
  width: window.innerWidth,
  height: window.innerHeight,
});

const layer = new Konva.Layer();
stage.add(layer);

// create shapes with names
const circle1 = new Konva.Circle({
  x: 50,
  y: stage.height() / 2,
  radius: 30,
  fill: 'red',
  name: 'myCircle'
});

const circle2 = new Konva.Circle({
  x: 150,
  y: stage.height() / 2,
  radius: 30,
  fill: 'green',
  name: 'myCircle'
});

const rect = new Konva.Rect({
  x: 250,
  y: stage.height() / 2 - 25,
  width: 50,
  height: 50,
  fill: 'blue',
  name: 'myRect'
});

layer.add(circle1);
layer.add(circle2);
layer.add(rect);

// find all circles by name
const circles = layer.find('.myCircle');
circles.forEach(circle => {
  // add animation to circles only
  circle.to({
    duration: 1,
    rotation: 360,
    easing: Konva.Easings.EaseInOut
  });
});

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React

import { Stage, Layer, Circle, Rect } from 'react-konva';
import { useEffect, useRef } from 'react';

const App = () => {
  const layerRef = useRef(null);
  
  useEffect(() => {
    // find all circles by name and animate them
    const circles = layerRef.current.find('.myCircle');
    circles.forEach(circle => {
      circle.to({
        duration: 1,
        rotation: 360,
        easing: Konva.Easings.EaseInOut
      });
    });
  }, []);

  return (
    <Stage width={window.innerWidth} height={window.innerHeight}>
      <Layer ref={layerRef}>
        <Circle
          x={50}
          y={window.innerHeight / 2}
          radius={30}
          fill="red"
          name="myCircle"
        />
        <Circle
          x={150}
          y={window.innerHeight / 2}
          radius={30}
          fill="green"
          name="myCircle"
        />
        <Rect
          x={250}
          y={window.innerHeight / 2 - 25}
          width={50}
          height={50}
          fill="blue"
          name="myRect"
        />
      </Layer>
    </Stage>
  );
};

export default App;

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Vue

<template>
  <v-stage :config="stageSize">
    <v-layer ref="layerRef">
      <v-circle :config="circle1Config" />
      <v-circle :config="circle2Config" />
      <v-rect :config="rectConfig" />
    </v-layer>
  </v-stage>
</template>

<script setup>
import { ref, onMounted } from 'vue';
import Konva from 'konva';

const stageSize = {
  width: window.innerWidth,
  height: window.innerHeight
};

const circle1Config = {
  x: 50,
  y: window.innerHeight / 2,
  radius: 30,
  fill: 'red',
  name: 'myCircle'
};

const circle2Config = {
  x: 150,
  y: window.innerHeight / 2,
  radius: 30,
  fill: 'green',
  name: 'myCircle'
};

const rectConfig = {
  x: 250,
  y: window.innerHeight / 2 - 25,
  width: 50,
  height: 50,
  fill: 'blue',
  name: 'myRect'
};

const layerRef = ref(null);

onMounted(() => {
  // find all circles by name and animate them
  const circles = layerRef.value.getNode().find('.myCircle');
  circles.forEach(circle => {
    circle.to({
      duration: 1,
      rotation: 360,
      easing: Konva.Easings.EaseInOut
    });
  });
});
</script>

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